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| * | | arm64: kpti: Add KRYO{3, 4}XX silver CPU cores to kpti safelistSai Prakash Ranjan2020-06-241-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | QCOM KRYO{3,4}XX silver/LITTLE CPU cores are based on Cortex-A55 and are meltdown safe, hence add them to kpti_safe_list[]. Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Link: https://lore.kernel.org/r/20200624123406.3472-1-saiprakash.ranjan@codeaurora.org Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: Don't insert a BTI instruction at inner labelsJean-Philippe Brucker2020-06-241-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some ftrace features are broken since commit 714a8d02ca4d ("arm64: asm: Override SYM_FUNC_START when building the kernel with BTI"). For example the function_graph tracer: $ echo function_graph > /sys/kernel/debug/tracing/current_tracer [ 36.107016] WARNING: CPU: 0 PID: 115 at kernel/trace/ftrace.c:2691 ftrace_modify_all_code+0xc8/0x14c When ftrace_modify_graph_caller() attempts to write a branch at ftrace_graph_call, it finds the "BTI J" instruction inserted by SYM_INNER_LABEL() instead of a NOP, and aborts. It turns out we don't currently need the BTI landing pads inserted by SYM_INNER_LABEL: * ftrace_call and ftrace_graph_call are only used for runtime patching of the active tracer. The patched code is not reached from a branch. * install_el2_stub is reached from a CBZ instruction, which doesn't change PSTATE.BTYPE. * __guest_exit is reached from B instructions in the hyp-entry vectors, which aren't subject to BTI checks either. Remove the BTI annotation from SYM_INNER_LABEL. Fixes: 714a8d02ca4d ("arm64: asm: Override SYM_FUNC_START when building the kernel with BTI") Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20200624112253.1602786-1-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: vdso: Don't use gcc plugins for building vgettimeofday.cAlexander Popov2020-06-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't use gcc plugins for building arch/arm64/kernel/vdso/vgettimeofday.c to avoid unneeded instrumentation. Signed-off-by: Alexander Popov <alex.popov@linux.com> Link: https://lore.kernel.org/r/20200624123330.83226-4-alex.popov@linux.com Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: vdso: Only pass --no-eh-frame-hdr when linker supports itWill Deacon2020-06-241-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 87676cfca141 ("arm64: vdso: Disable dwarf unwinding through the sigreturn trampoline") unconditionally passes the '--no-eh-frame-hdr' option to the linker when building the native vDSO in an attempt to prevent generation of the .eh_frame_hdr section, the presence of which has been implicated in segfaults originating from the libgcc unwinder. Unfortunately, not all versions of binutils support this option, which has been shown to cause build failures in linux-next: | CALL scripts/atomic/check-atomics.sh | CALL scripts/checksyscalls.sh | LD arch/arm64/kernel/vdso/vdso.so.dbg | ld: unrecognized option '--no-eh-frame-hdr' | ld: use the --help option for usage information | arch/arm64/kernel/vdso/Makefile:64: recipe for target | 'arch/arm64/kernel/vdso/vdso.so.dbg' failed | make[1]: *** [arch/arm64/kernel/vdso/vdso.so.dbg] Error 1 | arch/arm64/Makefile:175: recipe for target 'vdso_prepare' failed | make: *** [vdso_prepare] Error 2 Only link the vDSO with '--no-eh-frame-hdr' when the linker supports it. If we end up with the section due to linker defaults, the absence of CFI information in the sigreturn trampoline will prevent the unwinder from breaking. Link: https://lore.kernel.org/r/7a7e31a8-9a7b-2428-ad83-2264f20bdc2d@hisilicon.com Fixes: 87676cfca141 ("arm64: vdso: Disable dwarf unwinding through the sigreturn trampoline") Reported-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: Depend on newer binutils when building PACMark Brown2020-06-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Versions of binutils prior to 2.33.1 don't understand the ELF notes that are added by modern compilers to indicate the PAC and BTI options used to build the code. This causes them to emit large numbers of warnings in the form: aarch64-linux-gnu-nm: warning: .tmp_vmlinux.kallsyms2: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0000000 during the kernel build which is currently causing quite a bit of disruption for automated build testing using clang. In commit 15cd0e675f3f76b (arm64: Kconfig: ptrauth: Add binutils version check to fix mismatch) we added a dependency on binutils to avoid this issue when building with versions of GCC that emit the notes but did not do so for clang as it was believed that the existing check for .cfi_negate_ra_state was already requiring a new enough binutils. This does not appear to be the case for some versions of binutils (eg, the binutils in Debian 10) so instead refactor so we require a new enough GNU binutils in all cases other than when we are using an old GCC version that does not emit notes. Other, more exotic, combinations of tools are possible such as using clang, lld and gas together are possible and may have further problems but rather than adding further version checks it looks like the most robust thing will be to just test that we can build cleanly with the configured tools but that will require more review and discussion so do this for now to address the immediate problem disrupting build testing. Reported-by: KernelCI <bot@kernelci.org> Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://github.com/ClangBuiltLinux/linux/issues/1054 Link: https://lore.kernel.org/r/20200619123550.48098-1-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: compat: Remove 32-bit sigreturn code from the vDSOWill Deacon2020-06-233-71/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sigreturn code in the compat vDSO is unused. Remove it. Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: compat: Always use sigpage for sigreturn trampolineWill Deacon2020-06-231-25/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 32-bit sigreturn trampoline in the compat sigpage matches the binary representation of the arch/arm/ sigpage exactly. This is important for debuggers (e.g. GDB) and unwinders (e.g. libunwind) since they rely on matching the instruction sequence in order to identify that they are unwinding through a signal. The same cannot be said for the sigreturn trampoline in the compat vDSO, which defeats the unwinder heuristics and instead attempts to use unwind directives for the unwinding. This is in contrast to arch/arm/, which never uses the vDSO for sigreturn. Ensure compatibility with arch/arm/ and existing unwinders by always using the sigpage for the sigreturn trampoline, regardless of the presence of the compat vDSO. Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: compat: Allow 32-bit vdso and sigpage to co-existWill Deacon2020-06-234-36/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for removing the signal trampoline from the compat vDSO, allow the sigpage and the compat vDSO to co-exist. For the moment the vDSO signal trampoline will still be used when built. Subsequent patches will move to the sigpage consistently. Acked-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: vdso: Disable dwarf unwinding through the sigreturn trampolineWill Deacon2020-06-232-21/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 7e9f5e6629f6 ("arm64: vdso: Add --eh-frame-hdr to ldflags") results in a .eh_frame_hdr section for the vDSO, which in turn causes the libgcc unwinder to unwind out of signal handlers using the .eh_frame information populated by our .cfi directives. In conjunction with a4eb355a3fda ("arm64: vdso: Fix CFI directives in sigreturn trampoline"), this has been shown to cause segmentation faults originating from within the unwinder during thread cancellation: | Thread 14 "virtio-net-rx" received signal SIGSEGV, Segmentation fault. | 0x0000000000435e24 in uw_frame_state_for () | (gdb) bt | #0 0x0000000000435e24 in uw_frame_state_for () | #1 0x0000000000436e88 in _Unwind_ForcedUnwind_Phase2 () | #2 0x00000000004374d8 in _Unwind_ForcedUnwind () | #3 0x0000000000428400 in __pthread_unwind (buf=<optimized out>) at unwind.c:121 | #4 0x0000000000429808 in __do_cancel () at ./pthreadP.h:304 | #5 sigcancel_handler (sig=32, si=0xffff33c743f0, ctx=<optimized out>) at nptl-init.c:200 | #6 sigcancel_handler (sig=<optimized out>, si=0xffff33c743f0, ctx=<optimized out>) at nptl-init.c:165 | #7 <signal handler called> | #8 futex_wait_cancelable (private=0, expected=0, futex_word=0x3890b708) at ../sysdeps/unix/sysv/linux/futex-internal.h:88 After considerable bashing of heads, it appears that our CFI directives for unwinding out of the sigreturn trampoline are only processed by libgcc when both a .eh_frame_hdr section is present *and* the mysterious NOP is covered by an entry in .eh_frame. With both of these now in place, it has highlighted that our CFI directives are not comprehensive enough to restore the stack pointer of the interrupted context. This results in libgcc falling back to an arm64-specific unwinder after computing a bogus PC value from the unwind tables. The unwinder promptly dereferences this bogus address in an attempt to see if the pointed-to instruction sequence looks like the sigreturn trampoline. Restore the old unwind behaviour, which relied solely on heuristics in the unwinder, by removing the .eh_frame_hdr section from the vDSO and commenting out the insufficient CFI directives for now. Add comments to explain the current, miserable state of affairs. Cc: Tamas Zsoldos <tamas.zsoldos@arm.com> Cc: Szabolcs Nagy <szabolcs.nagy@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Daniel Kiss <daniel.kiss@arm.com> Acked-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reported-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
* | | | arm64: use PAGE_KERNEL_ROX directly in alloc_insn_pageChristoph Hellwig2020-06-261-9/+3
