- Available from 12.x branch, by the time it lands next year in FreeBSD tree, the 11.x's might be EOL.
- Intentionally changed the getrandom test to C code as with 12.0 (might be fixed in CURRENT since), there is a linkage issue in C++ context.
Reviewers: emaste, dim, vitalybuka
Reviewed-By: vitalybuka
Differential Revision: https://reviews.llvm.org/D68451
llvm-svn: 374315
Summary:
Quote from http://eel.is/c++draft/expr.add#4:
```
4 When an expression J that has integral type is added to or subtracted
from an expression P of pointer type, the result has the type of P.
(4.1) If P evaluates to a null pointer value and J evaluates to 0,
the result is a null pointer value.
(4.2) Otherwise, if P points to an array element i of an array object x with n
elements ([dcl.array]), the expressions P + J and J + P
(where J has the value j) point to the (possibly-hypothetical) array
element i+j of x if 0≤i+j≤n and the expression P - J points to the
(possibly-hypothetical) array element i−j of x if 0≤i−j≤n.
(4.3) Otherwise, the behavior is undefined.
```
Therefore, as per the standard, applying non-zero offset to `nullptr`
(or making non-`nullptr` a `nullptr`, by subtracting pointer's integral value
from the pointer itself) is undefined behavior. (*if* `nullptr` is not defined,
i.e. e.g. `-fno-delete-null-pointer-checks` was *not* specified.)
To make things more fun, in C (6.5.6p8), applying *any* offset to null pointer
is undefined, although Clang front-end pessimizes the code by not lowering
that info, so this UB is "harmless".
Since rL369789 (D66608 `[InstCombine] icmp eq/ne (gep inbounds P, Idx..), null -> icmp eq/ne P, null`)
LLVM middle-end uses those guarantees for transformations.
If the source contains such UB's, said code may now be miscompiled.
Such miscompilations were already observed:
* https://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190826/687838.html
* https://github.com/google/filament/pull/1566
Surprisingly, UBSan does not catch those issues
... until now. This diff teaches UBSan about these UB's.
`getelementpointer inbounds` is a pretty frequent instruction,
so this does have a measurable impact on performance;
I've addressed most of the obvious missing folds (and thus decreased the performance impact by ~5%),
and then re-performed some performance measurements using my [[ https://github.com/darktable-org/rawspeed | RawSpeed ]] benchmark:
(all measurements done with LLVM ToT, the sanitizer never fired.)
* no sanitization vs. existing check: average `+21.62%` slowdown
* existing check vs. check after this patch: average `22.04%` slowdown
* no sanitization vs. this patch: average `48.42%` slowdown
Reviewers: vsk, filcab, rsmith, aaron.ballman, vitalybuka, rjmccall, #sanitizers
Reviewed By: rsmith
Subscribers: kristof.beyls, nickdesaulniers, nikic, ychen, dtzWill, xbolva00, dberris, arphaman, rupprecht, reames, regehr, llvm-commits, cfe-commits
Tags: #clang, #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D67122
llvm-svn: 374293
Dereferences with addresses above the 48-bit hardware addressable range
produce "invalid instruction" (instead of "invalid access") hardware
exceptions (there is no hardware address decoding logic for those bits),
and the address provided by this exception is the address of the
instruction (not the faulting address). The kernel maps the "invalid
instruction" to SEGV, but fails to provide the real fault address.
Because of this ASan lies and says that those cases are null
dereferences. This downgrades the severity of a found bug in terms of
security. In the ASan signal handler, we can not provide the real
faulting address, but at least we can try not to lie.
rdar://50366151
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D68676
llvm-svn: 374265
Summary:
Following up on D68471, this CL introduces some `getStats` APIs to
gather statistics in char buffers (`ScopedString` really) instead of
printing them out right away. Ultimately `printStats` will just
output the buffer, but that allows us to potentially do some work
on the intermediate buffer, and can be used for a `mallocz` type
of functionality. This allows us to pretty much get rid of all the
`Printf` calls around, but I am keeping the function in for
debugging purposes.
This changes the existing tests to use the new APIs when required.
I will add new tests as suggested in D68471 in another CL.
Reviewers: morehouse, hctim, vitalybuka, eugenis, cferris
Reviewed By: morehouse
Subscribers: delcypher, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D68653
llvm-svn: 374173
Summary:
Don't use weak exports when building tsan into a shared library for Go. gcc can't handle the pragmas used to make the weak references.
Include files that have been added since the last update to build.bat. (We should really find a better way to list all the files needed.)
