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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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