| /* Copyright (C) 2005-2014 Free Software Foundation, Inc. |
| |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public License as |
| published by the Free Software Foundation; either version 2.1 of the |
| License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <stddef.h> |
| #include <asm/sigcontext.h> |
| #include <linux/signal.h> |
| #include <asm-generic/ucontext.h> |
| #include <asm/unistd.h> |
| |
| int |
| _identify_sighandler (unsigned long fp, unsigned long pc, |
| unsigned long *pprev_fp, unsigned long *pprev_pc, |
| unsigned long *retaddr) |
| { |
| unsigned long *tramp = 0; |
| struct ucontext *uc; |
| |
| if (*retaddr == 0) |
| { |
| /* Kernel inserts the tramp between the signal handler frame and the |
| caller frame in signal handling. */ |
| tramp = (unsigned long *) pc; |
| tramp += 2; |
| if ((*tramp == (0x31800000 | __NR_rt_sigreturn)) |
| && (*(tramp+1) == 0xb9cc0008)) |
| { |
| /* Signal handler function argument are: |
| int sig_num, siginfo_t * info, void * ucontext |
| therefore ucontext is the 3rd argument. */ |
| unsigned long ucptr = ((unsigned long) tramp |
| - sizeof (struct ucontext)); |
| uc = (struct ucontext *) ucptr; |
| *pprev_pc = uc->uc_mcontext.regs.pc; |
| /* Need to record the return address since the return address of the |
| function which causes this signal may not be recorded in the |
| stack. */ |
| *pprev_fp = uc->uc_mcontext.regs.r1; |
| *retaddr = uc->uc_mcontext.regs.r15; |
| /* It is a signal handler. */ |
| return 1; |
| } |
| } |
| return 0; |
| } |
