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* kcsan: Support distinguishing volatile accessesMarco Elver2020-06-111-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the kernel, the "volatile" keyword is used in various concurrent contexts, whether in low-level synchronization primitives or for legacy reasons. If supported by the compiler, it will be assumed that aligned volatile accesses up to sizeof(long long) (matching compiletime_assert_rwonce_type()) are atomic. Recent versions of Clang [1] (GCC tentative [2]) can instrument volatile accesses differently. Add the option (required) to enable the instrumentation, and provide the necessary runtime functions. None of the updated compilers are widely available yet (Clang 11 will be the first release to support the feature). [1] https://github.com/llvm/llvm-project/commit/5a2c31116f412c3b6888be361137efd705e05814 [2] https://gcc.gnu.org/pipermail/gcc-patches/2020-April/544452.html This change allows removing of any explicit checks in primitives such as READ_ONCE() and WRITE_ONCE(). [ bp: Massage commit message a bit. ] Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Will Deacon <will@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200521142047.169334-4-elver@google.com
* kcsan: Avoid inserting __tsan_func_entry/exit if possibleMarco Elver2020-06-111-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | To avoid inserting __tsan_func_{entry,exit}, add option if supported by compiler. Currently only Clang can be told to not emit calls to these functions. It is safe to not emit these, since KCSAN does not rely on them. Note that, if we disable __tsan_func_{entry,exit}(), we need to disable tail-call optimization in sanitized compilation units, as otherwise we may skip frames in the stack trace; in particular when the tail called function is one of the KCSAN's runtime functions, and a report is generated, we might miss the function where the actual access occurred. Since __tsan_func_{entry,exit}() insertion effectively disabled tail-call optimization, there should be no observable change. This was caught and confirmed with kcsan-test & UNWINDER_ORC. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Will Deacon <will@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200521142047.169334-3-elver@google.com
* Rebase locking/kcsan to locking/urgentThomas Gleixner2020-06-115-5/+31
|\ | | | | | | | | | | | | | | | | | | | | Merge the state of the locking kcsan branch before the read/write_once() and the atomics modifications got merged. Squash the fallout of the rebase on top of the read/write once and atomic fallback work into the merge. The history of the original branch is preserved in tag locking-kcsan-2020-06-02. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * Merge branch 'kcsan-for-tip' of ↵Thomas Gleixner2020-05-081-0/+8
| |\ | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into locking/kcsan Pull KCSAN updates from Paul McKenney.
| | * checkpatch: Warn about data_race() without commentMarco Elver2020-05-061-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | Warn about applications of data_race() without a comment, to encourage documenting the reasoning behind why it was deemed safe. Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| * | Merge tag 'v5.7-rc1' into locking/kcsan, to resolve conflicts and refreshIngo Molnar2020-04-1363-577/+1138
| |\ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | Resolve these conflicts: arch/x86/Kconfig arch/x86/kernel/Makefile Do a minor "evil merge" to move the KCSAN entry up a bit by a few lines in the Kconfig to reduce the probability of future conflicts. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | asm-generic, atomic-instrumented: Use generic instrumented.hMarco Elver2020-03-211-16/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This switches atomic-instrumented.h to use the generic instrumentation wrappers provided by instrumented.h. No functional change intended. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Marco Elver <elver@google.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | Merge branch 'linus' into locking/kcsan, to pick up fixesIngo Molnar2020-03-217-21/+30
| |\ \ | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * \ \ Merge branch 'x86/kdump' into locking/kcsan, to resolve conflictsIngo Molnar2020-03-2159-1158/+1033
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/purgatory/Makefile Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * \ \ \ Merge branch 'kcsan.2020.01.07a' into locking/kcsanIngo Molnar2020-01-2422-23/+27
