int sigaction(int signal, const struct sigaction* bionic_new_action, struct sigaction* bionic_old_action) {
#if __LP64__
__kernel_sigaction kernel_new_action;
if (bionic_new_action != NULL) {
kernel_new_action.sa_flags = bionic_new_action->sa_flags;
kernel_new_action.sa_handler = bionic_new_action->sa_handler;
kernel_new_action.sa_mask = bionic_new_action->sa_mask;
kernel_new_action.sa_restorer = bionic_new_action->sa_restorer;
if (!(kernel_new_action.sa_flags & SA_RESTORER)) {
kernel_new_action.sa_flags |= SA_RESTORER;
kernel_new_action.sa_restorer = &__rt_sigreturn;
}
}
__kernel_sigaction kernel_old_action;
int result = __rt_sigaction(signal,
(bionic_new_action != NULL) ? &kernel_new_action : NULL,
(bionic_old_action != NULL) ? &kernel_old_action : NULL,
sizeof(sigset_t));
if (bionic_old_action != NULL) {
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;
bionic_old_action->sa_restorer = kernel_old_action.sa_restorer;
if (bionic_old_action->sa_restorer == &__rt_sigreturn) {
bionic_old_action->sa_flags &= ~SA_RESTORER;
}
}
return result;
#else
// The 32-bit ABI is broken. struct sigaction includes a too-small sigset_t.
// TODO: if we also had correct struct sigaction definitions available, we could copy in and out.
return __sigaction(signal, bionic_new_action, bionic_old_action);
#endif
}
int sigaction(int signal, const struct sigaction* bionic_new_action, struct sigaction* bionic_old_action) {
__kernel_sigaction kernel_new_action;
if (bionic_new_action != NULL) {
kernel_new_action.sa_flags = bionic_new_action->sa_flags;
kernel_new_action.sa_handler = bionic_new_action->sa_handler;
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 != NULL) ? &kernel_new_action : NULL,
(bionic_old_action != NULL) ? &kernel_old_action : NULL,
sizeof(sigset_t));
if (bionic_old_action != NULL) {
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;
}
int __libc_sigaction(int signum, const struct sigaction *act, struct sigaction *oldact) {
return __rt_sigaction(signum, act, oldact, 0, _NSIG/8);
}