This migrates all LLVM (except Kaleidoscope and
CodeGen/StackProtector.cpp) DebugLoc::get to DILocation::get.
The CodeGen/StackProtector.cpp usage may have a nullptr Scope
and can trigger an assertion failure, so I don't migrate it.
Reviewed By: #debug-info, dblaikie
Differential Revision: https://reviews.llvm.org/D93087
Commit 9385aaa848 ("[sancov] Fix PR33732") added zeroext to
__sanitizer_cov_trace(_const)?_cmp[1248] parameters for x86_64 only,
however, it is useful on other targets, in particular, on SystemZ: it
fixes swap-cmp.test.
Therefore, use it on all targets. This is safe: if target ABI does not
require zero extension for a particular parameter, zeroext is simply
ignored. A similar change has been implemeted as part of commit
3bc439bdff ("[MSan] Add instrumentation for SystemZ"), and there were
no problems with it.
Reviewed By: morehouse
Differential Revision: https://reviews.llvm.org/D85689
If a section is supposed to hold elements of type T, then the
corresponding CreateSecStartEnd()'s Ty parameter represents T*.
Forwarding it to GlobalVariable constructor causes the resulting
GlobalVariable's type to be T*, and its SSA value type to be T**, which
is one indirection too many. This issue is mostly masked by pointer
casts, however, the global variable still gets an incorrect alignment,
which causes SystemZ to choose wrong instructions to access the
section.
Summary: `nomerge` attribute was added at D78659. So, we can remove the EmptyAsm workaround in ASan the MSan and use this attribute.
Reviewers: vitalybuka
Reviewed By: vitalybuka
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D82322
Keep deprecated -fsanitize-coverage-{white,black}list as aliases for compatibility for now.
Reviewed By: echristo
Differential Revision: https://reviews.llvm.org/D82244
https://reviews.llvm.org/D63616 added `-fsanitize-coverage-whitelist`
and `-fsanitize-coverage-blacklist` for clang.
However, it was done only for legacy pass manager.
This patch enable it for new pass manager as well.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D79653
This method has been commented as deprecated for a while. Remove
it and replace all uses with the equivalent getCalledOperand().
I also made a few cleanups in here. For example, to removes use
of getElementType on a pointer when we could just use getFunctionType
from the call.
Differential Revision: https://reviews.llvm.org/D78882
Summary:
Following up on the comments on D77638.
Not undoing rGd6525eff5ebfa0ef1d6cd75cb9b40b1881e7a707 here at the moment, since I don't know how to test mac builds. Please let me know if I should include that here too.
Reviewers: vitalybuka
Reviewed By: vitalybuka
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77889
Summary:
This commit adds two command-line options to clang.
These options let the user decide which functions will receive SanitizerCoverage instrumentation.
This is most useful in the libFuzzer use case, where it enables targeted coverage-guided fuzzing.
Patch by Yannis Juglaret of DGA-MI, Rennes, France
libFuzzer tests its target against an evolving corpus, and relies on SanitizerCoverage instrumentation to collect the code coverage information that drives corpus evolution. Currently, libFuzzer collects such information for all functions of the target under test, and adds to the corpus every mutated sample that finds a new code coverage path in any function of the target. We propose instead to let the user specify which functions' code coverage information is relevant for building the upcoming fuzzing campaign's corpus. To this end, we add two new command line options for clang, enabling targeted coverage-guided fuzzing with libFuzzer. We see targeted coverage guided fuzzing as a simple way to leverage libFuzzer for big targets with thousands of functions or multiple dependencies. We publish this patch as work from DGA-MI of Rennes, France, with proper authorization from the hierarchy.
Targeted coverage-guided fuzzing can accelerate bug finding for two reasons. First, the compiler will avoid costly instrumentation for non-relevant functions, accelerating fuzzer execution for each call to any of these functions. Second, the built fuzzer will produce and use a more accurate corpus, because it will not keep the samples that find new coverage paths in non-relevant functions.
