maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[asan] Allow -fsanitize-address-globals-dead-stripping with -fno-data-sections for ELF 

-fdata-sections decides whether global variables go into different sections.
This is orthogonal to whether we place their metadata (`.data` or `asan_globals`) into different sections.

With -fno-data-sections, `-fsanitize-address-globals-dead-stripping` can still:

* deduplicate COMDAT `asan.module_ctor` and `asan.module_dtor`
* (with ld --gc-sections): for a data section (e.g. `.data`), if all global variables defined relative to it are unreferenced, discard them and associated `asan_globals` sections (rare but no need to exclude this case)

Similar to c7b90947bd for PE/COFF.

Reviewed By: #sanitizers, kstoimenov, vitalybuka

Differential Revision: https://reviews.llvm.org/D120394
This commit is contained in:
Fangrui Song 2022-02-23 16:08:25 -08:00
parent 454c149898
commit 0477cac332
3 changed files with 3 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
clang/lib/CodeGen/BackendUtil.cpp
View File

@ -281,7 +281,7 @@ static bool asanUseGlobalsGC(const Triple &T, const CodeGenOptions &CGOpts) {
case Triple::COFF:
return true;
case Triple::ELF:
return CGOpts.DataSections && !CGOpts.DisableIntegratedAS;
return !CGOpts.DisableIntegratedAS;
case Triple::GOFF:
llvm::report_fatal_error("ASan not implemented for GOFF");
case Triple::XCOFF:

3
clang/test/CodeGen/asan-globals-gc.cpp
View File

@ -1,6 +1,5 @@
// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITH-GC
// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITH-GC
// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fno-integrated-as -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fno-integrated-as -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
// RUN: %clang_cc1 -fsanitize=address -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC

4
clang/test/CodeGen/asan-no-globals-no-comdat.cpp
View File

@ -1,9 +1,7 @@
// Test that on Linux asan constructor is placed in a comdat iff globals-gc is on.
// Even if there are no globals in the module.
// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITH-GC
// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fno-integrated-as -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITH-GC
// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fno-integrated-as -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
// RUN: %clang_cc1 -fsanitize=address -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC