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| author | Ingo Molnar <mingo@kernel.org> | 2019-11-19 19:54:39 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-11-19 19:56:28 +0100 |
| commit | 8e1d58ae0c8d4af9ab0141f7e8a9ca95720df01c (patch) | |
| tree | 7b09138ee1aca2825f86f5534bfd2caad83190ec | |
| parent | af42d3466bdc8f39806b26f593604fdc54140bcb (diff) | |
| parent | 40d04110f87940b6a03bf0aa19cd29e84f465f20 (diff) | |
| download | linux-8e1d58ae0c8d4af9ab0141f7e8a9ca95720df01c.tar.gz linux-8e1d58ae0c8d4af9ab0141f7e8a9ca95720df01c.tar.bz2 linux-8e1d58ae0c8d4af9ab0141f7e8a9ca95720df01c.zip | |
Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into locking/kcsan
Pull the KCSAN subsystem from Paul E. McKenney:
"This pull request contains base kernel concurrency sanitizer
(KCSAN) enablement for x86, courtesy of Marco Elver. KCSAN is a
sampling watchpoint-based data-race detector, and is documented in
Documentation/dev-tools/kcsan.rst. KCSAN was announced in September,
and much feedback has since been incorporated:
http://lkml.kernel.org/r/CANpmjNPJ_bHjfLZCAPV23AXFfiPiyXXqqu72n6TgWzb2Gnu1eA@mail.gmail.com
The data races located thus far have resulted in a number of fixes:
https://github.com/google/ktsan/wiki/KCSAN#upstream-fixes-of-data-races-found-by-kcsan
Additional information may be found here:
https://lore.kernel.org/lkml/20191114180303.66955-1-elver@google.com/
"
Signed-off-by: Ingo Molnar <mingo@kernel.org>
45 files changed, 2623 insertions, 206 deletions
diff --git a/Documentation/dev-tools/index.rst b/Documentation/dev-tools/index.rst index b0522a4dd107..1b756a7014e0 100644 --- a/Documentation/dev-tools/index.rst +++ b/Documentation/dev-tools/index.rst @@ -21,6 +21,7 @@ whole; patches welcome! kasan ubsan kmemleak + kcsan gdb-kernel-debugging kgdb kselftest diff --git a/Documentation/dev-tools/kcsan.rst b/Documentation/dev-tools/kcsan.rst new file mode 100644 index 000000000000..a6f4f92df2fa --- /dev/null +++ b/Documentation/dev-tools/kcsan.rst @@ -0,0 +1,256 @@ +The Kernel Concurrency Sanitizer (KCSAN) +======================================== + +Overview +-------- + +*Kernel Concurrency Sanitizer (KCSAN)* is a dynamic data race detector for +kernel space. KCSAN is a sampling watchpoint-based data race detector. Key +priorities in KCSAN's design are lack of false positives, scalability, and +simplicity. More details can be found in `Implementation Details`_. + +KCSAN uses compile-time instrumentation to instrument memory accesses. KCSAN is +supported in both GCC and Clang. With GCC it requires version 7.3.0 or later. +With Clang it requires version 7.0.0 or later. + +Usage +----- + +To enable KCSAN configure kernel with:: + + CONFIG_KCSAN = y + +KCSAN provides several other configuration options to customize behaviour (see +their respective help text for more info). + +Error reports +~~~~~~~~~~~~~ + +A typical data race report looks like this:: + + ================================================================== + BUG: KCSAN: data-race in generic_permission / kernfs_refresh_inode + + write to 0xffff8fee4c40700c of 4 bytes by task 175 on cpu 4: + kernfs_refresh_inode+0x70/0x170 + kernfs_iop_permission+0x4f/0x90 + inode_permission+0x190/0x200 + link_path_walk.part.0+0x503/0x8e0 + path_lookupat.isra.0+0x69/0x4d0 + filename_lookup+0x136/0x280 + user_path_at_empty+0x47/0x60 + vfs_statx+0x9b/0x130 + __do_sys_newlstat+0x50/0xb0 + __x64_sys_newlstat+0x37/0x50 + do_syscall_64+0x85/0x260 + entry_SYSCALL_64_after_hwframe+0x44/0xa9 + + read to 0xffff8fee4c40700c of 4 bytes by task 166 on cpu 6: + generic_permission+0x5b/0x2a0 + kernfs_iop_permission+0x66/0x90 + inode_permission+0x190/0x200 + link_path_walk.part.0+0x503/0x8e0 + path_lookupat.isra.0+0x69/0x4d0 + filename_lookup+0x136/0x280 + user_path_at_empty+0x47/0x60 + do_faccessat+0x11a/0x390 + __x64_sys_access+0x3c/0x50 + do_syscall_64+0x85/0x260 + entry_SYSCALL_64_after_hwframe+0x44/0xa9 + + Reported by Kernel Concurrency Sanitizer on: + CPU: 6 PID: 166 Comm: systemd-journal Not tainted 5.3.0-rc7+ #1 + Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 + ================================================================== + +The header of the report provides a short summary of the functions involved in +the race. It is followed by the access types and stack traces of the 2 threads +involved in the data race. + +The other less common type of data race report looks like this:: + + ================================================================== + BUG: KCSAN: data-race in e1000_clean_rx_irq+0x551/0xb10 + + race at unknown origin, with read to 0xffff933db8a2ae6c of 1 bytes by interrupt on cpu 0: + e1000_clean_rx_irq+0x551/0xb10 + e1000_clean+0x533/0xda0 + net_rx_action+0x329/0x900 + __do_softirq+0xdb/0x2db + irq_exit+0x9b/0xa0 + do_IRQ+0x9c/0xf0 + ret_from_intr+0x0/0x18 + default_idle+0x3f/0x220 + arch_cpu_idle+0x21/0x30 + do_idle+0x1df/0x230 + cpu_startup_entry+0x14/0x20 + rest_init+0xc5/0xcb + arch_call_rest_init+0x13/0x2b + start_kernel+0x6db/0x700 + + Reported by Kernel Concurrency Sanitizer on: + CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc7+ #2 + Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 + ================================================================== + +This report is generated where it was not possible to determine the other +racing thread, but a race was inferred due to the data value of the watched +memory location having changed. These can occur either due to missing +instrumentation or e.g. DMA accesses. + +Selective analysis +~~~~~~~~~~~~~~~~~~ + +To disable KCSAN data race detection for an entire subsystem, add to the +respective ``Makefile``:: + + KCSAN_SANITIZE := n + +To disable KCSAN on a per-file basis, add to the ``Makefile``:: + + KCSAN_SANITIZE_file.o := n + +KCSAN also understands the ``data_race(expr)`` annotation, which tells KCSAN +that any data races due to accesses in ``expr`` should be ignored and resulting +behaviour when encountering a data race is deemed safe. + +debugfs +~~~~~~~ + +* The file ``/sys/kernel/debug/kcsan`` can be read to get stats. + +* KCSAN can be turned on or off by writing ``on`` or ``off`` to + ``/sys/kernel/debug/kcsan``. + +* Writing ``!some_func_name`` to ``/sys/kernel/debug/kcsan`` adds + ``some_func_name`` to the report filter list, which (by default) blacklists + reporting data races where either one of the top stackframes are a function + in the list. + +* Writing either ``blacklist`` or ``whitelist`` to ``/sys/kernel/debug/kcsan`` + changes the report filtering behaviour. For example, the blacklist feature + can be used to silence frequently occurring data races; the whitelist feature + can help with reproduction and testing of fixes. + +Data Races +---------- + +Informally, two operations *conflict* if they access the same memory location, +and at least one of them is a write operation. In an execution, two memory +operations from different threads form a **data race** if they *conflict*, at +least one of them is a *plain access* (non-atomic), and they are *unordered* in +the "happens-before" order according to the `LKMM +<../../tools/memory-model/Documentation/explanation.txt>`_. + +Relationship with the Linux Kernel Memory Model (LKMM) +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The LKMM defines the propagation and ordering rules of various memory +operations, which gives developers the ability to reason about concurrent code. +Ultimately this allows to determine the possible executions of concurrent code, +and if that code is free from data races. + +KCSAN is aware of *atomic* accesses (``READ_ONCE``, ``WRITE_ONCE``, +``atomic_*``, etc.), but is oblivious of any ordering guarantees. In other +words, KCSAN assumes that as long as a plain access is not observed to race +with another conflicting access, memory operations are correctly ordered. + +This means that KCSAN will not report *potential* data races due to missing +memory ordering. If, however, missing memory ordering (that is observable with +a particular compiler and architecture) leads to an observable data race (e.g. +entering a critical section erroneously), KCSAN would report the resulting +data race. + +Race conditions vs. data races +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Race conditions are logic bugs, where unexpected interleaving of racing +concurrent operations result in an erroneous state. + +Data races on the other hand are defined at the *memory model/language level*. +Many data races are also harmful race conditions, which a tool like KCSAN +reports! However, not all data races are race conditions and vice-versa. +KCSAN's intent is to report data races according to the LKMM. A data race +detector can only work at the memory model/language level. + +Deeper analysis, to find high-level race conditions only, requires conveying +the intended kernel logic to a tool. This requires (1) the developer writing a +specification or model of their code, and then (2) the tool verifying that the +implementation matches. This has been done for small bits of code using model +checkers and other formal methods, but does not scale to the level of what can +be covered with a dynamic analysis based data race detector such as KCSAN. + +For reasons outlined in this `article <https://lwn.net/Articles/793253/>`_, +data races can be much more subtle, but can cause no less harm than high-level +race conditions. + +Implementation Details +---------------------- + +The general approach is inspired by `DataCollider +<http://usenix.org/legacy/events/osdi10/tech/full_papers/Erickson.pdf>`_. +Unlike DataCollider, KCSAN does not use hardware watchpoints, but instead +relies on compiler instrumentation. Watchpoints are implemented using an +efficient encoding that stores access type, size, and address in a long; the +benefits of using "soft watchpoints" are portability and greater flexibility in +limiting which accesses trigger a watchpoint. + +More specifically, KCSAN requires instrumenting plain (unmarked, non-atomic) +memory operations; for each instrumented plain access: + +1. Check if a matching watchpoint exists; if yes, and at least one access is a + write, then we encountered a racing access. + +2. Periodically, if no matching watchpoint exists, set up a watchpoint and + stall for a small delay. + +3. Also check the data value before the delay, and re-check the data value + after delay; if the values mismatch, we infer a race of unknown origin. + +To detect data races between plain and atomic memory operations, KCSAN also +annotates atomic accesses, but only to check if a watchpoint exists +(``kcsan_check_atomic_*``); i.e. KCSAN never sets up a watchpoint on atomic +accesses. + +Key Properties +~~~~~~~~~~~~~~ + +1. **Memory Overhead:** The current implementation uses a small array of longs + to encode watchpoint information, which is negligible. + +2. **Performance Overhead:** KCSAN's runtime aims to be minimal, using an + efficient watchpoint encoding that does not require acquiring any shared + locks in the fast-path. For kernel boot on a system with 8 CPUs: + + - 5.0x slow-down with the default KCSAN config; + - 2.8x slow-down from runtime fast-path overhead only (set very large + ``KCSAN_SKIP_WATCH`` and unset ``KCSAN_SKIP_WATCH_RANDOMIZE``). + +3. **Annotation Overheads:** Minimal annotations are required outside the KCSAN + runtime. As a result, maintenance overheads are minimal as the kernel + evolves. + +4. **Detects Racy Writes from Devices:** Due to checking data values upon + setting up watchpoints, racy writes from devices can also be detected. + +5. **Memory Ordering:** KCSAN is *not* explicitly aware of the LKMM's ordering + rules; this may result in missed data races (false negatives). + +6. **Analysis Accuracy:** For observed executions, due to using a sampling + strategy, the analysis is *unsound* (false negatives possible), but aims to + be complete (no false positives). + +Alternatives Considered +----------------------- + +An alternative data race detection approach for the kernel can be found in +`Kernel Thread Sanitizer (KTSAN) <https://github.com/google/ktsan/wiki>`_. +KTSAN is a happens-before data race detector, which explicitly establishes the +happens-before order between memory operations, which can then be used to +determine data races as defined in `Data Races`_. To build a correct +happens-before relation, KTSAN must be aware of all ordering rules of the LKMM +and synchronization primitives. Unfortunately, any omission leads to false +positives, which is especially important in the context of the kernel which +includes numerous custom synchronization mechanisms. Furthermore, KTSAN's +implementation requires metadata for each memory location (shadow memory); +currently, for each page, KTSAN requires 4 pages of shadow memory. diff --git a/MAINTAINERS b/MAINTAINERS index e4f170d8bc29..d0a544d84837 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8850,6 +8850,17 @@ F: Documentation/kbuild/kconfig* F: scripts/kconfig/ F: scripts/Kconfig.include +KCSAN +M: Marco Elver <elver@google.com> +R: Dmitry Vyukov <dvyukov@google.com> +L: kasan-dev@googlegroups.com +S: Maintained +F: Documentation/dev-tools/kcsan.rst +F: include/linux/kcsan*.h +F: kernel/kcsan/ +F: lib/Kconfig.kcsan +F: scripts/Makefile.kcsan + KDUMP M: Dave Young <dyoung@redhat.com> M: Baoquan He <bhe@redhat.com> @@ -478,7 +478,7 @@ export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE -export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN +export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN CFLAGS_KCSAN export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL @@ -900,6 +900,7 @@ endif include scripts/Makefile.kasan include scripts/Makefile.extrawarn include scripts/Makefile.ubsan +include scripts/Makefile.kcsan # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments KBUILD_CPPFLAGS += $(KCPPFLAGS) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 8ef85139553f..9933ca8ffe16 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -226,6 +226,7 @@ config X86 select VIRT_TO_BUS select X86_FEATURE_NAMES if PROC_FS select PROC_PID_ARCH_STATUS if PROC_FS + select HAVE_ARCH_KCSAN if X86_64 config INSTRUCTION_DECODER def_bool y diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index e2839b5c246c..9c7942794164 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -9,7 +9,9 @@ # Changed by many, many contributors over the years. # +# Sanitizer runtimes are unavailable and cannot be linked for early boot code. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Kernel does not boot with kcov instrumentation here. diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 6b84afdd7538..a1c248b8439f 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -17,7 +17,9 @@ # (see scripts/Makefile.lib size_append) # compressed vmlinux.bin.all + u32 size of vmlinux.bin.all +# Sanitizer runtimes are unavailable and cannot be linked for early boot code. