1/* libunwind - a platform-independent unwind library 2 Copyright (C) 2008 CodeSourcery 3 Copyright 2011 Linaro Limited 4 Copyright (C) 2012 Tommi Rantala <tt.rantala@gmail.com> 5 6This file is part of libunwind. 7 8Permission is hereby granted, free of charge, to any person obtaining 9a copy of this software and associated documentation files (the 10"Software"), to deal in the Software without restriction, including 11without limitation the rights to use, copy, modify, merge, publish, 12distribute, sublicense, and/or sell copies of the Software, and to 13permit persons to whom the Software is furnished to do so, subject to 14the following conditions: 15 16The above copyright notice and this permission notice shall be 17included in all copies or substantial portions of the Software. 18 19THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 20EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 21MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 22NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 23LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 24OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 25WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ 26 27#include "unwind_i.h" 28#include "offsets.h" 29 30PROTECTED int 31unw_handle_signal_frame (unw_cursor_t *cursor) 32{ 33 struct cursor *c = (struct cursor *) cursor; 34 int ret; 35 unw_word_t sc_addr, sp, sp_addr = c->dwarf.cfa; 36 struct dwarf_loc sp_loc = DWARF_LOC (sp_addr, 0); 37 38 if ((ret = dwarf_get (&c->dwarf, sp_loc, &sp)) < 0) 39 return -UNW_EUNSPEC; 40 41 ret = unw_is_signal_frame (cursor); 42 Debug(1, "unw_is_signal_frame()=%d\n", ret); 43 44 /* Save the SP and PC to be able to return execution at this point 45 later in time (unw_resume). */ 46 c->sigcontext_sp = c->dwarf.cfa; 47 c->sigcontext_pc = c->dwarf.ip; 48 49 if (ret == 1) 50 { 51 /* Handle non-RT signal frame. */ 52 c->sigcontext_format = SH_SCF_LINUX_SIGFRAME; 53 sc_addr = sp_addr; 54 } 55 else if (ret == 2) 56 { 57 /* Handle RT signal frame. */ 58 c->sigcontext_format = SH_SCF_LINUX_RT_SIGFRAME; 59 sc_addr = sp_addr + sizeof (siginfo_t) + LINUX_UC_MCONTEXT_OFF; 60 } 61 else 62 return -UNW_EUNSPEC; 63 64 c->sigcontext_addr = sc_addr; 65 66 /* Update the dwarf cursor. 67 Set the location of the registers to the corresponding addresses of the 68 uc_mcontext / sigcontext structure contents. */ 69 c->dwarf.loc[UNW_SH_R0] = DWARF_LOC (sc_addr + LINUX_SC_R0_OFF, 0); 70 c->dwarf.loc[UNW_SH_R1] = DWARF_LOC (sc_addr + LINUX_SC_R1_OFF, 0); 71 c->dwarf.loc[UNW_SH_R2] = DWARF_LOC (sc_addr + LINUX_SC_R2_OFF, 0); 72 c->dwarf.loc[UNW_SH_R3] = DWARF_LOC (sc_addr + LINUX_SC_R3_OFF, 0); 73 c->dwarf.loc[UNW_SH_R4] = DWARF_LOC (sc_addr + LINUX_SC_R4_OFF, 0); 74 c->dwarf.loc[UNW_SH_R5] = DWARF_LOC (sc_addr + LINUX_SC_R5_OFF, 0); 75 c->dwarf.loc[UNW_SH_R6] = DWARF_LOC (sc_addr + LINUX_SC_R6_OFF, 0); 76 c->dwarf.loc[UNW_SH_R7] = DWARF_LOC (sc_addr + LINUX_SC_R7_OFF, 0); 77 c->dwarf.loc[UNW_SH_R8] = DWARF_LOC (sc_addr + LINUX_SC_R8_OFF, 0); 78 c->dwarf.loc[UNW_SH_R9] = DWARF_LOC (sc_addr + LINUX_SC_R9_OFF, 0); 79 c->dwarf.loc[UNW_SH_R10] = DWARF_LOC (sc_addr + LINUX_SC_R10_OFF, 0); 80 c->dwarf.loc[UNW_SH_R11] = DWARF_LOC (sc_addr + LINUX_SC_R11_OFF, 0); 81 c->dwarf.loc[UNW_SH_R12] = DWARF_LOC (sc_addr + LINUX_SC_R12_OFF, 0); 82 c->dwarf.loc[UNW_SH_R13] = DWARF_LOC (sc_addr + LINUX_SC_R13_OFF, 0); 83 c->dwarf.loc[UNW_SH_R14] = DWARF_LOC (sc_addr + LINUX_SC_R14_OFF, 0); 84 c->dwarf.loc[UNW_SH_R15] = DWARF_LOC (sc_addr + LINUX_SC_R15_OFF, 0); 85 c->dwarf.loc[UNW_SH_PR] = DWARF_LOC (sc_addr + LINUX_SC_PR_OFF, 0); 86 c->dwarf.loc[UNW_SH_PC] = DWARF_LOC (sc_addr + LINUX_SC_PC_OFF, 0); 87 88 /* Set SP/CFA and PC/IP. */ 89 dwarf_get (&c->dwarf, c->dwarf.loc[UNW_SH_R15], &c->dwarf.cfa); 90 dwarf_get (&c->dwarf, c->dwarf.loc[UNW_SH_PC], &c->dwarf.ip); 91 92 c->dwarf.pi_valid = 0; 93 94 return 1; 95} 96 97PROTECTED int 98unw_step (unw_cursor_t *cursor) 99{ 100 struct cursor *c = (struct cursor *) cursor; 101 int ret; 102 103 Debug (1, "(cursor=%p)\n", c); 104 105 if (unw_is_signal_frame (cursor)) 106 return unw_handle_signal_frame (cursor); 107 108 ret = dwarf_step (&c->dwarf); 109 110 if (unlikely (ret == -UNW_ESTOPUNWIND)) 111 return ret; 112 113 if (unlikely (ret < 0)) 114 return 0; 115 116 return (c->dwarf.ip == 0) ? 0 : 1; 117} 118