diff options
Diffstat (limited to 'sysdeps/generic/segfault.c')
| -rw-r--r-- | sysdeps/generic/segfault.c | 88 |
1 files changed, 20 insertions, 68 deletions
diff --git a/sysdeps/generic/segfault.c b/sysdeps/generic/segfault.c index 47f2447169..f141fff661 100644 --- a/sysdeps/generic/segfault.c +++ b/sysdeps/generic/segfault.c @@ -19,11 +19,13 @@ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ +#include <alloca.h> #include <ctype.h> #include <errno.h> #include <execinfo.h> #include <fcntl.h> #include <signal.h> +#include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> @@ -33,9 +35,6 @@ #include <bp-checks.h> -/* Get the definition of "struct layout". */ -#include <frame.h> - /* This file defines macros to access the content of the sigcontext element passed up by the signal handler. */ #include <sigcontextinfo.h> @@ -43,35 +42,6 @@ /* Get code to possibly dump the content of all registers. */ #include <register-dump.h> -/* This implementation assumes a stack layout that matches the defaults - used by gcc's `__builtin_frame_address' and `__builtin_return_address' - (FP is the frame pointer register): - - +-----------------+ +-----------------+ - FP -> | previous FP --------> | previous FP ------>... - | | | | - | return address | | return address | - +-----------------+ +-----------------+ - - */ - -/* Get some notion of the current stack. Need not be exactly the top - of the stack, just something somewhere in the current frame. */ -#ifndef CURRENT_STACK_FRAME -# define CURRENT_STACK_FRAME ({ char __csf; &__csf; }) -#endif - -/* By default we assume that the stack grows downward. */ -#ifndef INNER_THAN -# define INNER_THAN < -#endif - -/* By default assume the `next' pointer in struct layout points to the - next struct layout. */ -#ifndef ADVANCE_STACK_FRAME -# define ADVANCE_STACK_FRAME(next) BOUNDED_1 ((struct layout *) (next)) -#endif - /* We'll use tis a lot. */ #define WRITE_STRING(s) write (fd, s, strlen (s)) @@ -102,13 +72,10 @@ write_strsignal (int fd, int signal) static void catch_segfault (int signal, SIGCONTEXT ctx) { - struct layout *current; - void *__unbounded top_frame; - void *__unbounded top_stack; - int fd; + int fd, cnt, i; void **arr; - size_t cnt; struct sigaction sa; + uintptr_t pc; /* This is the name of the file we are writing to. If none is given or we cannot write to this file write to stderr. */ @@ -130,41 +97,26 @@ catch_segfault (int signal, SIGCONTEXT ctx) WRITE_STRING ("\nBacktrace:\n"); - top_frame = GET_FRAME (ctx); - top_stack = GET_STACK (ctx); + /* Get the backtrace. */ + arr = alloca (256 * sizeof (void *)); + cnt = backtrace (arr, 256); - /* First count how many entries we'll have. */ - cnt = 1; - current = BOUNDED_1 ((struct layout *) top_frame); - while (!((void *) current INNER_THAN top_stack - || !((void *) current INNER_THAN __libc_stack_end))) - { - ++cnt; - - current = ADVANCE_STACK_FRAME (current->next); - } - - arr = alloca (cnt * sizeof (void *)); - - /* First handle the program counter from the structure. */ - arr[0] = GET_PC (ctx); - - current = BOUNDED_1 ((struct layout *) top_frame); - cnt = 1; - while (!((void *) current INNER_THAN top_stack - || !((void *) current INNER_THAN __libc_stack_end))) - { - arr[cnt++] = current->return_address; - - current = ADVANCE_STACK_FRAME (current->next); - } + /* Now try to locate the PC from signal context in the backtrace. + Normally it will be found at arr[2], but it might appear later + if there were some signal handler wrappers. Allow a few bytes + difference to cope with as many arches as possible. */ + pc = (uintptr_t) GET_PC (ctx); + for (i = 0; i < cnt; ++i) + if ((uintptr_t) arr[i] >= pc - 16 && (uintptr_t) arr[i] <= pc + 16) + break; - /* If the last return address was NULL, assume that it doesn't count. */ - if (arr[cnt-1] == NULL) - cnt--; + /* If we haven't found it, better dump full backtrace even including + the signal handler frames instead of not dumping anything. */ + if (i == cnt) + i = 0; /* Now generate nicely formatted output. */ - __backtrace_symbols_fd (arr, cnt, fd); + __backtrace_symbols_fd (arr + i, cnt - i, fd); #ifdef HAVE_PROC_SELF /* Now the link map. */ |