1/* libunwind - a platform-independent unwind library 2 Copyright (C) 2008 CodeSourcery 3 4This file is part of libunwind. 5 6Permission is hereby granted, free of charge, to any person obtaining 7a copy of this software and associated documentation files (the 8"Software"), to deal in the Software without restriction, including 9without limitation the rights to use, copy, modify, merge, publish, 10distribute, sublicense, and/or sell copies of the Software, and to 11permit persons to whom the Software is furnished to do so, subject to 12the following conditions: 13 14The above copyright notice and this permission notice shall be 15included in all copies or substantial portions of the Software. 16 17THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 18EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 19MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 20NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 21LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 22OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 23WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ 24 25#include "unwind_i.h" 26#include "offsets.h" 27 28PROTECTED int 29unw_handle_signal_frame (unw_cursor_t *cursor) 30{ 31 struct cursor *c = (struct cursor *) cursor; 32 unw_word_t sc_addr, sp, sp_addr = c->dwarf.cfa; 33 unw_word_t ra, fp; 34 int ret; 35 36 /* FIXME (simon): Save the SP and PC to be able to return execution 37 at this point later in time (unw_resume). */ 38 // c->sigcontext_sp = c->dwarf.cfa; 39 // c->sigcontext_pc = c->dwarf.ip; 40 41 switch (unw_is_signal_frame (cursor)) { 42 case 1: 43 sc_addr = sp_addr + LINUX_SF_TRAMP_SIZE + sizeof (siginfo_t) + 44 LINUX_UC_MCONTEXT_OFF; 45 break; 46 case 2: 47 sc_addr = sp_addr + LINUX_UC_MCONTEXT_OFF; 48 break; 49 default: 50 return -UNW_EUNSPEC; 51 } 52 53 if (tdep_big_endian(c->dwarf.as)) 54 sc_addr += 4; 55 56 c->sigcontext_addr = sc_addr; 57 58 /* Update the dwarf cursor. */ 59 c->dwarf.loc[UNW_MIPS_R0] = DWARF_LOC (sc_addr + LINUX_SC_R0_OFF, 0); 60 c->dwarf.loc[UNW_MIPS_R1] = DWARF_LOC (sc_addr + LINUX_SC_R1_OFF, 0); 61 c->dwarf.loc[UNW_MIPS_R2] = DWARF_LOC (sc_addr + LINUX_SC_R2_OFF, 0); 62 c->dwarf.loc[UNW_MIPS_R3] = DWARF_LOC (sc_addr + LINUX_SC_R3_OFF, 0); 63 c->dwarf.loc[UNW_MIPS_R4] = DWARF_LOC (sc_addr + LINUX_SC_R4_OFF, 0); 64 c->dwarf.loc[UNW_MIPS_R5] = DWARF_LOC (sc_addr + LINUX_SC_R5_OFF, 0); 65 c->dwarf.loc[UNW_MIPS_R6] = DWARF_LOC (sc_addr + LINUX_SC_R6_OFF, 0); 66 c->dwarf.loc[UNW_MIPS_R7] = DWARF_LOC (sc_addr + LINUX_SC_R7_OFF, 0); 67 c->dwarf.loc[UNW_MIPS_R8] = DWARF_LOC (sc_addr + LINUX_SC_R8_OFF, 0); 68 c->dwarf.loc[UNW_MIPS_R9] = DWARF_LOC (sc_addr + LINUX_SC_R9_OFF, 0); 69 c->dwarf.loc[UNW_MIPS_R10] = DWARF_LOC (sc_addr + LINUX_SC_R10_OFF, 0); 70 c->dwarf.loc[UNW_MIPS_R11] = DWARF_LOC (sc_addr + LINUX_SC_R11_OFF, 0); 71 c->dwarf.loc[UNW_MIPS_R12] = DWARF_LOC (sc_addr + LINUX_SC_R12_OFF, 0); 72 c->dwarf.loc[UNW_MIPS_R13] = DWARF_LOC (sc_addr + LINUX_SC_R13_OFF, 0); 73 c->dwarf.loc[UNW_MIPS_R14] = DWARF_LOC (sc_addr + LINUX_SC_R14_OFF, 