diff options
Diffstat (limited to 'coroutine/arm64/Context.S')
| -rw-r--r-- | coroutine/arm64/Context.S | 67 |
1 files changed, 57 insertions, 10 deletions
diff --git a/coroutine/arm64/Context.S b/coroutine/arm64/Context.S index 07d50d30df..5251ab214d 100644 --- a/coroutine/arm64/Context.S +++ b/coroutine/arm64/Context.S @@ -18,11 +18,25 @@ .align 2 #endif +## NOTE(PAC): Use we HINT mnemonics instead of PAC mnemonics to +## keep compatibility with those assemblers that don't support PAC. +## +## See "Providing protection for complex software" for more details about PAC/BTI +## https://developer.arm.com/architectures/learn-the-architecture/providing-protection-for-complex-software + .global PREFIXED_SYMBOL(SYMBOL_PREFIX,coroutine_transfer) PREFIXED_SYMBOL(SYMBOL_PREFIX,coroutine_transfer): +#if defined(__ARM_FEATURE_PAC_DEFAULT) && (__ARM_FEATURE_PAC_DEFAULT != 0) + # paciasp (it also acts as BTI landing pad, so no need to insert BTI also) + hint #25 +#elif defined(__ARM_FEATURE_BTI_DEFAULT) && (__ARM_FEATURE_BTI_DEFAULT != 0) + # For the case PAC is not enabled but BTI is. + # bti c + hint #34 +#endif # Make space on the stack for caller registers - sub sp, sp, 0xb0 + sub sp, sp, 0xa0 # Save caller registers stp d8, d9, [sp, 0x00] @@ -36,9 +50,6 @@ PREFIXED_SYMBOL(SYMBOL_PREFIX,coroutine_transfer): stp x27, x28, [sp, 0x80] stp x29, x30, [sp, 0x90] - # Save return address - str x30, [sp, 0xa0] - # Save stack pointer to x0 (first argument) mov x2, sp str x2, [x0, 0] @@ -59,15 +70,51 @@ PREFIXED_SYMBOL(SYMBOL_PREFIX,coroutine_transfer): ldp x27, x28, [sp, 0x80] ldp x29, x30, [sp, 0x90] - # Load return address into x4 - ldr x4, [sp, 0xa0] - # Pop stack frame - add sp, sp, 0xb0 + add sp, sp, 0xa0 - # Jump to return address (in x4) - ret x4 +#if defined(__ARM_FEATURE_PAC_DEFAULT) && (__ARM_FEATURE_PAC_DEFAULT != 0) + # autiasp: Authenticate x30 (LR) with SP and key A + hint #29 +#endif + + # Jump to return address (in x30) + ret #if defined(__linux__) && defined(__ELF__) .section .note.GNU-stack,"",%progbits #endif + +#if __ARM_FEATURE_BTI_DEFAULT != 0 || __ARM_FEATURE_PAC_DEFAULT != 0 +/* See "ELF for the Arm 64-bit Architecture (AArch64)" + https://github.com/ARM-software/abi-aa/blob/2023Q3/aaelf64/aaelf64.rst#program-property */ +# define GNU_PROPERTY_AARCH64_FEATURE_1_BTI (1<<0) +# define GNU_PROPERTY_AARCH64_FEATURE_1_PAC (1<<1) + +# if __ARM_FEATURE_BTI_DEFAULT != 0 +# define BTI_FLAG GNU_PROPERTY_AARCH64_FEATURE_1_BTI +# else +# define BTI_FLAG 0 +# endif +# if __ARM_FEATURE_PAC_DEFAULT != 0 +# define PAC_FLAG GNU_PROPERTY_AARCH64_FEATURE_1_PAC +# else +# define PAC_FLAG 0 +# endif + + # The note section format is described by Note Section in Chapter 5 + # of "System V Application Binary Interface, Edition 4.1". + .pushsection .note.gnu.property, "a" + .p2align 3 + .long 0x4 /* Name size ("GNU\0") */ + .long 0x10 /* Descriptor size */ + .long 0x5 /* Type: NT_GNU_PROPERTY_TYPE_0 */ + .asciz "GNU" /* Name */ + # Begin descriptor + .long 0xc0000000 /* Property type: GNU_PROPERTY_AARCH64_FEATURE_1_AND */ + .long 0x4 /* Property size */ + .long (BTI_FLAG|PAC_FLAG) + .long 0x0 /* 8-byte alignment padding */ + # End descriptor + .popsection +#endif |