diff options
Diffstat (limited to 'include/linux/compiler.h')
| -rw-r--r-- | include/linux/compiler.h | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index ac45f6d40d39..df5b405e6305 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -24,7 +24,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, long ______r; \ static struct ftrace_likely_data \ __aligned(4) \ - __section(_ftrace_annotated_branch) \ + __section("_ftrace_annotated_branch") \ ______f = { \ .data.func = __func__, \ .data.file = __FILE__, \ @@ -60,7 +60,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, #define __trace_if_value(cond) ({ \ static struct ftrace_branch_data \ __aligned(4) \ - __section(_ftrace_branch) \ + __section("_ftrace_branch") \ __if_trace = { \ .func = __func__, \ .file = __FILE__, \ @@ -76,15 +76,31 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, #else # define likely(x) __builtin_expect(!!(x), 1) # define unlikely(x) __builtin_expect(!!(x), 0) +# define likely_notrace(x) likely(x) +# define unlikely_notrace(x) unlikely(x) #endif /* Optimization barrier */ #ifndef barrier -# define barrier() __memory_barrier() +/* The "volatile" is due to gcc bugs */ +# define barrier() __asm__ __volatile__("": : :"memory") #endif #ifndef barrier_data -# define barrier_data(ptr) barrier() +/* + * This version is i.e. to prevent dead stores elimination on @ptr + * where gcc and llvm may behave differently when otherwise using + * normal barrier(): while gcc behavior gets along with a normal + * barrier(), llvm needs an explicit input variable to be assumed + * clobbered. The issue is as follows: while the inline asm might + * access any memory it wants, the compiler could have fit all of + * @ptr into memory registers instead, and since @ptr never escaped + * from that, it proved that the inline asm wasn't touching any of + * it. This version works well with both compilers, i.e. we're telling + * the compiler that the inline asm absolutely may see the contents + * of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495 + */ +# define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory") #endif /* workaround for GCC PR82365 if needed */ @@ -118,7 +134,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, ".popsection\n\t" /* Annotate a C jump table to allow objtool to follow the code flow */ -#define __annotate_jump_table __section(.rodata..c_jump_table) +#define __annotate_jump_table __section(".rodata..c_jump_table") #else #define annotate_reachable() @@ -206,7 +222,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, * visible to the compiler. */ #define __ADDRESSABLE(sym) \ - static void * __section(.discard.addressable) __used \ + static void * __section(".discard.addressable") __used \ __UNIQUE_ID(__PASTE(__addressable_,sym)) = (void *)&sym; /** |