0); 74 c->dwarf.loc[UNW_MIPS_R15] = DWARF_LOC (sc_addr + LINUX_SC_R15_OFF, 0); 75 c->dwarf.loc[UNW_MIPS_R16] = DWARF_LOC (sc_addr + LINUX_SC_R16_OFF, 0); 76 c->dwarf.loc[UNW_MIPS_R17] = DWARF_LOC (sc_addr + LINUX_SC_R17_OFF, 0); 77 c->dwarf.loc[UNW_MIPS_R18] = DWARF_LOC (sc_addr + LINUX_SC_R18_OFF, 0); 78 c->dwarf.loc[UNW_MIPS_R19] = DWARF_LOC (sc_addr + LINUX_SC_R19_OFF, 0); 79 c->dwarf.loc[UNW_MIPS_R20] = DWARF_LOC (sc_addr + LINUX_SC_R20_OFF, 0); 80 c->dwarf.loc[UNW_MIPS_R21] = DWARF_LOC (sc_addr + LINUX_SC_R21_OFF, 0); 81 c->dwarf.loc[UNW_MIPS_R22] = DWARF_LOC (sc_addr + LINUX_SC_R22_OFF, 0); 82 c->dwarf.loc[UNW_MIPS_R23] = DWARF_LOC (sc_addr + LINUX_SC_R23_OFF, 0); 83 c->dwarf.loc[UNW_MIPS_R24] = DWARF_LOC (sc_addr + LINUX_SC_R24_OFF, 0); 84 c->dwarf.loc[UNW_MIPS_R25] = DWARF_LOC (sc_addr + LINUX_SC_R25_OFF, 0); 85 c->dwarf.loc[UNW_MIPS_R26] = DWARF_LOC (sc_addr + LINUX_SC_R26_OFF, 0); 86 c->dwarf.loc[UNW_MIPS_R27] = DWARF_LOC (sc_addr + LINUX_SC_R27_OFF, 0); 87 c->dwarf.loc[UNW_MIPS_R28] = DWARF_LOC (sc_addr + LINUX_SC_R28_OFF, 0); 88 c->dwarf.loc[UNW_MIPS_R29] = DWARF_LOC (sc_addr + LINUX_SC_R29_OFF, 0); 89 c->dwarf.loc[UNW_MIPS_R30] = DWARF_LOC (sc_addr + LINUX_SC_R30_OFF, 0); 90 c->dwarf.loc[UNW_MIPS_R31] = DWARF_LOC (sc_addr + LINUX_SC_R31_OFF, 0); 91 c->dwarf.loc[UNW_MIPS_PC] = DWARF_LOC (sc_addr + LINUX_SC_PC_OFF, 0); 92 93 /* Set SP/CFA and PC/IP. */ 94 dwarf_get (&c->dwarf, c->dwarf.loc[UNW_MIPS_R29], &c->dwarf.cfa); 95 //dwarf_get (&c->dwarf, c->dwarf.loc[UNW_MIPS_R31], &c->dwarf.ip); 96 97 if ((ret = dwarf_get(&c->dwarf, DWARF_LOC(sc_addr + LINUX_SC_PC_OFF, 0), 98 &c->dwarf.ip)) < 0) 99 return ret; 100 101 if ((ret = dwarf_get(&c->dwarf, DWARF_LOC(sc_addr + LINUX_SC_R31_OFF, 0), 102 &ra)) < 0) 103 return ret; 104 if ((ret = dwarf_get(&c->dwarf, DWARF_LOC(sc_addr + LINUX_SC_R30_OFF, 0), 105 &fp)) < 0) 106 return ret; 107 108 Debug (2, "SH (ip=0x%016llx, ra=0x%016llx, sp=0x%016llx, fp=0x%016llx)\n", 109 (unsigned long long)c->dwarf.ip, (unsigned long long)ra, 110 (unsigned long long)c->dwarf.cfa, (unsigned long long)fp); 111 112 c->dwarf.pi_valid = 0; 113 c->dwarf.use_prev_instr = 0; 114 115 return 1; 116} 117 118PROTECTED int 119unw_step (unw_cursor_t *cursor) 120{ 121 struct cursor *c = (struct cursor *) cursor; 122 int ret; 123 124 unw_word_t old_ip = c->dwarf.ip; 125 unw_word_t old_cfa = c->dwarf.cfa; 126 127 ret = unw_handle_signal_frame (cursor); 128 if (ret < 0) 129 /* Not a signal frame, try DWARF-based unwinding. */ 130 ret = dwarf_step (&c->dwarf); 131 132 if (unlikely (ret == -UNW_ESTOPUNWIND)) 133 return ret; 134 135 /* Dwarf unwinding didn't work, stop. */ 136 if (unlikely (ret < 0)) 137 return 0; 138 139 /* If the decode yields the exact same ip/cfa as before, then indicate 140 the unwind is complete. */ 141 if (c->dwarf.ip == old_ip && c->dwarf.cfa == old_cfa) 142 { 143 Dprintf ("%s: ip and cfa unchanged; stopping here (ip=0x%lx)\n", 144 __FUNCTION__, (long) c->dwarf.ip); 145 return -UNW_EBADFRAME; 146 } 147 148 return (c->dwarf.ip == 0) ? 0 : 1; 149} 150