Add windows version defines (WINVER and _WIN32_WINNT) to get AcquireSRWLockExclusive and ReleaseSRWLockExclusive defined.
Define GetProcessMemoryInfo to use the kernel32 version. This is kind of a hack, the windows header files should do this translation for us. I think we're not in the right family partition (we're using Desktop, but that translation only happens for App and System partitions???), but hacking the family partition seems equally gross and I have no idea what the consequences of that might be.
Patch by Keith Randall.
Reviewers: dvyukov, vitalybuka
Reviewed By: vitalybuka
Subscribers: jfb, delcypher, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D68599
llvm-svn: 373984
Summary:
There was an issue in `releaseToOSMaybe`: one of the criteria to
decide if we should proceed with the release was wrong. Namely:
```
const uptr N = Sci->Stats.PoppedBlocks - Sci->Stats.PushedBlocks;
if (N * BlockSize < PageSize)
return; // No chance to release anything.
```
I meant to check if the amount of bytes in the free list was lower
than a page, but this actually checks if the amount of **in use** bytes
was lower than a page.
The correct code is:
```
const uptr BytesInFreeList =
Region->AllocatedUser -
(Region->Stats.PoppedBlocks - Region->Stats.PushedBlocks) * BlockSize;
if (BytesInFreeList < PageSize)
return 0; // No chance to release anything.
```
Consequences of the bug:
- if a class size has less than a page worth of in-use bytes (allocated
or in a cache), reclaiming would not occur, whatever the amount of
blocks in the free list; in real world scenarios this is unlikely to
happen and be impactful;
- if a class size had less than a page worth of free bytes (and enough
in-use bytes, etc), then reclaiming would be attempted, with likely
no result. This means the reclaiming was overzealous at times.
I didn't have a good way to test for this, so I changed the prototype
of the function to return the number of bytes released, allowing to
get the information needed. The test added fails with the initial
criteria.
Another issue is that `ReleaseToOsInterval` can actually be 0, meaning
we always try to release (side note: it's terrible for performances).
so change a `> 0` check to `>= 0`.
Additionally, decrease the `CanRelease` threshold to `PageSize / 32`.
I still have to make that configurable but I will do it at another time.
Finally, rename some variables in `printStats`: I feel like "available"
was too ambiguous, so change it to "total".
Reviewers: morehouse, hctim, eugenis, vitalybuka, cferris
Reviewed By: morehouse
Subscribers: delcypher, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D68471
llvm-svn: 373930
Summary:
Initially, our malloc_info was returning ENOTSUP, but Android would
rather have it return successfully and write a barebone XML to the
stream, so we will oblige.
Add an associated test.
Reviewers: cferris, morehouse, hctim, eugenis, vitalybuka
Reviewed By: morehouse
Subscribers: delcypher, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D68427
llvm-svn: 373754
Summary:
https://reviews.llvm.org/D28596 exposed OnPrint in the global namespace,
which can cause collisions with user-defined OnPrint() functions.
Reviewers: vitalybuka, dvyukov
Reviewed By: vitalybuka, dvyukov
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67987
llvm-svn: 373518
Revert "compiler-rt: move all __GLIBC_PREREQ into own header file"
"move all __GLIBC_PREREQ" breaks build on some bots
This reverts commit 2d75ee9373.
This reverts commit 7a6461fcc2.
llvm-svn: 373367
Summary:
It's needed to use __GLIBC_PREREQ from <features.h>
tsan didn't let us to include <features.h> by using --sysroot=. to disable system includes on
anything that is not named as "tsan*posix*", "tsan*mac*", "tsan*linux*".
See compiler-rt/lib/tsan/CMakeLists.txt
Reviewers: eugenis, dvyukov, kcc
Reviewed By: kcc
Subscribers: mgorny, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D68176
llvm-svn: 373282
Summary:
This interceptor is useful on its own, but the main purpose of this
change is to intercept libpthread initialization on linux/glibc in
order to run __msan_init before any .preinit_array constructors.
We used to trigger on pthread_initialize_minimal -> getrlimit(), but
that call has changed to __getrlimit at some point.
Reviewers: vitalybuka, pcc
Subscribers: jfb, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D68168
llvm-svn: 373239
We can't use short granules with stack instrumentation when targeting older
API levels because the rest of the system won't understand the short granule
tags stored in shadow memory.