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index 0f2154106d01..a23debaad5b9 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -10,8 +10,11 @@ ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE include $(srctree)/lib/vdso/Makefile KBUILD_CFLAGS += $(DISABLE_LTO) + +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n UBSAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 7d1f6a49bfae..542b63ddc8aa 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -201,8 +201,12 @@ arch_test_and_change_bit(long nr, volatile unsigned long *addr) return GEN_BINARY_RMWcc(LOCK_PREFIX __ASM_SIZE(btc), *addr, c, "Ir", nr); } -static __always_inline bool constant_test_bit(long nr, const volatile unsigned long *addr) +static __no_kcsan_or_inline bool constant_test_bit(long nr, const volatile unsigned long *addr) { + /* + * Because this is a plain access, we need to disable KCSAN here to + * avoid double instrumentation via instrumented bitops. + */ return ((1UL << (nr & (BITS_PER_LONG-1))) & (addr[nr >> _BITOPS_LONG_SHIFT])) != 0; } diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 3578ad248bc9..a9a1cab437bc 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -28,6 +28,10 @@ KASAN_SANITIZE_dumpstack_$(BITS).o := n KASAN_SANITIZE_stacktrace.o := n KASAN_SANITIZE_paravirt.o := n +# With some compiler versions the generated code results in boot hangs, caused +# by several compilation units. To be safe, disable all instrumentation. +KCSAN_SANITIZE := n + OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o := y OBJECT_FILES_NON_STANDARD_test_nx.o := y OBJECT_FILES_NON_STANDARD_paravirt_patch.o := y diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index 890f60083eca..a704fb9ee98e 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -13,6 +13,9 @@ endif KCOV_INSTRUMENT_common.o := n KCOV_INSTRUMENT_perf_event.o := n +# As above, instrumenting secondary CPU boot code causes boot hangs. +KCSAN_SANITIZE_common.o := n + # Make sure load_percpu_segment has no stackprotector nostackp := $(call cc-option, -fno-stack-protector) CFLAGS_common.o := $(nostackp) diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 5246db42de45..432a07705677 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -6,10 +6,14 @@ # Produces uninteresting flaky coverage. KCOV_INSTRUMENT_delay.o := n +# KCSAN uses udelay for introducing watchpoint delay; avoid recursion. +KCSAN_SANITIZE_delay.o := n + # Early boot use of cmdline; don't instrument it ifdef CONFIG_AMD_MEM_ENCRYPT KCOV_INSTRUMENT_cmdline.o := n KASAN_SANITIZE_cmdline.o := n +KCSAN_SANITIZE_cmdline.o := n ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_cmdline.o = -pg diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 84373dc9b341..3559f4297ee1 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -7,6 +7,10 @@ KCOV_INSTRUMENT_mem_encrypt_identity.o := n KASAN_SANITIZE_mem_encrypt.o := n KASAN_SANITIZE_mem_encrypt_identity.o := n +# Disable KCSAN entirely, because otherwise we get warnings that some functions +# reference __initdata sections. +KCSAN_SANITIZE := n + ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_mem_encrypt.o = -pg CFLAGS_REMOVE_mem_encrypt_identity.o = -pg diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index fb4ee5444379..69379bce9574 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -17,7 +17,9 @@ CFLAGS_sha256.o := -D__DISABLE_EXPORTS LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib targets += purgatory.ro +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n +KCSAN_SANITIZE := n KCOV_INSTRUMENT := n # These are adjustments to the compiler flags used for objects that diff --git a/arch/x86/realmode/Makefile b/arch/x86/realmode/Makefile index 682c895753d9..6b1f3a4eeb44 100644 --- a/arch/x86/realmode/Makefile +++ b/arch/x86/realmode/Makefile @@ -6,7 +6,10 @@ # for more details. # # + +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y subdir- := rm diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile index f60501a384f9..fdbbb945c216 100644 --- a/arch/x86/realmode/rm/Makefile +++ b/arch/x86/realmode/rm/Makefile @@ -6,7 +6,10 @@ # for more details. # # + +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index ee0661ddb25b..5d0a645c0de8 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -31,7 +31,9 @@ KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \ -D__DISABLE_EXPORTS GCOV_PROFILE := n +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n +KCSAN_SANITIZE := n UBSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y diff --git a/include/asm-generic/atomic-instrumented.h b/include/asm-generic/atomic-instrumented.h index e8730c6b9fe2..3dc0f38544f6 100644 --- a/include/asm-generic/atomic-instrumented.h +++ b/include/asm-generic/atomic-instrumented.h @@ -19,11 +19,24 @@ #include <linux/build_bug.h> #include <linux/kasan-checks.h> +#include <linux/kcsan-checks.h> + +static inline void __atomic_check_read(const volatile void *v, size_t size) +{ + kasan_check_read(v, size); + kcsan_check_atomic_read(v, size); +} + +static inline void __atomic_check_write(const volatile void *v, size_t size) +{ + kasan_check_write(v, size); + kcsan_check_atomic_write(v, size); +} static inline int atomic_read(const atomic_t *v) { - kasan_check_read(v, sizeof(*v)); + __atomic_check_read(v, sizeof(*v)); return arch_atomic_read(v); } #define atomic_read atomic_read @@ -32,7 +45,7 @@ atomic_read(const atomic_t *v) static inline int atomic_read_acquire(const atomic_t *v) { - kasan_check_read(v, sizeof(*v)); + __atomic_check_read(v, sizeof(*v)); return arch_atomic_read_acquire(v); } #define atomic_read_acquire atomic_read_acquire @@ -41,7 +54,7 @@ atomic_read_acquire(const atomic_t *v) static inline void atomic_set(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic_set(v, i); } #define atomic_set atomic_set @@ -50,7 +63,7 @@ atomic_set(atomic_t *v, int i) static inline void atomic_set_release(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic_set_release(v, i); } #define atomic_set_release atomic_set_release @@ -59,7 +72,7 @@ atomic_set_release(atomic_t *v, int i) static inline void atomic_add(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic_add(i, v); } #define atomic_add atomic_add @@ -68,7 +81,7 @@ atomic_add(int i, atomic_t *v) static inline int atomic_add_return(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_add_return(i, v); } #define atomic_add_return atomic_add_return @@ -78,7 +91,7 @@ atomic_add_return(int i, atomic_t *v) static inline int atomic_add_return_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_add_return_acquire(i, v); } #define atomic_add_return_acquire atomic_add_return_acquire @@ -88,7 +101,7 @@ atomic_add_return_acquire(int i, atomic_t *v) static inline int atomic_add_return_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_add_return_release(i, v); } #define atomic_add_return_release atomic_add_return_release @@ -98,7 +111,7 @@ atomic_add_return_release(int i, atomic_t *v) static inline int atomic_add_return_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_add_return_relaxed(i, v); } #define atomic_add_return_relaxed atomic_add_return_relaxed @@ -108,7 +121,7 @@ atomic_add_return_relaxed(int i, atomic_t *v) static inline int atomic_fetch_add(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_add(i, v); } #define atomic_fetch_add atomic_fetch_add @@ -118,7 +131,7 @@ atomic_fetch_add(int i, atomic_t *v) static inline int atomic_fetch_add_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_add_acquire(i, v); } #define atomic_fetch_add_acquire atomic_fetch_add_acquire @@ -128,7 +141,7 @@ atomic_fetch_add_acquire(int i, atomic_t *v) static inline int atomic_fetch_add_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_add_release(i, v); } #define atomic_fetch_add_release atomic_fetch_add_release @@ -138,7 +151,7 @@ atomic_fetch_add_release(int i, atomic_t *v) static inline int atomic_fetch_add_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_add_relaxed(i, v); } #define atomic_fetch_add_relaxed atomic_fetch_add_relaxed @@ -147,7 +160,7 @@ atomic_fetch_add_relaxed(int i, atomic_t *v) static inline void atomic_sub(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic_sub(i, v); } #define atomic_sub atomic_sub @@ -156,7 +169,7 @@ atomic_sub(int i, atomic_t *v) static inline int atomic_sub_return(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_sub_return(i, v); } #define atomic_sub_return atomic_sub_return @@ -166,7 +179,7 @@ atomic_sub_return(int i, atomic_t *v) static inline int atomic_sub_return_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_sub_return_acquire(i, v); } #define atomic_sub_return_acquire atomic_sub_return_acquire @@ -176,7 +189,7 @@ atomic_sub_return_acquire(int i, atomic_t *v) static inline int atomic_sub_return_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_sub_return_release(i, v); } #define atomic_sub_return_release atomic_sub_return_release @@ -186,7 +199,7 @@ atomic_sub_return_release(int i, atomic_t *v) static inline int atomic_sub_return_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_sub_return_relaxed(i, v); } #define atomic_sub_return_relaxed atomic_sub_return_relaxed @@ -196,7 +209,7 @@ atomic_sub_return_relaxed(int i, atomic_t *v) static inline int atomic_fetch_sub(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_sub(i, v); } #define atomic_fetch_sub atomic_fetch_sub @@ -206,7 +219,7 @@ atomic_fetch_sub(int i, atomic_t *v) static inline int atomic_fetch_sub_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_sub_acquire(i, v); } #define atomic_fetch_sub_acquire atomic_fetch_sub_acquire @@ -216,7 +229,7 @@ atomic_fetch_sub_acquire(int i, atomic_t *v) static inline int atomic_fetch_sub_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_sub_release(i, v); } #define atomic_fetch_sub_release atomic_fetch_sub_release @@ -226,7 +239,7 @@ atomic_fetch_sub_release(int i, atomic_t *v) static inline int atomic_fetch_sub_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_sub_relaxed(i, v); } #define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed @@ -236,7 +249,7 @@ atomic_fetch_sub_relaxed(int i, atomic_t *v) static inline void atomic_inc(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic_inc(v); } #define atomic_inc atomic_inc @@ -246,7 +259,7 @@ atomic_inc(atomic_t *v) static inline int atomic_inc_return(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_inc_return(v); } #define atomic_inc_return atomic_inc_return @@ -256,7 +269,7 @@ atomic_inc_return(atomic_t *v) static inline int atomic_inc_return_acquire(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_inc_return_acquire(v); } #define atomic_inc_return_acquire atomic_inc_return_acquire @@ -266,7 +279,7 @@ atomic_inc_return_acquire(atomic_t *v) static inline int atomic_inc_return_release(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_inc_return_release(v); } #define atomic_inc_return_release atomic_inc_return_release @@ -276,7 +289,7 @@ atomic_inc_return_release(atomic_t *v) static inline int atomic_inc_return_relaxed(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_inc_return_relaxed(v); } #define atomic_inc_return_relaxed atomic_inc_return_relaxed @@ -286,7 +299,7 @@ atomic_inc_return_relaxed(atomic_t *v) static inline int atomic_fetch_inc(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_inc(v); } #define atomic_fetch_inc atomic_fetch_inc @@ -296,7 +309,7 @@ atomic_fetch_inc(atomic_t *v) static inline int atomic_fetch_inc_acquire(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_inc_acquire(v); } #define atomic_fetch_inc_acquire atomic_fetch_inc_acquire @@ -306,7 +319,7 @@ atomic_fetch_inc_acquire(atomic_t *v) static inline int atomic_fetch_inc_release(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_inc_release(v); } #define atomic_fetch_inc_release atomic_fetch_inc_release @@ -316,7 +329,7 @@ atomic_fetch_inc_release(atomic_t *v) static inline int atomic_fetch_inc_relaxed(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_inc_relaxed(v); } #define atomic_fetch_inc_relaxed atomic_fetch_inc_relaxed @@ -326,7 +339,7 @@ atomic_fetch_inc_relaxed(atomic_t *v) static inline void atomic_dec(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic_dec(v); } #define atomic_dec atomic_dec @@ -336,7 +349,7 @@ atomic_dec(atomic_t *v) static inline int atomic_dec_return(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_dec_return(v); } #define atomic_dec_return atomic_dec_return @@ -346,7 +359,7 @@ atomic_dec_return(atomic_t *v) static inline int atomic_dec_return_acquire(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_dec_return_acquire(v); } #define atomic_dec_return_acquire atomic_dec_return_acquire @@ -356,7 +369,7 @@ atomic_dec_return_acquire(atomic_t *v) static inline int atomic_dec_return_release(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_dec_return_release(v); } #define atomic_dec_return_release atomic_dec_return_release @@ -366,7 +379,7 @@ atomic_dec_return_release(atomic_t *v) static inline int atomic_dec_return_relaxed(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_dec_return_relaxed(v); } #define atomic_dec_return_relaxed atomic_dec_return_relaxed @@ -376,7 +389,7 @@ atomic_dec_return_relaxed(atomic_t *v) static inline int atomic_fetch_dec(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_dec(v); } #define atomic_fetch_dec atomic_fetch_dec @@ -386,7 +399,7 @@ atomic_fetch_dec(atomic_t *v) static inline int atomic_fetch_dec_acquire(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_dec_acquire(v); } #define atomic_fetch_dec_acquire atomic_fetch_dec_acquire @@ -396,7 +409,7 @@ atomic_fetch_dec_acquire(atomic_t *v) static inline int atomic_fetch_dec_release(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_dec_release(v); } #define atomic_fetch_dec_release atomic_fetch_dec_release @@ -406,7 +419,7 @@ atomic_fetch_dec_release(atomic_t *v) static inline int atomic_fetch_dec_relaxed(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_dec_relaxed(v); } #define atomic_fetch_dec_relaxed atomic_fetch_dec_relaxed @@ -415,7 +428,7 @@ atomic_fetch_dec_relaxed(atomic_t *v) static inline void atomic_and(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic_and(i, v); } #define atomic_and atomic_and @@ -424,7 +437,7 @@ atomic_and(int i, atomic_t *v) static inline int atomic_fetch_and(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_and(i, v); } #define atomic_fetch_and atomic_fetch_and @@ -434,7 +447,7 @@ atomic_fetch_and(int i, atomic_t *v) static inline int atomic_fetch_and_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_and_acquire(i, v); } #define atomic_fetch_and_acquire atomic_fetch_and_acquire @@ -444,7 +457,7 @@ atomic_fetch_and_acquire(int i, atomic_t *v) static inline int atomic_fetch_and_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_and_release(i, v); } #define atomic_fetch_and_release atomic_fetch_and_release @@ -454,7 +467,7 @@ atomic_fetch_and_release(int i, atomic_t *v) static inline int atomic_fetch_and_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_and_relaxed(i, v); } #define atomic_fetch_and_relaxed atomic_fetch_and_relaxed @@ -464,7 +477,7 @@ atomic_fetch_and_relaxed(int i, atomic_t *v) static inline void atomic_andnot(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic_andnot(i, v); } #define atomic_andnot atomic_andnot @@ -474,7 +487,7 @@ atomic_andnot(int i, atomic_t *v) static inline int atomic_fetch_andnot(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_andnot(i, v); } #define atomic_fetch_andnot atomic_fetch_andnot @@ -484,7 +497,7 @@ atomic_fetch_andnot(int i, atomic_t *v) static inline int atomic_fetch_andnot_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_andnot_acquire(i, v); } #define atomic_fetch_andnot_acquire atomic_fetch_andnot_acquire @@ -494,7 +507,7 @@ atomic_fetch_andnot_acquire(int i, atomic_t *v) static inline int atomic_fetch_andnot_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_andnot_release(i, v); } #define atomic_fetch_andnot_release atomic_fetch_andnot_release @@ -504,7 +517,7 @@ atomic_fetch_andnot_release(int i, atomic_t *v) static inline int atomic_fetch_andnot_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_andnot_relaxed(i, v); } #define atomic_fetch_andnot_relaxed atomic_fetch_andnot_relaxed @@ -513,7 +526,7 @@ atomic_fetch_andnot_relaxed(int i, atomic_t *v) static inline void atomic_or(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic_or(i, v); } #define atomic_or atomic_or @@ -522,7 +535,7 @@ atomic_or(int i, atomic_t *v) static inline int atomic_fetch_or(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_or(i, v); } #define atomic_fetch_or atomic_fetch_or @@ -532,7 +545,7 @@ atomic_fetch_or(int i, atomic_t *v) static inline int atomic_fetch_or_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_or_acquire(i, v); } #define atomic_fetch_or_acquire atomic_fetch_or_acquire @@ -542,7 +555,7 @@ atomic_fetch_or_acquire(int i, atomic_t *v) static inline int atomic_fetch_or_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_or_release(i, v); } #define atomic_fetch_or_release atomic_fetch_or_release @@ -552,7 +565,7 @@ atomic_fetch_or_release(int i, atomic_t *v) static inline int atomic_fetch_or_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_or_relaxed(i, v); } #define atomic_fetch_or_relaxed atomic_fetch_or_relaxed @@ -561,7 +574,7 @@ atomic_fetch_or_relaxed(int i, atomic_t *v) static inline void atomic_xor(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic_xor(i, v); } #define atomic_xor atomic_xor @@ -570,7 +583,7 @@ atomic_xor(int i, atomic_t *v) static inline int atomic_fetch_xor(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_xor(i, v); } #define atomic_fetch_xor atomic_fetch_xor @@ -580,7 +593,7 @@ atomic_fetch_xor(int i, atomic_t *v) static inline int atomic_fetch_xor_acquire(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_xor_acquire(i, v); } #define atomic_fetch_xor_acquire atomic_fetch_xor_acquire @@ -590,7 +603,7 @@ atomic_fetch_xor_acquire(int i, atomic_t *v) static inline int atomic_fetch_xor_release(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_xor_release(i, v); } #define atomic_fetch_xor_release atomic_fetch_xor_release @@ -600,7 +613,7 @@ atomic_fetch_xor_release(int i, atomic_t *v) static inline int atomic_fetch_xor_relaxed(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_xor_relaxed(i, v); } #define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed @@ -610,7 +623,7 @@ atomic_fetch_xor_relaxed(int i, atomic_t *v) static inline int atomic_xchg(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_xchg(v, i); } #define atomic_xchg atomic_xchg @@ -620,7 +633,7 @@ atomic_xchg(atomic_t *v, int i) static inline int atomic_xchg_acquire(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_xchg_acquire(v, i); } #define atomic_xchg_acquire atomic_xchg_acquire @@ -630,7 +643,7 @@ atomic_xchg_acquire(atomic_t *v, int i) static inline int atomic_xchg_release(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_xchg_release(v, i); } #define atomic_xchg_release atomic_xchg_release @@ -640,7 +653,7 @@ atomic_xchg_release(atomic_t *v, int i) static inline int atomic_xchg_relaxed(atomic_t *v, int i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_xchg_relaxed(v, i); } #define atomic_xchg_relaxed atomic_xchg_relaxed @@ -650,7 +663,7 @@ atomic_xchg_relaxed(atomic_t *v, int i) static inline int atomic_cmpxchg(atomic_t *v, int old, int new) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_cmpxchg(v, old, new); } #define atomic_cmpxchg atomic_cmpxchg @@ -660,7 +673,7 @@ atomic_cmpxchg(atomic_t *v, int old, int new) static inline int atomic_cmpxchg_acquire(atomic_t *v, int old, int new) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_cmpxchg_acquire(v, old, new); } #define atomic_cmpxchg_acquire atomic_cmpxchg_acquire @@ -670,7 +683,7 @@ atomic_cmpxchg_acquire(atomic_t *v, int old, int new) static inline int atomic_cmpxchg_release(atomic_t *v, int old, int new) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_cmpxchg_release(v, old, new); } #define atomic_cmpxchg_release atomic_cmpxchg_release @@ -680,7 +693,7 @@ atomic_cmpxchg_release(atomic_t *v, int old, int new) static inline int atomic_cmpxchg_relaxed(atomic_t *v, int old, int new) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_cmpxchg_relaxed(v, old, new); } #define atomic_cmpxchg_relaxed atomic_cmpxchg_relaxed @@ -690,8 +703,8 @@ atomic_cmpxchg_relaxed(atomic_t *v, int old, int new) static inline bool atomic_try_cmpxchg(atomic_t *v, int *old, int new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + __atomic_check_write(v, sizeof(*v)); + __atomic_check_write(old, sizeof(*old)); return arch_atomic_try_cmpxchg(v, old, new); } #define atomic_try_cmpxchg atomic_try_cmpxchg @@ -701,8 +714,8 @@ atomic_try_cmpxchg(atomic_t *v, int *old, int new) static inline bool atomic_try_cmpxchg_acquire(atomic_t *v, int *old, int new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + __atomic_check_write(v, sizeof(*v)); + __atomic_check_write(old, sizeof(*old)); return arch_atomic_try_cmpxchg_acquire(v, old, new); } #define atomic_try_cmpxchg_acquire atomic_try_cmpxchg_acquire @@ -712,8 +725,8 @@ atomic_try_cmpxchg_acquire(atomic_t *v, int *old, int new) static inline bool atomic_try_cmpxchg_release(atomic_t *v, int *old, int new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + __atomic_check_write(v, sizeof(*v)); + __atomic_check_write(old, sizeof(*old)); return arch_atomic_try_cmpxchg_release(v, old, new); } #define atomic_try_cmpxchg_release atomic_try_cmpxchg_release @@ -723,8 +736,8 @@ atomic_try_cmpxchg_release(atomic_t *v, int *old, int new) static inline bool atomic_try_cmpxchg_relaxed(atomic_t *v, int *old, int new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + __atomic_check_write(v, sizeof(*v)); + __atomic_check_write(old, sizeof(*old)); return arch_atomic_try_cmpxchg_relaxed(v, old, new); } #define atomic_try_cmpxchg_relaxed atomic_try_cmpxchg_relaxed @@ -734,7 +747,7 @@ atomic_try_cmpxchg_relaxed(atomic_t *v, int *old, int new) static inline bool atomic_sub_and_test(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_sub_and_test(i, v); } #define atomic_sub_and_test atomic_sub_and_test @@ -744,7 +757,7 @@ atomic_sub_and_test(int i, atomic_t *v) static inline bool atomic_dec_and_test(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_dec_and_test(v); } #define atomic_dec_and_test atomic_dec_and_test @@ -754,7 +767,7 @@ atomic_dec_and_test(atomic_t *v) static inline bool atomic_inc_and_test(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_inc_and_test(v); } #define atomic_inc_and_test atomic_inc_and_test @@ -764,7 +777,7 @@ atomic_inc_and_test(atomic_t *v) static inline bool atomic_add_negative(int i, atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_add_negative(i, v); } #define atomic_add_negative atomic_add_negative @@ -774,7 +787,7 @@ atomic_add_negative(int i, atomic_t *v) static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_fetch_add_unless(v, a, u); } #define atomic_fetch_add_unless atomic_fetch_add_unless @@ -784,7 +797,7 @@ atomic_fetch_add_unless(atomic_t *v, int a, int u) static inline bool atomic_add_unless(atomic_t *v, int a, int u) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_add_unless(v, a, u); } #define atomic_add_unless atomic_add_unless @@ -794,7 +807,7 @@ atomic_add_unless(atomic_t *v, int a, int u) static inline bool atomic_inc_not_zero(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_inc_not_zero(v); } #define atomic_inc_not_zero atomic_inc_not_zero @@ -804,7 +817,7 @@ atomic_inc_not_zero(atomic_t *v) static inline bool atomic_inc_unless_negative(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_inc_unless_negative(v); } #define atomic_inc_unless_negative atomic_inc_unless_negative @@ -814,7 +827,7 @@ atomic_inc_unless_negative(atomic_t *v) static inline bool atomic_dec_unless_positive(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_dec_unless_positive(v); } #define atomic_dec_unless_positive atomic_dec_unless_positive @@ -824,7 +837,7 @@ atomic_dec_unless_positive(atomic_t *v) static inline int atomic_dec_if_positive(atomic_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic_dec_if_positive(v); } #define atomic_dec_if_positive atomic_dec_if_positive @@ -833,7 +846,7 @@ atomic_dec_if_positive(atomic_t *v) static inline s64 atomic64_read(const atomic64_t *v) { - kasan_check_read(v, sizeof(*v)); + __atomic_check_read(v, sizeof(*v)); return arch_atomic64_read(v); } #define atomic64_read atomic64_read @@ -842,7 +855,7 @@ atomic64_read(const atomic64_t *v) static inline s64 atomic64_read_acquire(const atomic64_t *v) { - kasan_check_read(v, sizeof(*v)); + __atomic_check_read(v, sizeof(*v)); return arch_atomic64_read_acquire(v); } #define atomic64_read_acquire atomic64_read_acquire @@ -851,7 +864,7 @@ atomic64_read_acquire(const atomic64_t *v) static inline void atomic64_set(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic64_set(v, i); } #define atomic64_set atomic64_set @@ -860,7 +873,7 @@ atomic64_set(atomic64_t *v, s64 i) static inline void atomic64_set_release(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic64_set_release(v, i); } #define atomic64_set_release atomic64_set_release @@ -869,7 +882,7 @@ atomic64_set_release(atomic64_t *v, s64 i) static inline void atomic64_add(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic64_add(i, v); } #define atomic64_add atomic64_add @@ -878,7 +891,7 @@ atomic64_add(s64 i, atomic64_t *v) static inline s64 atomic64_add_return(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_add_return(i, v); } #define atomic64_add_return atomic64_add_return @@ -888,7 +901,7 @@ atomic64_add_return(s64 i, atomic64_t *v) static inline s64 atomic64_add_return_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_add_return_acquire(i, v); } #define atomic64_add_return_acquire atomic64_add_return_acquire @@ -898,7 +911,7 @@ atomic64_add_return_acquire(s64 i, atomic64_t *v) static inline s64 atomic64_add_return_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_add_return_release(i, v); } #define atomic64_add_return_release atomic64_add_return_release @@ -908,7 +921,7 @@ atomic64_add_return_release(s64 i, atomic64_t *v) static inline s64 atomic64_add_return_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_add_return_relaxed(i, v); } #define atomic64_add_return_relaxed atomic64_add_return_relaxed @@ -918,7 +931,7 @@ atomic64_add_return_relaxed(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_add(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_add(i, v); } #define atomic64_fetch_add atomic64_fetch_add @@ -928,7 +941,7 @@ atomic64_fetch_add(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_add_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_add_acquire(i, v); } #define atomic64_fetch_add_acquire atomic64_fetch_add_acquire @@ -938,7 +951,7 @@ atomic64_fetch_add_acquire(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_add_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_add_release(i, v); } #define atomic64_fetch_add_release atomic64_fetch_add_release @@ -948,7 +961,7 @@ atomic64_fetch_add_release(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_add_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_add_relaxed(i, v); } #define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed @@ -957,7 +970,7 @@ atomic64_fetch_add_relaxed(s64 i, atomic64_t *v) static inline void atomic64_sub(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic64_sub(i, v); } #define atomic64_sub atomic64_sub @@ -966,7 +979,7 @@ atomic64_sub(s64 i, atomic64_t *v) static inline s64 atomic64_sub_return(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_sub_return(i, v); } #define atomic64_sub_return atomic64_sub_return @@ -976,7 +989,7 @@ atomic64_sub_return(s64 i, atomic64_t *v) static inline s64 atomic64_sub_return_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_sub_return_acquire(i, v); } #define atomic64_sub_return_acquire atomic64_sub_return_acquire @@ -986,7 +999,7 @@ atomic64_sub_return_acquire(s64 i, atomic64_t *v) static inline s64 atomic64_sub_return_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_sub_return_release(i, v); } #define atomic64_sub_return_release atomic64_sub_return_release @@ -996,7 +1009,7 @@ atomic64_sub_return_release(s64 i, atomic64_t *v) static inline s64 atomic64_sub_return_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_sub_return_relaxed(i, v); } #define atomic64_sub_return_relaxed atomic64_sub_return_relaxed @@ -1006,7 +1019,7 @@ atomic64_sub_return_relaxed(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_sub(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_sub(i, v); } #define atomic64_fetch_sub atomic64_fetch_sub @@ -1016,7 +1029,7 @@ atomic64_fetch_sub(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_sub_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_sub_acquire(i, v); } #define atomic64_fetch_sub_acquire atomic64_fetch_sub_acquire @@ -1026,7 +1039,7 @@ atomic64_fetch_sub_acquire(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_sub_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_sub_release(i, v); } #define atomic64_fetch_sub_release atomic64_fetch_sub_release @@ -1036,7 +1049,7 @@ atomic64_fetch_sub_release(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_sub_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_sub_relaxed(i, v); } #define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed @@ -1046,7 +1059,7 @@ atomic64_fetch_sub_relaxed(s64 i, atomic64_t *v) static inline void atomic64_inc(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic64_inc(v); } #define atomic64_inc atomic64_inc @@ -1056,7 +1069,7 @@ atomic64_inc(atomic64_t *v) static inline s64 atomic64_inc_return(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_inc_return(v); } #define atomic64_inc_return atomic64_inc_return @@ -1066,7 +1079,7 @@ atomic64_inc_return(atomic64_t *v) static inline s64 atomic64_inc_return_acquire(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_inc_return_acquire(v); } #define atomic64_inc_return_acquire atomic64_inc_return_acquire @@ -1076,7 +1089,7 @@ atomic64_inc_return_acquire(atomic64_t *v) static inline s64 atomic64_inc_return_release(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_inc_return_release(v); } #define atomic64_inc_return_release atomic64_inc_return_release @@ -1086,7 +1099,7 @@ atomic64_inc_return_release(atomic64_t *v) static inline s64 atomic64_inc_return_relaxed(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_inc_return_relaxed(v); } #define atomic64_inc_return_relaxed atomic64_inc_return_relaxed @@ -1096,7 +1109,7 @@ atomic64_inc_return_relaxed(atomic64_t *v) static inline s64 atomic64_fetch_inc(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_inc(v); } #define atomic64_fetch_inc atomic64_fetch_inc @@ -1106,7 +1119,7 @@ atomic64_fetch_inc(atomic64_t *v) static inline s64 atomic64_fetch_inc_acquire(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_inc_acquire(v); } #define atomic64_fetch_inc_acquire atomic64_fetch_inc_acquire @@ -1116,7 +1129,7 @@ atomic64_fetch_inc_acquire(atomic64_t *v) static inline s64 atomic64_fetch_inc_release(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_inc_release(v); } #define atomic64_fetch_inc_release atomic64_fetch_inc_release @@ -1126,7 +1139,7 @@ atomic64_fetch_inc_release(atomic64_t *v) static inline s64 atomic64_fetch_inc_relaxed(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_inc_relaxed(v); } #define atomic64_fetch_inc_relaxed atomic64_fetch_inc_relaxed @@ -1136,7 +1149,7 @@ atomic64_fetch_inc_relaxed(atomic64_t *v) static inline void atomic64_dec(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic64_dec(v); } #define atomic64_dec atomic64_dec @@ -1146,7 +1159,7 @@ atomic64_dec(atomic64_t *v) static inline s64 atomic64_dec_return(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_dec_return(v); } #define atomic64_dec_return atomic64_dec_return @@ -1156,7 +1169,7 @@ atomic64_dec_return(atomic64_t *v) static inline s64 atomic64_dec_return_acquire(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_dec_return_acquire(v); } #define atomic64_dec_return_acquire atomic64_dec_return_acquire @@ -1166,7 +1179,7 @@ atomic64_dec_return_acquire(atomic64_t *v) static inline s64 atomic64_dec_return_release(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_dec_return_release(v); } #define atomic64_dec_return_release atomic64_dec_return_release @@ -1176,7 +1189,7 @@ atomic64_dec_return_release(atomic64_t *v) static inline s64 atomic64_dec_return_relaxed(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_dec_return_relaxed(v); } #define atomic64_dec_return_relaxed atomic64_dec_return_relaxed @@ -1186,7 +1199,7 @@ atomic64_dec_return_relaxed(atomic64_t *v) static inline s64 atomic64_fetch_dec(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_dec(v); } #define atomic64_fetch_dec atomic64_fetch_dec @@ -1196,7 +1209,7 @@ atomic64_fetch_dec(atomic64_t *v) static inline s64 atomic64_fetch_dec_acquire(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_dec_acquire(v); } #define atomic64_fetch_dec_acquire atomic64_fetch_dec_acquire @@ -1206,7 +1219,7 @@ atomic64_fetch_dec_acquire(atomic64_t *v) static inline s64 atomic64_fetch_dec_release(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_dec_release(v); } #define atomic64_fetch_dec_release atomic64_fetch_dec_release @@ -1216,7 +1229,7 @@ atomic64_fetch_dec_release(atomic64_t *v) static inline s64 atomic64_fetch_dec_relaxed(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_dec_relaxed(v); } #define atomic64_fetch_dec_relaxed atomic64_fetch_dec_relaxed @@ -1225,7 +1238,7 @@ atomic64_fetch_dec_relaxed(atomic64_t *v) static inline void atomic64_and(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic64_and(i, v); } #define atomic64_and atomic64_and @@ -1234,7 +1247,7 @@ atomic64_and(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_and(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_and(i, v); } #define atomic64_fetch_and atomic64_fetch_and @@ -1244,7 +1257,7 @@ atomic64_fetch_and(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_and_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_and_acquire(i, v); } #define atomic64_fetch_and_acquire atomic64_fetch_and_acquire @@ -1254,7 +1267,7 @@ atomic64_fetch_and_acquire(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_and_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_and_release(i, v); } #define atomic64_fetch_and_release atomic64_fetch_and_release @@ -1264,7 +1277,7 @@ atomic64_fetch_and_release(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_and_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_and_relaxed(i, v); } #define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed @@ -1274,7 +1287,7 @@ atomic64_fetch_and_relaxed(s64 i, atomic64_t *v) static inline void atomic64_andnot(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic64_andnot(i, v); } #define atomic64_andnot atomic64_andnot @@ -1284,7 +1297,7 @@ atomic64_andnot(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_andnot(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_andnot(i, v); } #define atomic64_fetch_andnot atomic64_fetch_andnot @@ -1294,7 +1307,7 @@ atomic64_fetch_andnot(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_andnot_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_andnot_acquire(i, v); } #define atomic64_fetch_andnot_acquire atomic64_fetch_andnot_acquire @@ -1304,7 +1317,7 @@ atomic64_fetch_andnot_acquire(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_andnot_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_andnot_release(i, v); } #define atomic64_fetch_andnot_release atomic64_fetch_andnot_release @@ -1314,7 +1327,7 @@ atomic64_fetch_andnot_release(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_andnot_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_andnot_relaxed(i, v); } #define atomic64_fetch_andnot_relaxed atomic64_fetch_andnot_relaxed @@ -1323,7 +1336,7 @@ atomic64_fetch_andnot_relaxed(s64 i, atomic64_t *v) static inline void atomic64_or(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic64_or(i, v); } #define atomic64_or atomic64_or @@ -1332,7 +1345,7 @@ atomic64_or(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_or(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_or(i, v); } #define atomic64_fetch_or atomic64_fetch_or @@ -1342,7 +1355,7 @@ atomic64_fetch_or(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_or_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_or_acquire(i, v); } #define atomic64_fetch_or_acquire atomic64_fetch_or_acquire @@ -1352,7 +1365,7 @@ atomic64_fetch_or_acquire(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_or_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_or_release(i, v); } #define atomic64_fetch_or_release atomic64_fetch_or_release @@ -1362,7 +1375,7 @@ atomic64_fetch_or_release(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_or_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_or_relaxed(i, v); } #define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed @@ -1371,7 +1384,7 @@ atomic64_fetch_or_relaxed(s64 i, atomic64_t *v) static inline void atomic64_xor(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); arch_atomic64_xor(i, v); } #define atomic64_xor atomic64_xor @@ -1380,7 +1393,7 @@ atomic64_xor(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_xor(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_xor(i, v); } #define atomic64_fetch_xor atomic64_fetch_xor @@ -1390,7 +1403,7 @@ atomic64_fetch_xor(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_xor_acquire(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_xor_acquire(i, v); } #define atomic64_fetch_xor_acquire atomic64_fetch_xor_acquire @@ -1400,7 +1413,7 @@ atomic64_fetch_xor_acquire(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_xor_release(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_xor_release(i, v); } #define atomic64_fetch_xor_release atomic64_fetch_xor_release @@ -1410,7 +1423,7 @@ atomic64_fetch_xor_release(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_xor_relaxed(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_xor_relaxed(i, v); } #define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed @@ -1420,7 +1433,7 @@ atomic64_fetch_xor_relaxed(s64 i, atomic64_t *v) static inline s64 atomic64_xchg(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_xchg(v, i); } #define atomic64_xchg atomic64_xchg @@ -1430,7 +1443,7 @@ atomic64_xchg(atomic64_t *v, s64 i) static inline s64 atomic64_xchg_acquire(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_xchg_acquire(v, i); } #define atomic64_xchg_acquire atomic64_xchg_acquire @@ -1440,7 +1453,7 @@ atomic64_xchg_acquire(atomic64_t *v, s64 i) static inline s64 atomic64_xchg_release(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_xchg_release(v, i); } #define atomic64_xchg_release atomic64_xchg_release @@ -1450,7 +1463,7 @@ atomic64_xchg_release(atomic64_t *v, s64 i) static inline s64 atomic64_xchg_relaxed(atomic64_t *v, s64 i) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_xchg_relaxed(v, i); } #define atomic64_xchg_relaxed atomic64_xchg_relaxed @@ -1460,7 +1473,7 @@ atomic64_xchg_relaxed(atomic64_t *v, s64 i) static inline s64 atomic64_cmpxchg(atomic64_t *v, s64 old, s64 new) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_cmpxchg(v, old, new); } #define atomic64_cmpxchg atomic64_cmpxchg @@ -1470,7 +1483,7 @@ atomic64_cmpxchg(atomic64_t *v, s64 old, s64 new) static inline s64 atomic64_cmpxchg_acquire(atomic64_t *v, s64 old, s64 new) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_cmpxchg_acquire(v, old, new); } #define atomic64_cmpxchg_acquire atomic64_cmpxchg_acquire @@ -1480,7 +1493,7 @@ atomic64_cmpxchg_acquire(atomic64_t *v, s64 old, s64 new) static inline s64 atomic64_cmpxchg_release(atomic64_t *v, s64 old, s64 new) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_cmpxchg_release(v, old, new); } #define atomic64_cmpxchg_release atomic64_cmpxchg_release @@ -1490,7 +1503,7 @@ atomic64_cmpxchg_release(atomic64_t *v, s64 old, s64 new) static inline s64 atomic64_cmpxchg_relaxed(atomic64_t *v, s64 old, s64 new) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_cmpxchg_relaxed(v, old, new); } #define atomic64_cmpxchg_relaxed atomic64_cmpxchg_relaxed @@ -1500,8 +1513,8 @@ atomic64_cmpxchg_relaxed(atomic64_t *v, s64 old, s64 new) static inline bool atomic64_try_cmpxchg(atomic64_t *v, s64 *old, s64 new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + __atomic_check_write(v, sizeof(*v)); + __atomic_check_write(old, sizeof(*old)); return arch_atomic64_try_cmpxchg(v, old, new); } #define atomic64_try_cmpxchg atomic64_try_cmpxchg @@ -1511,8 +1524,8 @@ atomic64_try_cmpxchg(atomic64_t *v, s64 *old, s64 new) static inline bool atomic64_try_cmpxchg_acquire(atomic64_t *v, s64 *old, s64 new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + __atomic_check_write(v, sizeof(*v)); + __atomic_check_write(old, sizeof(*old)); return arch_atomic64_try_cmpxchg_acquire(v, old, new); } #define atomic64_try_cmpxchg_acquire atomic64_try_cmpxchg_acquire @@ -1522,8 +1535,8 @@ atomic64_try_cmpxchg_acquire(atomic64_t *v, s64 *old, s64 new) static inline bool atomic64_try_cmpxchg_release(atomic64_t *v, s64 *old, s64 new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + __atomic_check_write(v, sizeof(*v)); + __atomic_check_write(old, sizeof(*old)); return arch_atomic64_try_cmpxchg_release(v, old, new); } #define atomic64_try_cmpxchg_release atomic64_try_cmpxchg_release @@ -1533,8 +1546,8 @@ atomic64_try_cmpxchg_release(atomic64_t *v, s64 *old, s64 new) static inline bool atomic64_try_cmpxchg_relaxed(atomic64_t *v, s64 *old, s64 new) { - kasan_check_write(v, sizeof(*v)); - kasan_check_write(old, sizeof(*old)); + __atomic_check_write(v, sizeof(*v)); + __atomic_check_write(old, sizeof(*old)); return arch_atomic64_try_cmpxchg_relaxed(v, old, new); } #define atomic64_try_cmpxchg_relaxed atomic64_try_cmpxchg_relaxed @@ -1544,7 +1557,7 @@ atomic64_try_cmpxchg_relaxed(atomic64_t *v, s64 *old, s64 new) static inline bool atomic64_sub_and_test(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_sub_and_test(i, v); } #define atomic64_sub_and_test atomic64_sub_and_test @@ -1554,7 +1567,7 @@ atomic64_sub_and_test(s64 i, atomic64_t *v) static inline bool atomic64_dec_and_test(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_dec_and_test(v); } #define atomic64_dec_and_test atomic64_dec_and_test @@ -1564,7 +1577,7 @@ atomic64_dec_and_test(atomic64_t *v) static inline bool atomic64_inc_and_test(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_inc_and_test(v); } #define atomic64_inc_and_test atomic64_inc_and_test @@ -1574,7 +1587,7 @@ atomic64_inc_and_test(atomic64_t *v) static inline bool atomic64_add_negative(s64 i, atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_add_negative(i, v); } #define atomic64_add_negative atomic64_add_negative @@ -1584,7 +1597,7 @@ atomic64_add_negative(s64 i, atomic64_t *v) static inline s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_fetch_add_unless(v, a, u); } #define atomic64_fetch_add_unless atomic64_fetch_add_unless @@ -1594,7 +1607,7 @@ atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u) static inline bool atomic64_add_unless(atomic64_t *v, s64 a, s64 u) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_add_unless(v, a, u); } #define atomic64_add_unless atomic64_add_unless @@ -1604,7 +1617,7 @@ atomic64_add_unless(atomic64_t *v, s64 a, s64 u) static inline bool atomic64_inc_not_zero(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_inc_not_zero(v); } #define atomic64_inc_not_zero atomic64_inc_not_zero @@ -1614,7 +1627,7 @@ atomic64_inc_not_zero(atomic64_t *v) static inline bool atomic64_inc_unless_negative(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_inc_unless_negative(v); } #define atomic64_inc_unless_negative atomic64_inc_unless_negative @@ -1624,7 +1637,7 @@ atomic64_inc_unless_negative(atomic64_t *v) static inline bool atomic64_dec_unless_positive(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_dec_unless_positive(v); } #define atomic64_dec_unless_positive atomic64_dec_unless_positive @@ -1634,7 +1647,7 @@ atomic64_dec_unless_positive(atomic64_t *v) static inline s64 atomic64_dec_if_positive(atomic64_t *v) { - kasan_check_write(v, sizeof(*v)); + __atomic_check_write(v, sizeof(*v)); return arch_atomic64_dec_if_positive(v); } #define atomic64_dec_if_positive atomic64_dec_if_positive @@ -1644,7 +1657,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define xchg(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_xchg(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1653,7 +1666,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define xchg_acquire(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_xchg_acquire(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1662,7 +1675,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define xchg_release(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_xchg_release(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1671,7 +1684,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define xchg_relaxed(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_xchg_relaxed(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1680,7 +1693,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1689,7 +1702,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg_acquire(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg_acquire(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1698,7 +1711,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg_release(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg_release(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1707,7 +1720,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg_relaxed(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg_relaxed(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1716,7 +1729,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg64(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg64(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1725,7 +1738,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg64_acquire(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg64_acquire(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1734,7 +1747,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg64_release(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg64_release(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1743,7 +1756,7 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg64_relaxed(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg64_relaxed(__ai_ptr, __VA_ARGS__); \ }) #endif @@ -1751,28 +1764,28 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg_local(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg_local(__ai_ptr, __VA_ARGS__); \ }) #define cmpxchg64_local(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_cmpxchg64_local(__ai_ptr, __VA_ARGS__); \ }) #define sync_cmpxchg(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, sizeof(*__ai_ptr)); \ arch_sync_cmpxchg(__ai_ptr, __VA_ARGS__); \ }) #define cmpxchg_double(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \ arch_cmpxchg_double(__ai_ptr, __VA_ARGS__); \ }) @@ -1780,9 +1793,9 @@ atomic64_dec_if_positive(atomic64_t *v) #define cmpxchg_double_local(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ - kasan_check_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \ + __atomic_check_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \ arch_cmpxchg_double_local(__ai_ptr, __VA_ARGS__); \ }) #endif /* _ASM_GENERIC_ATOMIC_INSTRUMENTED_H */ -// b29b625d5de9280f680e42c7be859b55b15e5f6a +// beea41c2a0f2c69e4958ed71bf26f59740fa4b12 diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index 333a6695a918..a213eb55e725 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -24,6 +24,15 @@ #define __no_sanitize_address #endif +#if __has_feature(thread_sanitizer) +/* emulate gcc's __SANITIZE_THREAD__ flag */ +#define __SANITIZE_THREAD__ +#define __no_sanitize_thread \ + __attribute__((no_sanitize("thread"))) +#else +#define __no_sanitize_thread +#endif + /* * Not all versions of clang implement the the type-generic versions * of the builtin overflow checkers. Fortunately, clang implements diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index d7ee4c6bad48..0eb2a1cc411d 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -145,6 +145,13 @@ #define __no_sanitize_address #endif +#if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__) +#define __no_sanitize_thread \ + __attribute__((__noinline__)) __attribute__((no_sanitize_thread)) +#else +#define __no_sanitize_thread +#endif + #if GCC_VERSION >= 50100 #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 #endif diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 5e88e7e33abe..7d3e77781578 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -178,6 +178,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, #endif #include <uapi/linux/types.h> +#include <linux/kcsan-checks.h> #define __READ_ONCE_SIZE \ ({ \ @@ -193,12 +194,6 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, } \ }) -static __always_inline -void __read_once_size(const volatile void *p, void *res, int size) -{ - __READ_ONCE_SIZE; -} - #ifdef CONFIG_KASAN /* * We can't declare function 'inline' because __no_sanitize_address confilcts @@ -207,18 +202,44 @@ void __read_once_size(const volatile void *p, void *res, int size) * '__maybe_unused' allows us to avoid defined-but-not-used warnings. */ # define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused +# define __no_sanitize_or_inline __no_kasan_or_inline #else # define __no_kasan_or_inline __always_inline #endif -static __no_kasan_or_inline +#ifdef __SANITIZE_THREAD__ +/* + * Rely on __SANITIZE_THREAD__ instead of CONFIG_KCSAN, to avoid not inlining in + * compilation units where instrumentation is disabled. + */ +# define __no_kcsan_or_inline __no_sanitize_thread notrace __maybe_unused +# define __no_sanitize_or_inline __no_kcsan_or_inline +#else +# define __no_kcsan_or_inline __always_inline +#endif + +#ifndef __no_sanitize_or_inline +#define __no_sanitize_or_inline __always_inline +#endif + +static __no_kcsan_or_inline +void __read_once_size(const volatile void *p, void *res, int size) +{ + kcsan_check_atomic_read(p, size); + __READ_ONCE_SIZE; +} + +static __no_sanitize_or_inline void __read_once_size_nocheck(const volatile void *p, void *res, int size) { __READ_ONCE_SIZE; } -static __always_inline void __write_once_size(volatile void *p, void *res, int size) +static __no_kcsan_or_inline +void __write_once_size(volatile void *p, void *res, int size) { + kcsan_check_atomic_write(p, size); + switch (size) { case 1: *(volatile __u8 *)p = *(__u8 *)res; break; case 2: *(volatile __u16 *)p = *(__u16 *)res; break; @@ -289,6 +310,26 @@ unsigned long read_word_at_a_time(const void *addr) __u.