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KCSAN updates from Paul E. McKenney: - UBSAN fixes - inlining updates - documentation updates Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | asm-generic/atomic: Use __always_inline for fallback wrappersMarco Elver2020-01-0720-19/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use __always_inline for atomic fallback wrappers. When building for size (CC_OPTIMIZE_FOR_SIZE), some compilers appear to be less inclined to inline even relatively small static inline functions that are assumed to be inlinable such as atomic ops. This can cause problems, for example in UACCESS regions. While the fallback wrappers aren't pure wrappers, they are trivial nonetheless, and the function they wrap should determine the final inlining policy. For x86 tinyconfig we observe: - vmlinux baseline: 1315988 - vmlinux with patch: 1315928 (-60 bytes) Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marco Elver <elver@google.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | * | | | asm-generic/atomic: Use __always_inline for pure wrappersMarco Elver2020-01-072-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prefer __always_inline for atomic wrappers. When building for size (CC_OPTIMIZE_FOR_SIZE), some compilers appear to be less inclined to inline even relatively small static inline functions that are assumed to be inlinable such as atomic ops. This can cause problems, for example in UACCESS regions. By using __always_inline, we let the real implementation and not the wrapper determine the final inlining preference. For x86 tinyconfig we observe: - vmlinux baseline: 1316204 - vmlinux with patch: 1315988 (-216 bytes) This came up when addressing UACCESS warnings with CC_OPTIMIZE_FOR_SIZE in the KCSAN runtime: http://lkml.kernel.org/r/58708908-84a0-0a81-a836-ad97e33dbb62@infradead.org Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Marco Elver <elver@google.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| * | | | | Merge tag 'v5.5-rc5' into locking/kcsan, to resolve conflictIngo Molnar2020-01-062-6/+5
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * \ \ \ \ \ Merge tag 'v5.5-rc4' into locking/kcsan, to resolve conflictsIngo Molnar2019-12-3034-921/+722
| |\ \ \ \ \ \ | | |_|/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: init/main.c lib/Kconfig.debug Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | Merge branch 'for-mingo' of ↵Ingo Molnar2019-11-193-2/+31
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| | * | | | | | locking/atomics, kcsan: Add KCSAN instrumentationMarco Elver2019-11-161-2/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds KCSAN instrumentation to atomic-instrumented.h. Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | * | | | | | kcsan: Add Kernel Concurrency Sanitizer infrastructureMarco Elver2019-11-162-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kernel Concurrency Sanitizer (KCSAN) is a dynamic data-race detector for kernel space. KCSAN is a sampling watchpoint-based data-race detector. See the included Documentation/dev-tools/kcsan.rst for more details. This patch adds basic infrastructure, but does not yet enable KCSAN for any architecture. Signed-off-by: Marco Elver <elver@google.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* | | | | | | | locking/atomics: Flip fallbacks and instrumentationPeter Zijlstra2020-06-1121-65/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* | | | | | | | asm-generic/atomic: Use __always_inline for fallback wrappersMarco Elver2020-06-1120-19/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use __always_inline for atomic fallback wrappers. When building for size (CC_OPTIMIZE_FOR_SIZE), some compilers appear to be less inclined to inline even relatively small static inline functions that are assumed to be inlinable such as atomic ops. This can cause problems, for example in UACCESS regions. While the fallback wrappers aren't pure wrappers, they are trivial nonetheless, and the function they wrap should determine the final inlining policy. For x86 tinyconfig we observe: - vmlinux baseline: 1315988 - vmlinux with patch: 1315928 (-60 bytes) [ tglx: Cherry-picked from KCSAN ] Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marco Elver <elver@google.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | | | | Merge branch 'rwonce/rework' of ↵Linus Torvalds2020-06-101-1/+1
|\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/will/linux Pull READ/WRITE_ONCE rework from Will Deacon: "This the READ_ONCE rework I've been working on for a while, which bumps the minimum GCC version and improves code-gen on arm64 when stack protector is enabled" [ Side note: I'm _really_ tempted to raise the minimum gcc version to 4.9, so that we can just say that we require _Generic() support. That would allow us to more cleanly handle a lot of the cases where we depend on very complex macros with 'sizeof' or __builtin_choose_expr() with __builtin_types_compatible_p() etc. This branch has a workaround for sparse not handling _Generic(), either, but that was already fixed in the sparse development branch, so it's really just gcc-4.9 that we'd require. - Linus ] * 'rwonce/rework' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux: compiler_types.h: Use unoptimized __unqual_scalar_typeof for sparse compiler_types.h: Optimize __unqual_scalar_typeof compilation time compiler.h: Enforce that READ_ONCE_NOCHECK() access size is sizeof(long) compiler-types.h: Include naked type in __pick_integer_type() match READ_ONCE: Fix comment describing 2x32-bit atomicity gcov: Remove old GCC 3.4 support arm64: barrier: Use '__unqual_scalar_typeof' for acquire/release macros locking/barriers: Use '__unqual_scalar_typeof' for load-acquire macros READ_ONCE: Drop pointer qualifiers when reading from scalar types READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses READ_ONCE: Simplify implementations of {READ,WRITE}_ONCE() arm64: csum: Disable KASAN for do_csum() fault_inject: Don't rely on "return value" from WRITE_ONCE() net: tls: Avoid assigning 'const' pointer to non-const pointer netfilter: Avoid assigning 'const' pointer to non-const pointer compiler/gcc: Raise minimum GCC version for kernel builds to 4.8
