sewardj | 267100d | 2005-04-24 12:33:12 +0000 | [diff] [blame] | 1 | |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 2 | /*--------------------------------------------------------------------*/ |
sewardj | 267100d | 2005-04-24 12:33:12 +0000 | [diff] [blame] | 3 | /*--- Take snapshots of client stacks. m_stacktrace.c ---*/ |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 4 | /*--------------------------------------------------------------------*/ |
| 5 | |
| 6 | /* |
| 7 | This file is part of Valgrind, a dynamic binary instrumentation |
| 8 | framework. |
| 9 | |
| 10 | Copyright (C) 2000-2005 Julian Seward |
| 11 | jseward@acm.org |
| 12 | |
| 13 | This program is free software; you can redistribute it and/or |
| 14 | modify it under the terms of the GNU General Public License as |
| 15 | published by the Free Software Foundation; either version 2 of the |
| 16 | License, or (at your option) any later version. |
| 17 | |
| 18 | This program is distributed in the hope that it will be useful, but |
| 19 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 21 | General Public License for more details. |
| 22 | |
| 23 | You should have received a copy of the GNU General Public License |
| 24 | along with this program; if not, write to the Free Software |
| 25 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 26 | 02111-1307, USA. |
| 27 | |
| 28 | The GNU General Public License is contained in the file COPYING. |
| 29 | */ |
| 30 | |
| 31 | #include "core.h" |
| 32 | #include "pub_core_stacktrace.h" |
| 33 | |
| 34 | /*------------------------------------------------------------*/ |
| 35 | /*--- Exported functions. ---*/ |
| 36 | /*------------------------------------------------------------*/ |
| 37 | |
| 38 | /* Take a snapshot of the client's stack, putting the up to 'n_ips' IPs |
| 39 | into 'ips'. In order to be thread-safe, we pass in the thread's IP |
| 40 | and FP. Returns number of IPs put in 'ips'. */ |
sewardj | 3516553 | 2005-04-30 18:47:48 +0000 | [diff] [blame] | 41 | UInt VG_(get_StackTrace2) ( Addr* ips, UInt n_ips, |
| 42 | Addr ip, Addr sp, Addr fp, |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 43 | Addr fp_min, Addr fp_max_orig ) |
| 44 | { |
| 45 | static const Bool debug = False; |
| 46 | Int i; |
| 47 | Addr fp_max; |
| 48 | UInt n_found = 0; |
| 49 | |
| 50 | VGP_PUSHCC(VgpExeContext); |
| 51 | |
| 52 | /* First snaffle IPs from the client's stack into ips[0 .. n_ips-1], |
| 53 | putting zeroes in when the trail goes cold, which we guess to be when |
| 54 | FP is not a reasonable stack location. We also assert that FP |
| 55 | increases down the chain. */ |
| 56 | |
| 57 | // Gives shorter stack trace for tests/badjump.c |
| 58 | // JRS 2002-aug-16: I don't think this is a big deal; looks ok for |
| 59 | // most "normal" backtraces. |
| 60 | // NJN 2002-sep-05: traces for pthreaded programs are particularly bad. |
| 61 | |
| 62 | // JRS 2002-sep-17: hack, to round up fp_max to the end of the |
| 63 | // current page, at least. Dunno if it helps. |
| 64 | // NJN 2002-sep-17: seems to -- stack traces look like 1.0.X again |
| 65 | fp_max = (fp_max_orig + VKI_PAGE_SIZE - 1) & ~(VKI_PAGE_SIZE - 1); |
| 66 | fp_max -= sizeof(Addr); |
| 67 | |
| 68 | if (debug) |
| 69 | VG_(printf)("n_ips=%d fp_min=%p fp_max_orig=%p, fp_max=%p ip=%p fp=%p\n", |
| 70 | n_ips, fp_min, fp_max_orig, fp_max, ip, fp); |
| 71 | |
| 72 | /* Assertion broken before main() is reached in pthreaded programs; the |