__val; \ }) +#include <linux/kcsan.h> + +/* + * data_race: macro to document that accesses in an expression may conflict with + * other concurrent accesses resulting in data races, but the resulting + * behaviour is deemed safe regardless. + * + * This macro *does not* affect normal code generation, but is a hint to tooling + * that data races here should be ignored. + */ +#define data_race(expr) \ + ({ \ + typeof(({ expr; })) __val; \ + kcsan_nestable_atomic_begin(); \ + __val = ({ expr; }); \ + kcsan_nestable_atomic_end(); \ + __val; \ + }) +#else + #endif /* __KERNEL__ */ /* diff --git a/include/linux/kcsan-checks.h b/include/linux/kcsan-checks.h new file mode 100644 index 000000000000..e78220661086 --- /dev/null +++ b/include/linux/kcsan-checks.h @@ -0,0 +1,97 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_KCSAN_CHECKS_H +#define _LINUX_KCSAN_CHECKS_H + +#include <linux/types.h> + +/* + * Access type modifiers. + */ +#define KCSAN_ACCESS_WRITE 0x1 +#define KCSAN_ACCESS_ATOMIC 0x2 + +/* + * __kcsan_*: Always calls into runtime when KCSAN is enabled. This may be used + * even in compilation units that selectively disable KCSAN, but must use KCSAN + * to validate access to an address. Never use these in header files! + */ +#ifdef CONFIG_KCSAN +/** + * __kcsan_check_access - check generic access for data race + * + * @ptr address of access + * @size size of access + * @type access type modifier + */ +void __kcsan_check_access(const volatile void *ptr, size_t size, int type); + +#else +static inline void __kcsan_check_access(const volatile void *ptr, size_t size, + int type) { } +#endif + +/* + * kcsan_*: Only calls into runtime when the particular compilation unit has + * KCSAN instrumentation enabled. May be used in header files. + */ +#ifdef __SANITIZE_THREAD__ +#define kcsan_check_access __kcsan_check_access +#else +static inline void kcsan_check_access(const volatile void *ptr, size_t size, + int type) { } +#endif + +/** + * __kcsan_check_read - check regular read access for data races + * + * @ptr address of access + * @size size of access + */ +#define __kcsan_check_read(ptr, size) __kcsan_check_access(ptr, size, 0) + +/** + * __kcsan_check_write - check regular write access for data races + * + * @ptr address of access + * @size size of access + */ +#define __kcsan_check_write(ptr, size) \ + __kcsan_check_access(ptr, size, KCSAN_ACCESS_WRITE) + +/** + * kcsan_check_read - check regular read access for data races + * + * @ptr address of access + * @size size of access + */ +#define kcsan_check_read(ptr, size) kcsan_check_access(ptr, size, 0) + +/** + * kcsan_check_write - check regular write access for data races + * + * @ptr address of access + * @size size of access + */ +#define kcsan_check_write(ptr, size) \ + kcsan_check_access(ptr, size, KCSAN_ACCESS_WRITE) + +/* + * Check for atomic accesses: if atomic access are not ignored, this simply + * aliases to kcsan_check_access, otherwise becomes a no-op. + */ +#ifdef CONFIG_KCSAN_IGNORE_ATOMICS +#define kcsan_check_atomic_read(...) \ + do { \ + } while (0) +#define kcsan_check_atomic_write(...) \ + do { \ + } while (0) +#else +#define kcsan_check_atomic_read(ptr, size) \ + kcsan_check_access(ptr, size, KCSAN_ACCESS_ATOMIC) +#define kcsan_check_atomic_write(ptr, size) \ + kcsan_check_access(ptr, size, KCSAN_ACCESS_ATOMIC | KCSAN_ACCESS_WRITE) +#endif + +#endif /* _LINUX_KCSAN_CHECKS_H */ diff --git a/include/linux/kcsan.h b/include/linux/kcsan.h new file mode 100644 index 000000000000..9047048fee84 --- /dev/null +++ b/include/linux/kcsan.h @@ -0,0 +1,115 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_KCSAN_H +#define _LINUX_KCSAN_H + +#include <linux/kcsan-checks.h> +#include <linux/types.h> + +#ifdef CONFIG_KCSAN + +/* + * Context for each thread of execution: for tasks, this is stored in + * task_struct, and interrupts access internal per-CPU storage. + */ +struct kcsan_ctx { + int disable_count; /* disable counter */ + int atomic_next; /* number of following atomic ops */ + + /* + * We distinguish between: (a) nestable atomic regions that may contain + * other nestable regions; and (b) flat atomic regions that do not keep + * track of nesting. Both (a) and (b) are entirely independent of each + * other, and a flat region may be started in a nestable region or + * vice-versa. + * + * This is required because, for example, in the annotations for + * seqlocks, we declare seqlock writer critical sections as (a) nestable + * atomic regions, but reader critical sections as (b) flat atomic + * regions, but have encountered cases where seqlock reader critical + * sections are contained within writer critical sections (the opposite + * may be possible, too). + * + * To support these cases, we independently track the depth of nesting + * for (a), and whether the leaf level is flat for (b). + */ + int atomic_nest_count; + bool in_flat_atomic; +}; + +/** + * kcsan_init - initialize KCSAN runtime + */ +void kcsan_init(void); + +/** + * kcsan_disable_current - disable KCSAN for the current context + * + * Supports nesting. + */ +void kcsan_disable_current(void); + +/** + * kcsan_enable_current - re-enable KCSAN for the current context + * + * Supports nesting. + */ +void kcsan_enable_current(void); + +/** + * kcsan_nestable_atomic_begin - begin nestable atomic region + * + * Accesses within the atomic region may appear to race with other accesses but + * should be considered atomic. + */ +void kcsan_nestable_atomic_begin(void); + +/** + * kcsan_nestable_atomic_end - end nestable atomic region + */ +void kcsan_nestable_atomic_end(void); + +/** + * kcsan_flat_atomic_begin - begin flat atomic region + * + * Accesses within the atomic region may appear to race with other accesses but + * should be considered atomic. + */ +void kcsan_flat_atomic_begin(void); + +/** + * kcsan_flat_atomic_end - end flat atomic region + */ +void kcsan_flat_atomic_end(void); + +/** + * kcsan_atomic_next - consider following accesses as atomic + * + * Force treating the next n memory accesses for the current context as atomic + * operations. + * + * @n number of following memory accesses to treat as atomic. + */ +void kcsan_atomic_next(int n); + +#else /* CONFIG_KCSAN */ + +static inline void kcsan_init(void) { } + +static inline void kcsan_disable_current(void) { } + +static inline void kcsan_enable_current(void) { } + +static inline void kcsan_nestable_atomic_begin(void) { } + +static inline void kcsan_nestable_atomic_end(void) { } + +static inline void kcsan_flat_atomic_begin(void) { } + +static inline void kcsan_flat_atomic_end(void) { } + +static inline void kcsan_atomic_next(int n) { } + +#endif /* CONFIG_KCSAN */ + +#endif /* _LINUX_KCSAN_H */ diff --git a/include/linux/sched.h b/include/linux/sched.h index 67a1d86981a9..ae4f341c1db4 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -31,6 +31,7 @@ #include <linux/task_io_accounting.h> #include <linux/posix-timers.h> #include <linux/rseq.h> +#include <linux/kcsan.h> /* task_struct member predeclarations (sorted alphabetically): */ struct audit_context; @@ -1172,6 +1173,9 @@ struct task_struct { #ifdef CONFIG_KASAN unsigned int kasan_depth; #endif +#ifdef CONFIG_KCSAN + struct kcsan_ctx kcsan_ctx; +#endif #ifdef CONFIG_FUNCTION_GRAPH_TRACER /* Index of current stored address in ret_stack: */ diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index bcf4cf26b8c8..f52c91be8939 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -37,9 +37,25 @@ #include <linux/preempt.h> #include <linux/lockdep.h> #include <linux/compiler.h> +#include <linux/kcsan.h> #include <asm/processor.h> /* + * The seqlock interface does not prescribe a precise sequence of read + * begin/retry/end. For readers, typically there is a call to + * read_seqcount_begin() and read_seqcount_retry(), however, there are more + * esoteric cases which do not follow this pattern. + * + * As a consequence, we take the following best-effort approach for raw usage + * via seqcount_t under KCSAN: upon beginning a seq-reader critical section, + * pessimistically mark then next KCSAN_SEQLOCK_REGION_MAX memory accesses as + * atomics; if there is a matching read_seqcount_retry() call, no following + * memory operations are considered atomic. Usage of seqlocks via seqlock_t + * interface is not affected. + */ +#define KCSAN_SEQLOCK_REGION_MAX 1000 + +/* * Version using sequence counter only. * This can be used when code has its own mutex protecting the * updating starting before the write_seqcountbeqin() and ending @@ -115,6 +131,7 @@ repeat: cpu_relax(); goto repeat; } + kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX); return ret; } @@ -131,6 +148,7 @@ static inline unsigned raw_read_seqcount(const seqcount_t *s) { unsigned ret = READ_ONCE(s->sequence); smp_rmb(); + kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX); return ret; } @@ -183,6 +201,7 @@ static inline unsigned raw_seqcount_begin(const seqcount_t *s) { unsigned ret = READ_ONCE(s->sequence); smp_rmb(); + kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX); return ret & ~1; } @@ -202,7 +221,8 @@ static inline unsigned raw_seqcount_begin(const seqcount_t *s) */ static inline int __read_seqcount_retry(const seqcount_t *s, unsigned start) { - return unlikely(s->sequence != start); + kcsan_atomic_next(0); + return unlikely(READ_ONCE(s->sequence) != start); } /** @@ -225,6 +245,7 @@ static inline int read_seqcount_retry(const seqcount_t *s, unsigned start) static inline void raw_write_seqcount_begin(seqcount_t *s) { + kcsan_nestable_atomic_begin(); s->sequence++; smp_wmb(); } @@ -233,6 +254,7 @@ static inline void raw_write_seqcount_end(seqcount_t *s) { smp_wmb(); s->sequence++; + kcsan_nestable_atomic_end(); } /** @@ -243,6 +265,13 @@ static inline void raw_write_seqcount_end(seqcount_t *s) * usual consistency guarantee. It is one wmb cheaper, because we can * collapse the two back-to-back wmb()s. * + * Note that, writes surrounding the barrier should be declared atomic (e.g. + * via WRITE_ONCE): a) to ensure the writes become visible to other threads + * atomically, avoiding compiler optimizations; b) to document which writes are + * meant to propagate to the reader critical section. This is necessary because + * neither writes before and after the barrier are enclosed in a seq-writer + * critical section that would ensure readers are aware of ongoing writes. + * * seqcount_t seq; * bool X = true, Y = false; * @@ -262,18 +291,20 @@ static inline void raw_write_seqcount_end(seqcount_t *s) * * void write(void) * { - * Y = true; + * WRITE_ONCE(Y, true); * * raw_write_seqcount_barrier(seq); * - * X = false; + * WRITE_ONCE(X, false); * } */ static inline void raw_write_seqcount_barrier(seqcount_t *s) { + kcsan_nestable_atomic_begin(); s->sequence++; smp_wmb(); s->sequence++; + kcsan_nestable_atomic_end(); } static inline int raw_read_seqcount_latch(seqcount_t *s) @@ -398,7 +429,9 @@ static inline void write_seqcount_end(seqcount_t *s) static inline void write_seqcount_invalidate(seqcount_t *s) { smp_wmb(); + kcsan_nestable_atomic_begin(); s->sequence+=2; + kcsan_nestable_atomic_end(); } typedef struct { @@ -430,11 +463,21 @@ typedef struct { */ static inline unsigned read_seqbegin(const seqlock_t *sl) { - return read_seqcount_begin(&sl->seqcount); + unsigned ret = read_seqcount_begin(&sl->seqcount); + + kcsan_atomic_next(0); /* non-raw usage, assume closing read_seqretry */ + kcsan_flat_atomic_begin(); + return ret; } static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start) { + /* + * Assume not nested: read_seqretry may be called multiple times when + * completing read critical section. + */ + kcsan_flat_atomic_end(); + return read_seqcount_retry(&sl->seqcount, start); } diff --git a/init/init_task.c b/init/init_task.c index 9e5cbe5eab7b..2b4fe98b0f09 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -161,6 +161,14 @@ struct task_struct init_task #ifdef CONFIG_KASAN .kasan_depth = 1, #endif +#ifdef CONFIG_KCSAN + .kcsan_ctx = { + .disable_count = 0, + .atomic_next = 0, + .atomic_nest_count = 0, + .in_flat_atomic = false, + }, +#endif #ifdef CONFIG_TRACE_IRQFLAGS .softirqs_enabled = 1, #endif diff --git a/init/main.c b/init/main.c index 91f6ebb30ef0..4d814de017ee 100644 --- a/init/main.c +++ b/init/main.c @@ -93,6 +93,7 @@ #include <linux/rodata_test.h> #include <linux/jump_label.h> #include <linux/mem_encrypt.h> +#include <linux/kcsan.h> #include <asm/io.h> #include <asm/bugs.h> @@ -779,6 +780,7 @@ asmlinkage __visible void __init start_kernel(void) acpi_subsystem_init(); arch_post_acpi_subsys_init(); sfi_init_late(); + kcsan_init(); /* Do the rest non-__init'ed, we're now alive */ arch_call_rest_init(); diff --git a/kernel/Makefile b/kernel/Makefile index daad787fb795..cc53f7c25446 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -23,6 +23,9 @@ endif # Prevents flicker of uninteresting __do_softirq()/__local_bh_disable_ip() # in coverage traces. KCOV_INSTRUMENT_softirq.o := n +# Avoid KCSAN instrumentation in softirq ("No shared variables, all the data +# are CPU local" => assume no data races), to reduce overhead in interrupts. +KCSAN_SANITIZE_softirq.o = n # These are called from save_stack_trace() on slub debug path, # and produce insane amounts of uninteresting coverage. KCOV_INSTRUMENT_module.o := n @@ -30,6 +33,7 @@ KCOV_INSTRUMENT_extable.o := n # Don't self-instrument. KCOV_INSTRUMENT_kcov.o := n KASAN_SANITIZE_kcov.o := n +KCSAN_SANITIZE_kcov.o := n CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) # cond_syscall is currently not LTO compatible @@ -102,6 +106,7 @@ obj-$(CONFIG_TRACEPOINTS) += trace/ obj-$(CONFIG_IRQ_WORK) += irq_work.o obj-$(CONFIG_CPU_PM) += cpu_pm.o obj-$(CONFIG_BPF) += bpf/ +obj-$(CONFIG_KCSAN) += kcsan/ obj-$(CONFIG_PERF_EVENTS) += events/ @@ -117,6 +122,7 @@ obj-$(CONFIG_RSEQ) += rseq.o obj-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak.o KASAN_SANITIZE_stackleak.o := n +KCSAN_SANITIZE_stackleak.o := n KCOV_INSTRUMENT_stackleak.o := n $(obj)/configs.o: $(obj)/config_data.gz diff --git a/kernel/kcsan/Makefile b/kernel/kcsan/Makefile new file mode 100644 index 000000000000..dd15b62ec0b5 --- /dev/null +++ b/kernel/kcsan/Makefile @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0 +KCSAN_SANITIZE := n +KCOV_INSTRUMENT := n + +CFLAGS_REMOVE_core.o = $(CC_FLAGS_FTRACE) + +CFLAGS_core.o := $(call cc-option,-fno-conserve-stack,) \ + $(call cc-option,-fno-stack-protector,) + +obj-y := core.o debugfs.o report.o +obj-$(CONFIG_KCSAN_SELFTEST) += test.o diff --git a/kernel/kcsan/atomic.h b/kernel/kcsan/atomic.h new file mode 100644 index 000000000000..c9c3fe628011 --- /dev/null +++ b/kernel/kcsan/atomic.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _KERNEL_KCSAN_ATOMIC_H +#define _KERNEL_KCSAN_ATOMIC_H + +#include <linux/jiffies.h> + +/* + * Helper that returns true if access to ptr should be considered as an atomic + * access, even though it is not explicitly atomic. + * + * List all volatile globals that have been observed in races, to suppress + * data race reports between accesses to these variables. + * + * For now, we assume that volatile accesses of globals are as strong as atomic + * accesses (READ_ONCE, WRITE_ONCE cast to volatile). The situation is still not + * entirely clear, as on some architectures (Alpha) READ_ONCE/WRITE_ONCE do more + * than cast to volatile. Eventually, we hope to be able to remove this + * function. + */ +static inline bool kcsan_is_atomic(const volatile void *ptr) +{ + /* only jiffies for now */ + return ptr == &jiffies; +} + +#endif /* _KERNEL_KCSAN_ATOMIC_H */ diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c new file mode 100644 index 000000000000..d9410d58c93e --- /dev/null +++ b/kernel/kcsan/core.c @@ -0,0 +1,626 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/atomic.h> +#include <linux/bug.h> +#include <linux/delay.h> +#include <linux/export.h> +#include <linux/init.h> +#include <linux/percpu.h> +#include <linux/preempt.h> +#include <linux/random.h> +#include <linux/sched.h> +#include <linux/uaccess.h> + +#include "atomic.h" +#include "encoding.h" +#include "kcsan.h" + +bool kcsan_enabled; + +/* Per-CPU kcsan_ctx for interrupts */ +static DEFINE_PER_CPU(struct kcsan_ctx, kcsan_cpu_ctx) = { + .disable_count = 0, + .atomic_next = 0, + .atomic_nest_count = 0, + .in_flat_atomic = false, +}; + +/* + * Helper macros to index into adjacent slots slots, starting from address slot + * itself, followed by the right and left slots. + * + * The purpose is 2-fold: + * + * 1. if during insertion the address slot is already occupied, check if + * any adjacent slots are free; + * 2. accesses that straddle a slot boundary due to size that exceeds a + * slot's range may check adjacent slots if any watchpoint matches. + * + * Note that accesses with very large size may still miss a watchpoint; however, + * given this should be rare, this is a reasonable trade-off to make, since this + * will avoid: + * + * 1. excessive contention between watchpoint checks and setup; + * 2. larger number of simultaneous watchpoints without sacrificing + * performance. + * + * Example: SLOT_IDX values for KCSAN_CHECK_ADJACENT=1, where i is [0, 1, 2]: + * + * slot=0: [ 1, 2, 0] + * slot=9: [10, 11, 9] + * slot=63: [64, 65, 63] + */ +#define NUM_SLOTS (1 + 2 * KCSAN_CHECK_ADJACENT) +#define SLOT_IDX(slot, i) (slot + ((i + KCSAN_CHECK_ADJACENT) % NUM_SLOTS)) + +/* + * SLOT_IDX_FAST is used in fast-path. Not first checking the address's primary + * slot (middle) is fine if we assume that data races occur rarely. The set of + * indices {SLOT_IDX(slot, i) | i in [0, NUM_SLOTS)} is equivalent to + * {SLOT_IDX_FAST(slot, i) | i in [0, NUM_SLOTS)}. + */ +#define SLOT_IDX_FAST(slot, i) (slot + i) + +/* + * Watchpoints, with each entry encoded as defined in encoding.h: in order to be + * able to safely update and access a watchpoint without introducing locking + * overhead, we encode each watchpoint as a single atomic long. The initial + * zero-initialized state matches INVALID_WATCHPOINT. + * + * Add NUM_SLOTS-1 entries to account for overflow; this helps avoid having to + * use more complicated SLOT_IDX_FAST calculation with modulo in fast-path. + */ +static atomic_long_t watchpoints[CONFIG_KCSAN_NUM_WATCHPOINTS + NUM_SLOTS - 1]; + +/* + * Instructions to skip watching counter, used in should_watch(). We use a + * per-CPU counter to avoid excessive contention. + */ +static DEFINE_PER_CPU(long, kcsan_skip); + +static inline atomic_long_t *find_watchpoint(unsigned long addr, size_t size, + bool expect_write, + long *encoded_watchpoint) +{ + const int slot = watchpoint_slot(addr); + const