[llvm] r360107 - [SanitizerCoverage] Use different module ctor names for trace-pc-guard and inline-8bit-counters
Fangrui Song via llvm-commits
llvm-commits at lists.llvm.org
Mon May 6 18:39:37 PDT 2019
Author: maskray
Date: Mon May 6 18:39:37 2019
New Revision: 360107
URL: http://llvm.org/viewvc/llvm-project?rev=360107&view=rev
Log:
[SanitizerCoverage] Use different module ctor names for trace-pc-guard and inline-8bit-counters
Fixes the main issue in PR41693
When both modes are used, two functions are created:
`sancov.module_ctor`, `sancov.module_ctor.$LastUnique`, where
$LastUnique is the current LastUnique counter that may be different in
another module.
`sancov.module_ctor.$LastUnique` belongs to the comdat group of the same
name (due to the non-null third field of the ctor in llvm.global_ctors).
COMDAT group section [ 9] `.group' [sancov.module_ctor] contains 6 sections:
[Index] Name
[ 10] .text.sancov.module_ctor
[ 11] .rela.text.sancov.module_ctor
[ 12] .text.sancov.module_ctor.6
[ 13] .rela.text.sancov.module_ctor.6
[ 23] .init_array.2
[ 24] .rela.init_array.2
# 2 problems:
# 1) If sancov.module_ctor in this module is discarded, this group
# has a relocation to a discarded section. ld.bfd and gold will
# error. (Another issue: it is silently accepted by lld)
# 2) The comdat group has an unstable name that may be different in
# another translation unit. Even if the linker allows the dangling relocation
# (with --noinhibit-exec), there will be many undesired .init_array entries
COMDAT group section [ 25] `.group' [sancov.module_ctor.6] contains 2 sections:
[Index] Name
[ 26] .init_array.2
[ 27] .rela.init_array.2
By using different module ctor names, the associated comdat group names
will also be different and thus stable across modules.
Reviewed By: morehouse, phosek
Differential Revision: https://reviews.llvm.org/D61510
Added:
llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-inline-8bit-counters.ll
Modified:
llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-comdat.ll
llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-nocomdat.ll
Modified: llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp?rev=360107&r1=360106&r2=360107&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp Mon May 6 18:39:37 2019
@@ -61,7 +61,10 @@ static const char *const SanCovTraceDiv4
static const char *const SanCovTraceDiv8 = "__sanitizer_cov_trace_div8";
static const char *const SanCovTraceGep = "__sanitizer_cov_trace_gep";
static const char *const SanCovTraceSwitchName = "__sanitizer_cov_trace_switch";
-static const char *const SanCovModuleCtorName = "sancov.module_ctor";
+static const char *const SanCovModuleCtorTracePcGuardName =
+ "sancov.module_ctor_trace_pc_guard";
+static const char *const SanCovModuleCtor8bitCountersName =
+ "sancov.module_ctor_8bit_counters";
static const uint64_t SanCtorAndDtorPriority = 2;
static const char *const SanCovTracePCGuardName =
@@ -209,8 +212,9 @@ private:
void CreateFunctionLocalArrays(Function &F, ArrayRef<BasicBlock *> AllBlocks);
void InjectCoverageAtBlock(Function &F, BasicBlock &BB, size_t Idx,
bool IsLeafFunc = true);
- Function *CreateInitCallsForSections(Module &M, const char *InitFunctionName,
- Type *Ty, const char *Section);
+ Function *CreateInitCallsForSections(Module &M, const char *CtorName,
+ const char *InitFunctionName, Type *Ty,
+ const char *Section);
std::pair<Value *, Value *> CreateSecStartEnd(Module &M, const char *Section,
Type *Ty);
@@ -275,18 +279,19 @@ SanitizerCoverageModule::CreateSecStartE
}
Function *SanitizerCoverageModule::CreateInitCallsForSections(
- Module &M, const char *InitFunctionName, Type *Ty,
+ Module &M, const char *CtorName, const char *InitFunctionName, Type *Ty,
const char *Section) {
auto SecStartEnd = CreateSecStartEnd(M, Section, Ty);
auto SecStart = SecStartEnd.first;
auto SecEnd = SecStartEnd.second;
Function *CtorFunc;
std::tie(CtorFunc, std::ignore) = createSanitizerCtorAndInitFunctions(
- M, SanCovModuleCtorName, InitFunctionName, {Ty, Ty}, {SecStart, SecEnd});
+ M, CtorName, InitFunctionName, {Ty, Ty}, {SecStart, SecEnd});
+ assert(CtorFunc->getName() == CtorName);
if (TargetTriple.supportsCOMDAT()) {
// Use comdat to dedup CtorFunc.
