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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;
/*
* SA_RESTORER is only relevant for act != NULL case
* (!act means caller only wants to know @oact)
*
* 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)) {
kact.sa_restorer = __default_rt_sa_restorer;
kact.sa_flags = act->sa_flags | SA_RESTORER;
kact.sa_handler = act->sa_handler;
kact.sa_mask = act->sa_mask;
act = &kact;
}
return INLINE_SYSCALL(rt_sigaction, 4,
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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