unsigned long addr_masked = addr & WATCHPOINT_ADDR_MASK; + atomic_long_t *watchpoint; + unsigned long wp_addr_masked; + size_t wp_size; + bool is_write; + int i; + + BUILD_BUG_ON(CONFIG_KCSAN_NUM_WATCHPOINTS < NUM_SLOTS); + + for (i = 0; i < NUM_SLOTS; ++i) { + watchpoint = &watchpoints[SLOT_IDX_FAST(slot, i)]; + *encoded_watchpoint = atomic_long_read(watchpoint); + if (!decode_watchpoint(*encoded_watchpoint, &wp_addr_masked, + &wp_size, &is_write)) + continue; + + if (expect_write && !is_write) + continue; + + /* Check if the watchpoint matches the access. */ + if (matching_access(wp_addr_masked, wp_size, addr_masked, size)) + return watchpoint; + } + + return NULL; +} + +static inline atomic_long_t *insert_watchpoint(unsigned long addr, size_t size, + bool is_write) +{ + const int slot = watchpoint_slot(addr); + const long encoded_watchpoint = encode_watchpoint(addr, size, is_write); + atomic_long_t *watchpoint; + int i; + + /* Check slot index logic, ensuring we stay within array bounds. */ + BUILD_BUG_ON(SLOT_IDX(0, 0) != KCSAN_CHECK_ADJACENT); + BUILD_BUG_ON(SLOT_IDX(0, KCSAN_CHECK_ADJACENT + 1) != 0); + BUILD_BUG_ON(SLOT_IDX(CONFIG_KCSAN_NUM_WATCHPOINTS - 1, + KCSAN_CHECK_ADJACENT) != + ARRAY_SIZE(watchpoints) - 1); + BUILD_BUG_ON(SLOT_IDX(CONFIG_KCSAN_NUM_WATCHPOINTS - 1, + KCSAN_CHECK_ADJACENT + 1) != + ARRAY_SIZE(watchpoints) - NUM_SLOTS); + + for (i = 0; i < NUM_SLOTS; ++i) { + long expect_val = INVALID_WATCHPOINT; + + /* Try to acquire this slot. */ + watchpoint = &watchpoints[SLOT_IDX(slot, i)]; + if (atomic_long_try_cmpxchg_relaxed(watchpoint, &expect_val, + encoded_watchpoint)) + return watchpoint; + } + + return NULL; +} + +/* + * Return true if watchpoint was successfully consumed, false otherwise. + * + * This may return false if: + * + * 1. another thread already consumed the watchpoint; + * 2. the thread that set up the watchpoint already removed it; + * 3. the watchpoint was removed and then re-used. + */ +static inline bool try_consume_watchpoint(atomic_long_t *watchpoint, + long encoded_watchpoint) +{ + return atomic_long_try_cmpxchg_relaxed(watchpoint, &encoded_watchpoint, + CONSUMED_WATCHPOINT); +} + +/* + * Return true if watchpoint was not touched, false if consumed. + */ +static inline bool remove_watchpoint(atomic_long_t *watchpoint) +{ + return atomic_long_xchg_relaxed(watchpoint, INVALID_WATCHPOINT) != + CONSUMED_WATCHPOINT; +} + +static inline struct kcsan_ctx *get_ctx(void) +{ + /* + * In interrupt, use raw_cpu_ptr to avoid unnecessary checks, that would + * also result in calls that generate warnings in uaccess regions. + */ + return in_task() ? ¤t->kcsan_ctx : raw_cpu_ptr(&kcsan_cpu_ctx); +} + +static inline bool is_atomic(const volatile void *ptr) +{ + struct kcsan_ctx *ctx = get_ctx(); + + if (unlikely(ctx->atomic_next > 0)) { + /* + * Because we do not have separate contexts for nested + * interrupts, in case atomic_next is set, we simply assume that + * the outer interrupt set atomic_next. In the worst case, we + * will conservatively consider operations as atomic. This is a + * reasonable trade-off to make, since this case should be + * extremely rare; however, even if extremely rare, it could + * lead to false positives otherwise. + */ + if ((hardirq_count() >> HARDIRQ_SHIFT) < 2) + --ctx->atomic_next; /* in task, or outer interrupt */ + return true; + } + if (unlikely(ctx->atomic_nest_count > 0 || ctx->in_flat_atomic)) + return true; + + return kcsan_is_atomic(ptr); +} + +static inline bool should_watch(const volatile void *ptr, int type) +{ + /* + * Never set up watchpoints when memory operations are atomic. + * + * Need to check this first, before kcsan_skip check below: (1) atomics + * should not count towards skipped instructions, and (2) to actually + * decrement kcsan_atomic_next for consecutive instruction stream. + */ + if ((type & KCSAN_ACCESS_ATOMIC) != 0 || is_atomic(ptr)) + return false; + + if (this_cpu_dec_return(kcsan_skip) >= 0) + return false; + + /* + * NOTE: If we get here, kcsan_skip must always be reset in slow path + * via reset_kcsan_skip() to avoid underflow. + */ + + /* this operation should be watched */ + return true; +} + +static inline void reset_kcsan_skip(void) +{ + long skip_count = CONFIG_KCSAN_SKIP_WATCH - + (IS_ENABLED(CONFIG_KCSAN_SKIP_WATCH_RANDOMIZE) ? + prandom_u32_max(CONFIG_KCSAN_SKIP_WATCH) : + 0); + this_cpu_write(kcsan_skip, skip_count); +} + +static inline bool kcsan_is_enabled(void) +{ + return READ_ONCE(kcsan_enabled) && get_ctx()->disable_count == 0; +} + +static inline unsigned int get_delay(void) +{ + unsigned int delay = in_task() ? CONFIG_KCSAN_UDELAY_TASK : + CONFIG_KCSAN_UDELAY_INTERRUPT; + return delay - (IS_ENABLED(CONFIG_KCSAN_DELAY_RANDOMIZE) ? + prandom_u32_max(delay) : + 0); +} + +/* + * Pull everything together: check_access() below contains the performance + * critical operations; the fast-path (including check_access) functions should + * all be inlinable by the instrumentation functions. + * + * The slow-path (kcsan_found_watchpoint, kcsan_setup_watchpoint) are + * non-inlinable -- note that, we prefix these with "kcsan_" to ensure they can + * be filtered from the stacktrace, as well as give them unique names for the + * UACCESS whitelist of objtool. Each function uses user_access_save/restore(), + * since they do not access any user memory, but instrumentation is still + * emitted in UACCESS regions. + */ + +static noinline void kcsan_found_watchpoint(const volatile void *ptr, + size_t size, bool is_write, + atomic_long_t *watchpoint, + long encoded_watchpoint) +{ + unsigned long flags; + bool consumed; + + if (!kcsan_is_enabled()) + return; + /* + * Consume the watchpoint as soon as possible, to minimize the chances + * of !consumed. Consuming the watchpoint must always be guarded by + * kcsan_is_enabled() check, as otherwise we might erroneously + * triggering reports when disabled. + */ + consumed = try_consume_watchpoint(watchpoint, encoded_watchpoint); + + /* keep this after try_consume_watchpoint */ + flags = user_access_save(); + + if (consumed) { + kcsan_report(ptr, size, is_write, true, raw_smp_processor_id(), + KCSAN_REPORT_CONSUMED_WATCHPOINT); + } else { + /* + * The other thread may not print any diagnostics, as it has + * already removed the watchpoint, or another thread consumed + * the watchpoint before this thread. + */ + kcsan_counter_inc(KCSAN_COUNTER_REPORT_RACES); + } + kcsan_counter_inc(KCSAN_COUNTER_DATA_RACES); + + user_access_restore(flags); +} + +static noinline void kcsan_setup_watchpoint(const volatile void *ptr, + size_t size, bool is_write) +{ + atomic_long_t *watchpoint; + union { + u8 _1; + u16 _2; + u32 _4; + u64 _8; + } expect_value; + bool value_change = false; + unsigned long ua_flags = user_access_save(); + unsigned long irq_flags; + + /* + * Always reset kcsan_skip counter in slow-path to avoid underflow; see + * should_watch(). + */ + reset_kcsan_skip(); + + if (!kcsan_is_enabled()) + goto out; + + if (!check_encodable((unsigned long)ptr, size)) { + kcsan_counter_inc(KCSAN_COUNTER_UNENCODABLE_ACCESSES); + goto out; + } + + /* + * Disable interrupts & preemptions to avoid another thread on the same + * CPU accessing memory locations for the set up watchpoint; this is to + * avoid reporting races to e.g. CPU-local data. + * + * An alternative would be adding the source CPU to the watchpoint + * encoding, and checking that watchpoint-CPU != this-CPU. There are + * several problems with this: + * 1. we should avoid stealing more bits from the watchpoint encoding + * as it would affect accuracy, as well as increase performance + * overhead in the fast-path; + * 2. if we are preempted, but there *is* a genuine data race, we + * would *not* report it -- since this is the common case (vs. + * CPU-local data accesses), it makes more sense (from a data race + * detection point of view) to simply disable preemptions to ensure + * as many tasks as possible run on other CPUs. + */ + local_irq_save(irq_flags); + + watchpoint = insert_watchpoint((unsigned long)ptr, size, is_write); + if (watchpoint == NULL) { + /* + * Out of capacity: the size of `watchpoints`, and the frequency + * with which `should_watch()` returns true should be tweaked so + * that this case happens very rarely. + */ + kcsan_counter_inc(KCSAN_COUNTER_NO_CAPACITY); + goto out_unlock; + } + + kcsan_counter_inc(KCSAN_COUNTER_SETUP_WATCHPOINTS); + kcsan_counter_inc(KCSAN_COUNTER_USED_WATCHPOINTS); + + /* + * Read the current value, to later check and infer a race if the data + * was modified via a non-instrumented access, e.g. from a device. + */ + switch (size) { + case 1: + expect_value._1 = READ_ONCE(*(const u8 *)ptr); + break; + case 2: + expect_value._2 = READ_ONCE(*(const u16 *)ptr); + break; + case 4: + expect_value._4 = READ_ONCE(*(const u32 *)ptr); + break; + case 8: + expect_value._8 = READ_ONCE(*(const u64 *)ptr); + break; + default: + break; /* ignore; we do not diff the values */ + } + + if (IS_ENABLED(CONFIG_KCSAN_DEBUG)) { + kcsan_disable_current(); + pr_err("KCSAN: watching %s, size: %zu, addr: %px [slot: %d, encoded: %lx]\n", + is_write ? "write" : "read", size, ptr, + watchpoint_slot((unsigned long)ptr), + encode_watchpoint((unsigned long)ptr, size, is_write)); + kcsan_enable_current(); + } + + /* + * Delay this thread, to increase probability of observing a racy + * conflicting access. + */ + udelay(get_delay()); + + /* + * Re-read value, and check if it is as expected; if not, we infer a + * racy access. + */ + switch (size) { + case 1: + value_change = expect_value._1 != READ_ONCE(*(const u8 *)ptr); + break; + case 2: + value_change = expect_value._2 != READ_ONCE(*(const u16 *)ptr); + break; + case 4: + value_change = expect_value._4 != READ_ONCE(*(const u32 *)ptr); + break; + case 8: + value_change = expect_value._8 != READ_ONCE(*(const u64 *)ptr); + break; + default: + break; /* ignore; we do not diff the values */ + } + + /* Check if this access raced with another. */ + if (!remove_watchpoint(watchpoint)) { + /* + * No need to increment 'data_races' counter, as the racing + * thread already did. + */ + kcsan_report(ptr, size, is_write, size > 8 || value_change, + smp_processor_id(), KCSAN_REPORT_RACE_SIGNAL); + } else if (value_change) { + /* Inferring a race, since the value should not have changed. */ + kcsan_counter_inc(KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN); + if (IS_ENABLED(CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN)) + kcsan_report(ptr, size, is_write, true, + smp_processor_id(), + KCSAN_REPORT_RACE_UNKNOWN_ORIGIN); + } + + kcsan_counter_dec(KCSAN_COUNTER_USED_WATCHPOINTS); +out_unlock: + local_irq_restore(irq_flags); +out: + user_access_restore(ua_flags); +} + +static __always_inline void check_access(const volatile void *ptr, size_t size, + int type) +{ + const bool is_write = (type & KCSAN_ACCESS_WRITE) != 0; + atomic_long_t *watchpoint; + long encoded_watchpoint; + + /* + * Avoid user_access_save in fast-path: find_watchpoint is safe without + * user_access_save, as the address that ptr points to is only used to + * check if a watchpoint exists; ptr is never dereferenced. + */ + watchpoint = find_watchpoint((unsigned long)ptr, size, !is_write, + &encoded_watchpoint); + /* + * It is safe to check kcsan_is_enabled() after find_watchpoint in the + * slow-path, as long as no state changes that cause a data race to be + * detected and reported have occurred until kcsan_is_enabled() is + * checked. + */ + + if (unlikely(watchpoint != NULL)) + kcsan_found_watchpoint(ptr, size, is_write, watchpoint, + encoded_watchpoint); + else if (unlikely(should_watch(ptr, type))) + kcsan_setup_watchpoint(ptr, size, is_write); +} + +/* === Public interface ===================================================== */ + +void __init kcsan_init(void) +{ + BUG_ON(!in_task()); + + kcsan_debugfs_init(); + + /* + * We are in the init task, and no other tasks should be running; + * WRITE_ONCE without memory barrier is sufficient. + */ + if (IS_ENABLED(CONFIG_KCSAN_EARLY_ENABLE)) + WRITE_ONCE(kcsan_enabled, true); +} + +/* === Exported interface =================================================== */ + +void kcsan_disable_current(void) +{ + ++get_ctx()->disable_count; +} +EXPORT_SYMBOL(kcsan_disable_current); + +void kcsan_enable_current(void) +{ + if (get_ctx()->disable_count-- == 0) { + /* + * Warn if kcsan_enable_current() calls are unbalanced with + * kcsan_disable_current() calls, which causes disable_count to + * become negative and should not happen. + */ + kcsan_disable_current(); /* restore to 0, KCSAN still enabled */ + kcsan_disable_current(); /* disable to generate warning */ + WARN(1, "Unbalanced %s()", __func__); + kcsan_enable_current(); + } +} +EXPORT_SYMBOL(kcsan_enable_current); + +void kcsan_nestable_atomic_begin(void) +{ + /* + * Do *not* check and warn if we are in a flat atomic region: nestable + * and flat atomic regions are independent from each other. + * See include/linux/kcsan.h: struct kcsan_ctx comments for more + * comments. + */ + + ++get_ctx()->atomic_nest_count; +} +EXPORT_SYMBOL(kcsan_nestable_atomic_begin); + +void kcsan_nestable_atomic_end(void) +{ + if (get_ctx()->atomic_nest_count-- == 0) { + /* + * Warn if kcsan_nestable_atomic_end() calls are unbalanced with + * kcsan_nestable_atomic_begin() calls, which causes + * atomic_nest_count to become negative and should not happen. + */ + kcsan_nestable_atomic_begin(); /* restore to 0 */ + kcsan_disable_current(); /* disable to generate warning */ + WARN(1, "Unbalanced %s()", __func__); + kcsan_enable_current(); + } +} +EXPORT_SYMBOL(kcsan_nestable_atomic_end); + +void kcsan_flat_atomic_begin(void) +{ + get_ctx()->in_flat_atomic = true; +} +EXPORT_SYMBOL(kcsan_flat_atomic_begin); + +void kcsan_flat_atomic_end(void) +{ + get_ctx()->in_flat_atomic = false; +} +EXPORT_SYMBOL(kcsan_flat_atomic_end); + +void kcsan_atomic_next(int n) +{ + get_ctx()->atomic_next = n; +} +EXPORT_SYMBOL(kcsan_atomic_next); + +void __kcsan_check_access(const volatile void *ptr, size_t size, int type) +{ + check_access(ptr, size, type); +} +EXPORT_SYMBOL(__kcsan_check_access); + +/* + * KCSAN uses the same instrumentation that is emitted by supported compilers + * for ThreadSanitizer (TSAN). + * + * When enabled, the compiler emits instrumentation calls (the functions + * prefixed with "__tsan" below) for all loads and stores that it generated; + * inline asm is not instrumented. + * + * Note that, not all supported compiler versions distinguish aligned/unaligned + * accesses, but e.g. recent versions of Clang do. We simply alias the unaligned + * version to the generic version, which can handle both. + */ + +#define DEFINE_TSAN_READ_WRITE(size) \ + void __tsan_read##size(void *ptr) \ + { \ + check_access(ptr, size, 0); \ + } \ + EXPORT_SYMBOL(__tsan_read##size); \ + void __tsan_unaligned_read##size(void *ptr) \ + __alias(__tsan_read##size); \ + EXPORT_SYMBOL(__tsan_unaligned_read##size); \ + void __tsan_write##size(void *ptr) \ + { \ + check_access(ptr, size, KCSAN_ACCESS_WRITE); \ + } \ + EXPORT_SYMBOL(__tsan_write##size); \ + void __tsan_unaligned_write##size(void *ptr) \ + __alias(__tsan_write##size); \ + EXPORT_SYMBOL(__tsan_unaligned_write##size) + +DEFINE_TSAN_READ_WRITE(1); +DEFINE_TSAN_READ_WRITE(2); +DEFINE_TSAN_READ_WRITE(4); +DEFINE_TSAN_READ_WRITE(8); +DEFINE_TSAN_READ_WRITE(16); + +void __tsan_read_range(void *ptr, size_t size) +{ + check_access(ptr, size, 0); +} +EXPORT_SYMBOL(__tsan_read_range); + +void __tsan_write_range(void *ptr, size_t size) +{ + check_access(ptr, size, KCSAN_ACCESS_WRITE); +} +EXPORT_SYMBOL(__tsan_write_range); + +/* + * The below are not required by KCSAN, but can still be emitted by the + * compiler. + */ +void __tsan_func_entry(void *call_pc) +{ +} +EXPORT_SYMBOL(__tsan_func_entry); +void __tsan_func_exit(void) +{ +} +EXPORT_SYMBOL(__tsan_func_exit); +void __tsan_init(void) +{ +} +EXPORT_SYMBOL(__tsan_init); diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c new file mode 100644 index 000000000000..041d520a0183 --- /dev/null +++ b/kernel/kcsan/debugfs.c @@ -0,0 +1,275 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/atomic.h> +#include <linux/bsearch.h> +#include <linux/bug.h> +#include <linux/debugfs.h> +#include <linux/init.h> +#include <linux/kallsyms.