Summary:
Rewrite asan's stack frame layout.
First, most of the stack layout logic is moved into a separte file
to make it more testable and (potentially) useful for other projects.
Second, make the frames more compact by using adaptive redzones
(smaller for small objects, larger for large objects).
Third, try to minimized gaps due to large alignments (this is hypothetical since
today we don't see many stack vars aligned by more than 32).
The frames indeed become more compact, but I'll still need to run more benchmarks
before committing, but I am sking for review now to get early feedback.
This change will be accompanied by a trivial change in compiler-rt tests
to match the new frame sizes.
Reviewers: samsonov, dvyukov
Reviewed By: samsonov
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2324
llvm-svn: 196568
This currently breaks clang/test/CodeGen/code-coverage.c. The root cause
is that the newly introduced access to Funcs[j] is out of bounds.
llvm-svn: 196365
gcov expects every function to contain an entry block that
unconditionally branches into the next block. clang does not implement
basic blocks in this manner, so gcov did not output correct branch info
if the entry block branched to multiple blocks.
This change splits every function's entry block into an empty block and
a block with the rest of the instructions. The instrumentation code will
take care of the rest.
llvm-svn: 195513
The new command line flags are -dfsan-ignore-pointer-label-on-store and -dfsan-ignore-pointer-label-on-load. Their default value matches the current labelling scheme.
Additionally, the function __dfsan_union_load is marked as readonly.
Patch by Lorenzo Martignoni!
Differential Revision: http://llvm-reviews.chandlerc.com/D2187
llvm-svn: 195382
Instead of permanently outputting "MVLL" as the file checksum, clang
will create gcno and gcda checksums by hashing the destination block
numbers of every arc. This allows for llvm-cov to check if the two gcov
files are synchronized.
Regenerated the test files so they contain the checksum. Also added
negative test to ensure error when the checksums don't match.
llvm-svn: 195191
I was able to successfully run a bootstrapped LTO build of clang with
r194701, so this change does not seem to be the cause of our failing
buildbots.
llvm-svn: 194789
This reverts commit 194701. Apple's bootstrapped LTO builds have been failing,
and this change (along with compiler-rt 194702-194704) is the only thing on
the blamelist. I will either reappy these changes or help debug the problem,
depending on whether this fixes the buildbots.
llvm-svn: 194780
Indirect call wrapping helps MSanDR (dynamic instrumentation companion tool
for MSan) to catch all cases where execution leaves a compiler-instrumented
module by allowing the tool to rewrite targets of indirect calls.
This change is an optimization that skips wrapping for calls when target is
inside the current module. This relies on the linker providing symbols at the
begin and end of the module code (or code + data, does not really matter).
Gold linker provides such symbols by default. GNU (BFD) linker needs a link
flag: -Wl,--defsym=__executable_start=0.
More info:
https://code.google.com/p/memory-sanitizer/wiki/MSanDR#Native_exec
llvm-svn: 194697
LLVM optimizers may widen accesses to packed structures that overflow the structure itself, but should be in bounds up to the alignment of the object
llvm-svn: 193317
Summary:
Given a global array G[N], which is declared in this CU and has static initializer
avoid instrumenting accesses like G[i], where 'i' is a constant and 0<=i<N.
Also add a bit of stats.
This eliminates ~1% of instrumentations on SPEC2006
and also partially helps when asan is being run together with coverage.
Reviewers: samsonov
Reviewed By: samsonov
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1947
llvm-svn: 192794
Currently MSan checks that arguments of *cvt* intrinsics are fully initialized.
That's too much to ask: some of them only operate on lower half, or even
quarter, of the input register.
llvm-svn: 192599
infrastructure.
This was essentially work toward PGO based on a design that had several
flaws, partially dating from a time when LLVM had a different
architecture, and with an effort to modernize it abandoned without being
completed. Since then, it has bitrotted for several years further. The
result is nearly unusable, and isn't helping any of the modern PGO
efforts. Instead, it is getting in the way, adding confusion about PGO
in LLVM and distracting everyone with maintenance on essentially dead
code. Removing it paves the way for modern efforts around PGO.
Among other effects, this removes the last of the runtime libraries from
LLVM. Those are being developed in the separate 'compiler-rt' project
now, with somewhat different licensing specifically more approriate for
runtimes.
llvm-svn: 191835
Adds a flag to the MemorySanitizer pass that enables runtime rewriting of
indirect calls. This is part of MSanDR implementation and is needed to return
control to the DynamiRio-based helper tool on transition between instrumented
and non-instrumented modules. Disabled by default.
llvm-svn: 191006
The work on this project was left in an unfinished and inconsistent state.
