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| author |   Peter Zijlstra <peterz@infradead.org> | 2022-05-02 12:15:23 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-05-27 12:34:43 +0200 |
| commit | a6a5eb269f6f3a2fe392f725a8d9052190c731e2 (patch) | |
| tree | eb976f890bfed9fcc3231423542da222b3dc58df /arch/x86/include/asm/cpufeature.h | |
| parent | objtool: Mark __ubsan_handle_builtin_unreachable() as noreturn (diff) | |
| download | linux-dev-a6a5eb269f6f3a2fe392f725a8d9052190c731e2.tar.xz linux-dev-a6a5eb269f6f3a2fe392f725a8d9052190c731e2.zip | |
x86/cpu: Elide KCSAN for cpu_has() and friends
As x86 uses the <asm-generic/bitops/instrumented-*.h> headers, the
regular forms of all bitops are instrumented with explicit calls to
KASAN and KCSAN checks. As these are explicit calls, these are not
suppressed by the noinstr function attribute.
This can result in calls to those check functions in noinstr code, which
objtool warns about:
vmlinux.o: warning: objtool: enter_from_user_mode+0x24: call to __kcsan_check_access() leaves .noinstr.text section
vmlinux.o: warning: objtool: syscall_enter_from_user_mode+0x28: call to __kcsan_check_access() leaves .noinstr.text section
vmlinux.o: warning: objtool: syscall_enter_from_user_mode_prepare+0x24: call to __kcsan_check_access() leaves .noinstr.text section
vmlinux.o: warning: objtool: irqentry_enter_from_user_mode+0x24: call to __kcsan_check_access() leaves .noinstr.text section
Prevent this by using the arch_*() bitops, which are the underlying
bitops without explciit instrumentation.
[null: Changelog]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220502111216.290518605@infradead.org
Diffstat (limited to 'arch/x86/include/asm/cpufeature.h')
| -rw-r--r-- | arch/x86/include/asm/cpufeature.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 66d3e3b1d24d..ea34cc31b047 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -54,7 +54,7 @@ extern const char * const x86_power_flags[32]; extern const char * const x86_bug_flags[NBUGINTS*32]; #define test_cpu_cap(c, bit) \ - test_bit(bit, (unsigned long *)((c)->x86_capability)) + arch_test_bit(bit, (unsigned long *)((c)->x86_capability)) /* * There are 32 bits/features in each mask word. The high bits |