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

6 files changed, 75 insertions, 0 deletions

diff --git a/llvm/test/Transforms/SafeStack/AArch64/abi.ll b/llvm/test/Transforms/SafeStack/AArch64/abi.ll
new file mode 100644
index 00000000000..942658a89d2
--- /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*)
diff --git a/llvm/test/Transforms/SafeStack/AArch64/lit.local.cfg b/llvm/test/Transforms/SafeStack/AArch64/lit.local.cfg
new file mode 100644
index 00000000000..cec29af5bbe
--- /dev/null
+++ b/llvm/test/Transforms/SafeStack/AArch64/lit.local.cfg
@@ -0,0 +1,3 @@
+if not 'AArch64' in config.root.targets:
+    config.unsupported = True
+
diff --git a/llvm/test/Transforms/SafeStack/ARM/abi.ll b/llvm/test/Transforms/SafeStack/ARM/abi.ll
new file mode 100644
index 00000000000..e33c913ae91
--- /dev/null
+++ b/llvm/test/Transforms/SafeStack/ARM/abi.ll
@@ -0,0 +1,18 @@
+; RUN: opt -safe-stack -S -mtriple=arm-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*)
diff --git a/llvm/test/Transforms/SafeStack/ARM/lit.local.cfg b/llvm/test/Transforms/SafeStack/ARM/lit.local.cfg
new file mode 100644
index 00000000000..98c6700c209
--- /dev/null
+++ b/llvm/test/Transforms/SafeStack/ARM/lit.local.cfg
@@ -0,0 +1,3 @@
+if not 'ARM' in config.root.targets:
+    config.unsupported = True
+
diff --git a/llvm/test/Transforms/SafeStack/X86/abi.ll b/llvm/test/Transforms/SafeStack/X86/abi.ll
new file mode 100644
index 00000000000..9914e9a850f
--- /dev/null
+++ b/llvm/test/Transforms/SafeStack/X86/abi.ll
@@ -0,0 +1,30 @@
+; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s --check-prefix=TLS
+; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s --check-prefix=TLS
+; RUN: opt -safe-stack -S -mtriple=i686-linux-android < %s -o - | FileCheck %s --check-prefix=DIRECT-TLS32
+; RUN: opt -safe-stack -S -mtriple=x86_64-linux-android < %s -o - | FileCheck %s --check-prefix=DIRECT-TLS64
+
+
+define void @foo() nounwind uwtable safestack {
+entry:
+; TLS: %[[USP:.*]] = load i8*, i8** @__safestack_unsafe_stack_ptr
+; TLS: %[[USST:.*]] = getelementptr i8, i8* %[[USP]], i32 -16
+; TLS: store i8* %[[USST]], i8** @__safestack_unsafe_stack_ptr
+
+; DIRECT-TLS32: %[[USP:.*]] = load i8*, i8* addrspace(36)* inttoptr (i32 256 to i8* addrspace(36)*)
+; DIRECT-TLS32: %[[USST:.*]] = getelementptr i8, i8* %[[USP]], i32 -16
+; DIRECT-TLS32: store i8* %[[USST]], i8* addrspace(36)* inttoptr (i32 256 to i8* addrspace(36)*)
+
+; DIRECT-TLS64: %[[USP:.*]] = load i8*, i8* addrspace(72)* inttoptr (i32 257 to i8* addrspace(72)*)
+; DIRECT-TLS64: %[[USST:.*]] = getelementptr i8, i8* %[[USP]], i32 -16
+; DIRECT-TLS64: store i8* %[[USST]], i8* addrspace(72)* inttoptr (i32 257 to i8* addrspace(72)*)
+
+  %a = alloca i8, align 8
+  call void @Capture(i8* %a)
+
+; TLS: store i8* %[[USP]], i8** @__safestack_unsafe_stack_ptr
+; DIRECT-TLS32: store i8* %[[USP]], i8* addrspace(36)* inttoptr (i32 256 to i8* addrspace(36)*)
+; DIRECT-TLS64: store i8* %[[USP]], i8* addrspace(72)* inttoptr (i32 257 to i8* addrspace(72)*)
+  ret void
+}
+
+declare void @Capture(i8*)
diff --git a/llvm/test/Transforms/SafeStack/X86/lit.local.cfg b/llvm/test/Transforms/SafeStack/X86/lit.local.cfg
new file mode 100644
index 00000000000..e71f3cc4c41
--- /dev/null
+++ b/llvm/test/Transforms/SafeStack/X86/lit.local.cfg
@@ -0,0 +1,3 @@
+if not 'X86' in config.root.targets:
+    config.unsupported = True
+