| /* DWARF2 EH unwinding support for GNU Hurd: x86. |
| Copyright (C) 2020-2024 Free Software Foundation, Inc. |
| Contributed by Samuel Thibault <samuel.thibault@gnu.org> |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3, or (at your option) |
| any later version. |
| |
| GCC is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| Under Section 7 of GPL version 3, you are granted additional |
| permissions described in the GCC Runtime Library Exception, version |
| 3.1, as published by the Free Software Foundation. |
| |
| You should have received a copy of the GNU General Public License and |
| a copy of the GCC Runtime Library Exception along with this program; |
| see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* Do code reading to identify a signal frame, and set the frame |
| state data appropriately. See unwind-dw2.c for the structs. */ |
| |
| #ifndef inhibit_libc |
| |
| #include <signal.h> |
| |
| #ifdef __x86_64__ |
| |
| #define MD_FALLBACK_FRAME_STATE_FOR x86_gnu_fallback_frame_state |
| |
| static _Unwind_Reason_Code |
| x86_gnu_fallback_frame_state |
| (struct _Unwind_Context *context, _Unwind_FrameState *fs) |
| { |
| static const unsigned char gnu_sigtramp_code[] = |
| { |
| /* rpc_wait_trampoline: */ |
| 0x48, 0xc7, 0xc0, 0xe7, 0xff, 0xff, 0xff, /* mov $-25,%rax */ |
| 0x0f, 0x05, /* syscall */ |
| 0x49, 0x89, 0x04, 0x24, /* mov %rax,(%r12) */ |
| 0x48, 0x89, 0xdc, /* mov %rbx,%rsp */ |
| |
| /* trampoline: */ |
| 0x5f, /* pop %rdi */ |
| 0x5e, /* pop %rsi */ |
| 0x5a, /* pop %rdx */ |
| 0x48, 0x83, 0xc4, 0x08, /* add $0x8,%rsp */ |
| 0x41, 0xff, 0xd5, /* call *%r13 */ |
| |
| /* RA HERE */ |
| 0x48, 0x8b, 0x7c, 0x24, 0x10, /* mov 0x10(%rsp),%rdi */ |
| 0xc3, /* ret */ |
| |
| /* firewall: */ |
| 0xf4, /* hlt */ |
| }; |
| |
| const size_t gnu_sigtramp_len = sizeof gnu_sigtramp_code; |
| const size_t gnu_sigtramp_tail = 7; /* length of tail after RA */ |
| |
| struct stack_contents { |
| void *sigreturn_addr; |
| void *sigreturn_returns_here; |
| struct sigcontext *return_scp; |
| } *stack_contents; |
| struct sigcontext *scp; |
| unsigned long usp; |
| |
| unsigned char *adjusted_pc = (unsigned char*)(context->ra) + |
| gnu_sigtramp_tail - gnu_sigtramp_len; |
| if (memcmp (adjusted_pc, gnu_sigtramp_code, gnu_sigtramp_len)) |
| return _URC_END_OF_STACK; |
| |
| stack_contents = context->cfa; |
| |
| scp = stack_contents->return_scp; |
| usp = scp->sc_ursp; |
| |
| fs->regs.reg[0].loc.offset = (unsigned long)&scp->sc_rax - usp; |
| fs->regs.reg[1].loc.offset = (unsigned long)&scp->sc_rdx - usp; |
| fs->regs.reg[2].loc.offset = (unsigned long)&scp->sc_rcx - usp; |
| fs->regs.reg[3].loc.offset = (unsigned long)&scp->sc_rbx - usp; |
| fs->regs.reg[4].loc.offset = (unsigned long)&scp->sc_rsi - usp; |
