[compiler-rt] [safestack] Enable for aarch64

This patch enables the safestack for aarch64. The frontend already have
it enabled on all supported architectures and no adjustment is required
in llvm.

The compiler-rt adjustments are basically add on the cmake configuration
to enable the tests and fix the pagesize debug check by getting its
value at runtime (since aarch64 has multiple pagesize depending of
kernel configuration).

llvm-svn: 255345

1 files changed, 6 insertions, 1 deletions

diff --git a/compiler-rt/lib/safestack/safestack.cc b/compiler-rt/lib/safestack/safestack.cc
index 5254462d92c..92c24b35d6d 100644
--- a/compiler-rt/lib/safestack/safestack.cc
+++ b/compiler-rt/lib/safestack/safestack.cc
@@ -18,6 +18,7 @@
 #include <pthread.h>
 #include <stddef.h>
 #include <stdint.h>
+#include <unistd.h>
 #include <sys/resource.h>
 #include <sys/types.h>
 #include <sys/user.h>
@@ -68,6 +69,9 @@ const unsigned kStackAlign = 16;
 /// size rlimit is set to infinity.
 const unsigned kDefaultUnsafeStackSize = 0x2800000;
 
+/// Runtime page size obtained through sysconf
+static unsigned pageSize;
+
 // TODO: To make accessing the unsafe stack pointer faster, we plan to
 // eventually store it directly in the thread control block data structure on
 // platforms where this structure is pointed to by %fs or %gs. This is exactly
@@ -185,7 +189,7 @@ INTERCEPTOR(int, pthread_create, pthread_t *thread,
 
   CHECK_NE(size, 0);
   CHECK_EQ((size & (kStackAlign - 1)), 0);
-  CHECK_EQ((guard & (PAGE_SIZE - 1)), 0);
+  CHECK_EQ((guard & (pageSize - 1)), 0);
 
   void *addr = unsafe_stack_alloc(size, guard);
   struct tinfo *tinfo =
@@ -217,6 +221,7 @@ void __safestack_init() {
   void *addr = unsafe_stack_alloc(size, guard);
 
   unsafe_stack_setup(addr, size, guard);
+  pageSize = sysconf(_SC_PAGESIZE);
 
   // Initialize pthread interceptors for thread allocation
   INTERCEPT_FUNCTION(pthread_create);