diff options
Diffstat (limited to 'libc/arch-x86/bionic/__restore.S')
| -rw-r--r-- | libc/arch-x86/bionic/__restore.S | 102 |
1 files changed, 73 insertions, 29 deletions
diff --git a/libc/arch-x86/bionic/__restore.S b/libc/arch-x86/bionic/__restore.S index 5977eab41..cb18fd027 100644 --- a/libc/arch-x86/bionic/__restore.S +++ b/libc/arch-x86/bionic/__restore.S @@ -27,7 +27,14 @@ */ #include <private/bionic_asm.h> -#include <private/bionic_asm_dwarf_exprs.h> + +// DWARF constants. +#define DW_CFA_def_cfa_expression 0x0f +#define DW_CFA_expression 0x10 +#define DW_EH_PE_pcrel 0x10 +#define DW_EH_PE_sdata4 0x0b +#define DW_OP_breg4 0x74 +#define DW_OP_deref 0x06 // Offsets into struct sigcontext. #define OFFSET_EDI 16 @@ -45,47 +52,84 @@ #define DW_x86_REG_ECX 1 #define DW_x86_REG_EDX 2 #define DW_x86_REG_EBX 3 -#define DW_x86_REG_ESP 4 #define DW_x86_REG_EBP 5 #define DW_x86_REG_ESI 6 #define DW_x86_REG_EDI 7 #define DW_x86_REG_EIP 8 -#define RESTORE_GPR(reg, extra_offset) \ - m_cfi_breg_offset DW_x86_REG_ ## reg, \ - DW_x86_REG_ESP, \ - (OFFSET_ ## reg + (extra_offset)); +#define cfi_signal_frame_start(f) \ +.section .eh_frame,"a",@progbits; \ +.L ## f ## _START_EH_FRAME: \ + .long 2f - 1f; /* CIE length. */ \ +1:.long 0; /* CIE ID. */ \ + .byte 1; /* Version. */ \ + .string "zRS"; /* Augmentation string. */ \ + .uleb128 1; /* Code alignment factor. */ \ + .sleb128 -4; /* Data alignment factor. */ \ + .uleb128 DW_x86_REG_EIP; /* Return address register. */ \ + .uleb128 1; /* 1 byte of augmentation data. */ \ + .byte (DW_EH_PE_pcrel|DW_EH_PE_sdata4); /* FDE encoding. */ \ + .align 8; \ +2: \ + .long .L ## f ## _END_FDE - .L ## f ## _START_FDE; /* FDE length. */ \ +.L ## f ## _START_FDE: \ + .long .L ## f ## _START_FDE - .L ## f ## _START_EH_FRAME; /* CIE location. */ \ + .long (.L ## f ## _START - 1) - .; /* pcrel start address (see FDE encoding above). */ \ + .long .L ## f ## _END - (.L ## f ## _START - 1); /* Function this FDE applies to. */ \ + .uleb128 0; /* FDE augmentation length. */ \ + +#define cfi_signal_frame_end(f) \ +.L ## f ## _END_FDE: \ -// Restoring ESP is unnecessary as the unwinder simply uses the CFA value. -#define RESTORE_GPRS(extra_offset) \ - m_cfi_def_cfa_deref DW_x86_REG_ESP, (OFFSET_ESP + (extra_offset)); \ - RESTORE_GPR(EDI, extra_offset) \ - RESTORE_GPR(ESI, extra_offset) \ - RESTORE_GPR(EBP, extra_offset) \ - RESTORE_GPR(EBX, extra_offset) \ - RESTORE_GPR(EDX, extra_offset) \ - RESTORE_GPR(ECX, extra_offset) \ - RESTORE_GPR(EAX, extra_offset) \ - RESTORE_GPR(EIP, extra_offset) \ +#define cfi_def_cfa(offset) \ + .byte DW_CFA_def_cfa_expression; \ + .uleb128 2f-1f; \ +1:.byte DW_OP_breg4; \ + .sleb128 offset; \ + .byte DW_OP_deref; \ +2: \ - .text +#define cfi_offset(reg_number,offset) \ + .byte DW_CFA_expression; \ + .uleb128 reg_number; \ + .uleb128 2f-1f; \ +1:.byte DW_OP_breg4; \ + .sleb128 offset; \ +2: \ - .cfi_startproc - .cfi_signal_frame - RESTORE_GPRS(4) - nop // See comment in libc/arch-x86_64/bionic/__restore_rt.S about this nop. -ENTRY_PRIVATE_NO_DWARF(__restore) +ENTRY_PRIVATE(__restore) +.L__restore_START: popl %eax - RESTORE_GPRS(0) movl $__NR_sigreturn, %eax int $0x80 +.L__restore_END: END(__restore) +cfi_signal_frame_start(__restore) + cfi_def_cfa(OFFSET_ESP + 4) + cfi_offset(DW_x86_REG_EDI, OFFSET_EDI + 4) + cfi_offset(DW_x86_REG_ESI, OFFSET_ESI + 4) + cfi_offset(DW_x86_REG_EBP, OFFSET_EBP + 4) + cfi_offset(DW_x86_REG_EBX, OFFSET_EBX + 4) + cfi_offset(DW_x86_REG_EDX, OFFSET_EDX + 4) + cfi_offset(DW_x86_REG_ECX, OFFSET_ECX + 4) + cfi_offset(DW_x86_REG_EAX, OFFSET_EAX + 4) + cfi_offset(DW_x86_REG_EIP, OFFSET_EIP + 4) +cfi_signal_frame_end(__restore) - .cfi_startproc - .cfi_signal_frame - RESTORE_GPRS(160) - nop // See comment in libc/arch-x86_64/bionic/__restore_rt.S about this nop. -ENTRY_PRIVATE_NO_DWARF(__restore_rt) +ENTRY_PRIVATE(__restore_rt) +.L__restore_rt_START: movl $__NR_rt_sigreturn, %eax int $0x80 +.L__restore_rt_END: END(__restore_rt) +cfi_signal_frame_start(__restore_rt) + cfi_def_cfa(OFFSET_ESP + 160) + cfi_offset(DW_x86_REG_EDI, OFFSET_EDI + 160) + cfi_offset(DW_x86_REG_ESI, OFFSET_ESI + 160) + cfi_offset(DW_x86_REG_EBP, OFFSET_EBP + 160) + cfi_offset(DW_x86_REG_EBX, OFFSET_EBX + 160) + cfi_offset(DW_x86_REG_EDX, OFFSET_EDX + 160) + cfi_offset(DW_x86_REG_ECX, OFFSET_ECX + 160) + cfi_offset(DW_x86_REG_EAX, OFFSET_EAX + 160) + cfi_offset(DW_x86_REG_EIP, OFFSET_EIP + 160) +cfi_signal_frame_end(__restore_rt) |