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#include <signal.h>
#include <errno.h>
#include <string.h>
#include "syscall.h"
#include "pthread_impl.h"
#include "libc.h"
#include "ksigaction.h"
volatile int dummy_lock[1] = { 0 };
__attribute__((__visibility__("hidden")))
weak_alias(dummy_lock, __abort_lock);
static int unmask_done;
static unsigned long handler_set[_NSIG/(8*sizeof(long))];
void __get_handler_set(sigset_t *set)
{
memcpy(set, handler_set, sizeof handler_set);
}
int __libc_sigaction(int sig, const struct sigaction *restrict sa, struct sigaction *restrict old)
{
struct k_sigaction ksa, ksa_old;
unsigned long set[_NSIG/(8*sizeof(long))];
if (sa) {
if ((uintptr_t)sa->sa_handler > 1UL) {
a_or_l(handler_set+(sig-1)/(8*sizeof(long)),
1UL<<(sig-1)%(8*sizeof(long)));
/* If pthread_create has not yet been called,
* implementation-internal signals might not
* yet have been unblocked. They must be
* unblocked before any signal handler is
* installed, so that an application cannot
* receive an illegal sigset_t (with them
* blocked) as part of the ucontext_t passed
* to the signal handler. */
if (!libc.threaded && !unmask_done) {
__syscall(SYS_rt_sigprocmask, SIG_UNBLOCK,
SIGPT_SET, 0, _NSIG/8);
unmask_done = 1;
}
}
/* Changing the disposition of SIGABRT to anything but
* SIG_DFL requires a lock, so that it cannot be changed
* while abort is terminating the process after simply
* calling raise(SIGABRT) failed to do so. */
if (sa->sa_handler != SIG_DFL && sig == SIGABRT) {
__block_all_sigs(&set);
LOCK(__abort_lock);
}
ksa.handler = sa->sa_handler;
ksa.flags = sa->sa_flags | SA_RESTORER;
ksa.restorer = (sa->sa_flags & SA_SIGINFO) ? __restore_rt : __restore;
memcpy(&ksa.mask, &sa->sa_mask, _NSIG/8);
}
int r = __syscall(SYS_rt_sigaction, sig, sa?&ksa:0, old?&ksa_old:0, _NSIG/8);
if (sig == SIGABRT && sa && sa->sa_handler != SIG_DFL) {
UNLOCK(__abort_lock);
__restore_sigs(&set);
}
if (old && !r) {
old->sa_handler = ksa_old.handler;
old->sa_flags = ksa_old.flags;
memcpy(&old->sa_mask, &ksa_old.mask, _NSIG/8);
}
return __syscall_ret(r);
}
int __sigaction(int sig, const struct sigaction *restrict sa, struct sigaction *restrict old)
{
if (sig-32U < 3 || sig-1U >= _NSIG-1) {
errno = EINVAL;
return -1;
}
return __libc_sigaction(sig, sa, old);
}
weak_alias(__sigaction, sigaction);
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