diff options
Diffstat (limited to 'include/linux/compiler.h')
| -rw-r--r-- | include/linux/compiler.h | 92 |
1 files changed, 62 insertions, 30 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index c836eb2dc44d..4dac1036594f 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -56,7 +56,7 @@ extern void __chk_io_ptr(const volatile void __iomem *); #include <linux/compiler-gcc.h> #endif -#ifdef CC_USING_HOTPATCH +#if defined(CC_USING_HOTPATCH) && !defined(__CHECKER__) #define notrace __attribute__((hotpatch(0,0))) #else #define notrace __attribute__((no_instrument_function)) @@ -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) \ ({ \ @@ -259,22 +299,6 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s __u.__val; \ }) -/** - * READ_ONCE_CTRL - Read a value heading a control dependency - * @x: The value to be read, heading the control dependency - * - * Control dependencies are tricky. See Documentation/memory-barriers.txt - * for important information on how to use them. Note that in many cases, - * use of smp_load_acquire() will be much simpler. Control dependencies - * should be avoided except on the hottest of hotpaths. - */ -#define READ_ONCE_CTRL(x) \ -({ \ - typeof(x) __val = READ_ONCE(x); \ - smp_read_barrier_depends(); /* Enforce control dependency. */ \ - __val; \ -}) - #endif /* __KERNEL__ */ #endif /* __ASSEMBLY__ */ @@ -393,6 +417,14 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s #define __visible #endif +/* + * Assume alignment of return value. + */ +#ifndef __assume_aligned +#define __assume_aligned(a, ...) +#endif + + /* Are two types/vars the same type (ignoring qualifiers)? */ #ifndef __same_type # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) |