Merge "Use the kernel's sa_restorer for aarch64."
diff --git a/libc/arch-arm64/arm64.mk b/libc/arch-arm64/arm64.mk
index 5c40faa..0dd3c27 100644
--- a/libc/arch-arm64/arm64.mk
+++ b/libc/arch-arm64/arm64.mk
@@ -36,7 +36,6 @@
libc_bionic_src_files_arm64 += \
arch-arm64/bionic/__bionic_clone.S \
arch-arm64/bionic/_exit_with_stack_teardown.S \
- arch-arm64/bionic/__restore_rt.S \
arch-arm64/bionic/_setjmp.S \
arch-arm64/bionic/setjmp.S \
arch-arm64/bionic/__set_tls.c \
diff --git a/libc/arch-arm64/bionic/__restore_rt.S b/libc/arch-arm64/bionic/__restore_rt.S
deleted file mode 100644
index 9506490..0000000
--- a/libc/arch-arm64/bionic/__restore_rt.S
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * 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 <private/bionic_asm.h>
-
-// This function must have exactly this instruction sequence for gdb and libunwind.
-ENTRY_PRIVATE(__restore_rt)
- mov x8, __NR_rt_sigreturn
- svc #0
-END(__restore_rt)
diff --git a/libc/bionic/sigaction.cpp b/libc/bionic/sigaction.cpp
index 920303b..0633748 100644
--- a/libc/bionic/sigaction.cpp
+++ b/libc/bionic/sigaction.cpp
@@ -31,27 +31,30 @@
extern "C" void __restore_rt(void);
extern "C" void __restore(void);
-#if __LP64__
+#if defined(__LP64__)
+
extern "C" int __rt_sigaction(int, const struct __kernel_sigaction*, struct __kernel_sigaction*, size_t);
-#else
-extern "C" int __sigaction(int, const struct sigaction*, struct sigaction*);
-#endif
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;
-#ifdef SA_RESTORER
+#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;
@@ -64,21 +67,27 @@
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;
-#ifdef SA_RESTORER
+#if defined(SA_RESTORER)
bionic_old_action->sa_restorer = kernel_old_action.sa_restorer;
#endif
}
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.
+
+extern "C" int __sigaction(int, const struct sigaction*, struct sigaction*);
+
+int sigaction(int signal, const struct sigaction* bionic_new_action, struct sigaction* bionic_old_action) {
+ // The 32-bit ABI is broken. struct sigaction includes a too-small sigset_t,
+ // so we have to use sigaction(2) rather than rt_sigaction(2).
struct 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;
-#ifdef SA_RESTORER
+#if defined(SA_RESTORER)
kernel_new_action.sa_restorer = bionic_new_action->sa_restorer;
if (!(kernel_new_action.sa_flags & SA_RESTORER)) {
@@ -88,5 +97,6 @@
#endif
}
return __sigaction(signal, (bionic_new_action != NULL) ? &kernel_new_action : NULL, bionic_old_action);
-#endif
}
+
+#endif