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/*
* Copyright (C) 2013 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <signal.h>
#include <string.h>
#include "private/sigrtmin.h"
extern "C" void __restore_rt(void);
extern "C" void __restore(void);
#if defined(__LP64__)
extern "C" int __rt_sigaction(int, const struct __kernel_sigaction*, struct __kernel_sigaction*, size_t);
int sigaction(int signal, const struct sigaction* bionic_new_action, struct sigaction* bionic_old_action) {
__kernel_sigaction kernel_new_action;
if (bionic_new_action != nullptr) {
kernel_new_action.sa_flags = bionic_new_action->sa_flags;
kernel_new_action.sa_handler = bionic_new_action->sa_handler;
// Don't filter signals here; if the caller asked for everything to be blocked, we should obey.
kernel_new_action.sa_mask = bionic_new_action->sa_mask;
#if defined(SA_RESTORER)
kernel_new_action.sa_restorer = bionic_new_action->sa_restorer;
#if defined(__aarch64__)
// arm64 has sa_restorer, but unwinding works best if you just let the
// kernel supply the default restorer from [vdso]. gdb doesn't care, but
// libgcc needs the nop that the kernel includes before the actual code.
// (We could add that ourselves, but why bother?)
#else
if (!(kernel_new_action.sa_flags & SA_RESTORER)) {
kernel_new_action.sa_flags |= SA_RESTORER;
kernel_new_action.sa_restorer = &__restore_rt;
}
#endif
#endif
}
__kernel_sigaction kernel_old_action;
int result = __rt_sigaction(signal,
(bionic_new_action != nullptr) ? &kernel_new_action : nullptr,
(bionic_old_action != nullptr) ? &kernel_old_action : nullptr,
sizeof(sigset_t));
if (bionic_old_action != nullptr) {
bionic_old_action->sa_flags = kernel_old_action.sa_flags;
bionic_old_action->sa_handler = kernel_old_action.sa_handler;
bionic_old_action->sa_mask = kernel_old_action.sa_mask;
#if defined(SA_RESTORER)
bionic_old_action->sa_restorer = kernel_old_action.sa_restorer;
#endif
}
return result;
}
__strong_alias(sigaction64, sigaction);
#else
extern "C" int __rt_sigaction(int, const struct sigaction64*, struct sigaction64*, size_t);
int sigaction(int signal, const struct sigaction* bionic_new, struct sigaction* bionic_old) {
// The 32-bit ABI is broken. struct sigaction includes a too-small sigset_t,
// so we have to translate to struct sigaction64 first.
struct sigaction64 kernel_new;
if (bionic_new) {
kernel_new = {};
kernel_new.sa_flags = bionic_new->sa_flags;
kernel_new.sa_handler = bionic_new->sa_handler;
#if defined(SA_RESTORER)
kernel_new.sa_restorer = bionic_new->sa_restorer;
#endif
// Don't filter signals here; if the caller asked for everything to be blocked, we should obey.
memcpy(&kernel_new.sa_mask, &bionic_new->sa_mask, sizeof(bionic_new->sa_mask));
}
struct sigaction64 kernel_old;
int result = sigaction64(signal, bionic_new ? &kernel_new : nullptr, &kernel_old);
if (bionic_old) {
*bionic_old = {};
bionic_old->sa_flags = kernel_old.sa_flags;
bionic_old->sa_handler = kernel_old.sa_handler;
#if defined(SA_RESTORER)
bionic_old->sa_restorer = kernel_old.sa_restorer;
#endif
memcpy(&bionic_old->sa_mask, &kernel_old.sa_mask, sizeof(bionic_old->sa_mask));
}
return result;
}
int sigaction64(int signal, const struct sigaction64* bionic_new, struct sigaction64* bionic_old) {
struct sigaction64 kernel_new;
if (bionic_new) {
kernel_new = *bionic_new;
#if defined(SA_RESTORER)
if (!(kernel_new.sa_flags & SA_RESTORER)) {
kernel_new.sa_flags |= SA_RESTORER;
kernel_new.sa_restorer = (kernel_new.sa_flags & SA_SIGINFO) ? &__restore_rt : &__restore;
}
#endif
// Don't filter signals here; if the caller asked for everything to be blocked, we should obey.
kernel_new.sa_mask = kernel_new.sa_mask;
}
return __rt_sigaction(signal,
bionic_new ? &kernel_new : nullptr,
bionic_old,
sizeof(kernel_new.sa_mask));
}
#endif
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