| /* libunwind - a platform-independent unwind library |
| Copyright (C) 2008 CodeSourcery |
| Copyright 2011 Linaro Limited |
| |
| This file is part of libunwind. |
| |
| Permission is hereby granted, free of charge, to any person obtaining |
| a copy of this software and associated documentation files (the |
| "Software"), to deal in the Software without restriction, including |
| without limitation the rights to use, copy, modify, merge, publish, |
| distribute, sublicense, and/or sell copies of the Software, and to |
| permit persons to whom the Software is furnished to do so, subject to |
| the following conditions: |
| |
| The above copyright notice and this permission notice shall be |
| included in all copies or substantial portions of the Software. |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE |
| LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION |
| OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION |
| WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ |
| |
| #include "unwind_i.h" |
| |
| #ifdef __linux__ |
| #define ARM_NR_sigreturn 119 |
| #define ARM_NR_rt_sigreturn 173 |
| #define ARM_NR_OABI_SYSCALL_BASE 0x900000 |
| |
| /* ARM EABI sigreturn (the syscall number is loaded into r7) */ |
| #define MOV_R7_SIGRETURN (0xe3a07000UL | ARM_NR_sigreturn) |
| #define MOV_R7_RT_SIGRETURN (0xe3a07000UL | ARM_NR_rt_sigreturn) |
| |
| /* ARM OABI sigreturn (using SWI) */ |
| #define ARM_SIGRETURN \ |
| (0xef000000UL | ARM_NR_sigreturn | ARM_NR_OABI_SYSCALL_BASE) |
| #define ARM_RT_SIGRETURN \ |
| (0xef000000UL | ARM_NR_rt_sigreturn | ARM_NR_OABI_SYSCALL_BASE) |
| |
| /* Thumb sigreturn (two insns, syscall number is loaded into r7) */ |
| #define THUMB_SIGRETURN (0xdf00UL << 16 | 0x2700 | ARM_NR_sigreturn) |
| #define THUMB_RT_SIGRETURN (0xdf00UL << 16 | 0x2700 | ARM_NR_rt_sigreturn) |
| #endif /* __linux__ */ |
| |
| /* Returns 1 in case of a non-RT signal frame and 2 in case of a RT signal |
| frame. */ |
| PROTECTED int |
| unw_is_signal_frame (unw_cursor_t *cursor) |
| { |
| #ifdef __linux__ |
| struct cursor *c = (struct cursor *) cursor; |
| unw_word_t w0, ip; |
| unw_addr_space_t as; |
| unw_accessors_t *a; |
| void *arg; |
| int ret; |
| |
| as = c->dwarf.as; |
| a = unw_get_accessors (as); |
| arg = c->dwarf.as_arg; |
| |
| ip = c->dwarf.ip; |
| |
| if ((ret = (*a->access_mem) (as, ip, &w0, 0, arg)) < 0) |
| return ret; |
| |
| /* Return 1 if the IP points to a non-RT sigreturn sequence. */ |
| if (w0 == MOV_R7_SIGRETURN || w0 == ARM_SIGRETURN || w0 == THUMB_SIGRETURN) |
| return 1; |
| /* Return 2 if the IP points to a RT sigreturn sequence. */ |
| else if (w0 == MOV_R7_RT_SIGRETURN || w0 == ARM_RT_SIGRETURN |
| || w0 == THUMB_RT_SIGRETURN) |
| return 2; |
| |
| return 0; |
| #elif defined (__Fuchsia__) |
| return 0; |
| #else |
| return -UNW_ENOINFO; |
| #endif |
| } |
| |
| PROTECTED int |
| unw_handle_signal_frame (unw_cursor_t *cursor) |
| { |
| #ifdef __linux__ |
| struct cursor *c = (struct cursor *) cursor; |
| int ret; |
| unw_word_t sc_addr, sp, sp_addr = c->dwarf.cfa; |
| struct dwarf_loc sp_loc = DWARF_LOC (sp_addr, 0); |
| |
| if ((ret = dwarf_get (&c->dwarf, sp_loc, &sp)) < 0) |
| return -UNW_EUNSPEC; |
| |
| /* Obtain signal frame type (non-RT or RT). */ |
| ret = unw_is_signal_frame (cursor); |
| |
| /* Save the SP and PC to be able to return execution at this point |
| later in time (unw_resume). */ |