The two new command line options are `-fsanitize-coverage-whitelist` and `-fsanitize-coverage-blacklist`. They accept files in the same format as the existing `-fsanitize-blacklist` option <https://clang.llvm.org/docs/SanitizerSpecialCaseList.html#format>. The new options influence SanitizerCoverage so that it will only instrument a subset of the functions in the target. We explain these options in detail in `clang/docs/SanitizerCoverage.rst`.
Consider now the woff2 fuzzing example from the libFuzzer tutorial <https://github.com/google/fuzzer-test-suite/blob/master/tutorial/libFuzzerTutorial.md>. We are aware that we cannot conclude much from this example because mutating compressed data is generally a bad idea, but let us use it anyway as an illustration for its simplicity. Let us use an empty blacklist together with one of the three following whitelists:
```
# (a)
src:*
fun:*
# (b)
src:SRC/*
fun:*
# (c)
src:SRC/src/woff2_dec.cc
fun:*
```
Running the built fuzzers shows how many instrumentation points the compiler adds, the fuzzer will output //XXX PCs//. Whitelist (a) is the instrument-everything whitelist, it produces 11912 instrumentation points. Whitelist (b) focuses coverage to instrument woff2 source code only, ignoring the dependency code for brotli (de)compression; it produces 3984 instrumented instrumentation points. Whitelist (c) focuses coverage to only instrument functions in the main file that deals with WOFF2 to TTF conversion, resulting in 1056 instrumentation points.
For experimentation purposes, we ran each fuzzer approximately 100 times, single process, with the initial corpus provided in the tutorial. We let the fuzzer run until it either found the heap buffer overflow or went out of memory. On this simple example, whitelists (b) and (c) found the heap buffer overflow more reliably and 5x faster than whitelist (a). The average execution times when finding the heap buffer overflow were as follows: (a) 904 s, (b) 156 s, and (c) 176 s.
We explain these results by the fact that WOFF2 to TTF conversion calls the brotli decompression algorithm's functions, which are mostly irrelevant for finding bugs in WOFF2 font reconstruction but nevertheless instrumented and used by whitelist (a) to guide fuzzing. This results in longer execution time for these functions and a partially irrelevant corpus. Contrary to whitelist (a), whitelists (b) and (c) will execute brotli-related functions without instrumentation overhead, and ignore new code paths found in them. This results in faster bug finding for WOFF2 font reconstruction.
The results for whitelist (b) are similar to the ones for whitelist (c). Indeed, WOFF2 to TTF conversion calls functions that are mostly located in SRC/src/woff2_dec.cc. The 2892 extra instrumentation points allowed by whitelist (b) do not tamper with bug finding, even though they are mostly irrelevant, simply because most of these functions do not get called. We get a slightly faster average time for bug finding with whitelist (b), which might indicate that some of the extra instrumentation points are actually relevant, or might just be random noise.
Reviewers: kcc, morehouse, vitalybuka
Reviewed By: morehouse, vitalybuka
Subscribers: pratyai, vitalybuka, eternalsakura, xwlin222, dende, srhines, kubamracek, #sanitizers, lebedev.ri, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D63616
Summary:
New SanitizerCoverage feature `inline-bool-flag` which inserts an
atomic store of `1` to a boolean (which is an 8bit integer in
practice) flag on every instrumented edge.
Implementation-wise it's very similar to `inline-8bit-counters`
features. So, much of wiring and test just follows the same pattern.
Reviewers: kcc, vitalybuka
Reviewed By: vitalybuka
Subscribers: llvm-commits, hiraditya, jfb, cfe-commits, #sanitizers
Tags: #clang, #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D77244
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.