Hopefully someone will eventually get a chance to implement this feature, but
in the meantime, it is better to put things back the way the were. I have
left support in the bitcode reader to handle the case-range bitcode format,
so that we do not lose bitcode compatibility with the llvm 3.3 release.
This reverts the following commits: 155464, 156374, 156377, 156613, 156704,
156757, 156804 156808, 156985, 157046, 157112, 157183, 157315, 157384, 157575,
157576, 157586, 157612, 157810, 157814, 157815, 157880, 157881, 157882, 157884,
157887, 157901, 158979, 157987, 157989, 158986, 158997, 159076, 159101, 159100,
159200, 159201, 159207, 159527, 159532, 159540, 159583, 159618, 159658, 159659,
159660, 159661, 159703, 159704, 160076, 167356, 172025, 186736
llvm-svn: 190328
instead of having its own implementation.
The implementation of isTBAAVtableAccess is in TypeBasedAliasAnalysis.cpp
since it is related to the format of TBAA metadata.
The path for struct-path tbaa will be exercised by
test/Instrumentation/ThreadSanitizer/read_from_global.ll, vptr_read.ll, and
vptr_update.ll when struct-path tbaa is on by default.
llvm-svn: 190216
Select condition shadow was being ignored resulting in false negatives.
This change OR-s sign-extended condition shadow into the result shadow.
llvm-svn: 189785
The code was erroneously reading overflow area shadow from the TLS slot,
bypassing the local copy. Reading shadow directly from TLS is wrong, because
it can be overwritten by a nested vararg call, if that happens before va_start.
llvm-svn: 189104
DFSan changes the ABI of each function in the module. This makes it possible
for a function with the native ABI to be called with the instrumented ABI,
or vice versa, thus possibly invoking undefined behavior. A simple way
of statically detecting instances of this problem is to prepend the prefix
"dfs$" to the name of each instrumented-ABI function.
This will not catch every such problem; in particular function pointers passed
across the instrumented-native barrier cannot be used on the other side.
These problems could potentially be caught dynamically.
Differential Revision: http://llvm-reviews.chandlerc.com/D1373
llvm-svn: 189052
There are situations which can affect the correctness (or at least expectation)
of the gcov output. For instance, if a call to __gcov_flush() occurs within a
block before the execution count is registered and then the program aborts in
some way, then that block will not be marked as executed. This is not normally
what the user expects.
If we move the code that's registering when a block is executed to the
beginning, we can catch these types of situations.
PR16893
llvm-svn: 188849
Summary:
When the -dfsan-debug-nonzero-labels parameter is supplied, the code
is instrumented such that when a call parameter, return value or load
produces a nonzero label, the function __dfsan_nonzero_label is called.
The idea is that a debugger breakpoint can be set on this function
in a nominally label-free program to help identify any bugs in the
instrumentation pass causing labels to be introduced.
Reviewers: eugenis
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1405
llvm-svn: 188472
This replaces the old incomplete greylist functionality with an ABI
list, which can provide more detailed information about the ABI and
semantics of specific functions. The pass treats every function in
the "uninstrumented" category in the ABI list file as conforming to
the "native" (i.e. unsanitized) ABI. Unless the ABI list contains
additional categories for those functions, a call to one of those
functions will produce a warning message, as the labelling behaviour
of the function is unknown. The other supported categories are
"functional", "discard" and "custom".
- "discard" -- This function does not write to (user-accessible) memory,
and its return value is unlabelled.
- "functional" -- This function does not write to (user-accessible)
memory, and the label of its return value is the union of the label of
its arguments.
- "custom" -- Instead of calling the function, a custom wrapper __dfsw_F
is called, where F is the name of the function. This function may wrap
the original function or provide its own implementation.
Differential Revision: http://llvm-reviews.chandlerc.com/D1345
llvm-svn: 188402
DataFlowSanitizer is a generalised dynamic data flow analysis.
Unlike other Sanitizer tools, this tool is not designed to detect a
specific class of bugs on its own. Instead, it provides a generic
dynamic data flow analysis framework to be used by clients to help
detect application-specific issues within their own code.
Differential Revision: http://llvm-reviews.chandlerc.com/D965
llvm-svn: 187923
The globals being generated here were given the 'private' linkage type. However,
this caused them to end up in different sections with the wrong prefix. E.g.,
they would be in the __TEXT,__const section with an 'L' prefix instead of an 'l'
(lowercase ell) prefix.
