commit e387c2f08841ac0f6578e903ab21b54d01f3266e
author Christopher Ferris <cferris@google.com> Fri Oct 06 17:08:34 2017 +0000
committer Gerrit Code Review <noreply-gerritcodereview@google.com> Fri Oct 06 17:08:34 2017 +0000
tree ee40a87bb99b95e38e95a505e7084d6b695c21c9
parent 7181e53cfed1ae9c877a6aacb7da6c48165e91f9
parent 93ea09f65c59585c082797bbfa4f4c7778d6e8b9

Merge "Add directives to force stop unwinding."

libc/Android.bp

diff --git a/libc/Android.bp b/libc/Android.bp
index 3391a6c..cd01efd 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -1826,7 +1826,6 @@
             "bionic/dl_iterate_phdr_static.cpp",
             "bionic/icu_static.cpp",
             "bionic/malloc_common.cpp",
-            "bionic/libc_init_static.cpp",
         ],
         cflags: ["-DLIBC_STATIC"],
         whole_static_libs: ["libc_init_static"],

libc/bionic/clone.cpp

diff --git a/libc/bionic/clone.cpp b/libc/bionic/clone.cpp
index d7ce37f..66ec503 100644
--- a/libc/bionic/clone.cpp
+++ b/libc/bionic/clone.cpp
@@ -34,11 +34,15 @@
 
 #include "pthread_internal.h"
 
+#include "private/bionic_macros.h"
+
 extern "C" pid_t __bionic_clone(uint32_t flags, void* child_stack, int* parent_tid, void* tls, int* child_tid, int (*fn)(void*), void* arg);
 extern "C" __noreturn void __exit(int status);
 
 // Called from the __bionic_clone assembler to call the thread function then exit.
 extern "C" __LIBC_HIDDEN__ void __start_thread(int (*fn)(void*), void* arg) {
+  BIONIC_STOP_UNWIND;
+
   pthread_internal_t* self = __get_thread();
   if (self && self->tid == -1) {
     self->tid = syscall(__NR_gettid);

libc/bionic/libc_init_dynamic.cpp

diff --git a/libc/bionic/libc_init_dynamic.cpp b/libc/bionic/libc_init_dynamic.cpp
index 7c73950..349d488 100644
--- a/libc/bionic/libc_init_dynamic.cpp
+++ b/libc/bionic/libc_init_dynamic.cpp
@@ -52,6 +52,7 @@
 #include "libc_init_common.h"
 
 #include "private/bionic_globals.h"
+#include "private/bionic_macros.h"
 #include "private/bionic_ssp.h"
 #include "private/bionic_tls.h"
 #include "private/KernelArgumentBlock.h"
@@ -108,6 +109,7 @@
                             void (*onexit)(void) __unused,
                             int (*slingshot)(int, char**, char**),
                             structors_array_t const * const structors) {
+  BIONIC_STOP_UNWIND;
 
   KernelArgumentBlock args(raw_args);
 

libc/bionic/libc_init_static.cpp

diff --git a/libc/bionic/libc_init_static.cpp b/libc/bionic/libc_init_static.cpp
index 5e06d39..93a63b5 100644
--- a/libc/bionic/libc_init_static.cpp
+++ b/libc/bionic/libc_init_static.cpp
@@ -40,6 +40,7 @@
 #include "pthread_internal.h"
 
 #include "private/bionic_globals.h"
+#include "private/bionic_macros.h"
 #include "private/bionic_page.h"
 #include "private/bionic_tls.h"
 #include "private/KernelArgumentBlock.h"
@@ -82,6 +83,8 @@
                             void (*onexit)(void) __unused,
                             int (*slingshot)(int, char**, char**),
                             structors_array_t const * const structors) {
+  BIONIC_STOP_UNWIND;
+
   KernelArgumentBlock args(raw_args);
   __libc_init_main_thread(args);
 

libc/private/bionic_macros.h

diff --git a/libc/private/bionic_macros.h b/libc/private/bionic_macros.h
index 303218e..b1dfc7f 100644
--- a/libc/private/bionic_macros.h
+++ b/libc/private/bionic_macros.h
@@ -66,4 +66,17 @@
   return reinterpret_cast<T*>(align_up(reinterpret_cast<uintptr_t>(p), align));
 }
 
+#if defined(__arm__)
+// Do not emit anything for arm, clang does not allow emiting an arm unwind
+// directive.
+// #define BIONIC_STOP_UNWIND asm volatile(".cantunwind")
+#define BIONIC_STOP_UNWIND
+#elif defined(__aarch64__)
+#define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined x30")
+#elif defined(__i386__)
+#define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined \%eip")
+#elif defined(__x86_64__)
+#define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined \%rip")
+#endif
+
 #endif // _BIONIC_MACROS_H_