diff options
Diffstat (limited to 'ports/sysdeps/unix/sysv/linux/generic/____longjmp_chk.c')
-rw-r--r-- | ports/sysdeps/unix/sysv/linux/generic/____longjmp_chk.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/generic/____longjmp_chk.c b/ports/sysdeps/unix/sysv/linux/generic/____longjmp_chk.c new file mode 100644 index 0000000000..619785d7e8 --- /dev/null +++ b/ports/sysdeps/unix/sysv/linux/generic/____longjmp_chk.c @@ -0,0 +1,57 @@ +/* Copyright (C) 2011 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011. + + 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 <jmpbuf-offsets.h> +#include <sysdep.h> +#include <setjmp.h> +#include <signal.h> +#include <stdio.h> +#include <stackinfo.h> + +#ifdef _STACK_GROWS_DOWN +#define called_from(this, saved) ((this) < (saved)) +#else +#define called_from(this, saved) ((this) > (saved)) +#endif + +extern void ____longjmp_chk (__jmp_buf __env, int __val) + __attribute__ ((__noreturn__)); + +void ____longjmp_chk (__jmp_buf env, int val) +{ + void *this_frame = __builtin_frame_address (0); + void *saved_frame = JB_FRAME_ADDRESS (env); + INTERNAL_SYSCALL_DECL (err); + stack_t ss; + + /* If "env" is from a frame that called us, we're all set. */ + if (called_from(this_frame, saved_frame)) + __longjmp (env, val); + + /* If we can't get the current stack state, give up and do the longjmp. */ + if (INTERNAL_SYSCALL (sigaltstack, err, 2, NULL, &ss) != 0) + __longjmp (env, val); + + /* If we we are executing on the alternate stack and within the + bounds, do the longjmp. */ + if (ss.ss_flags == SS_ONSTACK && + (this_frame >= ss.ss_sp && this_frame < (ss.ss_sp + ss.ss_size))) + __longjmp (env, val); + + __fortify_fail ("longjmp causes uninitialized stack frame"); +} |