The problem is that the linker will eat a literal label with 'L'. If a weak
symbol is then placed into the __TEXT,__const section near that literal, then it
cannot distinguish between the literal and the weak symbol.
Part of the problems here was introduced because the address sanitizer converted
some C strings into constant initializers with trailing nuls. (Thus putting them
in the __const section with the wrong prefix.) The others were variables that
the address sanitizer created but simply had the wrong linkage type.
llvm-svn: 187827
This patch provides basic support for powerpc64le as an LLVM target.
However, use of this target will not actually generate little-endian
code. Instead, use of the target will cause the correct little-endian
built-in defines to be generated, so that code that tests for
__LITTLE_ENDIAN__, for example, will be correctly parsed for
syntax-only testing. Code generation will otherwise be the same as
powerpc64 (big-endian), for now.
The patch leaves open the possibility of creating a little-endian
PowerPC64 back end, but there is no immediate intent to create such a
thing.
The LLVM portions of this patch simply add ppc64le coverage everywhere
that ppc64 coverage currently exists. There is nothing of any import
worth testing until such time as little-endian code generation is
implemented. In the corresponding Clang patch, there is a new test
case variant to ensure that correct built-in defines for little-endian
code are generated.
llvm-svn: 187179
A special case list can now specify categories for specific globals,
which can be used to instruct an instrumentation pass to treat certain
functions or global variables in a specific way, such as by omitting
certain aspects of instrumentation while keeping others, or informing
the instrumentation pass that a specific uninstrumentable function
has certain semantics, thus allowing the pass to instrument callers
according to those semantics.
For example, AddressSanitizer now uses the "init" category instead of
global-init prefixes for globals whose initializers should not be
instrumented, but which in all other respects should be instrumented.
The motivating use case is DataFlowSanitizer, which will have a
number of different categories for uninstrumentable functions, such
as "functional" which specifies that a function has pure functional
semantics, or "discard" which indicates that a function's return
value should not be labelled.
Differential Revision: http://llvm-reviews.chandlerc.com/D1092
llvm-svn: 185978
- Build debug metadata for 'bare' Modules using DIBuilder
- DebugIR can be constructed to generate an IR file (to be seen by a debugger)
or not in cases where the user already has an IR file on disk.
llvm-svn: 185193
No functionality change.
It should suffice to check the type of a debug info metadata, instead of
calling Verify. For cases where we know the type of a DI metadata, use
assert.
Also update testing cases to make them conform to the format of DI classes.
llvm-svn: 185135
Before this change, each module defined a weak_odr global __msan_track_origins
with a value of 1 if origin tracking is enabled, 0 if disabled. If there are
modules with different values, any of them may win. If 0 wins, and there is at
least one module with 1, the program will most likely crash.
With this change, __msan_track_origins is only emitted if origin tracking is
on. Then runtime library detects if there is at least one module with origin
tracking, and enables runtime support for it.
llvm-svn: 182997
- move AsmWriter.h from public headers into lib
- marked all AssemblyWriter functions as non-virtual; no need to override them
- DebugIR now "plugs into" AssemblyWriter with an AssemblyAnnotationWriter helper
- exposed flags to control hiding of a) debug metadata b) debug intrinsic calls
C/R: Paul Redmond
llvm-svn: 182617
- requires existing debug information to be present
- fixes up file name and line number information in metadata
- emits a "<orig_filename>-debug.ll" succinct IR file (without !dbg metadata
or debug intrinsics) that can be read by a debugger
- initialize pass in opt tool to enable the "-debug-ir" flag
- lit tests to follow
llvm-svn: 181467
the things, and renames it to CBindingWrapping.h. I also moved
CBindingWrapping.h into Support/.
This new file just contains the macros for defining different wrap/unwrap
methods.
The calls to those macros, as well as any custom wrap/unwrap definitions
(like for array of Values for example), are put into corresponding C++
headers.
Doing this required some #include surgery, since some .cpp files relied
on the fact that including Wrap.h implicitly caused the inclusion of a
bunch of other things.
This also now means that the C++ headers will include their corresponding
C API headers; for example Value.h must include llvm-c/Core.h. I think
this is harmless, since the C API headers contain just external function
declarations and some C types, so I don't believe there should be any
nasty dependency issues here.
llvm-svn: 180881
If we compile a single source program, the `.gcda' file will be generated where
the program was executed. This isn't desirable, because that place may be at an
unpredictable place (the program could call `chdir' for instance).
