Allocate a small guard region around the shadow call stack.
This lets us do two things:
1) Make setjmp and longjmp compatible with shadow call stack.
To avoid leaking the shadow call stack address into memory, only the
lower log2(SCS_SIZE) bits of x18 are stored to jmp_buf. This requires
allocating an additional guard page so that we're guaranteed to be
able to allocate a sufficiently aligned SCS.
2) SCS overflow detection. Overflows now result in a SIGSEGV instead
of corrupting the allocation that comes after it.
Change-Id: I04d6634f96162bf625684672a87fba8b402b7fd1
Test: bionic-unit-tests
diff --git a/tests/Android.bp b/tests/Android.bp
index 6a644b6..899fc66 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -121,6 +121,7 @@
"regex_test.cpp",
"resolv_test.cpp",
"sched_test.cpp",
+ "scs_test.cpp",
"scsi_sg_test.cpp",
"search_test.cpp",
"semaphore_test.cpp",