I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
recompiles touches affected_files header
342380 95 3604 llvm/include/llvm/ADT/STLExtras.h
314730 234 1345 llvm/include/llvm/InitializePasses.h
307036 118 2602 llvm/include/llvm/ADT/APInt.h
213049 59 3611 llvm/include/llvm/Support/MathExtras.h
170422 47 3626 llvm/include/llvm/Support/Compiler.h
162225 45 3605 llvm/include/llvm/ADT/Optional.h
158319 63 2513 llvm/include/llvm/ADT/Triple.h
140322 39 3598 llvm/include/llvm/ADT/StringRef.h
137647 59 2333 llvm/include/llvm/Support/Error.h
131619 73 1803 llvm/include/llvm/Support/FileSystem.h
Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.
Reviewers: bkramer, asbirlea, bollu, jdoerfert
Differential Revision: https://reviews.llvm.org/D70211
This patch merges the sancov module and funciton passes into one module pass.
The reason for this is because we ran into an out of memory error when
attempting to run asan fuzzer on some protobufs (pc.cc files). I traced the OOM
error to the destructor of SanitizerCoverage where we only call
appendTo[Compiler]Used which calls appendToUsedList. I'm not sure where precisely
in appendToUsedList causes the OOM, but I am able to confirm that it's calling
this function *repeatedly* that causes the OOM. (I hacked sancov a bit such that
I can still create and destroy a new sancov on every function run, but only call
appendToUsedList after all functions in the module have finished. This passes, but
when I make it such that appendToUsedList is called on every sancov destruction,
we hit OOM.)
I don't think the OOM is from just adding to the SmallSet and SmallVector inside
appendToUsedList since in either case for a given module, they'll have the same
max size. I suspect that when the existing llvm.compiler.used global is erased,
the memory behind it isn't freed. I could be wrong on this though.
This patch works around the OOM issue by just calling appendToUsedList at the
end of every module run instead of function run. The same amount of constants
still get added to llvm.compiler.used, abd we make the pass usage and logic
simpler by not having any inter-pass dependencies.
Differential Revision: https://reviews.llvm.org/D66988
llvm-svn: 370971
changes were made to the patch since then.
--------
[NewPM] Port Sancov
This patch contains a port of SanitizerCoverage to the new pass manager. This one's a bit hefty.
Changes:
- Split SanitizerCoverageModule into 2 SanitizerCoverage for passing over
functions and ModuleSanitizerCoverage for passing over modules.
- ModuleSanitizerCoverage exists for adding 2 module level calls to initialization
functions but only if there's a function that was instrumented by sancov.
- Added legacy and new PM wrapper classes that own instances of the 2 new classes.
- Update llvm tests and add clang tests.
llvm-svn: 367053
This patch contains a port of SanitizerCoverage to the new pass manager. This one's a bit hefty.
Changes:
- Split SanitizerCoverageModule into 2 SanitizerCoverage for passing over
functions and ModuleSanitizerCoverage for passing over modules.
- ModuleSanitizerCoverage exists for adding 2 module level calls to initialization
functions but only if there's a function that was instrumented by sancov.
- Added legacy and new PM wrapper classes that own instances of the 2 new classes.
- Update llvm tests and add clang tests.
Differential Revision: https://reviews.llvm.org/D62888
llvm-svn: 365838
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
llvm-svn: 360107
This patch adds a new option to SplitAllCriticalEdges and uses it to avoid splitting critical edges when the destination basic block ends with unreachable. Otherwise if we split the critical edge, sanitizer coverage will instrument the new block that gets inserted for the split. But since this block itself shouldn't be reachable this is pointless. These basic blocks will stick around and generate assembly, but they don't end in sane control flow and might get placed at the end of the function. This makes it look like one function has code that flows into the next function.
This showed up while compiling the linux kernel with clang. The kernel has a tool called objtool that detected the code that appeared to flow from one function to the next. https://github.com/ClangBuiltLinux/linux/issues/351#issuecomment-461698884
Differential Revision: https://reviews.llvm.org/D57982
llvm-svn: 355947
Summary:
These sorts of blocks often contain calls to noreturn functions, like
longjmp, throw, or trap. If they don't end the program, they are
"interesting" from the perspective of sanitizer coverage, so we should
instrument them. This was discussed in https://reviews.llvm.org/D57982.