| fs->regs.reg[5].loc.offset = (unsigned long)&scp->sc_rdi - usp; |
| fs->regs.reg[6].loc.offset = (unsigned long)&scp->sc_rbp - usp; |
| fs->regs.reg[8].loc.offset = (unsigned long)&scp->sc_r8 - usp; |
| fs->regs.reg[9].loc.offset = (unsigned long)&scp->sc_r9 - usp; |
| fs->regs.reg[10].loc.offset = (unsigned long)&scp->sc_r10 - usp; |
| fs->regs.reg[11].loc.offset = (unsigned long)&scp->sc_r11 - usp; |
| fs->regs.reg[12].loc.offset = (unsigned long)&scp->sc_r12 - usp; |
| fs->regs.reg[13].loc.offset = (unsigned long)&scp->sc_r13 - usp; |
| fs->regs.reg[14].loc.offset = (unsigned long)&scp->sc_r14 - usp; |
| fs->regs.reg[15].loc.offset = (unsigned long)&scp->sc_r15 - usp; |
| fs->regs.reg[16].loc.offset = (unsigned long)&scp->sc_rip - usp; |
| |
| /* Register 7 is rsp */ |
| fs->regs.cfa_how = CFA_REG_OFFSET; |
| fs->regs.cfa_reg = 7; |
| fs->regs.cfa_offset = usp - (unsigned long) context->cfa; |
| |
| fs->regs.how[0] = REG_SAVED_OFFSET; |
| fs->regs.how[1] = REG_SAVED_OFFSET; |
| fs->regs.how[2] = REG_SAVED_OFFSET; |
| fs->regs.how[3] = REG_SAVED_OFFSET; |
| fs->regs.how[4] = REG_SAVED_OFFSET; |
| fs->regs.how[5] = REG_SAVED_OFFSET; |
| fs->regs.how[6] = REG_SAVED_OFFSET; |
| fs->regs.how[8] = REG_SAVED_OFFSET; |
| fs->regs.how[9] = REG_SAVED_OFFSET; |
| fs->regs.how[10] = REG_SAVED_OFFSET; |
| fs->regs.how[11] = REG_SAVED_OFFSET; |
| fs->regs.how[12] = REG_SAVED_OFFSET; |
| fs->regs.how[13] = REG_SAVED_OFFSET; |
| fs->regs.how[14] = REG_SAVED_OFFSET; |
| fs->regs.how[15] = REG_SAVED_OFFSET; |
| fs->regs.how[16] = REG_SAVED_OFFSET; |
| |
| fs->retaddr_column = 16; |
| fs->signal_frame = 1; |
| |
| return _URC_NO_REASON; |
| } |
| |
| #else /* ifdef __x86_64__ */ |
| |
| #define MD_FALLBACK_FRAME_STATE_FOR x86_gnu_fallback_frame_state |
| |
| static _Unwind_Reason_Code |
| x86_gnu_fallback_frame_state |
| (struct _Unwind_Context *context, _Unwind_FrameState *fs) |
| { |
| struct handler_args { |
| int signo; |
| union |
| { |
| struct |
| { |
| long int sigcode; |
| struct sigcontext *scp; |
| } legacy; |
| struct |
| { |
| siginfo_t *siginfop; |
| ucontext_t *uctxp; |
| } posix; |
| }; |
| } *handler_args; |
| long int sigcode; |
| unsigned long usp; |
| |
| /* |
| * i386 sigtramp frame we are looking for follows. |
| * (see glibc/sysdeps/mach/hurd/i386/trampoline.c assembly) |
| * |
| * rpc_wait_trampoline: |
| * 0: b8 e7 ff ff ff mov $-25,%eax mach_msg_trap |
| * 5: 9a 00 00 00 00 07 00 lcall $7,$0 |
| * 12: 89 01 movl %eax, (%ecx) |
| * 14: 89 dc movl %ebx, %esp switch to signal stack |
| * |
| * trampoline: |
| * 16: ff d2 call *%edx call the handler function |
| * RA HERE |
| * 18: 83 c4 0c addl $12, %esp pop its args |
| * 21: c3 ret return to sigreturn |
| * |
| * firewall: |
| * 22: f4 hlt |
| */ |
| |
| if (!( *(unsigned int *)(context->ra ) == 0xc30cc483 |
| && *(unsigned char *)(context->ra + 4) == 0xf4 |
| |
| && *(unsigned int *)(context->ra - 4) == 0xd2ffdc89 |
| && *(unsigned int *)(context->ra - 8) == 0x01890007 |
| && *(unsigned int *)(context->ra - 12) == 0x00000000 |
| && *(unsigned int *)(context->ra - 16) == 0x9affffff |
| && *(unsigned short *)(context->ra - 18) == 0xe7b8)) |
| return _URC_END_OF_STACK; |
| |
| handler_args = context->cfa; |
| sigcode = handler_args->legacy.sigcode; |
| if (sigcode >= -16 && sigcode < 4096) |
| { |
| /* This cannot be a SIGINFO pointer, assume legacy. */ |
| struct sigcontext *scp = handler_args->legacy.scp; |
| usp = scp->sc_uesp; |
| |
| fs->regs.reg[0].loc.offset = (unsigned long)&scp->sc_eax - usp; |
| fs->regs.reg[1].loc.offset = (unsigned long)&scp->sc_ecx - usp; |
| fs->regs.reg[2].loc.offset = (unsigned long)&scp->sc_edx - usp; |
| fs->regs.reg[3].loc.offset = (unsigned long)&scp->sc_ebx - usp; |
| fs->regs.reg[5].loc.offset = (unsigned long)&scp->sc_ebp - usp; |
| fs->regs.reg[6].loc.offset = (unsigned long)&scp->sc_esi - usp; |
| fs->regs.reg[7].loc.offset = (unsigned long)&scp->sc_edi - usp; |
| fs->regs.reg[8].loc.offset = (unsigned long)&scp->sc_eip - usp; |
| } |
| else |
| { |
| /* This is not a valid sigcode, assume SIGINFO. */ |
| ucontext_t *uctxp = handler_args->posix.uctxp; |
| gregset_t *gregset = &uctxp->uc_mcontext.gregs; |
| usp = (*gregset)[REG_UESP]; |
| |
| fs->regs.reg[0].loc.offset = (unsigned long)&(*gregset)[REG_EAX] - usp; |
| fs->regs.reg[1].loc.offset = (unsigned long)&(*gregset)[REG_ECX] - usp; |
| fs->regs.reg[2].loc.offset = (unsigned long)&(*gregset)[REG_EDX] - usp; |
| fs->regs.reg[3].loc.offset = (unsigned long)&(*gregset)[REG_EBX] - usp; |
| fs->regs.reg[5].loc.offset = (unsigned long)&(*gregset)[REG_EBP] - usp; |
| fs->regs.reg[6].loc.offset = (unsigned long)&(*gregset)[REG_ESI] - usp; |
| fs->regs.reg[7].loc.offset = (unsigned long)&(*gregset)[REG_EDI] - usp; |
| fs->regs.reg[8].loc.offset = (unsigned long)&(*gregset)[REG_EIP] - usp; |
| } |
| |
| fs->regs.cfa_how = CFA_REG_OFFSET; |
| fs->regs.cfa_reg = 4; |
| fs->regs.cfa_offset = usp - (unsigned long) context->cfa; |
| |
| fs->regs.how[0] = REG_SAVED_OFFSET; |
| fs->regs.how[1] = REG_SAVED_OFFSET; |
| fs->regs.how[2] = REG_SAVED_OFFSET; |
| fs->regs.how[3] = REG_SAVED_OFFSET; |
| fs->regs.how[5] = REG_SAVED_OFFSET; |
| fs->regs.how[6] = REG_SAVED_OFFSET; |
| fs->regs.how[7] = REG_SAVED_OFFSET; |
| fs->regs.how[8] = REG_SAVED_OFFSET; |
| |
| fs->retaddr_column = 8; |
| fs->signal_frame = 1; |
| |
| return _URC_NO_REASON; |
| } |
| |
| #endif /* ifdef __x86_64__ */ |
| |
| #endif /* ifndef inhibit_libc */ |