| * | | | | | | | compiler/gcc: Raise minimum GCC version for kernel builds to 4.8Will Deacon2020-04-151-1/+1
| | |_|_|_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is very rare to see versions of GCC prior to 4.8 being used to build the mainline kernel. These old compilers are also know to have codegen issues which can lead to silent miscompilation: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 Raise the minimum GCC version for kernel build to 4.8 and remove some tautological Kconfig dependencies as a consequence. Cc: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Will Deacon <will@kernel.org>
* | | | | | | | Merge tag 'docs-5.8-2' of git://git.lwn.net/linuxLinus Torvalds2020-06-101-1/+1
|\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull more documentation updates from Jonathan Corbet: "A handful of late-arriving docs fixes, along with a patch changing a lot of HTTP links to HTTPS that had to be yanked and redone before the first pull" * tag 'docs-5.8-2' of git://git.lwn.net/linux: docs/memory-barriers.txt/kokr: smp_mb__{before,after}_atomic(): update Documentation Documentation: devres: add missing entry for devm_platform_get_and_ioremap_resource() Replace HTTP links with HTTPS ones: documentation docs: it_IT: address invalid reference warnings doc: zh_CN: use doc reference to resolve undefined label warning docs: Update the location of the LF NDA program docs: dev-tools: coccinelle: underlines
| * | | | | | | | Replace HTTP links with HTTPS ones: documentationAlexander A. Klimov2020-06-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Link: https://lore.kernel.org/r/20200526060544.25127-1-grandmaster@al2klimov.de Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | | | | | | | | Merge tag 'sh-for-5.8' of git://git.libc.org/linux-shLinus Torvalds2020-06-061-3/+0
|\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull arch/sh updates from Rich Felker: "Fix for arch/sh build regression with newer binutils, removal of SH5, fixes for module exports, and misc cleanup" * tag 'sh-for-5.8' of git://git.libc.org/linux-sh: sh: remove sh5 support sh: add missing EXPORT_SYMBOL() for __delay sh: Convert ins[bwl]/outs[bwl] macros to inline functions sh: Convert iounmap() macros to inline functions sh: Add missing DECLARE_EXPORT() for __ashiftrt_r4_xx sh: configs: Cleanup old Kconfig IO scheduler options arch/sh: vmlinux.scr sh: Replace CONFIG_MTD_M25P80 with CONFIG_MTD_SPI_NOR in sh7757lcr_defconfig sh: sh4a: Bring back tmu3_device early device
| * | | | | | | | | sh: remove sh5 supportArnd Bergmann2020-06-011-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sh5 never became a product and has probably never really worked. Remove it by recursively deleting all associated Kconfig options and all corresponding files. Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Rich Felker <dalias@libc.org>
* | | | | | | | | | Merge tag 'kconfig-v5.8' of ↵Linus Torvalds2020-06-0610-84/+46
|\ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kconfig updates from Masahiro Yamada: - allow only 'config', 'comment', 'if' statements inside 'choice' since the other statements are not sensible inside 'choice' and should be grammatical error - support LMC_KEEP env variable for 'make local{yes,mod}config' to preserve some CONFIG options - deprecate 'make kvmconfig' and 'make xenconfig' in favor of 'make kvm_guest.config' and 'make xen.config' - code cleanups * tag 'kconfig-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: announce removal of 'kvmconfig' and 'xenconfig' shorthands streamline_config.pl: add LMC_KEEP to preserve some kconfigs kconfig: allow only 'config', 'comment', and 'if' inside 'choice' kconfig: tests: remove randconfig test for choice in choice kconfig: do not assign a variable in the return statement kconfig: do not use OR-assignment for zero-cleared structure
| * | | | | | | | | | kconfig: announce removal of 'kvmconfig' and 'xenconfig' shorthandsMasahiro Yamada2020-05-261-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kvmconfig' is a shorthand for kvm_guest.config to save 7 character typing. xenconfig' is a shorthand for xen.config to save 1 character typing. There is nothing more than that. There are more files in kernel/configs/, so it is not maintainable to wire-up every config fragment to the Kconfig Makefile. Hence, we should not do this at all. These will be removed after Linux 5.10. Meanwhile, the following warning message will be displayed if they are used. WARNING: 'make kvmconfig' will be removed after Linux 5.10 Please use 'make kvm_guest.config' instead. