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Diffstat (limited to 'coroutine/arm64/Context.S')
| -rw-r--r-- | coroutine/arm64/Context.S | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/coroutine/arm64/Context.S b/coroutine/arm64/Context.S new file mode 100644 index 0000000000..ce219c0c4d --- /dev/null +++ b/coroutine/arm64/Context.S @@ -0,0 +1,160 @@ +## +## This file is part of the "Coroutine" project and released under the MIT License. +## +## Created by Samuel Williams on 10/5/2018. +## Copyright, 2018, by Samuel Williams. +## + +#define TOKEN_PASTE(x,y) x##y + +#if defined(__APPLE__) +#define x29 fp +#define x30 lr +.text +.p2align 2 +#else +.text +.align 2 +#endif + +#if defined(__ARM_FEATURE_PAC_DEFAULT) && (__ARM_FEATURE_PAC_DEFAULT & 0x02) != 0 +# error "-mbranch-protection flag specified b-key but Context.S does not support this" +#endif + +#if defined(_WIN32) +## Add more space for certain TEB values on each stack +#define TEB_OFFSET 0x20 +#else +#define TEB_OFFSET 0x00 +#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(coroutine_transfer) +PREFIXED_SYMBOL(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, 0xa0 + TEB_OFFSET + + # Save caller registers + stp d8, d9, [sp, 0x00 + TEB_OFFSET] + stp d10, d11, [sp, 0x10 + TEB_OFFSET] + stp d12, d13, [sp, 0x20 + TEB_OFFSET] + stp d14, d15, [sp, 0x30 + TEB_OFFSET] + stp x19, x20, [sp, 0x40 + TEB_OFFSET] + stp x21, x22, [sp, 0x50 + TEB_OFFSET] + stp x23, x24, [sp, 0x60 + TEB_OFFSET] + stp x25, x26, [sp, 0x70 + TEB_OFFSET] + stp x27, x28, [sp, 0x80 + TEB_OFFSET] + stp x29, x30, [sp, 0x90 + TEB_OFFSET] + +#if defined(_WIN32) + # Save certain values from Thread Environment Block (TEB) + # x18 points to the TEB on Windows + # Read TeStackBase and TeStackLimit at ksarm64.h from TEB + ldp x5, x6, [x18, #0x08] + # Save them + stp x5, x6, [sp, #0x00] + # Read TeDeallocationStack at ksarm64.h from TEB + ldr x5, [x18, #0x1478] + # Read TeFiberData at ksarm64.h from TEB + ldr x6, [x18, #0x20] + # Save current fiber data and deallocation stack + stp x5, x6, [sp, #0x10] +#endif + + # Save stack pointer to x0 (first argument) + mov x2, sp + str x2, [x0, 0] + + # Load stack pointer from x1 (second argument) + ldr x3, [x1, 0] + mov sp, x3 + +#if defined(_WIN32) + # Restore stack base and limit + ldp x5, x6, [sp, #0x00] + # Write TeStackBase and TeStackLimit at ksarm64.h to TEB + stp x5, x6, [x18, #0x08] + # Restore fiber data and deallocation stack + ldp x5, x6, [sp, #0x10] + # Write TeDeallocationStack at ksarm64.h to TEB + str x5, [x18, #0x1478] + # Write TeFiberData at ksarm64.h to TEB + str x6, [x18, #0x20] +#endif + + # Restore caller registers + ldp d8, d9, [sp, 0x00 + TEB_OFFSET] + ldp d10, d11, [sp, 0x10 + TEB_OFFSET] + ldp d12, d13, [sp, 0x20 + TEB_OFFSET] + ldp d14, d15, [sp, 0x30 + TEB_OFFSET] + ldp x19, x20, [sp, 0x40 + TEB_OFFSET] + ldp x21, x22, [sp, 0x50 + TEB_OFFSET] + ldp x23, x24, [sp, 0x60 + TEB_OFFSET] + ldp x25, x26, [sp, 0x70 + TEB_OFFSET] + ldp x27, x28, [sp, 0x80 + TEB_OFFSET] + ldp x29, x30, [sp, 0x90 + TEB_OFFSET] + + # Pop stack frame + add sp, sp, 0xa0 + TEB_OFFSET + +#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 (defined(__ARM_FEATURE_BTI_DEFAULT) && __ARM_FEATURE_BTI_DEFAULT != 0) || (defined(__ARM_FEATURE_PAC_DEFAULT) && __ARM_FEATURE_PAC_DEFAULT != 0) +#if defined(__ELF__) +/* 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 defined(__ARM_FEATURE_BTI_DEFAULT) && __ARM_FEATURE_BTI_DEFAULT != 0 +# define BTI_FLAG GNU_PROPERTY_AARCH64_FEATURE_1_BTI +# else +# define BTI_FLAG 0 +# endif +# if defined(__ARM_FEATURE_PAC_DEFAULT) && __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 +#endif |