diff options
Diffstat (limited to 'include/linux/compiler-gcc.h')
| -rw-r--r-- | include/linux/compiler-gcc.h | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index d24f29091f4b..34ad8bb549a6 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -64,6 +64,25 @@ __builtin_unreachable(); \ } while (0) +/* + * GCC 'asm goto' with outputs miscompiles certain code sequences: + * + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420 + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422 + * + * Work it around via the same compiler barrier quirk that we used + * to use for the old 'asm goto' workaround. + * + * Also, always mark such 'asm goto' statements as volatile: all + * asm goto statements are supposed to be volatile as per the + * documentation, but some versions of gcc didn't actually do + * that for asms with outputs: + * + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619 + */ +#define asm_goto_output(x...) \ + do { asm volatile goto(x); asm (""); } while (0) + #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) #define __HAVE_BUILTIN_BSWAP32__ #define __HAVE_BUILTIN_BSWAP64__ @@ -136,7 +155,7 @@ #endif #define __diag_ignore_all(option, comment) \ - __diag_GCC(8, ignore, option) + __diag(__diag_GCC_ignore option) /* * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size" |