- CtorFunc->setComdat(M.getOrInsertComdat(SanCovModuleCtorName));
+ CtorFunc->setComdat(M.getOrInsertComdat(CtorName));
appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority, CtorFunc);
} else {
appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority);
@@ -403,10 +408,12 @@ bool SanitizerCoverageModule::runOnModul
Function *Ctor = nullptr;
if (FunctionGuardArray)
- Ctor = CreateInitCallsForSections(M, SanCovTracePCGuardInitName, Int32PtrTy,
+ Ctor = CreateInitCallsForSections(M, SanCovModuleCtorTracePcGuardName,
+ SanCovTracePCGuardInitName, Int32PtrTy,
SanCovGuardsSectionName);
if (Function8bitCounterArray)
- Ctor = CreateInitCallsForSections(M, SanCov8bitCountersInitName, Int8PtrTy,
+ Ctor = CreateInitCallsForSections(M, SanCovModuleCtor8bitCountersName,
+ SanCov8bitCountersInitName, Int8PtrTy,
SanCovCountersSectionName);
if (Ctor && Options.PCTable) {
auto SecStartEnd = CreateSecStartEnd(M, SanCovPCsSectionName, IntptrPtrTy);
Modified: llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-comdat.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-comdat.ll?rev=360107&r1=360106&r2=360107&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-comdat.ll (original)
+++ llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-comdat.ll Mon May 6 18:39:37 2019
@@ -38,5 +38,4 @@ entry:
; CHECK_TRACE_PC_GUARD: call void @__sanitizer_cov_trace_pc_indir
; CHECK_TRACE_PC_GUARD: ret void
-; CHECK_TRACE_PC_GUARD-LABEL: define internal void @sancov.module_ctor() comdat
-
+; CHECK_TRACE_PC_GUARD-LABEL: define internal void @sancov.module_ctor_trace_pc_guard() comdat
Added: llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-inline-8bit-counters.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-inline-8bit-counters.ll?rev=360107&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-inline-8bit-counters.ll (added)
+++ llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-inline-8bit-counters.ll Mon May 6 18:39:37 2019
@@ -0,0 +1,13 @@
+; RUN: opt < %s -sancov -sanitizer-coverage-level=1 -sanitizer-coverage-trace-pc-guard -sanitizer-coverage-inline-8bit-counters -S | FileCheck %s
+
+; Module ctors should have stable names across modules, not something like
+; @sancov.module_ctor.3 that may cause duplicate ctors after linked together.
+
+; CHECK: define internal void @sancov.module_ctor_trace_pc_guard() comdat {
+; CHECK: define internal void @sancov.module_ctor_8bit_counters() comdat {
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-unknown-linux-gnu"
+define void @foo() {
+ ret void
+}
Modified: llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-nocomdat.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-nocomdat.ll?rev=360107&r1=360106&r2=360107&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-nocomdat.ll (original)
+++ llvm/trunk/test/Instrumentation/SanitizerCoverage/trace-pc-guard-nocomdat.ll Mon May 6 18:39:37 2019
@@ -38,5 +38,4 @@ entry:
; CHECK_TRACE_PC_GUARD: call void @__sanitizer_cov_trace_pc_indir
; CHECK_TRACE_PC_GUARD: ret void
-; CHECK_TRACE_PC_GUARD-LABEL: define internal void @sancov.module_ctor() {
-
+; CHECK_TRACE_PC_GUARD-LABEL: define internal void @sancov.module_ctor_trace_pc_guard() {
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