diff options
| author | Chris Lattner <sabre@nondot.org> | 2010-05-08 22:15:59 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-05-08 22:15:59 +0000 |
| commit | c7d7e0cbe0a83881e4a01b0be745e169bd1baea0 (patch) | |
| tree | 9f8309dc29adc503fd04011c1332eb63767bd5a7 /test/Transforms | |
| parent | 6745191070503f669b07bc14cd6f7e518bd4d5b0 (diff) | |
| download | external_llvm-c7d7e0cbe0a83881e4a01b0be745e169bd1baea0.zip external_llvm-c7d7e0cbe0a83881e4a01b0be745e169bd1baea0.tar.gz external_llvm-c7d7e0cbe0a83881e4a01b0be745e169bd1baea0.tar.bz2 | |
make simplifycfg insert an llvm.trap before the 'unreachable' it introduces
when it detects undefined behavior. llvm.trap generally codegens into some
thing really small (e.g. a 2 byte ud2 instruction on x86) and debugging this
sort of thing is "nontrivial". For example, we now compile:
void foo() { *(int*)0 = 42; }
into:
_foo:
pushl %ebp
movl %esp, %ebp
ud2
Some may even claim that this is a security hole, though that seems dubious
to me. This addresses rdar://7958343 - Optimizing away null dereference
potentially allows arbitrary code execution
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103356 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms')
| -rw-r--r-- | test/Transforms/SimplifyCFG/trapping-load-unreachable.ll | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll b/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll index 0c9cc8b..6956faa 100644 --- a/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll +++ b/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll @@ -1,19 +1,33 @@ -; RUN: opt < %s -simplifycfg -S | grep {volatile load} +; RUN: opt < %s -simplifycfg -S | FileCheck %s ; PR2967 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32" target triple = "i386-pc-linux-gnu" -define void @foo(i32 %x) nounwind { +define void @test1(i32 %x) nounwind { entry: %0 = icmp eq i32 %x, 0 ; <i1> [#uses=1] br i1 %0, label %bb, label %return bb: ; preds = %entry - %1 = volatile load i32* null ; <i32> [#uses=0] + %1 = volatile load i32* null unreachable + br label %return return: ; preds = %entry ret void +; CHECK: @test1 +; CHECK: volatile load +} + +; rdar://7958343 +define void @test2() nounwind { +entry: + store i32 4,i32* null + ret void + +; CHECK: @test2 +; CHECK: call void @llvm.trap +; CHECK: unreachable } |