Reviewers: kcc, vitalybuka
Subscribers: llvm-commits, craig.topper, efriedma, morehouse, hiraditya
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58740
llvm-svn: 355152
Summary:
If the user declares or defines `__sancov_lowest_stack` with an
unexpected type, then `getOrInsertGlobal` inserts a bitcast and the
following cast fails:
```
Constant *SanCovLowestStackConstant =
M.getOrInsertGlobal(SanCovLowestStackName, IntptrTy);
SanCovLowestStack = cast<GlobalVariable>(SanCovLowestStackConstant);
```
This variable is a SanitizerCoverage implementation detail and the user
should generally never have a need to access it, so we emit an error
now.
rdar://problem/44143130
Reviewers: morehouse
Differential Revision: https://reviews.llvm.org/D57633
llvm-svn: 353100
This cleans up all GetElementPtr creation in LLVM to explicitly pass a
value type rather than deriving it from the pointer's element-type.
Differential Revision: https://reviews.llvm.org/D57173
llvm-svn: 352913
This cleans up all LoadInst creation in LLVM to explicitly pass the
value type rather than deriving it from the pointer's element-type.
Differential Revision: https://reviews.llvm.org/D57172
llvm-svn: 352911
Recommit r352791 after tweaking DerivedTypes.h slightly, so that gcc
doesn't choke on it, hopefully.
Original Message:
The FunctionCallee type is effectively a {FunctionType*,Value*} pair,
and is a useful convenience to enable code to continue passing the
result of getOrInsertFunction() through to EmitCall, even once pointer
types lose their pointee-type.
Then:
- update the CallInst/InvokeInst instruction creation functions to
take a Callee,
- modify getOrInsertFunction to return FunctionCallee, and
- update all callers appropriately.
One area of particular note is the change to the sanitizer
code. Previously, they had been casting the result of
`getOrInsertFunction` to a `Function*` via
`checkSanitizerInterfaceFunction`, and storing that. That would report
an error if someone had already inserted a function declaraction with
a mismatching signature.
However, in general, LLVM allows for such mismatches, as
`getOrInsertFunction` will automatically insert a bitcast if
needed. As part of this cleanup, cause the sanitizer code to do the
same. (It will call its functions using the expected signature,
however they may have been declared.)
Finally, in a small number of locations, callers of
`getOrInsertFunction` actually were expecting/requiring that a brand
new function was being created. In such cases, I've switched them to
Function::Create instead.
Differential Revision: https://reviews.llvm.org/D57315
llvm-svn: 352827
This reverts commit f47d6b38c7 (r352791).
Seems to run into compilation failures with GCC (but not clang, where
I tested it). Reverting while I investigate.
llvm-svn: 352800
The FunctionCallee type is effectively a {FunctionType*,Value*} pair,
and is a useful convenience to enable code to continue passing the
result of getOrInsertFunction() through to EmitCall, even once pointer
types lose their pointee-type.
Then:
- update the CallInst/InvokeInst instruction creation functions to
take a Callee,
- modify getOrInsertFunction to return FunctionCallee, and
- update all callers appropriately.
One area of particular note is the change to the sanitizer
code. Previously, they had been casting the result of
`getOrInsertFunction` to a `Function*` via
`checkSanitizerInterfaceFunction`, and storing that. That would report
an error if someone had already inserted a function declaraction with
a mismatching signature.
However, in general, LLVM allows for such mismatches, as
`getOrInsertFunction` will automatically insert a bitcast if
needed. As part of this cleanup, cause the sanitizer code to do the
same. (It will call its functions using the expected signature,
however they may have been declared.)
Finally, in a small number of locations, callers of
`getOrInsertFunction` actually were expecting/requiring that a brand
new function was being created. In such cases, I've switched them to
Function::Create instead.
Differential Revision: https://reviews.llvm.org/D57315
llvm-svn: 352791
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
Comdat groups override weak symbol behavior, allowing the linker to keep
the comdats for weak symbols in favor of comdats for strong symbols.
