diff options
Diffstat (limited to 'libavutil/aarch64/asm.S')
| -rw-r--r-- | libavutil/aarch64/asm.S | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/libavutil/aarch64/asm.S b/libavutil/aarch64/asm.S index d1fa72b3c6..bee91d59c3 100644 --- a/libavutil/aarch64/asm.S +++ b/libavutil/aarch64/asm.S @@ -36,6 +36,35 @@ # define __has_feature(x) 0 #endif +/* Support macros for the Armv8.5-A Branch Target Identification feature which + * requires emitting a .note.gnu.property section with the appropriate + * architecture-dependent feature bits set. + * Read more: "ELF for the Arm® 64-bit Architecture" + */ +#if defined(__ARM_FEATURE_BTI_DEFAULT) && (__ARM_FEATURE_BTI_DEFAULT == 1) +# define GNU_PROPERTY_AARCH64_BTI (1 << 0) // Has BTI +# define AARCH64_VALID_CALL_TARGET hint #34 // BTI 'c' +# define AARCH64_VALID_JUMP_TARGET hint #38 // BTI 'j' +#else +# define GNU_PROPERTY_AARCH64_BTI 0 // No BTI +# define AARCH64_VALID_CALL_TARGET +# define AARCH64_VALID_JUMP_TARGET +#endif + +#if (GNU_PROPERTY_AARCH64_BTI != 0) + .pushsection .note.gnu.property, "a" + .balign 8 + .long 4 + .long 0x10 + .long 0x5 + .asciz "GNU" + .long 0xc0000000 /* GNU_PROPERTY_AARCH64_FEATURE_1_AND */ + .long 4 + .long GNU_PROPERTY_AARCH64_BTI + .long 0 + .popsection +#endif + .macro function name, export=0, align=2 .macro endfunc ELF .size \name, . - \name @@ -49,6 +78,7 @@ FUNC .endfunc ELF .type EXTERN_ASM\name, %function FUNC .func EXTERN_ASM\name EXTERN_ASM\name: + AARCH64_VALID_CALL_TARGET .else ELF .type \name, %function FUNC .func \name |