Android support for SafeStack.
Add two new ways of accessing the unsafe stack pointer:
* At a fixed offset from the thread TLS base. This is very similar to
StackProtector cookies, but we plan to extend it to other backends
(ARM in particular) soon. Bionic-side implementation here:
https://android-review.googlesource.com/170988.
* Via a function call, as a fallback for platforms that provide
neither a fixed TLS slot, nor a reasonable TLS implementation (i.e.
not emutls).
This is a re-commit of a change in r248357 that was reverted in
r248358.
llvm-svn: 248405
diff --git a/llvm/test/Transforms/SafeStack/AArch64/abi.ll b/llvm/test/Transforms/SafeStack/AArch64/abi.ll
new file mode 100644
index 0000000..942658a
--- /dev/null
+++ b/llvm/test/Transforms/SafeStack/AArch64/abi.ll
@@ -0,0 +1,18 @@
+; RUN: opt -safe-stack -S -mtriple=aarch64-linux-android < %s -o - | FileCheck %s
+
+
+define void @foo() nounwind uwtable safestack {
+entry:
+; CHECK: %[[SPA:.*]] = call i8** @__safestack_pointer_address()
+; CHECK: %[[USP:.*]] = load i8*, i8** %[[SPA]]
+; CHECK: %[[USST:.*]] = getelementptr i8, i8* %[[USP]], i32 -16
+; CHECK: store i8* %[[USST]], i8** %[[SPA]]
+
+ %a = alloca i8, align 8
+ call void @Capture(i8* %a)
+
+; CHECK: store i8* %[[USP]], i8** %[[SPA]]
+ ret void
+}
+
+declare void @Capture(i8*)