| Matt Fischer | e4fa46e | 2010-01-11 10:02:06 +0800 | [diff] [blame] | 1 | #include <signal.h> |
| 2 | |
| 3 | extern int __sigaction(int signum, const struct sigaction *act, struct sigaction *oldact); |
| 4 | extern void __sig_restorer(); |
| 5 | |
| 6 | int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact) |
| 7 | { |
| 8 | struct sigaction real_act; |
| 9 | |
| 10 | /* If the caller has not set a custom restorer, then set up a default one. |
| 11 | * The code will function properly without this, however GDB will not be |
| 12 | * able to recognize the stack frame as a signal trampoline, because it |
| 13 | * is hardcoded to look for the instruction sequence that glibc uses in |
| 14 | * its custom restorer. By creating our own restorer with the same |
| 15 | * sequence, we ensure that GDB correctly identifies this as a signal |
| 16 | * trampoline frame. |
| 17 | * |
| 18 | * See http://sourceware.org/ml/gdb/2010-01/msg00143.html for more |
| 19 | * information on this.*/ |
| 20 | if(act && !(act->sa_flags & SA_RESTORER)) { |
| 21 | real_act = *act; |
| 22 | real_act.sa_flags |= SA_RESTORER; |
| 23 | real_act.sa_restorer = __sig_restorer; |
| 24 | |
| 25 | act = &real_act; |
| 26 | } |
| 27 | |
| 28 | return __sigaction(signum, act, oldact); |
| 29 | } |