Instead, we will output the `.gcda' file in the same place we output the `.gcno'
file. I.e., the directory where the executable was generated. This matches GCC's
behavior.
<rdar://problem/13061072> & PR11809
llvm-svn: 178084
Before: the function name was stored by the compiler as a constant string
and the run-time was printing it.
Now: the PC is stored instead and the run-time prints the full symbolized frame.
This adds a couple of instructions into every function with non-empty stack frame,
but also reduces the binary size because we store less strings (I saw 2% size reduction).
This change bumps the asan ABI version to v3.
llvm part.
Example of report (now):
==31711==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fffa77cf1c5 at pc 0x41feb0 bp 0x7fffa77cefb0 sp 0x7fffa77cefa8
READ of size 1 at 0x7fffa77cf1c5 thread T0
#0 0x41feaf in Frame0(int, char*, char*, char*) stack-oob-frames.cc:20
#1 0x41f7ff in Frame1(int, char*, char*) stack-oob-frames.cc:24
#2 0x41f477 in Frame2(int, char*) stack-oob-frames.cc:28
#3 0x41f194 in Frame3(int) stack-oob-frames.cc:32
#4 0x41eee0 in main stack-oob-frames.cc:38
#5 0x7f0c5566f76c (/lib/x86_64-linux-gnu/libc.so.6+0x2176c)
#6 0x41eb1c (/usr/local/google/kcc/llvm_cmake/a.out+0x41eb1c)
Address 0x7fffa77cf1c5 is located in stack of thread T0 at offset 293 in frame
#0 0x41f87f in Frame0(int, char*, char*, char*) stack-oob-frames.cc:12 <<<<<<<<<<<<<< this is new
This frame has 6 object(s):
[32, 36) 'frame.addr'
[96, 104) 'a.addr'
[160, 168) 'b.addr'
[224, 232) 'c.addr'
[288, 292) 's'
[352, 360) 'd'
llvm-svn: 177724
Use the new `llvm_gcov_init' function to register the writeout and flush
functions. The initialization function will also call `atexit' for some cleanups
and final writout calls. But it does this only once. This is better than
checking for the `main' function, because in a library that function may not
exist.
<rdar://problem/12439551>
llvm-svn: 177579
We don't want to write out >1000 files at the same time. That could make things
prohibitively expensive. Instead, register the "writeout" function so that it's
emitted serially.
<rdar://problem/12439551>
llvm-svn: 177437
For each compile unit, we want to register a function that will flush that
compile unit. Otherwise, __gcov_flush() would only flush the counters within the
current compile unit, and not any outside of it.
PR15191 & <rdar://problem/13167507>
llvm-svn: 177340
constructs default arguments. It can now take default arguments from
cl::opt'ions. Add a new -default-gcov-version=... option, and actually test it!
Sink the reverse-order of the version into GCOVProfiling, hiding it from our
users.
llvm-svn: 177002
emitProfileNotes(), similar to emitProfileArcs(). Also update its comment.
Also add a comment on Version[4] (there will be another comment in clang later),
and compress lines that exceeded 80 columns.
llvm-svn: 176994
it. Fortunately, versions of gcov that predate the extra checksum also ignore
any extra data, so this isn't a problem. There will be a matching commit in
compiler-rt.
llvm-svn: 176745
into the actual gcov file.
Instead of using the bottom 4 bytes as the function identifier, use a counter.
This makes the identifier numbers stable across multiple runs.
llvm-svn: 176616
Shadow checks are disabled and memory loads always produce fully initialized
values in functions that don't have a sanitize_memory attribute. Value and
argument shadow is propagated as usual.
This change also updates blacklist behaviour to match the above.
llvm-svn: 176247
These are two related changes (one in llvm, one in clang).
LLVM:
- rename address_safety => sanitize_address (the enum value is the same, so we preserve binary compatibility with old bitcode)
- rename thread_safety => sanitize_thread
- rename no_uninitialized_checks -> sanitize_memory
CLANG:
- add __attribute__((no_sanitize_address)) as a synonym for __attribute__((no_address_safety_analysis))
- add __attribute__((no_sanitize_thread))
- add __attribute__((no_sanitize_memory))
for S in address thread memory
If -fsanitize=S is present and __attribute__((no_sanitize_S)) is not
set llvm attribute sanitize_S
llvm-svn: 176075
This patch makes asan instrument memory accesses with unusual sizes (e.g. 5 bytes or 10 bytes), e.g. long double or
packed structures.
