[clang] b52b2e1 - Recommit "[libFuzzer] Disable implicit builtin knowledge about memcmp-like functions when -fsanitize=fuzzer-no-link is given."
Dokyung Song via cfe-commits
cfe-commits at lists.llvm.org
Mon Jul 27 11:28:18 PDT 2020
Author: Dokyung Song
Date: 2020-07-27T18:27:49Z
New Revision: b52b2e1c188072e3cbc91500cfd503fb26d50ffc
URL: https://github.com/llvm/llvm-project/commit/b52b2e1c188072e3cbc91500cfd503fb26d50ffc
DIFF: https://github.com/llvm/llvm-project/commit/b52b2e1c188072e3cbc91500cfd503fb26d50ffc.diff
LOG: Recommit "[libFuzzer] Disable implicit builtin knowledge about memcmp-like functions when -fsanitize=fuzzer-no-link is given."
Summary: This patch disables implicit builtin knowledge about memcmp-like functions when compiling the program for fuzzing, i.e., when -fsanitize=fuzzer(-no-link) is given. This allows libFuzzer to always intercept memcmp-like functions as it effectively disables optimizing calls to such functions into different forms. This is done by adding a set of flags (-fno-builtin-memcmp and others) in the clang driver. Individual -fno-builtin-* flags previously used in several libFuzzer tests are now removed, as it is now done automatically in the clang driver.
The patch was once reverted in 8ef9e2bf355d05bc81d8b0fe1e5333eec59a0a91, as this patch was dependent on a reverted commit f78d9fceea736d431e9e3cbca291e3909e3aa46d. This reverted commit was recommitted in 831ae45e3dc609e43ba561af07670a8fe47461ef, so relanding this dependent patch too.
Reviewers: morehouse, hctim
Subscribers: cfe-commits, #sanitizers
Tags: #clang, #sanitizers
Differential Revision: https://reviews.llvm.org/D83987
Added:
compiler-rt/test/fuzzer/noasan-bcmp.test
Modified:
clang/lib/Driver/SanitizerArgs.cpp
compiler-rt/test/fuzzer/noasan-memcmp.test
compiler-rt/test/fuzzer/noasan-memcmp64.test
compiler-rt/test/fuzzer/noasan-strcmp.test
compiler-rt/test/fuzzer/noasan-strncmp.test
compiler-rt/test/fuzzer/noasan-strstr.test
Removed:
################################################################################
diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp
index e4fda752c041..8c49e92b2c0f 100644
--- a/clang/lib/Driver/SanitizerArgs.cpp
+++ b/clang/lib/Driver/SanitizerArgs.cpp
@@ -1088,6 +1088,23 @@ void SanitizerArgs::addArgs(const ToolChain &TC, const llvm::opt::ArgList &Args,
Sanitizers.has(SanitizerKind::Address))
CmdArgs.push_back("-fno-assume-sane-operator-new");
+ // libFuzzer wants to intercept calls to certain library functions, so the
+ // following -fno-builtin-* flags force the compiler to emit interposable
+ // libcalls to these functions. Other sanitizers effectively do the same thing
+ // by marking all library call sites with NoBuiltin attribute in their LLVM
+ // pass. (see llvm::maybeMarkSanitizerLibraryCallNoBuiltin)
+ if (Sanitizers.has(SanitizerKind::FuzzerNoLink)) {
+ CmdArgs.push_back("-fno-builtin-bcmp");
+ CmdArgs.push_back("-fno-builtin-memcmp");
+ CmdArgs.push_back("-fno-builtin-strncmp");
+ CmdArgs.push_back("-fno-builtin-strcmp");
+ CmdArgs.push_back("-fno-builtin-strncasecmp");
+ CmdArgs.push_back("-fno-builtin-strcasecmp");
+ CmdArgs.push_back("-fno-builtin-strstr");
+ CmdArgs.push_back("-fno-builtin-strcasestr");
+ CmdArgs.push_back("-fno-builtin-memmem");
+ }
+
// Require -fvisibility= flag on non-Windows when compiling if vptr CFI is
// enabled.
