133 lines
4.1 KiB
C
133 lines
4.1 KiB
C
/* DWARF2 EH unwinding support for S/390 Linux.
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Copyright (C) 2004-2022 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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/* Do code reading to identify a signal frame, and set the frame
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state data appropriately. See unwind-dw2.c for the structs. */
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#define MD_FALLBACK_FRAME_STATE_FOR s390_fallback_frame_state
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static _Unwind_Reason_Code
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s390_fallback_frame_state (struct _Unwind_Context *context,
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_Unwind_FrameState *fs)
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{
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static const unsigned char dwarf_to_fpr_map[16] =
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{ 0, 2, 4, 6, 1, 3, 5, 7, 8, 10, 12, 14, 9, 11, 13, 15 };
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unsigned char *pc = context->ra;
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long new_cfa;
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int i;
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typedef struct
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{
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unsigned long psw_mask;
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unsigned long psw_addr;
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unsigned long gprs[16];
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unsigned int acrs[16];
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unsigned int fpc;
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unsigned int __pad;
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double fprs[16];
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} __attribute__ ((__aligned__ (8))) sigregs_;
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sigregs_ *regs;
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int *signo;
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/* svc $__NR_sigreturn or svc $__NR_rt_sigreturn */
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if (pc[0] != 0x0a || (pc[1] != 119 && pc[1] != 173))
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return _URC_END_OF_STACK;
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/* Legacy frames:
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old signal mask (8 bytes)
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pointer to sigregs (8 bytes) - points always to next location
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sigregs
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retcode
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This frame layout was used on kernels < 2.6.9 for non-RT frames,
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and on kernels < 2.4.13 for RT frames as well. Note that we need
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to look at RA to detect this layout -- this means that if you use
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sa_restorer to install a different signal restorer on a legacy
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kernel, unwinding from signal frames will not work. */
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if (context->ra == context->cfa + 16 + sizeof (sigregs_))
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{
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regs = (sigregs_ *)(context->cfa + 16);
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signo = NULL;
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}
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/* New-style RT frame:
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retcode + alignment (8 bytes)
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siginfo (128 bytes)
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ucontext (contains sigregs) */
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else if (pc[1] == 173 /* __NR_rt_sigreturn */)
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{
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struct ucontext_
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{
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unsigned long uc_flags;
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struct ucontext_ *uc_link;
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unsigned long uc_stack[3];
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sigregs_ uc_mcontext;
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} *uc = context->cfa + 8 + 128;
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regs = &uc->uc_mcontext;
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signo = context->cfa + sizeof(long);
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}
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/* New-style non-RT frame:
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old signal mask (8 bytes)
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pointer to sigregs (followed by signal number) */
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else
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{
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regs = *(sigregs_ **)(context->cfa + 8);
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signo = (int *)(regs + 1);
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}
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new_cfa = regs->gprs[15] + 16*sizeof(long) + 32;
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fs->regs.cfa_how = CFA_REG_OFFSET;
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fs->regs.cfa_reg = 15;
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fs->regs.cfa_offset =
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new_cfa - (long) context->cfa + 16*sizeof(long) + 32;
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for (i = 0; i < 16; i++)
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{
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fs->regs.reg[i].how = REG_SAVED_OFFSET;
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fs->regs.reg[i].loc.offset =
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(long)®s->gprs[i] - new_cfa;
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}
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for (i = 0; i < 16; i++)
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{
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fs->regs.reg[16+i].how = REG_SAVED_OFFSET;
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fs->regs.reg[16+i].loc.offset =
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(long)®s->fprs[dwarf_to_fpr_map[i]] - new_cfa;
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}
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/* Load return addr from PSW into dummy register 32. */
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fs->regs.reg[32].how = REG_SAVED_OFFSET;
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fs->regs.reg[32].loc.offset = (long)®s->psw_addr - new_cfa;
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fs->retaddr_column = 32;
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/* SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr
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after the faulting instruction rather than before it.
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Don't set FS->signal_frame in that case. */
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if (!signo || (*signo != 4 && *signo != 5 && *signo != 8))
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fs->signal_frame = 1;
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return _URC_NO_REASON;
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}
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