Fixes the issue described in:
https://bugs.chromium.org/p/chromium/issues/detail?id=918662
Reviewers: eugenis, pcc, rnk
Reviewed By: pcc, rnk
Subscribers: smeenai, rnk, bd1976llvm, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D56516
llvm-svn: 351247
Summary:
Use appendToUsed instead of include to ensure that
SanitizerCoverage's constructors are not stripped.
Also, use isOSBinFormatCOFF() to determine if target
binary format is COFF.
Reviewers: pcc
Reviewed By: pcc
Subscribers: hiraditya
Differential Revision: https://reviews.llvm.org/D56369
llvm-svn: 351118
Summary:
Merge code used to get section start and section end pointers
for SanitizerCoverage constructors. This includes code that handles
getting the start pointers when targeting MSVC.
Reviewers: kcc, morehouse
Reviewed By: morehouse
Subscribers: kcc, hiraditya
Differential Revision: https://reviews.llvm.org/D53211
llvm-svn: 344657
Summary:
GetOrCreateFunctionComdat is currently used in SanitizerCoverage,
where it's defined. I'm planing to use it in HWASAN as well,
so moving it into a common location.
NFC
Reviewers: morehouse
Reviewed By: morehouse
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D53218
llvm-svn: 344433
Summary:
Linking with the /OPT:REF linker flag when building COFF files causes
the linker to strip SanitizerCoverage's constructors. Prevent this by
giving the constructors WeakODR linkage and by passing the linker a
directive to include sancov.module_ctor.
Include a test in compiler-rt to verify libFuzzer can be linked using
/OPT:REF
Reviewers: morehouse, rnk
Reviewed By: morehouse, rnk
Subscribers: rnk, morehouse, hiraditya
Differential Revision: https://reviews.llvm.org/D52119
llvm-svn: 344391
Summary:
Otherwise, at least on Mac, the linker eliminates unused symbols which
causes libFuzzer to error out due to a mismatch of the sizes of coverage tables.
Issue in Chromium: https://bugs.chromium.org/p/chromium/issues/detail?id=892167
Reviewers: morehouse, kcc, george.karpenkov
Reviewed By: morehouse
Subscribers: kubamracek, llvm-commits
Differential Revision: https://reviews.llvm.org/D53113
llvm-svn: 344345
Summary:
Place global arrays in comdat sections with their associated functions.
This makes sure they are stripped along with the functions they
reference, even on the BFD linker.
Reviewers: eugenis
Reviewed By: eugenis
Subscribers: eraman, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D51902
llvm-svn: 342186
Summary:
Place global arrays in comdat sections with their associated functions.
This makes sure they are stripped along with the functions they
reference, even on the BFD linker.
Reviewers: eugenis
Reviewed By: eugenis
Subscribers: eraman, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D51902
llvm-svn: 341987
Summary:
Place global arrays in comdat sections with their associated functions.
This makes sure they are stripped along with the functions they
reference, even on the BFD linker.
Reviewers: eugenis
Reviewed By: eugenis
Subscribers: eraman, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D51902
llvm-svn: 341951
Summary:
Port libFuzzer to windows-msvc.
This patch allows libFuzzer targets to be built and run on Windows, using -fsanitize=fuzzer and/or fsanitize=fuzzer-no-link. It allows these forms of coverage instrumentation to work on Windows as well.
It does not fix all issues, such as those with -fsanitize-coverage=stack-depth, which is not usable on Windows as of this patch.
It also does not fix any libFuzzer integration tests. Nearly all of them fail to compile, fixing them will come in a later patch, so libFuzzer tests are disabled on Windows until them.
Patch By: metzman
Reviewers: morehouse, rnk
Reviewed By: morehouse, rnk
Subscribers: #sanitizers, delcypher, morehouse, kcc, eraman
Differential Revision: https://reviews.llvm.org/D51022
llvm-svn: 341082
Kazu Hirata