Moreover, we need to be able to let old binaries (which won't understand
short granule tags) run on a new system that supports short granule
tags. Such binaries will call the __hwasan_tag_mismatch function when their
outlined checks fail. We can compensate for the binary's lack of support
for short granules by implementing the short granule part of the check in
the __hwasan_tag_mismatch function. Unfortunately we can't do anything about
inline checks, but I don't believe that we can generate these by default on
aarch64, nor did we do so when the ABI was fixed.
A new function, __hwasan_tag_mismatch_v2, is introduced that lets code
targeting the new runtime avoid redoing the short granule check. Because tag
mismatches are rare this isn't important from a performance perspective; the
main benefit is that it introduces a symbol dependency that prevents binaries
targeting the new runtime from running on older (i.e. incompatible) runtimes.
Differential Revision: https://reviews.llvm.org/D68059
llvm-svn: 373035
Adding annotation function variants __tsan_write_range_pc and
__tsan_read_range_pc to annotate ranged access to memory while providing a
program counter for the access.
Differential Revision: https://reviews.llvm.org/D66885
llvm-svn: 372730
Differential Revision: https://reviews.llvm.org/D67937
M lib/builtins/fp_add_impl.inc
M lib/builtins/fp_lib.h
M lib/builtins/fp_trunc_impl.inc
llvm-svn: 372684
This fixes buildbot failures for https://reviews.llvm.org/rL372459.
(at least on PowerPC/Z )
The fix is generated by running clang-format on the error lines only.
llvm-svn: 372511
Summary:
strerror(3) on NetBSD uses internally TSD with a destructor that is never
fired for exit(3). It's correctly called for pthread_exit(3) scenarios.
This is a case when a leak on exit(3) is expected, unavoidable and harmless.
Reviewers: joerg, vitalybuka, dvyukov, mgorny
Reviewed By: vitalybuka
Subscribers: dmgreen, kristof.beyls, jfb, llvm-commits, #sanitizers
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D67337
llvm-svn: 372461
Summary:
The atexit(3) and __cxa_atexit() calls allocate internally memory and free on exit,
after executing all callback. This causes false positives as DoLeakCheck() is called
from the atexit handler. In the LSan/ASan tests there are strict checks triggering
false positives here.
Intercept all atexit(3) and __cxa_atexit() calls and disable LSan when calling the
real functions.
Stop tracing allocations in pthread_atfork(3) funtions, as there are performed
internal allocations that are not freed for the time of running StopTheWorld()
code. This avoids false-positives.
The same changes have to be replicated in the ASan and LSan runtime.
Non-NetBSD OSs are not tested and this code is restricted to NetBSD only.
Reviewers: dvyukov, joerg, mgorny, vitalybuka, eugenis
Reviewed By: vitalybuka
Subscribers: jfb, llvm-commits, #sanitizers
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D67331
llvm-svn: 372459
Summary:
Do not grab the allocator lock before calling dl_iterate_phdr. This may
cause a lock order inversion with (valid) user code that uses malloc
inside a dl_iterate_phdr callback.
Reviewers: vitalybuka, hctim
Subscribers: jfb, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D67738
llvm-svn: 372348
Fuchsia doesn't have /proc/id/maps, so it relies on the kernel logging system
to provide the DSO map to be able to symbolize in the context of ASLR. The DSO
map is logged automatically on Fuchsia when encountering a crash or writing to
the sanitizer log for the first time in a process. There are several cases
where libFuzzer doesn't encounter a crash, e.g. on timeouts, OOMs, and when
configured to print new PCs as they become covered, to name a few. Therefore,
this change always writes to the sanitizer log on startup to ensure the DSO map
is available in the log.
Author: aarongreen
Differential Revision: https://reviews.llvm.org/D66233
llvm-svn: 372056
Summary:
.init_array gets optimized away when building with -O2 and as a result,
check_cxx_section_exists failed to pass -DCOMPILER_RT_HAS_INITFINI_ARRAY
when building crtbegin.o and crtend.o, which causes binaries linked with
them encounter segmentation fault. See https://crbug.com/855759 for
details. This change prevents .init_array section to be optimized away
even with -O2 or higher optimization level.
Subscribers: dberris, mgorny, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D67628
llvm-svn: 372038
Summary:
getauxval() is not available on NetBSD and there is no a direct equivalent.
Add a function that implements the same semantics with NetBSD internals.
Reorder the GetPageSize() functions to prefer the sysctl approach for NetBSD.
It no longer makes a difference which approach is better. Avoid changing
conditional code path.
Reviewers: vitalybuka, dvyukov, mgorny, joerg
Reviewed By: vitalybuka
Subscribers: llvm-commits, #sanitizers
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D67329
llvm-svn: 371758
Russell Gallop