| 73 | * offending stack traces only have one item. --njn, 2002-aug-16 */ |
| 74 | /* vg_assert(fp_min <= fp_max);*/ |
| 75 | |
sewardj | 3516553 | 2005-04-30 18:47:48 +0000 | [diff] [blame] | 76 | ips[0] = ip; |
| 77 | i = 1; |
| 78 | |
| 79 | if (fp_min + VG_(clo_max_stackframe) <= fp_max) { |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 80 | /* If the stack is ridiculously big, don't poke around ... but |
| 81 | don't bomb out either. Needed to make John Regehr's |
| 82 | user-space threads package work. JRS 20021001 */ |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 83 | } else { |
sewardj | 3516553 | 2005-04-30 18:47:48 +0000 | [diff] [blame] | 84 | |
| 85 | while (True) { |
| 86 | |
| 87 | if (i >= n_ips) |
| 88 | break; |
| 89 | |
| 90 | /* Try to derive a new (ip,sp,fp) triple from the current |
| 91 | set. */ |
| 92 | |
| 93 | /* First off, see if there is any CFI info to hand which can |
| 94 | be used. */ |
| 95 | if ( VG_(use_CFI_info)( &ip, &sp, &fp, fp_min, fp_max ) ) { |
| 96 | ips[i++] = ip; |
| 97 | if (debug) |
| 98 | VG_(printf)(" ipsC[%d]=%08p\n", i-1, ips[i-1]); |
| 99 | continue; |
| 100 | } |
| 101 | |
| 102 | /* If VG_(use_CFI_info) fails, it won't modify ip/sp/fp, so |
| 103 | we can safely try the old-fashioned method. */ |
| 104 | /* This bit is supposed to deal with frames resulting from |
| 105 | functions which begin "pushl% ebp ; movl %esp, %ebp" (x86) |
| 106 | or "pushl% ebp ; movl %esp, %ebp" (amd64). Unfortunately, |
| 107 | since we can't (easily) look at the insns at the start of |
| 108 | the fn, like GDB does, there's no reliable way to tell. |
| 109 | Hence the hack of first trying out CFI, and if that fails, |
| 110 | then use this as a fallback. */ |
| 111 | if (fp_min <= fp && fp <= fp_max) { |
| 112 | /* fp looks sane, so use it. */ |
| 113 | ip = VGA_STACK_FRAME_RET(fp); |
| 114 | sp = fp + sizeof(Addr) /*saved %ebp/%rbp*/ |
| 115 | + sizeof(Addr) /*ra*/; |
| 116 | fp = VGA_STACK_FRAME_NEXT(fp); |
| 117 | ips[i++] = ip; |
| 118 | if (debug) |
| 119 | VG_(printf)(" ipsF[%d]=%08p\n", i-1, ips[i-1]); |
| 120 | continue; |
| 121 | } |
| 122 | |
| 123 | /* No luck there. We have to give up. */ |
| 124 | break; |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 125 | } |
sewardj | 3516553 | 2005-04-30 18:47:48 +0000 | [diff] [blame] | 126 | |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 127 | } |
| 128 | n_found = i; |
| 129 | |
| 130 | /* Put zeroes in the rest. */ |
| 131 | for (; i < n_ips; i++) { |
| 132 | ips[i] = 0; |
| 133 | } |
| 134 | VGP_POPCC(VgpExeContext); |
| 135 | |
| 136 | return n_found; |
| 137 | } |
| 138 | |
| 139 | UInt VG_(get_StackTrace) ( ThreadId tid, StackTrace ips, UInt n_ips ) |
| 140 | { |
| 141 | /* thread in thread table */ |
| 142 | ThreadState* tst = & VG_(threads)[ tid ]; |
| 143 | Addr ip = INSTR_PTR(tst->arch); |
| 144 | Addr fp = FRAME_PTR(tst->arch); |
| 145 | Addr sp = STACK_PTR(tst->arch); |
njn | 50ba34e | 2005-04-04 02:41:42 +0000 | [diff] [blame] | 146 | Addr stack_highest_word = tst->client_stack_highest_word; |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 147 | |
sewardj | 520e349 | 2005-05-02 10:39:16 +0000 | [diff] [blame] | 148 | #if defined(VGP_x86_linux) |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 149 | /* Nasty little hack to deal with sysinfo syscalls - if libc is |
| 150 | using the sysinfo page for syscalls (the TLS version does), then |
| 151 | ip will always appear to be in that page when doing a syscall, |