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | streamline_config.pl: add LMC_KEEP to preserve some kconfigsChangbin Du2020-05-132-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sometimes it is useful to preserve batches of configs when making localmodconfig. For example, I usually don't want any usb and fs modules to be disabled. Now we can do it by: $ make LMC_KEEP="drivers/usb:fs" localmodconfig Signed-off-by: Changbin Du <changbin.du@gmail.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | kconfig: allow only 'config', 'comment', and 'if' inside 'choice'Masahiro Yamada2020-05-121-14/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code block surrounded by 'if' ... 'endif' is reduced into if_stmt, which is accepted in the 'choice' context. Therefore, you can write any statements within a choice block by wrapping 'if y' ... 'end'. For example, you can create a menu inside a choice, like follows: ---------------->8---------------- choice prompt "choice" config A bool "A" config B bool "B" if y menu "strange menu" config C bool "C" endmenu endif endchoice ---------------->8---------------- I want to change such a weird structure into a syntax error. In fact, the USB gadget Kconfig had used nested 'choice' for no good reason until commit df8df5e4bc37 ("usb: get rid of 'choice' for legacy gadget drivers") killed it. I think the 'source' inside 'choice' is on the fence. It is at least gramatically sensible as long as the included file contains only bool/tristate configs. However, it makes the code unreadable, and people tend to forget the fact that the file is included from the choice block. Commit 10e5e6c24963 ("usb: gadget: move choice ... endchoice to legacy/Kconfig") got rid of the only usecase. Going forward, you can only use 'config', 'comment', and 'if' inside 'choice'. This also recursively applies to 'if' blocks inside 'choice'. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | kconfig: tests: remove randconfig test for choice in choiceMasahiro Yamada2020-05-125-63/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nesting choice statements does not make any sense. Commit df8df5e4bc37 ("usb: get rid of 'choice' for legacy gadget drivers") got rid of the only usecase. I will turn it into a syntax error. Remove the test in advance. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | kconfig: do not assign a variable in the return statementMasahiro Yamada2020-05-121-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I am not a big fan of doing assignment in a return statement. Split it into two lines. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | kconfig: do not use OR-assignment for zero-cleared structureMasahiro Yamada2020-05-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The simple assignment is enough because memset() three lines above has zero-cleared the structure. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* | | | | | | | | | | Merge tag 'kbuild-v5.8' of ↵Linus Torvalds2020-06-0621-454/+483
|\ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32 - ensure to rebuild all objects when the compiler is upgraded - exclude system headers from dependency tracking and fixdep processing - fix potential bit-size mismatch between the kernel and BPF user-mode helper - add the new syntax 'userprogs' to build user-space programs for the target architecture (the same arch as the kernel) - compile user-space sample code under samples/ for the target arch instead of the host arch - make headers_install fail if a CONFIG option is leaked to user-space - sanitize the output format of scripts/checkstack.pl - handle ARM 'push' instruction in scripts/checkstack.pl - error out before modpost if a module name conflict is found - error out when multiple directories are passed to M= because this feature is broken for a long time - add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info - a lot of cleanups of modpost - dump vmlinux symbols out into vmlinux.symvers, and reuse it in the second pass of modpost - do not run the second pass of modpost if nothing in modules is updated - install modules.builtin(.modinfo) by 'make install' as well as by 'make modules_install' because it is useful even when CONFIG_MODULES=n - add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ to allow users to use alternatives such as pigz, pbzip2, etc. * tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (96 commits) kbuild: add variables for compression tools Makefile: install modules.builtin even if CONFIG_MODULES=n mksysmap: Fix the mismatch of '.L' symbols in System.map kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGS modpost: change elf_info->size to size_t modpost: remove is_vmlinux() helper modpost: strip .o from modname before calling new_module() modpost: set have_vmlinux in new_module() modpost: remove mod->skip struct member modpost: add mod->is_vmlinux struct member modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}() modpost: remove mod->is_dot_o struct member modpost: move -d option in scripts/Makefile.modpost modpost: remove -s option modpost: remove get_next_text() and make {grab,release_}file static modpost: use read_text_file() and get_line() for reading text files modpost: avoid false-positive file open error modpost: fix potential mmap'ed file overrun in get_src_version() modpost: add read_text_file() and get_line() helpers modpost: do not call get_modinfo() for vmlinux(.o) ...