| |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use PAGE_KERNEL_ROX directly instead of allocating RWX and setting the page read-only just after the allocation. Link: http://lkml.kernel.org/r/20200618064307.32739-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge tag 'kbuild-fixes-v5.8' of ↵Linus Torvalds2020-06-211-1/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - fix -gz=zlib compiler option test for CONFIG_DEBUG_INFO_COMPRESSED - improve cc-option in scripts/Kbuild.include to clean up temp files - improve cc-option in scripts/Kconfig.include for more reliable compile option test - do not copy modules.builtin by 'make install' because it would break existing systems - use 'userprogs' syntax for watch_queue sample * tag 'kbuild-fixes-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: samples: watch_queue: build sample program for target architecture Revert "Makefile: install modules.builtin even if CONFIG_MODULES=n" scripts: Fix typo in headers_install.sh kconfig: unify cc-option and as-option kbuild: improve cc-option to clean up all temporary files Makefile: Improve compressed debug info support detection
| * | | kconfig: unify cc-option and as-optionMasahiro Yamada2020-06-171-1/+1
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cc-option and as-option are almost the same; both pass the flag to $(CC). The main difference is the cc-option stops before the assemble stage (-S option) whereas as-option stops after (-c option). I chose -S because it is slightly faster, but $(cc-option,-gz=zlib) returns a wrong result (https://lkml.org/lkml/2020/6/9/1529). It has been fixed by commit 7b16994437c7 ("Makefile: Improve compressed debug info support detection"), but the assembler should always be invoked for more reliable compiler option tests. However, you cannot simply replace -S with -c because the following code in lib/Kconfig.debug would break: depends on $(cc-option,-gsplit-dwarf) The combination of -c and -gsplit-dwarf does not accept /dev/null as output. $ cat /dev/null | gcc -gsplit-dwarf -S -x c - -o /dev/null $ echo $? 0 $ cat /dev/null | gcc -gsplit-dwarf -c -x c - -o /dev/null objcopy: Warning: '/dev/null' is not an ordinary file $ echo $? 1 $ cat /dev/null | gcc -gsplit-dwarf -c -x c - -o tmp.o $ echo $? 0 There is another flag that creates an separate file based on the object file path: $ cat /dev/null | gcc -ftest-coverage -c -x c - -o /dev/null <stdin>:1: error: cannot open /dev/null.gcno So, we cannot use /dev/null to sink the output. Align the cc-option implementation with scripts/Kbuild.include. With -c option used in cc-option, as-option is unneeded. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org>
* | | Merge tag 'arm64-fixes' of ↵Linus Torvalds2020-06-1910-57/+63
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: "Unfortunately, we still have a number of outstanding issues so there will be more fixes to come, but this lot are a good start. - Fix handling of watchpoints triggered by uaccess routines - Fix initialisation of gigantic pages for CMA buffers - Raise minimum clang version for BTI to avoid miscompilation - Fix data race in SVE vector length configuration code - Ensure address tags are ignored in kern_addr_valid() - Dump register state on fatal BTI exception - kexec_file() cleanup to use struct_size() macro" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: hw_breakpoint: Don't invoke overflow handler on uaccess watchpoints arm64: kexec_file: Use struct_size() in kmalloc() arm64: mm: reserve hugetlb CMA after numa_init arm64: bti: Require clang >= 10.0.1 for in-kernel BTI support arm64: sve: Fix build failure when ARM64_SVE=y and SYSCTL=n arm64: pgtable: Clear the GP bit for non-executable kernel pages arm64: mm: reset address tag set by kasan sw tagging arm64: traps: Dump registers prior to panic() in bad_mode() arm64/sve: Eliminate data races on sve_default_vl docs/arm64: Fix typo'd #define in sve.rst arm64: remove TEXT_OFFSET randomization
| * | arm64: hw_breakpoint: Don't invoke overflow handler on uaccess watchpointsWill Deacon2020-06-181-18/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unprivileged memory accesses generated by the so-called "translated" instructions (e.g. STTR) at EL1 can cause EL0 watchpoints to fire unexpectedly if kernel debugging is enabled. In such cases, the hw_breakpoint logic will invoke the user overflow handler which will typically raise a SIGTRAP back to the current task. This is futile when returning back to the kernel because (a) the signal won't have been delivered and (b) userspace can't handle the thing anyway. Avoid invoking the user overflow handler for watchpoints triggered by kernel uaccess routines, and instead single-step over the faulting instruction as we would if no overflow handler had been installed. (Fixes tag identifies the introduction of unprivileged memory accesses, which exposed this latent bug in the hw_breakpoint code) Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Fixes: 57f4959bad0a ("arm64: kernel: Add support for User Access Override") Reported-by: Luis Machado <luis.machado@linaro.org> Signed-off-by: Will Deacon <will@kernel.org>
| * | arm64: kexec_file: Use struct_size() in kmalloc()Gustavo A. R. Silva2020-06-181-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. This code was detected with the help of Coccinelle and, audited and fixed manually. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20200617213407.GA1385@embeddedor Signed-off-by: Will Deacon <will@kernel.org>