| 152 | not the actual libc function doing the syscall. This check sees |
| 153 | if IP is within the syscall code, and pops the return address |
| 154 | off the stack so that ip is placed within the library function |
| 155 | calling the syscall. This makes stack backtraces much more |
| 156 | useful. */ |
| 157 | if (ip >= VG_(client_trampoline_code)+VG_(tramp_syscall_offset) && |
| 158 | ip < VG_(client_trampoline_code)+VG_(trampoline_code_length) && |
| 159 | VG_(is_addressable)(sp, sizeof(Addr), VKI_PROT_READ)) { |
| 160 | ip = *(Addr *)sp; |
| 161 | sp += sizeof(Addr); |
| 162 | } |
| 163 | #endif |
| 164 | if (0) |
| 165 | VG_(printf)("tid %d: stack_highest=%p ip=%p sp=%p fp=%p\n", |
| 166 | tid, stack_highest_word, ip, sp, fp); |
| 167 | |
sewardj | 3516553 | 2005-04-30 18:47:48 +0000 | [diff] [blame] | 168 | return VG_(get_StackTrace2)(ips, n_ips, ip, sp, fp, sp, stack_highest_word); |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 169 | } |
| 170 | |
| 171 | static void printIpDesc(UInt n, Addr ip) |
| 172 | { |
njn | 47b209a | 2005-03-25 23:47:16 +0000 | [diff] [blame] | 173 | static UChar buf[VG_ERRTXT_LEN]; |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 174 | |
njn | 47b209a | 2005-03-25 23:47:16 +0000 | [diff] [blame] | 175 | VG_(describe_IP)(ip, buf, VG_ERRTXT_LEN); |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 176 | VG_(message)(Vg_UserMsg, " %s %s", ( n == 0 ? "at" : "by" ), buf); |
| 177 | } |
| 178 | |
| 179 | /* Print a StackTrace. */ |
| 180 | void VG_(pp_StackTrace) ( StackTrace ips, UInt n_ips ) |
| 181 | { |
| 182 | vg_assert( n_ips > 0 ); |
| 183 | VG_(apply_StackTrace)( printIpDesc, ips, n_ips ); |
| 184 | } |
| 185 | |
| 186 | /* Get and immediately print a StackTrace. */ |
| 187 | void VG_(get_and_pp_StackTrace) ( ThreadId tid, UInt n_ips ) |
| 188 | { |
| 189 | Addr ips[n_ips]; |
| 190 | VG_(get_StackTrace)(tid, ips, n_ips); |
| 191 | VG_(pp_StackTrace) ( ips, n_ips); |
| 192 | } |
| 193 | |
| 194 | |
| 195 | void VG_(apply_StackTrace)( void(*action)(UInt n, Addr ip), |
| 196 | StackTrace ips, UInt n_ips ) |
| 197 | { |
| 198 | #define MYBUF_LEN 10 // only needs to be long enough for "main" |
| 199 | |
| 200 | Bool main_done = False; |
| 201 | Char mybuf[MYBUF_LEN]; // ok to stack allocate mybuf[] -- it's tiny |
| 202 | Int i = 0; |
| 203 | |
| 204 | vg_assert(n_ips > 0); |
| 205 | do { |
| 206 | Addr ip = ips[i]; |
| 207 | if (i > 0) |
njn | 9fb73db | 2005-03-27 01:55:21 +0000 | [diff] [blame] | 208 | ip -= VGA_MIN_INSTR_SIZE; // point to calling line |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 209 | |
| 210 | // Stop after "main"; if main() is recursive, stop after last main(). |
| 211 | if ( ! VG_(clo_show_below_main)) { |
| 212 | VG_(get_fnname_nodemangle)( ip, mybuf, MYBUF_LEN ); |
| 213 | if ( VG_STREQ("main", mybuf) ) |
| 214 | main_done = True; |
| 215 | else if (main_done) |
| 216 | break; |
| 217 | } |
| 218 | |
| 219 | // Act on the ip |
| 220 | action(i, ip); |
| 221 | |
| 222 | i++; |
| 223 | } while (i < n_ips && ips[i] != 0); |
| 224 | |
| 225 | #undef MYBUF_LEN |
| 226 | } |
| 227 | |
| 228 | |
| 229 | /*--------------------------------------------------------------------*/ |
sewardj | 267100d | 2005-04-24 12:33:12 +0000 | [diff] [blame] | 230 | /*--- end m_stacktrace.c ---*/ |
njn | d01fef7 | 2005-03-25 23:35:48 +0000 | [diff] [blame] | 231 | /*--------------------------------------------------------------------*/ |