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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-10-23 22:34:32 +0900 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-10-23 22:34:32 +0900 |
commit | 03867292476e6fa7679395838d768dda0a0816c7 (patch) | |
tree | 5fc5c83bee40a3fb404e44bfbef8c44540ac9dcf /include | |
parent | df55793680d36e37e6fc384fbd90c39ed83cbe75 (diff) | |
parent | f7d27c35ddff7c100d7a98db499ac0040149ac05 (diff) | |
download | linux-stable-03867292476e6fa7679395838d768dda0a0816c7.tar.gz linux-stable-03867292476e6fa7679395838d768dda0a0816c7.tar.bz2 linux-stable-03867292476e6fa7679395838d768dda0a0816c7.zip |
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Misc fixes: two KASAN fixes, two EFI boot fixes, two boot-delay
optimization fixes, and a fix for a IRQ handling hang observed on
virtual platforms"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm, kasan: Silence KASAN warnings in get_wchan()
compiler, atomics, kasan: Provide READ_ONCE_NOCHECK()
x86, kasan: Fix build failure on KASAN=y && KMEMCHECK=y kernels
x86/smpboot: Fix CPU #1 boot timeout
x86/smpboot: Fix cpu_init_udelay=10000 corner case boot parameter misbehavior
x86/ioapic: Disable interrupts when re-routing legacy IRQs
x86/setup: Extend low identity map to cover whole kernel range
x86/efi: Fix multiple GOP device support
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/compiler-gcc.h | 13 | ||||
-rw-r--r-- | include/linux/compiler.h | 66 |
2 files changed, 66 insertions, 13 deletions
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index dfaa7b3e9ae9..8efb40e61d6e 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -237,12 +237,25 @@ #define KASAN_ABI_VERSION 3 #endif +#if GCC_VERSION >= 40902 +/* + * Tell the compiler that address safety instrumentation (KASAN) + * should not be applied to that function. + * Conflicts with inlining: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368 + */ +#define __no_sanitize_address __attribute__((no_sanitize_address)) +#endif + #endif /* gcc version >= 40000 specific checks */ #if !defined(__noclone) #define __noclone /* not needed */ #endif +#if !defined(__no_sanitize_address) +#define __no_sanitize_address +#endif + /* * A trick to suppress uninitialized variable warning without generating any * code diff --git a/include/linux/compiler.h b/include/linux/compiler.h index c836eb2dc44d..3d7810341b57 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -198,19 +198,45 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); #include <uapi/linux/types.h> -static __always_inline void __read_once_size(const volatile void *p, void *res, int size) +#define __READ_ONCE_SIZE \ +({ \ + switch (size) { \ + case 1: *(__u8 *)res = *(volatile __u8 *)p; break; \ + case 2: *(__u16 *)res = *(volatile __u16 *)p; break; \ + case 4: *(__u32 *)res = *(volatile __u32 *)p; break; \ + case 8: *(__u64 *)res = *(volatile __u64 *)p; break; \ + default: \ + barrier(); \ + __builtin_memcpy((void *)res, (const void *)p, size); \ + barrier(); \ + } \ +}) + +static __always_inline +void __read_once_size(const volatile void *p, void *res, int size) { - switch (size) { - case 1: *(__u8 *)res = *(volatile __u8 *)p; break; - case 2: *(__u16 *)res = *(volatile __u16 *)p; break; - case 4: *(__u32 *)res = *(volatile __u32 *)p; break; - case 8: *(__u64 *)res = *(volatile __u64 *)p; break; - default: - barrier(); - __builtin_memcpy((void *)res, (const void *)p, size); - barrier(); - } + __READ_ONCE_SIZE; +} + +#ifdef CONFIG_KASAN +/* + * This function is not 'inline' because __no_sanitize_address confilcts + * with inlining. Attempt to inline it may cause a build failure. + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368 + * '__maybe_unused' allows us to avoid defined-but-not-used warnings. + */ +static __no_sanitize_address __maybe_unused +void __read_once_size_nocheck(const volatile void *p, void *res, int size) +{ + __READ_ONCE_SIZE; +} +#else +static __always_inline +void __read_once_size_nocheck(const volatile void *p, void *res, int size) +{ + __READ_ONCE_SIZE; } +#endif static __always_inline void __write_once_size(volatile void *p, void *res, int size) { @@ -248,8 +274,22 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s * required ordering. */ -#define READ_ONCE(x) \ - ({ union { typeof(x) __val; char __c[1]; } __u; __read_once_size(&(x), __u.__c, sizeof(x)); __u.__val; }) +#define __READ_ONCE(x, check) \ +({ \ + union { typeof(x) __val; char __c[1]; } __u; \ + if (check) \ + __read_once_size(&(x), __u.__c, sizeof(x)); \ + else \ + __read_once_size_nocheck(&(x), __u.__c, sizeof(x)); \ + __u.__val; \ +}) +#define READ_ONCE(x) __READ_ONCE(x, 1) + +/* + * Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need + * to hide memory access from KASAN. + */ +#define READ_ONCE_NOCHECK(x) __READ_ONCE(x, 0) #define WRITE_ONCE(x, val) \ ({ \ |