| * | arm64: mm: reserve hugetlb CMA after numa_initBarry Song2020-06-181-5/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hugetlb_cma_reserve() is called at the wrong place. numa_init has not been done yet. so all reserved memory will be located at node0. Fixes: cf11e85fc08c ("mm: hugetlb: optionally allocate gigantic hugepages using cma") Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200617215828.25296-1-song.bao.hua@hisilicon.com Signed-off-by: Will Deacon <will@kernel.org>
| * | arm64: bti: Require clang >= 10.0.1 for in-kernel BTI supportWill Deacon2020-06-171-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unfortunately, most versions of clang that support BTI are capable of miscompiling the kernel when converting a switch statement into a jump table. As an example, attempting to spawn a KVM guest results in a panic: [ 56.253312] Kernel panic - not syncing: bad mode [ 56.253834] CPU: 0 PID: 279 Comm: lkvm Not tainted 5.8.0-rc1 #2 [ 56.254225] Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 [ 56.254712] Call trace: [ 56.254952] dump_backtrace+0x0/0x1d4 [ 56.255305] show_stack+0x1c/0x28 [ 56.255647] dump_stack+0xc4/0x128 [ 56.255905] panic+0x16c/0x35c [ 56.256146] bad_el0_sync+0x0/0x58 [ 56.256403] el1_sync_handler+0xb4/0xe0 [ 56.256674] el1_sync+0x7c/0x100 [ 56.256928] kvm_vm_ioctl_check_extension_generic+0x74/0x98 [ 56.257286] __arm64_sys_ioctl+0x94/0xcc [ 56.257569] el0_svc_common+0x9c/0x150 [ 56.257836] do_el0_svc+0x84/0x90 [ 56.258083] el0_sync_handler+0xf8/0x298 [ 56.258361] el0_sync+0x158/0x180 This is because the switch in kvm_vm_ioctl_check_extension_generic() is executed as an indirect branch to tail-call through a jump table: ffff800010032dc8: 3869694c ldrb w12, [x10, x9] ffff800010032dcc: 8b0c096b add x11, x11, x12, lsl #2 ffff800010032dd0: d61f0160 br x11 However, where the target case uses the stack, the landing pad is elided due to the presence of a paciasp instruction: ffff800010032e14: d503233f paciasp ffff800010032e18: a9bf7bfd stp x29, x30, [sp, #-16]! ffff800010032e1c: 910003fd mov x29, sp ffff800010032e20: aa0803e0 mov x0, x8 ffff800010032e24: 940017c0 bl ffff800010038d24 <kvm_vm_ioctl_check_extension> ffff800010032e28: 93407c00 sxtw x0, w0 ffff800010032e2c: a8c17bfd ldp x29, x30, [sp], #16 ffff800010032e30: d50323bf autiasp ffff800010032e34: d65f03c0 ret Unfortunately, this results in a fatal exception because paciasp is compatible only with branch-and-link (call) instructions and not simple indirect branches. A fix is being merged into Clang 10.0.1 so that a 'bti j' instruction is emitted as an explicit landing pad in this situation. Make in-kernel BTI depend on that compiler version when building with clang. Cc: Tom Stellard <tstellar@redhat.com> Cc: Daniel Kiss <daniel.kiss@arm.com> Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Acked-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20200615105524.GA2694@willie-the-truck Link: https://lore.kernel.org/r/20200616183630.2445-1-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
| * | arm64: sve: Fix build failure when ARM64_SVE=y and SYSCTL=nWill Deacon2020-06-161-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When I squashed the 'allnoconfig' compiler warning about the set_sve_default_vl() function being defined but not used in commit 1e570f512cbd ("arm64/sve: Eliminate data races on sve_default_vl"), I accidentally broke the build for configs where ARM64_SVE is enabled, but SYSCTL is not. Fix this by only compiling the SVE sysctl support if both CONFIG_SVE=y and CONFIG_SYSCTL=y. Cc: Dave Martin <Dave.Martin@arm.com> Reported-by: Qian Cai <cai@lca.pw> Link: https://lore.kernel.org/r/20200616131808.GA1040@lca.pw Signed-off-by: Will Deacon <will@kernel.org>
| * | arm64: pgtable: Clear the GP bit for non-executable kernel pagesWill Deacon2020-06-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit cca98e9f8b5e ("mm: enforce that vmap can't map pages executable") introduced 'pgprot_nx(prot)' for arm64 but collided silently with the BTI support during the merge window, which endeavours to clear the GP bit for non-executable kernel mappings in set_memory_nx(). For consistency between the two APIs, clear the GP bit in pgprot_nx(). Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20200615154642.3579-1-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
| * | arm64: mm: reset address tag set by kasan sw taggingShyam Thombre2020-06-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KASAN sw tagging sets a random tag of 8 bits in the top byte of the pointer returned by the memory allocating functions. So for the functions unaware of this change, the top 8 bits of the address must be reset which is done by the function arch_kasan_reset_tag(). Signed-off-by: Shyam Thombre <sthombre@codeaurora.org> Link: https://lore.kernel.org/r/1591787384-5823-1-git-send-email-sthombre@codeaurora.org Signed-off-by: Will Deacon <will@kernel.org>
