shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

[llvm][StackProtector] Add noreturn to __stack_chk_fail call (#143976)

Browse Source 
This is a reland for 99e53cb4139eda491f97cb33ee42ea424d352200 with the
appropriate test fixes.

It's possible for __stack_chk_fail to be an alias when using CrossDSOCFI
since it will make a jump table entry for this function and replace it
with an alias. StackProtector can crash since it always expects this to
be a regular function. Instead add the noreturn attribute to the call.
This commit is contained in:
Leonard Chan 2025-07-16 13:09:04 -07:00
parent 3a6ef8b359
commit 94382c8e56
3 changed files with 58 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
llvm/lib/CodeGen/StackProtector.cpp
View File

@ -731,8 +731,8 @@ BasicBlock *CreateFailBB(Function *F, const TargetLowering &TLI) {
}
if (StackChkFail) {
cast<Function>(StackChkFail.getCallee())->addFnAttr(Attribute::NoReturn);
B.CreateCall(StackChkFail, Args);
CallInst *Call = B.CreateCall(StackChkFail, Args);
Call->addFnAttr(Attribute::NoReturn);
}
B.CreateUnreachable();

34
llvm/test/Transforms/StackProtector/cross-dso-cfi-stack-chk-fail.ll Normal file
View File

@ -0,0 +1,34 @@
;; This is a minimal reproducer that caused StackProtector to crash with a bad cast when
;; CrossDSOCFI is used. This test just needs to not crash.
; REQUIRES: x86-registered-target
; RUN: opt -mtriple=x86_64-pc-linux-gnu %s -passes=lowertypetests,cross-dso-cfi,stack-protector
define hidden void @__stack_chk_fail() !type !1{
unreachable
}
define void @store_captures() sspstrong {
entry:
%a = alloca i32, align 4
%j = alloca ptr, align 8
store ptr %a, ptr %j, align 8
ret void
}
define void @func(ptr %0) {
entry:
%1 = call i1 @llvm.type.test(ptr %0, metadata !"typeid")
br i1 %1, label %cont, label %trap
trap: ; preds = %entry
call void @llvm.trap()
unreachable
cont: ; preds = %entry
call void %0()
ret void
}
!llvm.module.flags = !{!0}
!0 = !{i32 4, !"Cross-DSO CFI", i32 1}
!1 = !{i64 0, !"typeid"}

22
llvm/test/Transforms/StackProtector/stack-chk-fail-alias.ll Normal file
View File

@ -0,0 +1,22 @@
;; __stack_chk_fail should have the noreturn attr even if it is an alias
; REQUIRES: x86-registered-target
; RUN: opt -mtriple=x86_64-pc-linux-gnu %s -passes=stack-protector -S | FileCheck %s
define hidden void @__stack_chk_fail_impl() {
unreachable
}
@__stack_chk_fail = hidden alias void (), ptr @__stack_chk_fail_impl
; CHECK-LABEL: @store_captures(
; CHECK: CallStackCheckFailBlk:
; CHECK-NEXT: call void @__stack_chk_fail() [[ATTRS:#.*]]
define void @store_captures() sspstrong {
entry:
%a = alloca i32, align 4
%j = alloca ptr, align 8
store ptr %a, ptr %j, align 8
ret void
}
; CHECK: attributes [[ATTRS]] = { noreturn }