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llvm-project/llvm/test/Instrumentation/MemorySanitizer/msan_llvm_launder_invariant.ll

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Handle llvm.launder.invariant.group in msan. Summary: [MSan] handle llvm.launder.invariant.group Msan used to give false-positives in class Foo { public: virtual ~Foo() {}; }; // Return true iff *x is set. bool f1(void **x, bool flag); Foo* f() { void *p; bool found; found = f1(&p,flag); if (found) { // p is always set here. return static_cast<Foo*>(p); // False positive here. } return nullptr; } Patch by Ilya Tokar. Reviewers: #sanitizers, eugenis Reviewed By: #sanitizers, eugenis Subscribers: eugenis, Prazek, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68236 llvm-svn: 373515
2019-10-03 03:53:19 +08:00
; Make sure MSan handles llvm.launder.invariant.group correctly.
; RUN: opt < %s -msan -msan-kernel=1 -O1 -S | FileCheck -check-prefixes=CHECK %s
; RUN: opt < %s -msan -O1 -S | FileCheck -check-prefixes=CHECK %s
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
%class.Foo = type { i32 (...)** }
@flag = dso_local local_unnamed_addr global i8 0, align 1
define dso_local %class.Foo* @_Z1fv() local_unnamed_addr #0 {
entry:
%p = alloca i8*, align 8
%0 = bitcast i8** %p to i8*
call void @llvm.lifetime.start.p0i8(i64 8, i8* nonnull %0)
%1 = load i8, i8* @flag, align 1
%tobool = icmp ne i8 %1, 0
%call = call zeroext i1 @_Z2f1PPvb(i8** nonnull %p, i1 zeroext %tobool)
%2 = load i8*, i8** %p, align 8
%3 = call i8* @llvm.launder.invariant.group.p0i8(i8* %2)
%4 = bitcast i8* %3 to %class.Foo*
%retval.0 = select i1 %call, %class.Foo* %4, %class.Foo* null
call void @llvm.lifetime.end.p0i8(i64 8, i8* nonnull %0)
ret %class.Foo* %retval.0
}
[MSAN] Pass Origin by parameter to __msan_warning functions Summary: Normally, the Origin is passed over TLS, which seems like it introduces unnecessary overhead. It's in the (extremely) cold path though, so the only overhead is in code size. But with eager-checks, calls to __msan_warning functions are extremely common, so this becomes a useful optimization. This can save ~5% code size. Reviewers: eugenis, vitalybuka Reviewed By: eugenis, vitalybuka Subscribers: hiraditya, #sanitizers, llvm-commits Tags: #sanitizers, #llvm Differential Revision: https://reviews.llvm.org/D81700
2020-06-16 06:17:00 +08:00
; CHECK-NOT: call void @__msan_warning_with_origin_noreturn
Handle llvm.launder.invariant.group in msan. Summary: [MSan] handle llvm.launder.invariant.group Msan used to give false-positives in class Foo { public: virtual ~Foo() {}; }; // Return true iff *x is set. bool f1(void **x, bool flag); Foo* f() { void *p; bool found; found = f1(&p,flag); if (found) { // p is always set here. return static_cast<Foo*>(p); // False positive here. } return nullptr; } Patch by Ilya Tokar. Reviewers: #sanitizers, eugenis Reviewed By: #sanitizers, eugenis Subscribers: eugenis, Prazek, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68236 llvm-svn: 373515
2019-10-03 03:53:19 +08:00
declare dso_local zeroext i1 @_Z2f1PPvb(i8**, i1 zeroext) local_unnamed_addr
declare i8* @llvm.launder.invariant.group.p0i8(i8*)
declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture)
declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture)
attributes #0 = { sanitize_memory uwtable }