| * | arm64: traps: Dump registers prior to panic() in bad_mode()Will Deacon2020-06-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When panicing due to an unknown/unhandled exception at EL1, dump the registers of the faulting context so that it's easier to figure out what went wrong. In particular, this makes it a lot easier to debug in-kernel BTI failures since it pretty-prints PSTATE.BTYPE in the crash log. Cc: Mark Brown <broonie@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200615113458.2884-1-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
| * | arm64/sve: Eliminate data races on sve_default_vlDave Martin2020-06-151-7/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sve_default_vl can be modified via the /proc/sys/abi/sve_default_vl sysctl concurrently with use, and modified concurrently by multiple threads. Adding a lock for this seems overkill, and I don't want to think any more than necessary, so just define wrappers using READ_ONCE()/ WRITE_ONCE(). This will avoid the possibility of torn accesses and repeated loads and stores. There's no evidence yet that this is going wrong in practice: this is just hygiene. For generic sysctl users, it would be better to build this kind of thing into the sysctl common code somehow. Reported-by: Will Deacon <will@kernel.org> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/1591808590-20210-3-git-send-email-Dave.Martin@arm.com [will: move set_sve_default_vl() inside #ifdef to squash allnoconfig warning] Signed-off-by: Will Deacon <will@kernel.org>
| * | arm64: remove TEXT_OFFSET randomizationArd Biesheuvel2020-06-152-21/+0
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TEXT_OFFSET was recently changed to 0x0, in preparation for its removal at a later stage, and a warning is emitted into the kernel log when the bootloader appears to have failed to take the TEXT_OFFSET image header value into account. Ironically, this warning itself fails to take TEXT_OFFSET into account, and compares the kernel image's alignment modulo 2M against a hardcoded value of 0x0, and so the warning will trigger spuriously when TEXT_OFFSET randomization is enabled. Given the intent to get rid of TEXT_OFFSET entirely, let's fix this oversight by just removing support for TEXT_OFFSET randomization. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200615101939.634391-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
* | maccess: rename probe_kernel_address to get_kernel_nofaultChristoph Hellwig2020-06-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | Better describe what this helper does, and match the naming of copy_from_kernel_nofault. Also switch the argument order around, so that it acts and looks like get_user(). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofaultChristoph Hellwig2020-06-171-2/+2
|/ | | | | | | | Better describe what these functions do. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'kbuild-v5.8-2' of ↵Linus Torvalds2020-06-132-5/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - fix build rules in binderfs sample - fix build errors when Kbuild recurses to the top Makefile - covert '---help---' in Kconfig to 'help' * tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: treewide: replace '---help---' in Kconfig files with 'help' kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables samples: binderfs: really compile this sample and fix build issues
| * treewide: replace '---help---' in Kconfig files with 'help'Masahiro Yamada2020-06-142-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2020-06-1213-102/+171
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull more KVM updates from Paolo Bonzini: "The guest side of the asynchronous page fault work has been delayed to 5.9 in order to sync with Thomas's interrupt entry rework, but here's the rest of the KVM updates for this merge window. MIPS: - Loongson port PPC: - Fixes ARM: - Fixes x86: - KVM_SET_USER_MEMORY_REGION optimizations - Fixes - Selftest fixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (62 commits) KVM: x86: do not pass poisoned hva to __kvm_set_memory_region KVM: selftests: fix sync_with_host() in smm_test KVM: async_pf: Inject 'page ready' event only if 'page not present' was previously injected KVM: async_pf: Cleanup kvm_setup_async_pf() kvm: i8254: remove redundant assignment to pointer s KVM: x86: respect singlestep when emulating instruction KVM: selftests: Don't probe KVM_CAP_HYPERV_ENLIGHTENED_VMCS when nested VMX is unsupported KVM: selftests: do not substitute SVM/VMX check with KVM_CAP_NESTED_STATE check KVM: nVMX: Consult only the "basic" exit reason when routing nested exit KVM: arm64: Move hyp_symbol_addr() to kvm_asm.h KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception KVM: arm64: Make vcpu_cp1x() work on Big Endian hosts KVM: arm64: Remove host_cpu_context member from vcpu structure KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr KVM: arm64: Handle PtrAuth traps early KVM: x86: Unexport x86_fpu_cache and make it static KVM: selftests: Ignore KVM 5-level paging support for VM_MODE_PXXV48_4K KVM: arm64: Save the host's PtrAuth keys in non-preemptible context KVM: arm64: Stop save/restoring ACTLR_EL1 KVM: arm64: Add emulation for 32bit guests accessing ACTLR2 ...
