Per-thread -fstack-protector guards for x86.

Based on a pair of patches from Intel:

  https://android-review.googlesource.com/#/c/43909/
  https://android-review.googlesource.com/#/c/44903/

For x86, this patch supports _both_ the global that ARM/MIPS use
and the per-thread TLS entry (%gs:20) that GCC uses by default. This
lets us support binaries built with any x86 toolchain (right now,
the NDK is emitting x86 code that uses the global).

I've also extended the original tests to cover ARM/MIPS too, and
be a little more thorough for x86.

Change-Id: I02f279a80c6b626aecad449771dec91df235ad01

1 files changed, 5 insertions, 3 deletions

diff --git a/tests/string_test.cpp b/tests/string_test.cpp
index 47469d853..472aacb0e 100644
--- a/tests/string_test.cpp
+++ b/tests/string_test.cpp
@@ -29,12 +29,13 @@ TEST(string, strerror) {
   ASSERT_STREQ("Unknown error 1234", strerror(1234));
 }
 
-static void* ConcurrentStrErrorFn(void* arg) {
+#if __BIONIC__ // glibc's strerror isn't thread safe, only its strsignal.
+
+static void* ConcurrentStrErrorFn(void*) {
   bool equal = (strcmp("Unknown error 2002", strerror(2002)) == 0);
   return reinterpret_cast<void*>(equal);
 }
 
-#if __BIONIC__ // glibc's strerror isn't thread safe, only its strsignal.
 TEST(string, strerror_concurrent) {
   const char* strerror1001 = strerror(1001);
   ASSERT_STREQ("Unknown error 1001", strerror1001);
@@ -47,6 +48,7 @@ TEST(string, strerror_concurrent) {
 
   ASSERT_STREQ("Unknown error 1001", strerror1001);
 }
+
 #endif
 
 #if __BIONIC__ // glibc's strerror_r doesn't even have the same signature as the POSIX one.
@@ -88,7 +90,7 @@ TEST(string, strsignal) {
   ASSERT_STREQ("Unknown signal 1234", strsignal(1234)); // Too large.
 }
 
-static void* ConcurrentStrSignalFn(void* arg) {
+static void* ConcurrentStrSignalFn(void*) {
   bool equal = (strcmp("Unknown signal 2002", strsignal(2002)) == 0);
   return reinterpret_cast<void*>(equal);
 }