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/*
* Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
*
* Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
*/
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <sys/syscall.h>
#include <bits/kernel_sigaction.h>
extern void __default_rt_sa_restorer(void);
//libc_hidden_proto(__default_rt_sa_restorer);
#define SA_RESTORER 0x04000000
/* If @act is not NULL, change the action for @sig to @act.
If @oact is not NULL, put the old action for @sig in @oact. */
int
__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
{
struct sigaction kact;
/* !act means caller only wants to know @oact
* Hence only otherwise, do SA_RESTORER stuff
*
* For the normal/default cases (user not providing SA_RESTORER) use
* a real sigreturn stub to avoid kernel synthesizing one on user stack
* at runtime, which needs PTE permissions update (hence TLB entry
* update) and costly cache line flushes for code modification
*/
if (act && !(act->sa_flags & SA_RESTORER)) {
memcpy(&kact, act, sizeof(kact));
kact.sa_restorer = __default_rt_sa_restorer;
kact.sa_flags |= SA_RESTORER;
act = &kact;
}
return __syscall_rt_sigaction(sig, act, oact, sizeof(act->sa_mask));
}
#ifndef LIBC_SIGACTION
# ifndef __UCLIBC_HAS_THREADS__
strong_alias(__libc_sigaction,sigaction)
libc_hidden_def(sigaction)
# else
weak_alias(__libc_sigaction,sigaction)
libc_hidden_weak(sigaction)
# endif
#endif
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