Instrumentation is done with two 1-byte checks
(first and last bytes) and if the error is found
__asan_report_load_n(addr, real_size) or
__asan_report_store_n(addr, real_size)
is called.
Also, call these two new functions in memset/memcpy
instrumentation.
asan-rt part will follow.
llvm-svn: 175507
This flag makes asan use a small (<2G) offset for 64-bit asan shadow mapping.
On x86_64 this saves us a register, thus achieving ~2/3 of the
zero-base-offset's benefits in both performance and code size.
Thanks Jakub Jelinek for the idea.
llvm-svn: 174886
This reverts r171041. This was a nice idea that didn't work out well.
Clang warnings need to be associated with warning groups so that they can
be selectively disabled, promoted to errors, etc. This simplistic patch didn't
allow for that. Enhancing it to provide some way for the backend to specify
a front-end warning type seems like overkill for the few uses of this, at
least for now.
llvm-svn: 174748
It is way too slow. Change the default option value to 0.
Always do exact shadow propagation for unsigned ICmp with constants, it is
cheap (under 1% cpu time) and required for correctness.
llvm-svn: 173682
Only for integers, pointers, and vectors of those. No floats.
Instrumentation seems very heavy, and may need to be replaced
with some approximation in the future.
llvm-svn: 173452
This fixes va_start/va_copy of a va_list field which happens to not
be laid out at a 16-byte boundary.
Differential Revision: http://llvm-reviews.chandlerc.com/D276
llvm-svn: 172128
code that includes Intrinsics.gen directly.
This never showed up in my testing because the old Intrinsics.gen was
still kicking around in the make build system and was correct there. =[
Thankfully, some of the bots to clean rebuilds and that caught this.
llvm-svn: 171373
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.
There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.
The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.
I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).
I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.
llvm-svn: 171366
utils/sort_includes.py script.
Most of these are updating the new R600 target and fixing up a few
regressions that have creeped in since the last time I sorted the
includes.
llvm-svn: 171362
directly.
This is in preparation for removing the use of the 'Attribute' class as a
collection of attributes. That will shift to the AttributeSet class instead.
llvm-svn: 171253
When the backend is used from clang, it should produce proper diagnostics
instead of just printing messages to errs(). Other clients may also want to
register their own error handlers with the LLVMContext, and the same handler
should work for warnings in the same way as the existing emitError methods.
llvm-svn: 171041
This changes adds shadow and origin propagation for unknown intrinsics
by examining the arguments and ModRef behaviour. For now, only 3 classes
of intrinsics are handled:
- those that look like simple SIMD store
- those that look like simple SIMD load
- those that don't have memory effects and look like arithmetic/logic/whatever
operation on simple types.
llvm-svn: 170530
This change moves the code for default shadow propagaition (handleShadowOr)
and origin tracking (setOriginForNaryOp) into a new builder-like class. Also
gets rid of handleShadowOrBinary.
llvm-svn: 170192
When ASan replaces <alloca instruction> with
<offset into a common large alloca>, it should also patch
llvm.dbg.declare calls and replace debug info descriptors to mark
that we've replaced alloca with a value that stores an address
of the user variable, not the user variable itself.
See PR11818 for more context.
llvm-svn: 169984
Use explicitely aligned store and load instructions to deal with argument and
retval shadow. This matters when an argument's alignment is higher than
__msan_param_tls alignment (which is the case with __m128i).
llvm-svn: 169859
The `-mno-red-zone' flag wasn't being propagated to the functions that code
coverage generates. This allowed some of them to use the red zone when that
wasn't allowed.
<rdar://problem/12843084>
llvm-svn: 169754
MSan uses a TLS slot to pass shadow for function arguments and return values.
This makes all instrumented functions not readonly, and at the same time
requires that all callees of an instrumented function that may be
MSan-instrumented do not have readonly attribute (otherwise some of the
instrumentation may be optimized out).
llvm-svn: 169591
Instead of unconditionally storing origin with every application store,
only do this when the shadow of the stored value is != 0.
This change also delays instrumentation of stores until after the walk over
function's instructions, because adding new basic blocks confuses InstVisitor.
We only keep 1 origin value per 4 bytes of application memory. This change
fixes the bug when a store of a single clean byte wiped the origin for the
whole 4-byte area.
Since stores of uninitialized values are relatively uncommon, this change
improves performance of track-origins mode by 5% median and by up to 47% on
specs.
llvm-svn: 169490
NAKAMURA Takumi