| * \ Merge tag 'kvmarm-fixes-5.8-1' of ↵Paolo Bonzini2020-06-1113-97/+171
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for Linux 5.8, take #1 * 32bit VM fixes: - Fix embarassing mapping issue between AArch32 CSSELR and AArch64 ACTLR - Add ACTLR2 support for AArch32 - Get rid of the useless ACTLR_EL1 save/restore - Fix CP14/15 accesses for AArch32 guests on BE hosts - Ensure that we don't loose any state when injecting a 32bit exception when running on a VHE host * 64bit VM fixes: - Fix PtrAuth host saving happening in preemptible contexts - Optimize PtrAuth lazy enable - Drop vcpu to cpu context pointer - Fix sparse warnings for HYP per-CPU accesses
| | * \ Merge branch 'kvm-arm64/ptrauth-fixes' into kvmarm-master/nextMarc Zyngier2020-06-1011-85/+111
| | |\ \ | | | | | | | | | | | | | | | Signed-off-by: Marc Zyngier <maz@kernel.org>
| | | * | KVM: arm64: Move hyp_symbol_addr() to kvm_asm.hMarc Zyngier2020-06-102-20/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent refactoring of the arm64 code make it awkward to have hyp_symbol_addr() in kvm_mmu.h. Instead, move it next to its main user, which is __hyp_this_cpu_ptr(). Signed-off-by: Marc Zyngier <maz@kernel.org>
| | | * | KVM: arm64: Remove host_cpu_context member from vcpu structureMarc Zyngier2020-06-096-19/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For very long, we have kept this pointer back to the per-cpu host state, despite having working per-cpu accessors at EL2 for some time now. Recent investigations have shown that this pointer is easy to abuse in preemptible context, which is a sure sign that it would better be gone. Not to mention that a per-cpu pointer is faster to access at all times. Reported-by: Andrew Scull <ascull@google.com> Acked-by: Mark Rutland <mark.rutland@arm.com Reviewed-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
| | | * | KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptrMarc Zyngier2020-06-091-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparse complains that __hyp_this_cpu_ptr() returns something that is flagged noderef and not in the correct address space (both being the result of the __percpu annotation). Pretend that __hyp_this_cpu_ptr() knows what it is doing by forcefully casting the pointer with __kernel __force. Signed-off-by: Marc Zyngier <maz@kernel.org>
| | | * | KVM: arm64: Handle PtrAuth traps earlyMarc Zyngier2020-06-094-38/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current way we deal with PtrAuth is a bit heavy handed: - We forcefully save the host's keys on each vcpu_load() - Handling the PtrAuth trap forces us to go all the way back to the exit handling code to just set the HCR bits Overall, this is pretty cumbersome. A better approach would be to handle it the same way we deal with the FPSIMD registers: - On vcpu_load() disable PtrAuth for the guest - On first use, save the host's keys, enable PtrAuth in the guest Crucially, this can happen as a fixup, which is done very early on exit. We can then reenter the guest immediately without leaving the hypervisor role. Another thing is that it simplify the rest of the host handling: exiting all the way to the host means that the only possible outcome for this trap is to inject an UNDEF. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
| | | * | KVM: arm64: Save the host's PtrAuth keys in non-preemptible contextMarc Zyngier2020-06-093-24/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using the PtrAuth feature in a guest, we need to save the host's keys before allowing the guest to program them. For that, we dump them in a per-CPU data structure (the so called host context). But both call sites that do this are in preemptible context, which may end up in disaster should the vcpu thread get preempted before reentering the guest. Instead, save the keys eagerly on each vcpu_load(). This has an increased overhead, but is at least safe. Cc: stable@vger.kernel.org Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
| | * | | KVM: arm64: Synchronize sysreg state on injecting an AArch32 exceptionMarc Zyngier2020-06-101-0/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On a VHE system, the EL1 state is left in the CPU most of the time, and only syncronized back to memory when vcpu_put() is called (most of the time on preemption). Which means that when injecting an exception, we'd better have a way to either: (1) write directly to the EL1 sysregs (2) synchronize the state back to memory, and do the changes there For an AArch64, we already do (1), so we are safe. Unfortunately, doing the same thing for AArch32 would be pretty invasive. Instead, we can easily implement (2) by calling the put/load architectural backends, and keep preemption disabled. We can then reload the state back into EL1. Cc: stable@vger.kernel.org Reported-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
| | * | | KVM: arm64: Make vcpu_cp1x() work on Big Endian hostsMarc Zyngier2020-06-101-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | AArch32 CP1x registers are overlayed on their AArch64 counterparts in the vcpu struct. This leads to an interesting problem as they are stored in their CPU-local format, and thus a CP1x register doesn't "hit" the lower 32bit portion of the AArch64 register on a BE host. To workaround this unfortunate situation, introduce a bias trick in the vcpu_cp1x() accessors which picks the correct half of the 64bit register. Cc: stable@vger.kernel.org Reported-by: James Morse <james.morse@arm.com> Tested-by: James Morse <james.morse@arm.com> Acked-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
| | * | | KVM: arm64: Stop save/restoring ACTLR_EL1James Morse2020-06-092-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KVM sets HCR_EL2.TACR via HCR_GUEST_FLAGS. This means ACTLR* accesses from the guest are always trapped, and always return the value in the sys_regs array. The guest can't change the value of these registers, so we are save restoring the reset value, which came from the host. Stop save/restoring this register. Keep the storage for this register in sys_regs[] as this is how the value is exposed to user-space, removing it would break migration. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200529150656.7339-4-james.morse@arm.com
