libgcc/config/csky/linux-unwind.h

   1 /* DWARF2 EH unwinding support for C-SKY Linux.
   2    Copyright (C) 2018-2023 Free Software Foundation, Inc.
   3    Contributed by C-SKY Microsystems and Mentor Graphics.
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3, or (at your option)
  10    any later version.
  11
  12    GCC is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    Under Section 7 of GPL version 3, you are granted additional
  18    permissions described in the GCC Runtime Library Exception, version
  19    3.1, as published by the Free Software Foundation.
  20
  21    You should have received a copy of the GNU General Public License and
  22    a copy of the GCC Runtime Library Exception along with this program;
  23    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24    <http://www.gnu.org/licenses/>.  */
  25
  26 #ifndef inhibit_libc
  27
  28 /* Do code reading to identify a signal frame, and set the frame state data
  29    appropriately.  See unwind-dw2.c for the structs.  */
  30
  31 #include <signal.h>
  32 #include <asm/unistd.h>
  33
  34 #define TRAP0_V1 0x0008
  35 #define MOVI_R1_119_V1 (0x6000 + (119 << 4) + 1)
  36 #define MOVI_R1_127_V1 (0x6000 + (127 << 4) + 1)
  37 #define ADDI_R1_32_V1 (0x2000 + (31 << 4) + 1)
  38 #define ADDI_R1_14_V1 (0x2000 + (13 << 4) + 1)
  39 #define ADDI_R1_12_V1 (0x2000 + (11 << 4) + 1)
  40
  41 #define TRAP0_V2_PART0 0xc000
  42 #define TRAP0_V2_PART1 0x2020
  43 #define MOVI_R7_119_V2_PART0 0xea07
  44 #define MOVI_R7_119_V2_PART1 119
  45 #define MOVI_R7_173_V2_PART0 0xea07
  46 #define MOVI_R7_173_V2_PART1 173
  47 #define MOVI_R7_139_V2_PART0 0xea07
  48 #define MOVI_R7_139_V2_PART1 139
  49
  50 #define sc_pt_regs(x) (sc->sc_pt_regs.x)
  51 #define sc_pt_regs_lr (sc->sc_pt_regs.lr)
  52 #define sc_pt_regs_tls(x) sc_pt_regs(x)
  53
  54 #define MD_FALLBACK_FRAME_STATE_FOR csky_fallback_frame_state
  55
  56 static _Unwind_Reason_Code
  57 csky_fallback_frame_state (struct _Unwind_Context *context,
  58                            _Unwind_FrameState *fs)
  59 {
  60   u_int16_t *pc = (u_int16_t *) context->ra;
  61   struct sigcontext *sc;
  62   _Unwind_Ptr new_cfa;
  63   int i;
  64
  65   /* movi r7, __NR_rt_sigreturn; trap 0  */
  66   if ((*(pc + 0) == MOVI_R7_139_V2_PART0)
  67       && (*(pc + 1) == MOVI_R7_139_V2_PART1) && (*(pc + 2) == TRAP0_V2_PART0)
  68       && (*(pc + 3) == TRAP0_V2_PART1))
  69     {
  70       struct rt_sigframe
  71       {
  72         int sig;
  73         struct siginfo *pinfo;
  74         void *puc;
  75         siginfo_t info;
  76         ucontext_t uc;
  77       } *_rt = context->cfa;
  78       sc = &(_rt->uc.uc_mcontext);
  79     }
  80   else
  81     return _URC_END_OF_STACK;
  82
  83   new_cfa = (_Unwind_Ptr) sc_pt_regs (usp);
  84   fs->regs.cfa_how = CFA_REG_OFFSET;
  85   fs->regs.cfa_reg = STACK_POINTER_REGNUM;
  86   fs->regs.cfa_offset = new_cfa - (_Unwind_Ptr) context->cfa;
  87
  88   fs->regs.how[0] = REG_SAVED_OFFSET;
  89   fs->regs.reg[0].loc.offset = (_Unwind_Ptr) & sc_pt_regs (a0) - new_cfa;
  90
  91   fs->regs.how[1] = REG_SAVED_OFFSET;
  92   fs->regs.reg[1].loc.offset = (_Unwind_Ptr) & sc_pt_regs (a1) - new_cfa;
  93
  94   fs->regs.how[2] = REG_SAVED_OFFSET;
  95   fs->regs.reg[2].loc.offset = (_Unwind_Ptr) & sc_pt_regs (a2) - new_cfa;
  96
  97   fs->regs.how[3] = REG_SAVED_OFFSET;
  98   fs->regs.reg[3].loc.offset = (_Unwind_Ptr) & sc_pt_regs (a3) - new_cfa;
  99
 100   for (i = 4; i < 14; i++)
 101     {
 102       fs->regs.how[i] = REG_SAVED_OFFSET;
 103       fs->regs.reg[i].loc.offset =
 104         (_Unwind_Ptr) & sc_pt_regs (regs[i - 4]) - new_cfa;
 105     }
 106
 107   for (i = 16; i < 31; i++)
 108     {
 109       fs->regs.how[i] = REG_SAVED_OFFSET;
 110       fs->regs.reg[i].loc.offset =
 111         (_Unwind_Ptr) & sc_pt_regs (exregs[i - 16]) - new_cfa;
 112     }
 113
 114   fs->regs.reg[31].loc.offset =
 115     (_Unwind_Ptr) & sc_pt_regs_tls (tls) - new_cfa;
 116   /* FIXME : hi lo ? */
 117   fs->regs.how[15] = REG_SAVED_OFFSET;
 118   fs->regs.reg[15].loc.offset = (_Unwind_Ptr) & sc_pt_regs_lr - new_cfa;
 119
 120   fs->regs.how[32] = REG_SAVED_OFFSET;
 121   fs->regs.reg[32].loc.offset = (_Unwind_Ptr) & sc_pt_regs (pc) - new_cfa;
 122   fs->retaddr_column = 32;
 123   fs->signal_frame = 1;
 124
 125   return _URC_NO_REASON;
 126 }
 127
 128 #endif