projects / thirdparty / gcc.git / blame
| Commit | Line | Data |
|---|---|---|
| 6c633d45 | 1 | /* DWARF2 EH unwinding support for Xtensa. |
| 5624e564 | 2 | Copyright (C) 2008-2015 Free Software Foundation, Inc. |
| 6c633d45 BW |
3 | |
| 4 | This file is part of GCC. | |
| 5 | ||
| 6 | GCC is free software; you can redistribute it and/or modify | |
| 7 | it under the terms of the GNU General Public License as published by | |
| 748086b7 | 8 | the Free Software Foundation; either version 3, or (at your option) |
| 6c633d45 BW |
9 | any later version. |
| 10 | ||
| 6c633d45 BW |
11 | GCC is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 14 | GNU General Public License for more details. | |
| 15 | ||
| 748086b7 JJ |
16 | Under Section 7 of GPL version 3, you are granted additional |
| 17 | permissions described in the GCC Runtime Library Exception, version | |
| 18 | 3.1, as published by the Free Software Foundation. | |
| 19 | ||
| 20 | You should have received a copy of the GNU General Public License and | |
| 21 | a copy of the GCC Runtime Library Exception along with this program; | |
| 22 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
| 23 | <http://www.gnu.org/licenses/>. */ | |
| 6c633d45 BW |
24 | |
| 25 | /* Do code reading to identify a signal frame, and set the frame | |
| 26 | state data appropriately. See unwind-dw2-xtensa.c for the structs. | |
| 27 | Don't use this at all if inhibit_libc is used. */ | |
| 28 | ||
| 29 | #ifndef inhibit_libc | |
| 30 | ||
| 31 | #include <signal.h> | |
| 32 | #include <sys/ucontext.h> | |
| 33 | ||
| 34 | /* Encoded bytes for Xtensa instructions: | |
| 35 | movi a2, __NR_rt_sigreturn | |
| 36 | syscall | |
| 37 | entry (first byte only) | |
| 38 | Some of the bytes are endian-dependent. */ | |
| 39 | ||
| 40 | #define MOVI_BYTE0 0x22 | |
| 41 | #define MOVI_BYTE2 225 /* __NR_rt_sigreturn */ | |
| 42 | #define SYSC_BYTE0 0 | |
| 43 | #define SYSC_BYTE2 0 | |
| 44 | ||
| 45 | #ifdef __XTENSA_EB__ | |
| 46 | #define MOVI_BYTE1 0x0a | |
| 47 | #define SYSC_BYTE1 0x05 | |
| 48 | #define ENTRY_BYTE 0x6c | |
| 49 | #else | |
| 50 | #define MOVI_BYTE1 0xa0 | |
| 51 | #define SYSC_BYTE1 0x50 | |
| 52 | #define ENTRY_BYTE 0x36 | |
| 53 | #endif | |
| 54 | ||
| 590e2636 | 55 | #ifdef __XTENSA_WINDOWED_ABI__ |
| 6c633d45 BW |
56 | #define MD_FALLBACK_FRAME_STATE_FOR xtensa_fallback_frame_state |
| 57 | ||
| 58 | static _Unwind_Reason_Code | |
| 59 | xtensa_fallback_frame_state (struct _Unwind_Context *context, | |
| 60 | _Unwind_FrameState *fs) | |
| 61 | { | |
| 62 | unsigned char *pc = context->ra; | |
| 63 | struct sigcontext *sc; | |
| 64 | ||
| 65 | struct rt_sigframe { | |
| 1bde7dab | 66 | siginfo_t info; |
| 6c633d45 BW |
67 | struct ucontext uc; |
| 68 | } *rt_; | |
| 69 | ||
| 70 | /* movi a2, __NR_rt_sigreturn; syscall */ | |
| 71 | if (pc[0] != MOVI_BYTE0 | |
| 72 | || pc[1] != MOVI_BYTE1 | |
| 73 | || pc[2] != MOVI_BYTE2 | |
| 74 | || pc[3] != SYSC_BYTE0 | |
| 75 | || pc[4] != SYSC_BYTE1 | |
| 76 | || pc[5] != SYSC_BYTE2) | |
| 77 | return _URC_END_OF_STACK; | |
| 78 | ||
| 79 | rt_ = context->sp; | |
| 80 | sc = &rt_->uc.uc_mcontext; | |
| 81 | fs->signal_regs = (_Unwind_Word *) sc->sc_a; | |
| 82 | ||
| 83 | /* If the signal arrived just before an ENTRY instruction, find the return | |
| 84 | address and pretend the signal arrived before executing the CALL. */ | |
| 85 | if (*(unsigned char *) sc->sc_pc == ENTRY_BYTE) | |
| 86 | { | |
| 87 | unsigned callinc = (sc->sc_ps >> 16) & 3; | |
| 88 | fs->signal_ra = ((sc->sc_a[callinc << 2] & XTENSA_RA_FIELD_MASK) | |
| 89 | | context->ra_high_bits) - 3; | |
| 90 | } | |
| 91 | else | |
| 92 | fs->signal_ra = sc->sc_pc; | |
| 93 | ||
| 94 | fs->signal_frame = 1; | |
| 95 | return _URC_NO_REASON; | |
| 96 | } | |
| 97 | ||
| 590e2636 MF |
98 | #endif /* __XTENSA_WINDOWED_ABI__ */ |
| 99 | ||
| 6c633d45 | 100 | #endif /* ifdef inhibit_libc */ |