diff --git a/Python/asm_trampoline.S b/Python/asm_trampoline.S index 616752459ba4d9..ec205a08ef65f2 100644 --- a/Python/asm_trampoline.S +++ b/Python/asm_trampoline.S @@ -1,3 +1,5 @@ +#include "asm_trampoline_aarch64.h" + .text .globl _Py_trampoline_func_start # The following assembly is equivalent to: @@ -20,10 +22,12 @@ _Py_trampoline_func_start: #if defined(__aarch64__) && defined(__AARCH64EL__) && !defined(__ILP32__) // ARM64 little endian, 64bit ABI // generate with aarch64-linux-gnu-gcc 12.1 + SIGN_LR stp x29, x30, [sp, -16]! mov x29, sp blr x3 ldp x29, x30, [sp], 16 + VERIFY_LR ret #endif #ifdef __riscv diff --git a/Python/asm_trampoline_aarch64.h b/Python/asm_trampoline_aarch64.h new file mode 100644 index 00000000000000..4b0ec4a7dcb64e --- /dev/null +++ b/Python/asm_trampoline_aarch64.h @@ -0,0 +1,50 @@ +#ifndef ASM_TRAMPOLINE_AARCH_64_H_ +#define ASM_TRAMPOLINE_AARCH_64_H_ + +/* + * References: + * - https://developer.arm.com/documentation/101028/0012/5--Feature-test-macros + * - https://github.com/ARM-software/abi-aa/blob/main/aaelf64/aaelf64.rst + */ + +#if defined(__ARM_FEATURE_BTI_DEFAULT) && __ARM_FEATURE_BTI_DEFAULT == 1 + #define BTI_J hint 36 /* bti j: for jumps, IE br instructions */ + #define BTI_C hint 34 /* bti c: for calls, IE bl instructions */ + #define GNU_PROPERTY_AARCH64_BTI 1 /* bit 0 GNU Notes is for BTI support */ +#else + #define BTI_J + #define BTI_C + #define GNU_PROPERTY_AARCH64_BTI 0 +#endif + +#if defined(__ARM_FEATURE_PAC_DEFAULT) + #if __ARM_FEATURE_PAC_DEFAULT & 1 + #define SIGN_LR hint 25 /* paciasp: sign with the A key */ + #define VERIFY_LR hint 29 /* autiasp: verify with the A key */ + #elif __ARM_FEATURE_PAC_DEFAULT & 2 + #define SIGN_LR hint 27 /* pacibsp: sign with the b key */ + #define VERIFY_LR hint 31 /* autibsp: verify with the b key */ + #endif + #define GNU_PROPERTY_AARCH64_POINTER_AUTH 2 /* bit 1 GNU Notes is for PAC support */ +#else + #define SIGN_LR BTI_C + #define VERIFY_LR + #define GNU_PROPERTY_AARCH64_POINTER_AUTH 0 +#endif + +/* Add the BTI and PAC support to GNU Notes section */ +#if GNU_PROPERTY_AARCH64_BTI != 0 || GNU_PROPERTY_AARCH64_POINTER_AUTH != 0 + .pushsection .note.gnu.property, "a"; /* Start a new allocatable section */ + .balign 8; /* align it on a byte boundry */ + .long 4; /* size of "GNU\0" */ + .long 0x10; /* size of descriptor */ + .long 0x5; /* NT_GNU_PROPERTY_TYPE_0 */ + .asciz "GNU"; + .long 0xc0000000; /* GNU_PROPERTY_AARCH64_FEATURE_1_AND */ + .long 4; /* Four bytes of data */ + .long (GNU_PROPERTY_AARCH64_BTI|GNU_PROPERTY_AARCH64_POINTER_AUTH); /* BTI or PAC is enabled */ + .long 0; /* padding for 8 byte alignment */ + .popsection; /* end the section */ +#endif + +#endif