| | * | | KVM: arm64: Add emulation for 32bit guests accessing ACTLR2James Morse2020-06-091-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ACTLR_EL1 is a 64bit register while the 32bit ACTLR is obviously 32bit. For 32bit software, the extra bits are accessible via ACTLR2... which KVM doesn't emulate. Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200529150656.7339-3-james.morse@arm.com
| | * | | KVM: arm64: Stop writing aarch32's CSSELR into ACTLRJames Morse2020-06-091-2/+8
| | |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | aarch32 has pairs of registers to access the high and low parts of 64bit registers. KVM has a union of 64bit sys_regs[] and 32bit copro[]. The 32bit accessors read the high or low part of the 64bit sys_reg[] value through the union. Both sys_reg_descs[] and cp15_regs[] list access_csselr() as the accessor for CSSELR{,_EL1}. access_csselr() is only aware of the 64bit sys_regs[], and expects r->reg to be 'CSSELR_EL1' in the enum, index 2 of the 64bit array. cp15_regs[] uses the 32bit copro[] alias of sys_regs[]. Here CSSELR is c0_CSSELR which is the same location in sys_reg[]. r->reg is 'c0_CSSELR', index 4 in the 32bit array. access_csselr() uses the 32bit r->reg value to access the 64bit array, so reads and write the wrong value. sys_regs[4], is ACTLR_EL1, which is subsequently save/restored when we enter the guest. ACTLR_EL1 is supposed to be read-only for the guest. This register only affects execution at EL1, and the host's value is restored before we return to host EL1. Convert the 32bit register index back to the 64bit version. Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200529150656.7339-2-james.morse@arm.com
| | * | KVM: arm64: Flush the instruction cache if not unmapping the VM on rebootMarc Zyngier2020-05-311-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On a system with FWB, we don't need to unmap Stage-2 on reboot, as even if userspace takes this opportunity to repaint the whole of memory, FWB ensures that the data side stays consistent even if the guest uses non-cacheable mappings. However, the I-side is not necessarily coherent with the D-side if CTR_EL0.DIC is 0. In this case, invalidate the i-cache to preserve coherency. Reported-by: Alexandru Elisei <alexandru.elisei@arm.com> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Fixes: 892713e97ca1 ("KVM: arm64: Sidestep stage2_unmap_vm() on vcpu reset when S2FWB is supported") Signed-off-by: Marc Zyngier <maz@kernel.org>
| * | | KVM: let kvm_destroy_vm_debugfs clean up vCPU debugfs directoriesPaolo Bonzini2020-06-041-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After commit 63d0434 ("KVM: x86: move kvm_create_vcpu_debugfs after last failure point") we are creating the pre-vCPU debugfs files after the creation of the vCPU file descriptor. This makes it possible for userspace to reach kvm_vcpu_release before kvm_create_vcpu_debugfs has finished. The vcpu->debugfs_dentry then does not have any associated inode anymore, and this causes a NULL-pointer dereference in debugfs_create_file. The solution is simply to avoid removing the files; they are cleaned up when the VM file descriptor is closed (and that must be after KVM_CREATE_VCPU returns). We can stop storing the dentry in struct kvm_vcpu too, because it is not needed anywhere after kvm_create_vcpu_debugfs returns. Reported-by: syzbot+705f4401d5a93a59b87d@syzkaller.appspotmail.com Fixes: 63d04348371b ("KVM: x86: move kvm_create_vcpu_debugfs after last failure point") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | Merge tag 'locking-urgent-2020-06-11' of ↵Linus Torvalds2020-06-111-3/+3
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull atomics rework from Thomas Gleixner: "Peter Zijlstras rework of atomics and fallbacks. This solves two problems: 1) Compilers uninline small atomic_* static inline functions which can expose them to instrumentation. 2) The instrumentation of atomic primitives was done at the architecture level while composites or fallbacks were provided at the generic level. As a result there are no uninstrumented variants of the fallbacks. Both issues were in the way of fully isolating fragile entry code pathes and especially the text poke int3 handler which is prone to an endless recursion problem when anything in that code path is about to be instrumented. This was always a problem, but got elevated due to the new batch mode updates of tracing. The solution is to mark the functions __always_inline and to flip the fallback and instrumentation so the non-instrumented variants are at the architecture level and the instrumentation is done in generic code. The latter introduces another fallback variant which will go away once all architectures have been moved over to arch_atomic_*" * tag 'locking-urgent-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/atomics: Flip fallbacks and instrumentation asm-generic/atomic: Use __always_inline for fallback wrappers
| * | | | locking/atomics: Flip fallbacks and instrumentationPeter Zijlstra2020-06-111-3/+3
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently instrumentation of atomic primitives is done at the architecture level, while composites or fallbacks are provided at the generic level. The result is that there are no uninstrumented variants of the fallbacks. Since there is now need of such variants to isolate text poke from any form of instrumentation invert this ordering. Doing this means moving the instrumentation into the generic code as well as having (for now) two variants of the fallbacks. Notes: - the various *cond_read* primitives are not proper fallbacks and got moved into linux/atomic.c. No arch_ variants are generated because the base primitives smp_cond_load*() are instrumented. - once all architectures are moved over to arch_atomic_ one of the fallback variants can be removed and some 2300 lines reclaimed. - atomic_{read,set}*() are no longer double-instrumented Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lkml.kernel.org/r/20200505134058.769149955@linutronix.de
