1 /* libunwind - a platform-independent unwind library 2 Copyright (C) 2003-2005 Hewlett-Packard Co 3 Contributed by David Mosberger-Tang <davidm (at) hpl.hp.com> 4 5 This file is part of libunwind. 6 7 Permission is hereby granted, free of charge, to any person obtaining 8 a copy of this software and associated documentation files (the 9 "Software"), to deal in the Software without restriction, including 10 without limitation the rights to use, copy, modify, merge, publish, 11 distribute, sublicense, and/or sell copies of the Software, and to 12 permit persons to whom the Software is furnished to do so, subject to 13 the following conditions: 14 15 The above copyright notice and this permission notice shall be 16 included in all copies or substantial portions of the Software. 17 18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 20 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 21 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 22 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 23 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 24 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ 25 26 #define UNW_LOCAL_ONLY 27 28 #include <setjmp.h> 29 30 #include "libunwind_i.h" 31 #include "jmpbuf.h" 32 #include "setjmp_i.h" 33 34 #if !defined(_NSIG) && defined(_SIG_MAXSIG) 35 # define _NSIG (_SIG_MAXSIG - 1) 36 #endif 37 38 #if defined(__GLIBC__) 39 #if __GLIBC_PREREQ(2, 4) 40 41 /* Starting with glibc-2.4, {sig,}setjmp in GLIBC obfuscates the 42 register values in jmp_buf by XORing them with a "random" 43 canary value. 44 45 This makes it impossible to implement longjmp, as we 46 can never match wp[JB_SP], unless we decode the canary first. 47 48 Doing so is possible, but doesn't appear to be worth the trouble, 49 so we simply defer to glibc siglongjmp here. */ 50 51 #define siglongjmp __nonworking_siglongjmp 52 static void siglongjmp (sigjmp_buf env, int val) UNUSED; 53 #endif 54 #endif /* __GLIBC_PREREQ */ 55 56 void 57 siglongjmp (sigjmp_buf env, int val) 58 { 59 unw_word_t *wp = (unw_word_t *) env; 60 extern int _UI_siglongjmp_cont; 61 extern int _UI_longjmp_cont; 62 unw_context_t uc; 63 unw_cursor_t c; 64 unw_word_t sp; 65 int *cont; 66 67 if (unw_getcontext (&uc) < 0 || unw_init_local (&c, &uc) < 0) 68 abort (); 69 70 do 71 { 72 if (unw_get_reg (&c, UNW_REG_SP, &sp) < 0) 73 abort (); 74 #ifdef __FreeBSD__ 75 if (sp != wp[JB_SP] + sizeof(unw_word_t)) 76 #else 77 if (sp != wp[JB_SP]) 78 #endif 79 continue; 80 81 if (!bsp_match (&c, wp)) 82 continue; 83 84 /* found the right frame: */ 85 86 /* default to resuming without restoring signal-mask */ 87 cont = &_UI_longjmp_cont; 88 89 /* Order of evaluation is important here: if unw_resume() 90 restores signal mask, we must set it up appropriately, even 91 if wp[JB_MASK_SAVED] is FALSE. */ 92 if (!resume_restores_sigmask (&c, wp) && wp[JB_MASK_SAVED]) 93 { 94 /* sigmask was saved */ 95 #if defined(__linux__) 96 if (UNW_NUM_EH_REGS < 4 || _NSIG > 16 * sizeof (unw_word_t)) 97 /* signal mask doesn't fit into EH arguments and we can't 98 put it on the stack without overwriting something 99 else... */ 100 abort (); 101 else 102 if (unw_set_reg (&c, UNW_REG_EH + 2, wp[JB_MASK]) < 0 103 || (_NSIG > 8 * sizeof (unw_word_t) 104 && unw_set_reg (&c, UNW_REG_EH + 3, wp[JB_MASK + 1]) < 0)) 105 abort (); 106 #elif defined(__FreeBSD__) 107 if (unw_set_reg (&c, UNW_REG_EH + 2, &wp[JB_MASK]) < 0) 108 abort(); 109 #else 110 #error Port me 111 #endif 112 cont = &_UI_siglongjmp_cont; 113 } 114 115 if (unw_set_reg (&c, UNW_REG_EH + 0, wp[JB_RP]) < 0 116 || unw_set_reg (&c, UNW_REG_EH + 1, val) < 0 117 || unw_set_reg (&c, UNW_REG_IP, (unw_word_t) (uintptr_t) cont)) 118 abort (); 119 120 unw_resume (&c); 121 122 abort (); 123 } 124 while (unw_step (&c) > 0); 125 126 abort (); 127 } 128