if (Sanitizers.hasOneOf(CFIClasses) && !TC.getTriple().isOSWindows() &&
diff --git a/compiler-rt/test/fuzzer/noasan-bcmp.test b/compiler-rt/test/fuzzer/noasan-bcmp.test
new file mode 100644
index 000000000000..a3dd17bf6e2b
--- /dev/null
+++ b/compiler-rt/test/fuzzer/noasan-bcmp.test
@@ -0,0 +1,4 @@
+UNSUPPORTED: darwin, freebsd, windows
+RUN: %cpp_compiler -fno-sanitize=address -DMEMCMP=bcmp %S/MemcmpTest.cpp -o %t
+RUN: not %run %t -seed=1 -runs=10000000 2>&1 | FileCheck %s
+CHECK: BINGO
diff --git a/compiler-rt/test/fuzzer/noasan-memcmp.test b/compiler-rt/test/fuzzer/noasan-memcmp.test
index c90755c53a90..c5ce2fff8c9f 100644
--- a/compiler-rt/test/fuzzer/noasan-memcmp.test
+++ b/compiler-rt/test/fuzzer/noasan-memcmp.test
@@ -1,9 +1,9 @@
UNSUPPORTED: darwin, freebsd, windows
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-memcmp %S/MemcmpTest.cpp -o %t-NoAsanMemcmpTest
+RUN: %cpp_compiler -fno-sanitize=address %S/MemcmpTest.cpp -o %t-NoAsanMemcmpTest
RUN: not %run %t-NoAsanMemcmpTest -seed=1 -runs=10000000 2>&1 | FileCheck %s
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc -fno-builtin-memcmp %S/CustomAllocator.cpp %S/MemcmpTest.cpp -o %t-NoAsanCustomAllocatorMemcmpTest
+RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc %S/CustomAllocator.cpp %S/MemcmpTest.cpp -o %t-NoAsanCustomAllocatorMemcmpTest
RUN: not %run %t-NoAsanCustomAllocatorMemcmpTest -seed=1 -runs=10000000 2>&1 | FileCheck %s
CHECK: BINGO
diff --git a/compiler-rt/test/fuzzer/noasan-memcmp64.test b/compiler-rt/test/fuzzer/noasan-memcmp64.test
index a6b8f88594d0..496ee386193e 100644
--- a/compiler-rt/test/fuzzer/noasan-memcmp64.test
+++ b/compiler-rt/test/fuzzer/noasan-memcmp64.test
@@ -1,6 +1,6 @@
UNSUPPORTED: darwin, freebsd, windows
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-memcmp %S/Memcmp64BytesTest.cpp -o %t-NoAsanMemcmp64BytesTest
+RUN: %cpp_compiler -fno-sanitize=address %S/Memcmp64BytesTest.cpp -o %t-NoAsanMemcmp64BytesTest
RUN: not %run %t-NoAsanMemcmp64BytesTest -seed=1 -runs=1000000 2>&1 | FileCheck %s
CHECK: BINGO
diff --git a/compiler-rt/test/fuzzer/noasan-strcmp.test b/compiler-rt/test/fuzzer/noasan-strcmp.test
index 76b7c5de7c7b..c264dec6bea2 100644
--- a/compiler-rt/test/fuzzer/noasan-strcmp.test
+++ b/compiler-rt/test/fuzzer/noasan-strcmp.test
@@ -1,9 +1,9 @@
UNSUPPORTED: darwin, freebsd, windows
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-strcmp %S/StrcmpTest.cpp -o %t-NoAsanStrcmpTest
+RUN: %cpp_compiler -fno-sanitize=address %S/StrcmpTest.cpp -o %t-NoAsanStrcmpTest
RUN: not %run %t-NoAsanStrcmpTest -seed=1 -runs=2000000 2>&1 | FileCheck %s
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc -fno-builtin-strcmp %S/CustomAllocator.cpp %S/StrcmpTest.cpp -o %t-NoAsanCustomAllocatorStrcmpTest
+RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc %S/CustomAllocator.cpp %S/StrcmpTest.cpp -o %t-NoAsanCustomAllocatorStrcmpTest
RUN: not %run %t-NoAsanCustomAllocatorStrcmpTest -seed=1 -runs=2000000 2>&1 | FileCheck %s
CHECK: BINGO
diff --git a/compiler-rt/test/fuzzer/noasan-strncmp.test b/compiler-rt/test/fuzzer/noasan-strncmp.test
index 705781ec3958..dd0f25460922 100644
--- a/compiler-rt/test/fuzzer/noasan-strncmp.test
+++ b/compiler-rt/test/fuzzer/noasan-strncmp.test
@@ -1,9 +1,9 @@
UNSUPPORTED: darwin, freebsd, windows
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-strncmp %S/StrncmpTest.cpp -o %t-NoAsanStrncmpTest
+RUN: %cpp_compiler -fno-sanitize=address %S/StrncmpTest.cpp -o %t-NoAsanStrncmpTest
RUN: not %run %t-NoAsanStrncmpTest -seed=2 -runs=10000000 2>&1 | FileCheck %s
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc -fno-builtin-strncmp %S/CustomAllocator.cpp %S/StrncmpTest.cpp -o %t-NoAsanCustomAllocatorStrncmpTest
+RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc %S/CustomAllocator.cpp %S/StrncmpTest.cpp -o %t-NoAsanCustomAllocatorStrncmpTest
RUN: not %run %t-NoAsanCustomAllocatorStrncmpTest -seed=2 -runs=10000000 2>&1 | FileCheck %s
CHECK: BINGO
diff --git a/compiler-rt/test/fuzzer/noasan-strstr.test b/compiler-rt/test/fuzzer/noasan-strstr.test
index f06e903149bd..e969170bfac9 100644
--- a/compiler-rt/test/fuzzer/noasan-strstr.test
+++ b/compiler-rt/test/fuzzer/noasan-strstr.test
@@ -1,9 +1,9 @@
UNSUPPORTED: darwin, freebsd, windows
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-strstr %S/StrstrTest.cpp -o %t-NoAsanStrstrTest
+RUN: %cpp_compiler -fno-sanitize=address %S/StrstrTest.cpp -o %t-NoAsanStrstrTest
RUN: not %run %t-NoAsanStrstrTest -seed=1 -runs=2000000 2>&1 | FileCheck %s
-RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc -fno-builtin-strstr %S/CustomAllocator.cpp %S/StrstrTest.cpp -o %t-NoAsanCustomAllocatorStrstrTest
+RUN: %cpp_compiler -fno-sanitize=address -fno-builtin-calloc %S/CustomAllocator.cpp %S/StrstrTest.cpp -o %t-NoAsanCustomAllocatorStrstrTest
RUN: not %run %t-NoAsanCustomAllocatorStrstrTest -seed=1 -runs=2000000 2>&1 | FileCheck %s
CHECK: BINGO
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