| * | | | | | | | | | | kbuild: add variables for compression toolsDenis Efremov2020-06-064-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow user to use alternative implementations of compression tools, such as pigz, pbzip2, pxz. For example, multi-threaded tools to speed up the build: $ make GZIP=pigz BZIP2=pbzip2 Variables _GZIP, _BZIP2, _LZOP are used internally because original env vars are reserved by the tools. The use of GZIP in gzip tool is obsolete since 2015. However, alternative implementations (e.g., pigz) still rely on it. BZIP2, BZIP, LZOP vars are not obsolescent. The credit goes to @grsecurity. As a sidenote, for multi-threaded lzma, xz compression one can use: $ export XZ_OPT="--threads=0" Signed-off-by: Denis Efremov <efremov@linux.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | mksysmap: Fix the mismatch of '.L' symbols in System.mapashimida2020-06-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When System.map was generated, the kernel used mksysmap to filter the kernel symbols, but all the symbols with the second letter 'L' in the kernel were filtered out, not just the symbols starting with 'dot + L'. For example: ashimida@ubuntu:~/linux$ cat System.map |grep ' .L' ashimida@ubuntu:~/linux$ nm -n vmlinux |grep ' .L' ffff0000088028e0 t bLength_show ...... ffff0000092e0408 b PLLP_OUTC_lock ffff0000092e0410 b PLLP_OUTA_lock The original intent should be to filter out all local symbols starting with '.L', so the dot should be escaped. Fixes: 00902e984732 ("mksysmap: Add h8300 local symbol pattern") Signed-off-by: ashimida <ashimida@linux.alibaba.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: change elf_info->size to size_tMasahiro Yamada2020-06-062-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Align with the mmap / munmap APIs. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: remove is_vmlinux() helperMasahiro Yamada2020-06-061-15/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that is_vmlinux() is called only in new_module(), we can inline the function call. modname is the basename with '.o' is stripped. No need to compare it with 'vmlinux.o'. vmlinux is always located at the current working directory. No need to strip the directory path. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: strip .o from modname before calling new_module()Masahiro Yamada2020-06-062-10/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | new_module() conditionally strips the .o because the modname has .o suffix when it is called from read_symbols(), but no .o when it is called from read_dump(). It is clearer to strip .o in read_symbols(). I also used flexible-array for mod->name. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: set have_vmlinux in new_module()Masahiro Yamada2020-06-061-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Set have_vmlinux flag in a single place. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: remove mod->skip struct memberMasahiro Yamada2020-06-062-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The meaning of 'skip' is obscure since it does not explain "what to skip". mod->skip is set when it is vmlinux or the module info came from a dump file. So, mod->skip is equivalent to (mod->is_vmlinux || mod->from_dump). For the check in write_namespace_deps_files(), mod->is_vmlinux is unneeded because the -d option is not passed in the first pass of modpost. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: add mod->is_vmlinux struct memberMasahiro Yamada2020-06-062-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | is_vmlinux() is called in several places to check whether the current module is vmlinux or not. It is faster and clearer to check mod->is_vmlinux flag. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}()Masahiro Yamada2020-06-061-12/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | check_exports() is never called for vmlinux because mod->skip is set for vmlinux. Hence, check_for_gpl_usage() and check_for_unused() are not called for vmlinux, either. is_vmlinux() is always false here. Remove the is_vmlinux() calls, and hard-code the ".ko" suffix. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: remove mod->is_dot_o struct memberMasahiro Yamada2020-06-062-13/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, there were two cases where mod->is_dot_o is unset: [1] the executable 'vmlinux' in the second pass of modpost [2] modules loaded by read_dump() I think [1] was intended usage to distinguish 'vmlinux.o' and 'vmlinux'. Now that modpost does not parse the executable 'vmlinux', this case does not happen. [2] is obscure, maybe a bug. Module.symver stores module paths without extension. So, none of modules loaded by read_dump() has the .o suffix, and new_module() unsets ->is_dot_o. Anyway, it is not a big deal because handle_symbol() is not called for the case. To sum up, all the parsed ELF files are .o files. mod->is_dot_o is unneeded. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: move -d option in scripts/Makefile.modpostMasahiro Yamada2020-06-061-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Collect options for modules into a single place. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: remove -s optionMasahiro Yamada2020-06-062-9/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The -s option was added by commit 8d8d8289df65 ("kbuild: do not do section mismatch checks on vmlinux in 2nd pass"). Now that the second pass does not parse vmlinux, this option is unneeded. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: remove get_next_text() and make {grab,release_}file staticMasahiro Yamada2020-06-062-39/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_next_line() is no longer used. Remove. grab_file() and release_file() are only used in modpost.c. Make them static. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: use read_text_file() and get_line() for reading text filesMasahiro Yamada2020-06-062-17/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | grab_file() mmaps a file, but it is not so efficient here because get_next_line() copies every line to the temporary buffer anyway. read_text_file() and get_line() are simpler. get_line() exploits the library function strchr(). Going forward, the missing *.symvers or *.cmd is a fatal error. This should not happen because scripts/Makefile.modpost guards the -i option files with $(wildcard $(input-symdump)). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: avoid false-positive file open errorMasahiro Yamada2020-06-061-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One problem of grab_file() is that it cannot distinguish the following two cases: - It cannot read the file (the file does not exist, or read permission is not set) - It can read the file, but the file size is zero This is because grab_file() calls mmap(), which requires the mapped length is greater than 0. Hence, grab_file() fails for both cases. If an empty header file were included for checksum calculation, the following warning would be printed: WARNING: modpost: could not open ...: Invalid argument An empty file is a valid source file, so it should not fail. Use read_text_file() instead. It can read a zero-length file. Then, parse_file() will succeed with doing nothing. Going forward, the first case (it cannot read the file) is a fatal error. If the source file from which an object was compiled is missing, something went wrong. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: fix potential mmap'ed file overrun in get_src_version()Masahiro Yamada2020-06-061-17/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I do not know how reliably this function works, but it looks dangerous to me. strchr(sources, '\n'); ... continues searching until it finds '\n' or it reaches the '\0' terminator. In other words, 'sources' should be a null-terminated string. However, grab_file() just mmaps a file, so 'sources' is not terminated with null byte. If the file does not contain '\n' at all, strchr() will go beyond the mmap'ed memory. Use read_text_file(), which loads the file content into a malloc'ed buffer, appending null byte. Here we are interested only in the first line of *.mod files. Use get_line() helper to get the first line. This also makes missing *.mod file a fatal error. Commit 4be40e22233c ("kbuild: do not emit src version warning for non-modules") ignored missing *.mod files. I do not fully understand what that commit addressed, but commit 91341d4b2c19 ("kbuild: introduce new option to enhance section mismatch analysis") introduced partial section checks by using modpost. built-in.o was parsed by modpost. Even modules had a problem because *.mod files were created after the modpost check. Commit b7dca6dd1e59 ("kbuild: create *.mod with full directory path and remove MODVERDIR") stopped doing that. Now that modpost is only invoked after the directory descend, *.mod files should always exist at the modpost stage. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| * | | | | | | | | | | modpost: add read_text_file() and get_line() helpersMasahiro Yamada2020-06-062-0/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | modpost uses grab_file() to open a file, but it is not suitable for a text file because the mmap'ed file is not terminated by null byte. Actually, I see some issues for the use of grab_file(). The new helper, read_text_file() loads the whole file content into a malloc'ed buffer, and appends a null byte. Then, get_line() reads each line. To handle text files, I intend to replace as follows: grab_file() -> read_text_file() get_new_line() -> get_line() Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>