| c->sigcontext_sp = c->dwarf.cfa; |
| c->sigcontext_pc = c->dwarf.ip; |
| |
| /* Since kernel version 2.6.18 the non-RT signal frame starts with a |
| ucontext while the RT signal frame starts with a siginfo, followed |
| by a sigframe whose first element is an ucontext. |
| Prior 2.6.18 the non-RT signal frame starts with a sigcontext while |
| the RT signal frame starts with two pointers followed by a siginfo |
| and an ucontext. The first pointer points to the start of the siginfo |
| structure and the second one to the ucontext structure. */ |
| |
| if (ret == 1) |
| { |
| /* Handle non-RT signal frames. Check if the first word on the stack |
| is the magic number. */ |
| if (sp == 0x5ac3c35a) |
| { |
| c->sigcontext_format = ARM_SCF_LINUX_SIGFRAME; |
| sc_addr = sp_addr + LINUX_UC_MCONTEXT_OFF; |
| } |
| else |
| { |
| c->sigcontext_format = ARM_SCF_LINUX_OLD_SIGFRAME; |
| sc_addr = sp_addr; |
| } |
| } |
| else if (ret == 2) |
| { |
| /* Handle RT signal frames. Check if the first word on the stack is a |
| pointer to the siginfo structure. */ |
| if (sp == sp_addr + 8) |
| { |
| c->sigcontext_format = ARM_SCF_LINUX_OLD_RT_SIGFRAME; |
| sc_addr = sp_addr + 8 + sizeof (siginfo_t) + LINUX_UC_MCONTEXT_OFF; |
| } |
| else |
| { |
| c->sigcontext_format = ARM_SCF_LINUX_RT_SIGFRAME; |
| sc_addr = sp_addr + sizeof (siginfo_t) + LINUX_UC_MCONTEXT_OFF; |
| } |
| } |
| else |
| return -UNW_EUNSPEC; |
| |
| c->sigcontext_addr = sc_addr; |
| c->frame_info.frame_type = UNW_ARM_FRAME_SIGRETURN; |
| c->frame_info.cfa_reg_offset = sc_addr - sp_addr; |
| |
| /* Update the dwarf cursor. |
| Set the location of the registers to the corresponding addresses of the |
| uc_mcontext / sigcontext structure contents. */ |
| c->dwarf.loc[UNW_ARM_R0] = DWARF_LOC (sc_addr + LINUX_SC_R0_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R1] = DWARF_LOC (sc_addr + LINUX_SC_R1_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R2] = DWARF_LOC (sc_addr + LINUX_SC_R2_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R3] = DWARF_LOC (sc_addr + LINUX_SC_R3_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R4] = DWARF_LOC (sc_addr + LINUX_SC_R4_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R5] = DWARF_LOC (sc_addr + LINUX_SC_R5_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R6] = DWARF_LOC (sc_addr + LINUX_SC_R6_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R7] = DWARF_LOC (sc_addr + LINUX_SC_R7_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R8] = DWARF_LOC (sc_addr + LINUX_SC_R8_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R9] = DWARF_LOC (sc_addr + LINUX_SC_R9_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R10] = DWARF_LOC (sc_addr + LINUX_SC_R10_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R11] = DWARF_LOC (sc_addr + LINUX_SC_FP_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R12] = DWARF_LOC (sc_addr + LINUX_SC_IP_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R13] = DWARF_LOC (sc_addr + LINUX_SC_SP_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R14] = DWARF_LOC (sc_addr + LINUX_SC_LR_OFF, 0); |
| c->dwarf.loc[UNW_ARM_R15] = DWARF_LOC (sc_addr + LINUX_SC_PC_OFF, 0); |
| |
| /* Set SP/CFA and PC/IP. */ |
| dwarf_get (&c->dwarf, c->dwarf.loc[UNW_ARM_R13], &c->dwarf.cfa); |
| dwarf_get (&c->dwarf, c->dwarf.loc[UNW_ARM_R15], &c->dwarf.ip); |
| |
| c->dwarf.pi_valid = 0; |
| |
| return 1; |
| #else |
| return -UNW_EBADFRAME; |
| #endif |
| } |