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/sort.h> +#include <linux/string.h> +#include <linux/uaccess.h> + +#include "kcsan.h" + +/* + * Statistics counters. + */ +static atomic_long_t counters[KCSAN_COUNTER_COUNT]; + +/* + * Addresses for filtering functions from reporting. This list can be used as a + * whitelist or blacklist. + */ +static struct { + unsigned long *addrs; /* array of addresses */ + size_t size; /* current size */ + int used; /* number of elements used */ + bool sorted; /* if elements are sorted */ + bool whitelist; /* if list is a blacklist or whitelist */ +} report_filterlist = { + .addrs = NULL, + .size = 8, /* small initial size */ + .used = 0, + .sorted = false, + .whitelist = false, /* default is blacklist */ +}; +static DEFINE_SPINLOCK(report_filterlist_lock); + +static const char *counter_to_name(enum kcsan_counter_id id) +{ + switch (id) { + case KCSAN_COUNTER_USED_WATCHPOINTS: + return "used_watchpoints"; + case KCSAN_COUNTER_SETUP_WATCHPOINTS: + return "setup_watchpoints"; + case KCSAN_COUNTER_DATA_RACES: + return "data_races"; + case KCSAN_COUNTER_NO_CAPACITY: + return "no_capacity"; + case KCSAN_COUNTER_REPORT_RACES: + return "report_races"; + case KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN: + return "races_unknown_origin"; + case KCSAN_COUNTER_UNENCODABLE_ACCESSES: + return "unencodable_accesses"; + case KCSAN_COUNTER_ENCODING_FALSE_POSITIVES: + return "encoding_false_positives"; + case KCSAN_COUNTER_COUNT: + BUG(); + } + return NULL; +} + +void kcsan_counter_inc(enum kcsan_counter_id id) +{ + atomic_long_inc(&counters[id]); +} + +void kcsan_counter_dec(enum kcsan_counter_id id) +{ + atomic_long_dec(&counters[id]); +} + +/* + * The microbenchmark allows benchmarking KCSAN core runtime only. To run + * multiple threads, pipe 'microbench=<iters>' from multiple tasks into the + * debugfs file. + */ +static void microbenchmark(unsigned long iters) +{ + cycles_t cycles; + + pr_info("KCSAN: %s begin | iters: %lu\n", __func__, iters); + + cycles = get_cycles(); + while (iters--) { + /* + * We can run this benchmark from multiple tasks; this address + * calculation increases likelyhood of some accesses overlapping + * (they still won't conflict because all are reads). + */ + unsigned long addr = + iters % (CONFIG_KCSAN_NUM_WATCHPOINTS * PAGE_SIZE); + __kcsan_check_read((void *)addr, sizeof(long)); + } + cycles = get_cycles() - cycles; + + pr_info("KCSAN: %s end | cycles: %llu\n", __func__, cycles); +} + +static int cmp_filterlist_addrs(const void *rhs, const void *lhs) +{ + const unsigned long a = *(const unsigned long *)rhs; + const unsigned long b = *(const unsigned long *)lhs; + + return a < b ? -1 : a == b ? 0 : 1; +} + +bool kcsan_skip_report_debugfs(unsigned long func_addr) +{ + unsigned long symbolsize, offset; + unsigned long flags; + bool ret = false; + + if (!kallsyms_lookup_size_offset(func_addr, &symbolsize, &offset)) + return false; + func_addr -= offset; /* get function start */ + + spin_lock_irqsave(&report_filterlist_lock, flags); + if (report_filterlist.used == 0) + goto out; + + /* Sort array if it is unsorted, and then do a binary search. */ + if (!report_filterlist.sorted) { + sort(report_filterlist.addrs, report_filterlist.used, + sizeof(unsigned long), cmp_filterlist_addrs, NULL); + report_filterlist.sorted = true; + } + ret = !!bsearch(&func_addr, report_filterlist.addrs, + report_filterlist.used, sizeof(unsigned long), + cmp_filterlist_addrs); + if (report_filterlist.whitelist) + ret = !ret; + +out: + spin_unlock_irqrestore(&report_filterlist_lock, flags); + return ret; +} + +static void set_report_filterlist_whitelist(bool whitelist) +{ + unsigned long flags; + + spin_lock_irqsave(&report_filterlist_lock, flags); + report_filterlist.whitelist = whitelist; + spin_unlock_irqrestore(&report_filterlist_lock, flags); +} + +/* Returns 0 on success, error-code otherwise. */ +static ssize_t insert_report_filterlist(const char *func) +{ + unsigned long flags; + unsigned long addr = kallsyms_lookup_name(func); + ssize_t ret = 0; + + if (!addr) { + pr_err("KCSAN: could not find function: '%s'\n", func); + return -ENOENT; + } + + spin_lock_irqsave(&report_filterlist_lock, flags); + + if (report_filterlist.addrs == NULL) { + /* initial allocation */ + report_filterlist.addrs = + kmalloc_array(report_filterlist.size, + sizeof(unsigned long), GFP_KERNEL); + if (report_filterlist.addrs == NULL) { + ret = -ENOMEM; + goto out; + } + } else if (report_filterlist.used == report_filterlist.size) { + /* resize filterlist */ + size_t new_size = report_filterlist.size * 2; + unsigned long *new_addrs = + krealloc(report_filterlist.addrs, + new_size * sizeof(unsigned long), GFP_KERNEL); + + if (new_addrs == NULL) { + /* leave filterlist itself untouched */ + ret = -ENOMEM; + goto out; + } + + report_filterlist.size = new_size; + report_filterlist.addrs = new_addrs; + } + + /* Note: deduplicating should be done in userspace. */ + report_filterlist.addrs[report_filterlist.used++] = + kallsyms_lookup_name(func); + report_filterlist.sorted = false; + +out: + spin_unlock_irqrestore(&report_filterlist_lock, flags); + return ret; +} + +static int show_info(struct seq_file *file, void *v) +{ + int i; + unsigned long flags; + + /* show stats */ + seq_printf(file, "enabled: %i\n", READ_ONCE(kcsan_enabled)); + for (i = 0; i < KCSAN_COUNTER_COUNT; ++i) + seq_printf(file, "%s: %ld\n", counter_to_name(i), + atomic_long_read(&counters[i])); + + /* show filter functions, and filter type */ + spin_lock_irqsave(&report_filterlist_lock, flags); + seq_printf(file, "\n%s functions: %s\n", + report_filterlist.whitelist ? "whitelisted" : "blacklisted", + report_filterlist.used == 0 ? "none" : ""); + for (i = 0; i < report_filterlist.used; ++i) + seq_printf(file, " %ps\n", (void *)report_filterlist.addrs[i]); + spin_unlock_irqrestore(&report_filterlist_lock, flags); + + return 0; +} + +static int debugfs_open(struct inode *inode, struct file *file) +{ + return single_open(file, show_info, NULL); +} + +static ssize_t debugfs_write(struct file *file, const char __user *buf, + size_t count, loff_t *off) +{ + char kbuf[KSYM_NAME_LEN]; + char *arg; + int read_len = count < (sizeof(kbuf) - 1) ? count : (sizeof(kbuf) - 1); + + if (copy_from_user(kbuf, buf, read_len)) + return -EFAULT; + kbuf[read_len] = '\0'; + arg = strstrip(kbuf); + + if (!strcmp(arg, "on")) { + WRITE_ONCE(kcsan_enabled, true); + } else if (!strcmp(arg, "off")) { + WRITE_ONCE(kcsan_enabled, false); + } else if (!strncmp(arg, "microbench=", sizeof("microbench=") - 1)) { + unsigned long iters; + + if (kstrtoul(&arg[sizeof("microbench=") - 1], 0, &iters)) + return -EINVAL; + microbenchmark(iters); + } else if (!strcmp(arg, "whitelist")) { + set_report_filterlist_whitelist(true); + } else if (!strcmp(arg, "blacklist")) { + set_report_filterlist_whitelist(false); + } else if (arg[0] == '!') { + ssize_t ret = insert_report_filterlist(&arg[1]); + + if (ret < 0) + return ret; + } else { + return -EINVAL; + } + + return count; +} + +static const struct file_operations debugfs_ops = { .read = seq_read, + .open = debugfs_open, + .write = debugfs_write, + .release = single_release }; + +void __init kcsan_debugfs_init(void) +{ + debugfs_create_file("kcsan", 0644, NULL, NULL, &debugfs_ops); +} diff --git a/kernel/kcsan/encoding.h b/kernel/kcsan/encoding.h new file mode 100644 index 000000000000..e17bdac0e54b --- /dev/null +++ b/kernel/kcsan/encoding.h @@ -0,0 +1,94 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _KERNEL_KCSAN_ENCODING_H +#define _KERNEL_KCSAN_ENCODING_H + +#include <linux/bits.h> +#include <linux/log2.h> +#include <linux/mm.h> + +#include "kcsan.h" + +#define SLOT_RANGE PAGE_SIZE +#define INVALID_WATCHPOINT 0 +#define CONSUMED_WATCHPOINT 1 + +/* + * The maximum useful size of accesses for which we set up watchpoints is the + * max range of slots we check on an access. + */ +#define MAX_ENCODABLE_SIZE (SLOT_RANGE * (1 + KCSAN_CHECK_ADJACENT)) + +/* + * Number of bits we use to store size info. + */ +#define WATCHPOINT_SIZE_BITS bits_per(MAX_ENCODABLE_SIZE) +/* + * This encoding for addresses discards the upper (1 for is-write + SIZE_BITS); + * however, most 64-bit architectures do not use the full 64-bit address space. + * Also, in order for a false positive to be observable 2 things need to happen: + * + * 1. different addresses but with the same encoded address race; + * 2. and both map onto the same watchpoint slots; + * + * Both these are assumed to be very unlikely. However, in case it still happens + * happens, the report logic will filter out the false positive (see report.c). + */ +#define WATCHPOINT_ADDR_BITS (BITS_PER_LONG - 1 - WATCHPOINT_SIZE_BITS) + +/* + * Masks to set/retrieve the encoded data. + */ +#define WATCHPOINT_WRITE_MASK BIT(BITS_PER_LONG - 1) +#define WATCHPOINT_SIZE_MASK \ + GENMASK(BITS_PER_LONG - 2, BITS_PER_LONG - 2 - WATCHPOINT_SIZE_BITS) +#define WATCHPOINT_ADDR_MASK \ + GENMASK(BITS_PER_LONG - 3 - WATCHPOINT_SIZE_BITS, 0) + +static inline bool check_encodable(unsigned long addr, size_t size) +{ + return size <= MAX_ENCODABLE_SIZE; +} + +static inline long encode_watchpoint(unsigned long addr, size_t size, + bool is_write) +{ + return (long)((is_write ? WATCHPOINT_WRITE_MASK : 0) | + (size << WATCHPOINT_ADDR_BITS) | + (addr & WATCHPOINT_ADDR_MASK)); +} + +static inline bool decode_watchpoint(long watchpoint, + unsigned long *addr_masked, size_t *size, + bool *is_write) +{ + if (watchpoint == INVALID_WATCHPOINT || + watchpoint == CONSUMED_WATCHPOINT) + return false; + + *addr_masked = (unsigned long)watchpoint & WATCHPOINT_ADDR_MASK; + *size = ((unsigned long)watchpoint & WATCHPOINT_SIZE_MASK) >> + WATCHPOINT_ADDR_BITS; + *is_write = !!((unsigned long)watchpoint & WATCHPOINT_WRITE_MASK); + + return true; +} + +/* + * Return watchpoint slot for an address. + */ +static inline int watchpoint_slot(unsigned long addr) +{ + return (addr / PAGE_SIZE) % CONFIG_KCSAN_NUM_WATCHPOINTS; +} + +static inline bool matching_access(unsigned long addr1, size_t size1, + unsigned long addr2, size_t size2) +{ + unsigned long end_range1 = addr1 + size1 - 1; + unsigned long end_range2 = addr2 + size2 - 1; + + return addr1 <= end_range2 && addr2 <= end_range1; +} + +#endif /* _KERNEL_KCSAN_ENCODING_H */ diff --git a/kernel/kcsan/kcsan.h b/kernel/kcsan/kcsan.h new file mode 100644 index 000000000000..1bb2f1c0d61e --- /dev/null +++ b/kernel/kcsan/kcsan.h @@ -0,0 +1,108 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * The Kernel Concurrency Sanitizer (KCSAN) infrastructure. For more info please + * see Documentation/dev-tools/kcsan.rst. + */ + +#ifndef _KERNEL_KCSAN_KCSAN_H +#define _KERNEL_KCSAN_KCSAN_H + +#include <linux/kcsan.h> + +/* The number of adjacent watchpoints to check. */ +#define KCSAN_CHECK_ADJACENT 1 + +/* + * Globally enable and disable KCSAN. + */ +extern bool kcsan_enabled; + +/* + * Initialize debugfs file. + */ +void kcsan_debugfs_init(void); + +enum kcsan_counter_id { + /* + * Number of watchpoints currently in use. + */ + KCSAN_COUNTER_USED_WATCHPOINTS, + + /* + * Total number of watchpoints set up. + */ + KCSAN_COUNTER_SETUP_WATCHPOINTS, + + /* + * Total number of data races. + */ + KCSAN_COUNTER_DATA_RACES, + + /* + * Number of times no watchpoints were available. + */ + KCSAN_COUNTER_NO_CAPACITY, + + /* + * A thread checking a watchpoint raced with another checking thread; + * only one will be reported. + */ + KCSAN_COUNTER_REPORT_RACES, + + /* + * Observed data value change, but writer thread unknown. + */ + KCSAN_COUNTER_RACES_UNKNOWN_ORIGIN, + + /* + * The access cannot be encoded to a valid watchpoint. + */ + KCSAN_COUNTER_UNENCODABLE_ACCESSES, + + /* + * Watchpoint encoding caused a watchpoint to fire on mismatching + * accesses. + */ + KCSAN_COUNTER_ENCODING_FALSE_POSITIVES, + + KCSAN_COUNTER_COUNT, /* number of counters */ +}; + +/* + * Increment/decrement counter with given id; avoid calling these in fast-path. + */ +void kcsan_counter_inc(enum kcsan_counter_id id); +void kcsan_counter_dec(enum kcsan_counter_id id); + +/* + * Returns true if data races in the function symbol that maps to func_addr + * (offsets are ignored) should *not* be reported. + */ +bool kcsan_skip_report_debugfs(unsigned long func_addr); + +enum kcsan_report_type { + /* + * The thread that set up the watchpoint and briefly stalled was + * signalled that another thread triggered the watchpoint. + */ + KCSAN_REPORT_RACE_SIGNAL, + + /* + * A thread found and consumed a matching watchpoint. + */ + KCSAN_REPORT_CONSUMED_WATCHPOINT, + + /* + * No other thread was observed to race with the access, but the data + * value before and after the stall differs. + */ + KCSAN_REPORT_RACE_UNKNOWN_ORIGIN, +}; +/* + * Print a race report from thread that encountered the race. + */ +void kcsan_report(const volatile void *ptr, size_t size, bool is_write, + bool value_change, int cpu_id, enum kcsan_report_type type); + +#endif /* _KERNEL_KCSAN_KCSAN_H */ diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c new file mode 100644 index 000000000000..ead5610bafa7 --- /dev/null +++ b/kernel/kcsan/report.c @@ -0,0 +1,320 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/kernel.h> +#include <linux/preempt.h> +#include <linux/printk.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/stacktrace.h> + +#include "kcsan.h" +#include "encoding.h" + +/* + * Max. number of stack entries to show in the report. + */ +#define NUM_STACK_ENTRIES 64 + +/* + * Other thread info: communicated from other racing thread to thread that set + * up the watchpoint, which then prints the complete report atomically. Only + * need one struct, as all threads should to be serialized regardless to print + * the reports, with reporting being in the slow-path. + */ +static struct { + const volatile void *ptr; + size_t size; + bool is_write; + int task_pid; + int cpu_id; + unsigned long stack_entries[NUM_STACK_ENTRIES]; + int num_stack_entries; +} other_info = { .ptr = NULL }; + +/* + * This spinlock protects reporting and other_info, since other_info is usually + * required when reporting. + */ +static DEFINE_SPINLOCK(report_lock); + +/* + * Special rules to skip reporting. + */ +static bool skip_report(bool is_write, bool value_change, + unsigned long top_frame) +{ + if (IS_ENABLED(CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY) && is_write && + !value_change) { + /* + * The access is a write, but the data value did not change. + * + * We opt-out of this filter for certain functions at request of + * maintainers. + */ + char buf[64]; + + snprintf(buf, sizeof(buf), "%ps", (void *)top_frame); + if (!strnstr(buf, "rcu_", sizeof(buf)) && + !strnstr(buf, "_rcu", sizeof(buf)) && + !strnstr(buf, "_srcu", sizeof(buf))) + return true; + } + + return kcsan_skip_report_debugfs(top_frame); +} + +static inline const char *get_access_type(bool is_write) +{ + return is_write ? "write" : "read"; +} + +/* Return thread description: in task or interrupt. */ +static const char *get_thread_desc(int task_id) +{ + if (task_id != -1) { + static char buf[32]; /* safe: protected by report_lock */ + + snprintf(buf, sizeof(buf), "task %i", task_id); + return buf; + } + return "interrupt"; +} + +/* Helper to skip KCSAN-related functions in stack-trace. */ +static int get_stack_skipnr(unsigned long stack_entries[], int num_entries) +{ + char buf[64]; + int skip = 0; + + for (; skip < num_entries; ++skip) { + snprintf(buf, sizeof(buf), "%ps", (void *)stack_entries[skip]); + if (!strnstr(buf, "csan_", sizeof(buf)) && + !strnstr(buf, "tsan_", sizeof(buf)) && + !strnstr(buf, "_once_size", sizeof(buf))) { + break; + } + } + return skip; +} + +/* Compares symbolized strings of addr1 and addr2. */ +static int sym_strcmp(void *addr1, void *addr2) +{ + char buf1[64]; + char buf2[64]; + + snprintf(buf1, sizeof(buf1), "%pS", addr1); + snprintf(buf2, sizeof(buf2), "%pS", addr2); + return strncmp(buf1, buf2, sizeof(buf1)); +} + +/* + * Returns true if a report was generated, false otherwise. + */ +static bool print_report(const volatile void *ptr, size_t size, bool is_write, + bool value_change, int cpu_id, + enum kcsan_report_type type) +{ + unsigned long stack_entries[NUM_STACK_ENTRIES] = { 0 }; + int num_stack_entries = + stack_trace_save(stack_entries, NUM_STACK_ENTRIES, 1); + int skipnr = get_stack_skipnr(stack_entries, num_stack_entries); + int other_skipnr; + + /* + * Must check report filter rules before starting to print. + */ + if (skip_report(is_write, true, stack_entries[skipnr])) + return false; + + if (type == KCSAN_REPORT_RACE_SIGNAL) { + other_skipnr = get_stack_skipnr(other_info.stack_entries, + other_info.num_stack_entries); + + /* value_change is only known for the other thread */ + if (skip_report(other_info.is_write, value_change, + other_info.stack_entries[other_skipnr])) + return false; + } + + /* Print report header. */ + pr_err("==================================================================\n"); + switch (type) { + case KCSAN_REPORT_RACE_SIGNAL: { + void *this_fn = (void *)stack_entries[skipnr]; + void *other_fn = (void *)other_info.stack_entries[other_skipnr]; + int cmp; + + /* + * Order functions lexographically for consistent bug titles. + * Do not print offset of functions to keep title short. + */ + cmp = sym_strcmp(other_fn, this_fn); + pr_err("BUG: KCSAN: data-race in %ps / %ps\n", + cmp < 0 ? other_fn : this_fn, + cmp < 0 ? this_fn : other_fn); + } break; + + case KCSAN_REPORT_RACE_UNKNOWN_ORIGIN: + pr_err("BUG: KCSAN: data-race in %pS\n", + (void *)stack_entries[skipnr]); + break; + + default: + BUG(); + } + + pr_err("\n"); + + /* Print information about the racing accesses. */ + switch (type) { + case KCSAN_REPORT_RACE_SIGNAL: + pr_err("%s to 0x%px of %zu bytes by %s on cpu %i:\n", + get_access_type(other_info.is_write), other_info.ptr, + other_info.size, get_thread_desc(other_info.task_pid), + other_info.cpu_id); + + /* Print the other thread's stack trace. */ + stack_trace_print(other_info.stack_entries + other_skipnr, + other_info.num_stack_entries - other_skipnr, + 0); + + pr_err("\n"); + pr_err("%s to 0x%px of %zu bytes by %s on cpu %i:\n", + get_access_type(is_write), ptr, size, + get_thread_desc(in_task() ? task_pid_nr(current) : -1), + cpu_id); + break; + + case KCSAN_REPORT_RACE_UNKNOWN_ORIGIN: + pr_err("race at unknown origin, with %s to 0x%px of %zu bytes by %s on cpu %i:\n", + get_access_type(is_write), ptr, size, + get_thread_desc(in_task() ? task_pid_nr(current) : -1), + cpu_id); + break; + + default: + BUG(); + } + /* Print stack trace of this thread. */ + stack_trace_print(stack_entries + skipnr, num_stack_entries - skipnr, + 0); + + /* Print report footer. */ + pr_err("\n"); + pr_err("Reported by Kernel Concurrency Sanitizer on:\n"); + dump_stack_print_info(KERN_DEFAULT); + pr_err("==================================================================\n"); + + return true; +} + +static void release_report(unsigned long *flags, enum kcsan_report_type type) +{ + if (type == KCSAN_REPORT_RACE_SIGNAL) + other_info.ptr = NULL; /* mark for reuse */ + + spin_unlock_irqrestore(&report_lock, *flags); +} + +/* + * Depending on the report type either sets other_info and returns false, or + * acquires the matching other_info and returns true. If other_info is not + * required for the report type, simply acquires report_lock and returns true. + */ +static bool prepare_report(unsigned long *flags, const volatile void *ptr, + size_t size, bool is_write, int cpu_id, + enum kcsan_report_type type) +{ + if (type != KCSAN_REPORT_CONSUMED_WATCHPOINT && + type != KCSAN_REPORT_RACE_SIGNAL) { + /* other_info not required; just acquire report_lock */ + spin_lock_irqsave(&report_lock, *flags); + return true; + } + +retry: + spin_lock_irqsave(&report_lock, *flags); + + switch (type) { + case KCSAN_REPORT_CONSUMED_WATCHPOINT: + if (other_info.ptr != NULL) + break; /* still in use, retry */ + + other_info.ptr = ptr; + other_info.size = size; + other_info.is_write = is_write; + other_info.task_pid = in_task() ? task_pid_nr(current) : -1; + other_info.cpu_id = cpu_id; + other_info.num_stack_entries = stack_trace_save( + other_info.stack_entries, NUM_STACK_ENTRIES, 1); + + spin_unlock_irqrestore(&report_lock, *flags); + + /* + * The other thread will print the summary; other_info may now + * be consumed. + */ + return false; + + case KCSAN_REPORT_RACE_SIGNAL: + if (other_info.ptr == NULL) + break; /* no data available yet, retry */ + + /* + * First check if this is the other_info we are expecting, i.e. + * matches based on how watchpoint was encoded. + */ + if (!matching_access((unsigned long)other_info.ptr & + WATCHPOINT_ADDR_MASK, + other_info.size, + (unsigned long)ptr & WATCHPOINT_ADDR_MASK, + size)) + break; /* mismatching watchpoint, retry */ + + if (!matching_access((unsigned long)other_info.ptr, + other_info.size, (unsigned long)ptr, + size)) { + /* + * If the actual accesses to not match, this was a false + * positive due to watchpoint encoding. + */ + kcsan_counter_inc( + KCSAN_COUNTER_ENCODING_FALSE_POSITIVES); + + /* discard this other_info */ + release_report(flags, KCSAN_REPORT_RACE_SIGNAL); + return false; + } + + /* + * Matching & usable access in other_info: keep other_info_lock + * locked, as this thread consumes it to print the full report; + * unlocked in release_report. + */ + return true; + + default: + BUG(); + } + + spin_unlock_irqrestore(&report_lock, *flags); + goto retry; +} + +void kcsan_report(const volatile void *ptr, size_t size, bool is_write, + bool value_change, int cpu_id, enum kcsan_report_type type) +{ + unsigned long flags = 0; + + kcsan_disable_current(); + if (prepare_report(&flags, ptr, size, is_write, cpu_id, type)) { + if (print_report(ptr, size, is_write, value_change, cpu_id, + type) && + panic_on_warn) + panic("panic_on_warn set ...\n"); + + release_report(&flags, type); + } + kcsan_enable_current(); +} diff --git a/kernel/kcsan/test.c b/kernel/kcsan/test.c new file mode 100644 index 000000000000..0bae63c5ca65 --- /dev/null +++ b/kernel/kcsan/test.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/printk.h> +#include <linux/random.h> +#include <linux/types.h> + +#include "encoding.h" + +#define ITERS_PER_TEST 2000 + +/* Test requirements. */ +static bool test_requires(void) +{ + /* random should be initialized for the below tests */ + return prandom_u32() + prandom_u32() != 0; +} + +/* + * Test watchpoint encode and decode: check that encoding some access's info, + * and then subsequent decode preserves the access's info. + */ +static bool test_encode_decode(void) +{ + int i; + + for (i = 0; i < ITERS_PER_TEST; ++i) { + size_t size = prandom_u32_max(MAX_ENCODABLE_SIZE) + 1; + bool is_write = !!prandom_u32_max(2); + unsigned long addr; + + prandom_bytes(&addr, sizeof(addr)); + if (WARN_ON(!check_encodable(addr, size))) + return false; + + /* encode and decode */ + { + const long encoded_watchpoint = + encode_watchpoint(addr, size, is_write); + unsigned long verif_masked_addr; + size_t verif_size; + bool verif_is_write; + + /* check special watchpoints */ + if (WARN_ON(decode_watchpoint( + INVALID_WATCHPOINT, &verif_masked_addr, + &verif_size, &verif_is_write))) + return false; + if (WARN_ON(decode_watchpoint( + CONSUMED_WATCHPOINT, &verif_masked_addr, + &verif_size, &verif_is_write))) + return false; + + /* check decoding watchpoint returns same data */ + if (WARN_ON(!decode_watchpoint( + encoded_watchpoint, &verif_masked_addr, + &verif_size, &verif_is_write))) + return false; + if (WARN_ON(verif_masked_addr != + (addr & WATCHPOINT_ADDR_MASK))) + goto fail; + if (WARN_ON(verif_size != size)) + goto fail; + if (WARN_ON(is_write != verif_is_write)) + goto fail; + + continue; +fail: + pr_err("%s fail: %s %zu bytes @ %lx -> encoded: %lx -> %s %zu bytes @ %lx\n", + __func__, is_write ? "write" : "read", size, + addr, encoded_watchpoint, + verif_is_write ? "write" : "read", verif_size, + verif_masked_addr); + return false; + } + } + + return true; +} + +/* Test access matching function. */ +static bool test_matching_access(void) +{ + if (WARN_ON(!matching_access(10, 1, 10, 1))) + return false; + if (WARN_ON(!matching_access(10, 2, 11, 1))) + return false; + if (WARN_ON(!matching_access(10, 1, 9, 2))) + return false; + if (WARN_ON(matching_access(10, 1, 11, 1))) + return false; + if (WARN_ON(matching_access(9, 1, 10, 1))) + return false; + return true; +} + +static int __init kcsan_selftest(void) +{ + int passed = 0; + int total = 0; + +#define RUN_TEST(do_test) \ + do { \ + ++total; \ + if (do_test()) \ + ++passed; \ + else \ + pr_err("KCSAN selftest: " #do_test " failed"); \ + } while (0) + + RUN_TEST(test_requires); + RUN_TEST(test_encode_decode); + RUN_TEST(test_matching_access); + + pr_info("KCSAN selftest: %d/%d tests passed\n", passed, total); + if (passed != total) + panic("KCSAN selftests failed"); + return 0; +} +postcore_initcall(kcsan_selftest); diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile index 21fb5a5662b5..e9307a9c54e7 100644 --- a/kernel/sched/Makefile +++ b/kernel/sched/Makefile @@ -7,6 +7,12 @@ endif # that is not a function of syscall inputs. E.g. involuntary context switches. KCOV_INSTRUMENT := n +# There are numerous races here, however, most of them due to plain accesses. +# This would make it even harder for syzbot to find reproducers, because these +# bugs trigger without specific input. Disable by default, but should re-enable +# eventually. +KCSAN_SANITIZE := n + ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y) # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is # needed for x86 only. Why this used to be enabled for all architectures is beyond diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 93d97f9b0157..35accd1d93de 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2086,6 +2086,8 @@ source "lib/Kconfig.kgdb" source "lib/Kconfig.ubsan" +source "lib/Kconfig.kcsan" + config ARCH_HAS_DEVMEM_IS_ALLOWED bool diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan new file mode 100644 index 000000000000..5dd464e52ab4 --- /dev/null +++ b/lib/Kconfig.kcsan @@ -0,0 +1,118 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config HAVE_ARCH_KCSAN + bool + +menuconfig KCSAN + bool "KCSAN: watchpoint-based dynamic data race detector" + depends on HAVE_ARCH_KCSAN && !KASAN && STACKTRACE + default n + help + Kernel Concurrency Sanitizer is a dynamic data race detector, which + uses a watchpoint-based sampling approach to detect races. See + <file:Documentation/dev-tools/kcsan.rst> for more details. + +if KCSAN + +config KCSAN_DEBUG + bool "Debugging of KCSAN internals" + default n + +config KCSAN_SELFTEST + bool "Perform short selftests on boot" + default y + help + Run KCSAN selftests on boot. On test failure, causes kernel to panic. + +config KCSAN_EARLY_ENABLE + bool "Early enable during boot" + default y + help + If KCSAN should be enabled globally as soon as possible. KCSAN can + later be enabled/disabled via debugfs. + +config KCSAN_NUM_WATCHPOINTS + int "Number of available watchpoints" + default 64 + help + Total number of available watchpoints. An address range maps into a + specific watchpoint slot as specified in kernel/kcsan/encoding.h. + Although larger number of watchpoints may not be usable due to + limited number of CPUs, a larger value helps to improve performance + due to reducing cache-line contention. The chosen default is a + conservative value; we should almost never observe "no_capacity" + events (see /sys/kernel/debug/kcsan). + +config KCSAN_UDELAY_TASK + int "Delay in microseconds (for tasks)" + default 80 + help + For tasks, the microsecond delay after setting up a watchpoint. + +config KCSAN_UDELAY_INTERRUPT + int "Delay in microseconds (for interrupts)" + default 20 + help + For interrupts, the microsecond delay after setting up a watchpoint. + Interrupts have tighter latency requirements, and their delay should + be lower than for tasks. + +config KCSAN_DELAY_RANDOMIZE + bool "Randomize above delays" + default y + help + If delays should be randomized, where the maximum is KCSAN_UDELAY_*. + If false, the chosen delays are always KCSAN_UDELAY_* defined above. + +config KCSAN_SKIP_WATCH + int "Skip instructions before setting up watchpoint" + default 4000 + help + The number of per-CPU memory operations to skip, before another + watchpoint is set up, i.e. one in KCSAN_WATCH_SKIP per-CPU + memory operations are used to set up a watchpoint. A smaller value + results in more aggressive race detection, whereas a larger value + improves system performance at the cost of missing some races. + +config KCSAN_SKIP_WATCH_RANDOMIZE + bool "Randomize watchpoint instruction skip count" + default y + help + If instruction skip count should be randomized, where the maximum is + KCSAN_WATCH_SKIP. If false, the chosen value is always + KCSAN_WATCH_SKIP. + +# Note that, while some of the below options could be turned into boot +# parameters, to optimize for the common use-case, we avoid this because: (a) +# it would impact performance (and we want to avoid static branch for all +# {READ,WRITE}_ONCE, atomic_*, bitops, etc.), and (b) complicate the design +# without real benefit. The main purpose of the below options are for use in +# fuzzer configs to control reported data races, and are not expected to be +# switched frequently by a user. + +config KCSAN_REPORT_RACE_UNKNOWN_ORIGIN + bool "Report races of unknown origin" + default y + help + If KCSAN should report races where only one access is known, and the + conflicting access is of unknown origin. This type of race is + reported if it was only possible to infer a race due to a data value + change while an access is being delayed on a watchpoint. + +config KCSAN_REPORT_VALUE_CHANGE_ONLY + bool "Only report races where watcher observed a data value change" + default y + help + If enabled and a conflicting write is observed via watchpoint, but + the data value of the memory location was observed to remain + unchanged, do not report the data race. + +config KCSAN_IGNORE_ATOMICS + bool "Do not instrument marked atomic accesses" + default n + help + If enabled, never instruments marked atomic accesses. This results in + not reporting data races where one access is atomic and the other is + a plain access. + +endif # KCSAN diff --git a/lib/Makefile b/lib/Makefile index c5892807e06f..778ab704e3ad 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -24,6 +24,9 @@ KASAN_SANITIZE_string.o := n CFLAGS_string.o := $(call cc-option, -fno-stack-protector) endif +# Used by KCSAN while enabled, avoid recursion. +KCSAN_SANITIZE_random32.o := n + lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o timerqueue.o xarray.o \ idr.o extable.o \ diff --git a/mm/Makefile b/mm/Makefile index d996846697ef..56c1964bb3a1 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -7,6 +7,14 @@ KASAN_SANITIZE_slab_common.o := n KASAN_SANITIZE_slab.o := n KASAN_SANITIZE_slub.o := n +# These produce frequent data race reports: most of them are due to races on +# the same word but accesses to different bits of that word. Re-enable KCSAN +# for these when we have more consensus on what to do about them. +KCSAN_SANITIZE_slab_common.o := n +KCSAN_SANITIZE_slab.o := n +KCSAN_SANITIZE_slub.o := n +KCSAN_SANITIZE_page_alloc.o := n + # These files are disabled because they produce non-interesting and/or # flaky coverage that is not a function of syscall inputs. E.g. slab is out of # free pages, or a task is migrated between nodes. diff --git a/scripts/Makefile.kcsan b/scripts/Makefile.kcsan new file mode 100644 index 000000000000..caf1111a28ae --- /dev/null +++ b/scripts/Makefile.kcsan @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0 +ifdef CONFIG_KCSAN + +CFLAGS_KCSAN := -fsanitize=thread + +endif # CONFIG_KCSAN diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 179d55af5852..8952f909f7c9 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -152,6 +152,16 @@ _c_flags += $(if $(patsubst n%,, \ $(CFLAGS_KCOV)) endif +# +# Enable KCSAN flags except some files or directories we don't want to check +# (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE) +# +ifeq ($(CONFIG_KCSAN),y) +_c_flags += $(if $(patsubst n%,, \ + $(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \ + $(CFLAGS_KCSAN)) +endif + # $(srctree)/$(src) for including checkin headers from generated source files # $(objtree)/$(obj) for including generated headers from checkin source files ifeq ($(KBUILD_EXTMOD),) diff --git a/scripts/atomic/gen-atomic-instrumented.sh b/scripts/atomic/gen-atomic-instrumented.sh index e09812372b17..8b8b2a6f8d68 100755 --- a/scripts/atomic/gen-atomic-instrumented.sh +++ b/scripts/atomic/gen-atomic-instrumented.sh @@ -20,7 +20,7 @@ gen_param_check() # We don't write to constant parameters [ ${type#c} != ${type} ] && rw="read" - printf "\tkasan_check_${rw}(${name}, sizeof(*${name}));\n" + printf "\t__atomic_check_${rw}(${name}, sizeof(*${name}));\n" } #gen_param_check(arg...) @@ -107,7 +107,7 @@ cat <<EOF #define ${xchg}(ptr, ...) \\ ({ \\ typeof(ptr) __ai_ptr = (ptr); \\ - kasan_check_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\ + __atomic_check_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\ arch_${xchg}(__ai_ptr, __VA_ARGS__); \\ }) EOF @@ -148,6 +148,19 @@ cat << EOF #include <linux/build_bug.h> #include <linux/kasan-checks.h> +#include <linux/kcsan-checks.h> + +static inline void __atomic_check_read(const volatile void *v, size_t size) +{ + kasan_check_read(v, size); + kcsan_check_atomic_read(v, size); +} + +static inline void __atomic_check_write(const volatile void *v, size_t size) +{ + kasan_check_write(v, size); + kcsan_check_atomic_write(v, size); +} EOF diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 044c9a3cb247..e022a9a00ca1 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -466,6 +466,24 @@ static const char *uaccess_safe_builtin[] = { "__asan_report_store4_noabort", "__asan_report_store8_noabort", "__asan_report_store16_noabort", + /* KCSAN */ + "kcsan_found_watchpoint", + "kcsan_setup_watchpoint", + /* KCSAN/TSAN */ + "__tsan_func_entry", + "__tsan_func_exit", + "__tsan_read_range", + "__tsan_write_range", + "__tsan_read1", + "__tsan_read2", + "__tsan_read4", + "__tsan_read8", + "__tsan_read16", + "__tsan_write1", + "__tsan_write2", + "__tsan_write4", + "__tsan_write8", + "__tsan_write16", /* KCOV */ "write_comp_data", "__sanitizer_cov_trace_pc", |