Permalink
Cannot retrieve contributors at this time
Name already in use
A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?
glibc/hurd/catch-signal.c
Go to fileThis commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
167 lines (140 sloc)
5 KB
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
/* Convenience function to catch expected signals during an operation. | |
Copyright (C) 1996-2016 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 <hurd/signal.h> | |
#include <hurd/sigpreempt.h> | |
#include <string.h> | |
#include <assert.h> | |
error_t | |
hurd_catch_signal (sigset_t sigset, | |
unsigned long int first, unsigned long int last, | |
error_t (*operate) (struct hurd_signal_preemptor *), | |
sighandler_t handler) | |
{ | |
/* We need to restore the signal mask, because otherwise the | |
signal-handling code will have blocked the caught signal and for | |
instance calling hurd_catch_signal again would then dump core. */ | |
sigjmp_buf buf; | |
void throw (int signo, long int sigcode, struct sigcontext *scp) | |
{ siglongjmp (buf, scp->sc_error ?: EGRATUITOUS); } | |
struct hurd_signal_preemptor preemptor = | |
{ | |
sigset, first, last, | |
NULL, handler == SIG_ERR ? (sighandler_t) &throw : handler, | |
}; | |
struct hurd_sigstate *const ss = _hurd_self_sigstate (); | |
error_t error; | |
if (handler != SIG_ERR) | |
/* Not our handler; don't bother saving state. */ | |
error = 0; | |
else | |
/* This returns again with nonzero value when we preempt a signal. */ | |
error = sigsetjmp (buf, 1); | |
if (error == 0) | |
{ | |
/* Install a signal preemptor for the thread. */ | |
__spin_lock (&ss->lock); | |
preemptor.next = ss->preemptors; | |
ss->preemptors = &preemptor; | |
__spin_unlock (&ss->lock); | |
/* Try the operation that might crash. */ | |
(*operate) (&preemptor); | |
} | |
/* Either FUNCTION completed happily and ERROR is still zero, or it hit | |
an expected signal and `throw' made setjmp return the signal error | |
code in ERROR. Now we can remove the preemptor and return. */ | |
__spin_lock (&ss->lock); | |
assert (ss->preemptors == &preemptor); | |
ss->preemptors = preemptor.next; | |
__spin_unlock (&ss->lock); | |
return error; | |
} | |
error_t | |
hurd_safe_memset (void *dest, int byte, size_t nbytes) | |
{ | |
error_t operate (struct hurd_signal_preemptor *preemptor) | |
{ | |
memset (dest, byte, nbytes); | |
return 0; | |
} | |
return hurd_catch_signal (sigmask (SIGBUS) | sigmask (SIGSEGV), | |
(vm_address_t) dest, (vm_address_t) dest + nbytes, | |
&operate, SIG_ERR); | |
} | |
error_t | |
hurd_safe_copyout (void *dest, const void *src, size_t nbytes) | |
{ | |
error_t operate (struct hurd_signal_preemptor *preemptor) | |
{ | |
memcpy (dest, src, nbytes); | |
return 0; | |
} | |
return hurd_catch_signal (sigmask (SIGBUS) | sigmask (SIGSEGV), | |
(vm_address_t) dest, (vm_address_t) dest + nbytes, | |
&operate, SIG_ERR); | |
} | |
error_t | |
hurd_safe_copyin (void *dest, const void *src, size_t nbytes) | |
{ | |
error_t operate (struct hurd_signal_preemptor *preemptor) | |
{ | |
memcpy (dest, src, nbytes); | |
return 0; | |
} | |
return hurd_catch_signal (sigmask (SIGBUS) | sigmask (SIGSEGV), | |
(vm_address_t) src, (vm_address_t) src + nbytes, | |
&operate, SIG_ERR); | |
} | |
error_t | |
hurd_safe_memmove (void *dest, const void *src, size_t nbytes) | |
{ | |
jmp_buf buf; | |
void throw (int signo, long int sigcode, struct sigcontext *scp) | |
{ longjmp (buf, scp->sc_error ?: EGRATUITOUS); } | |
struct hurd_signal_preemptor src_preemptor = | |
{ | |
sigmask (SIGBUS) | sigmask (SIGSEGV), | |
(vm_address_t) src, (vm_address_t) src + nbytes, | |
NULL, (sighandler_t) &throw, | |
}; | |
struct hurd_signal_preemptor dest_preemptor = | |
{ | |
sigmask (SIGBUS) | sigmask (SIGSEGV), | |
(vm_address_t) dest, (vm_address_t) dest + nbytes, | |
NULL, (sighandler_t) &throw, | |
&src_preemptor | |
}; | |
struct hurd_sigstate *const ss = _hurd_self_sigstate (); | |
error_t error; | |
/* This returns again with nonzero value when we preempt a signal. */ | |
error = setjmp (buf); | |
if (error == 0) | |
{ | |
/* Install a signal preemptor for the thread. */ | |
__spin_lock (&ss->lock); | |
src_preemptor.next = ss->preemptors; | |
ss->preemptors = &dest_preemptor; | |
__spin_unlock (&ss->lock); | |
/* Do the copy; it might fault. */ | |
memmove (dest, src, nbytes); | |
} | |
/* Either memmove completed happily and ERROR is still zero, or it hit | |
an expected signal and `throw' made setjmp return the signal error | |
code in ERROR. Now we can remove the preemptor and return. */ | |
__spin_lock (&ss->lock); | |
assert (ss->preemptors == &dest_preemptor); | |
ss->preemptors = src_preemptor.next; | |
__spin_unlock (&ss->lock); | |
return error; | |
} |