* | | | Merge tag 'arm64-upstream' of ↵Linus Torvalds2020-06-116-5/+28
|\ \ \ \ | |/ / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: "arm64 fixes that came in during the merge window. There will probably be more to come, but it doesn't seem like it's worth me sitting on these in the meantime. - Fix SCS debug check to report max stack usage in bytes as advertised - Fix typo: CONFIG_FTRACE_WITH_REGS => CONFIG_DYNAMIC_FTRACE_WITH_REGS - Fix incorrect mask in HiSilicon L3C perf PMU driver - Fix compat vDSO compilation under some toolchain configurations - Fix false UBSAN warning from ACPI IORT parsing code - Fix booting under bootloaders that ignore TEXT_OFFSET - Annotate debug initcall function with '__init'" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: warn on incorrect placement of the kernel by the bootloader arm64: acpi: fix UBSAN warning arm64: vdso32: add CONFIG_THUMB2_COMPAT_VDSO drivers/perf: hisi: Fix wrong value for all counters enable arm64: ftrace: Change CONFIG_FTRACE_WITH_REGS to CONFIG_DYNAMIC_FTRACE_WITH_REGS arm64: debug: mark a function as __init to save some memory scs: Report SCS usage in bytes rather than number of entries
| * | | arm64: warn on incorrect placement of the kernel by the bootloaderArd Biesheuvel2020-06-112-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit cfa7ede20f133c ("arm64: set TEXT_OFFSET to 0x0 in preparation for removing it entirely") results in boot failures when booting kernels that are built without KASLR support on broken bootloaders that ignore the TEXT_OFFSET value passed via the header, and use the default of 0x80000 instead. To work around this, turn CONFIG_RELOCATABLE on by default, even if KASLR itself (CONFIG_RANDOMIZE_BASE) is turned off, and require CONFIG_EXPERT to be enabled to deviate from this. Then, emit a warning into the kernel log if we are not booting via the EFI stub (which is permitted to deviate from the placement restrictions) and the kernel base address is not placed according to the rules as laid out in Documentation/arm64/booting.rst. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20200611124330.252163-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: acpi: fix UBSAN warningNick Desaulniers2020-06-101-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Will reported a UBSAN warning: UBSAN: null-ptr-deref in arch/arm64/kernel/smp.c:596:6 member access within null pointer of type 'struct acpi_madt_generic_interrupt' CPU: 0 PID: 0 Comm: swapper Not tainted 5.7.0-rc6-00124-g96bc42ff0a82 #1 Call trace: dump_backtrace+0x0/0x384 show_stack+0x28/0x38 dump_stack+0xec/0x174 handle_null_ptr_deref+0x134/0x174 __ubsan_handle_type_mismatch_v1+0x84/0xa4 acpi_parse_gic_cpu_interface+0x60/0xe8 acpi_parse_entries_array+0x288/0x498 acpi_table_parse_entries_array+0x178/0x1b4 acpi_table_parse_madt+0xa4/0x110 acpi_parse_and_init_cpus+0x38/0x100 smp_init_cpus+0x74/0x258 setup_arch+0x350/0x3ec start_kernel+0x98/0x6f4 This is from the use of the ACPI_OFFSET in arch/arm64/include/asm/acpi.h. Replace its use with offsetof from include/linux/stddef.h which should implement the same logic using __builtin_offsetof, so that UBSAN wont warn. Reported-by: Will Deacon <will@kernel.org> Suggested-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Jeremy Linton <jeremy.linton@arm.com> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/20200521100952.GA5360@willie-the-truck/ Link: https://lore.kernel.org/r/20200608203818.189423-1-ndesaulniers@google.com Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: vdso32: add CONFIG_THUMB2_COMPAT_VDSONick Desaulniers2020-06-102-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow the compat vdso (32b) to be compiled as either THUMB2 (default) or ARM. For THUMB2, the register r7 is reserved for the frame pointer, but code in arch/arm64/include/asm/vdso/compat_gettimeofday.h uses r7. Explicitly set -fomit-frame-pointer, since unwinding through interworked THUMB2 and ARM is unreliable anyways. See also how CONFIG_UNWINDER_FRAME_POINTER cannot be selected for CONFIG_THUMB2_KERNEL for ARCH=arm. This also helps toolchains that differ in their implicit value if the choice of -f{no-}omit-frame-pointer is left unspecified, to not error on the use of r7. 2019 Q4 ARM AAPCS seeks to standardize the use of r11 as the reserved frame pointer register, but no production compiler that can compile the Linux kernel currently implements this. We're actively discussing such a transition with ARM toolchain developers currently. Reported-by: Luis Lozano <llozano@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Manoj Gupta <manojgupta@google.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Stephen Boyd <swboyd@google.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Dave Martin <Dave.Martin@arm.com> Link: https://static.docs.arm.com/ihi0042/i/aapcs32.pdf Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1084372 Link: https://lore.kernel.org/r/20200608205711.109418-1-ndesaulniers@google.com Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: ftrace: Change CONFIG_FTRACE_WITH_REGS to CONFIG_DYNAMIC_FTRACE_WITH_REGSJoe Perches2020-06-081-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CONFIG_FTRACE_WITH_REGS does not exist as a Kconfig symbol. Fixes: 3b23e4991fb6 ("arm64: implement ftrace with regs") Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/b9b27f2233bd1fa31d72ff937beefdae0e2104e5.camel@perches.com Signed-off-by: Will Deacon <will@kernel.org>
| * | | arm64: debug: mark a function as __init to save some memoryChristophe JAILLET2020-06-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'debug_monitors_init()' is only called via 'postcore_initcall'. It can be marked as __init to save a few bytes of memory. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20200531110015.598607-1-christophe.jaillet@wanadoo.fr Signed-off-by: Will Deacon <will@kernel.org>
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-12 00:55:34 +0000