Commit Graph

20 Commits

Author SHA1 Message Date
Teresa Johnson 311801a017 Revert "[MemProf] Defer profile file setup until dump time"
This reverts commit ea1826ee57.

This change is breaking the ability of tests to override the profile
output file. Need to add a mechanism to do that before resubmitting.
2022-11-28 06:29:24 -08:00
Teresa Johnson ea1826ee57 [MemProf] Defer profile file setup until dump time
With all of the writing of the memprof profile consolidated into one
place, there is no need to set up the profile file (which creates the
file and also redirects all printing from the runtime to it) until we
are ready to dump the profile.

This allows errors and other messages to be dumped to stderr instead of
the profile file, which by default is in a binary format. Additionally,
reset the output file to stderr after dumping the profile so that any
requested memprof allocator statistics are printed to stderr.

Differential Revision: https://reviews.llvm.org/D138175
2022-11-18 15:09:02 -08:00
Enna1 9e80add2cf [memprof] dump memprof profile when receive deadly signals
Currently memprof profile is dumped when program exits (call `FinishAndWrite()` in ~Allocator) or `__memprof_profile_dump` is manually called.
For programs that never exit (e.g. server-side application), it will be useful to dump memprof profile when specific signal is received.
This patch installs a signal handler for deadly signals(SIGSEGV, SIGBUS, SIGABRT, SIGILL, SIGTRAP, SIGFPE) like we do in other sanitizers. In the signal handler `__memprof_profile_dump` is called to dump memprof profile.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D134795
2022-10-08 10:08:23 +08:00
Julian Lettner ca50840b5b [Sanitizer][Darwin] Cleanup MaybeReexec() function and usage
While investigating another issue, I noticed that `MaybeReexec()` never
actually "re-executes via `execv()`" anymore.  `DyldNeedsEnvVariable()`
only returned true on macOS 10.10 and below.

Usually, I try to avoid "unnecessary" cleanups (it's hard to be certain
that there truly is no fallout), but I decided to do this one because:

* I initially tricked myself into thinking that `MaybeReexec()` was
  relevant to my original investigation (instead of being dead code).
* The deleted code itself is quite complicated.
* Over time a few other things were mushed into `MaybeReexec()`:
  initializing `MonotonicNanoTime()`, verifying interceptors are
  working, and stripping the `DYLD_INSERT_LIBRARIES` env var to avoid
  problems when forking.
* This platform-specific thing leaked into `sanitizer_common.h`.
* The `ReexecDisabled()` config nob relies on the "strong overrides weak
  pattern", which is now problematic and can be completely removed.
* `ReexecDisabled()` actually hid another issue with interceptors not
  working in unit tests.  I added an explicit `verify_interceptors`
  (defaults to `true`) option instead.

Differential Revision: https://reviews.llvm.org/D129157
2022-07-08 14:31:42 -07:00
Julian Lettner 7789c9afc1 Revert "[Sanitizer][Darwin] Cleanup MaybeReexec() function and usage"
Many tests for the `UBSan-Standalone-iossim-x86_64` fail with this.
Reverting so I can investigate.

This reverts commit 0a9667b0f5.
2022-07-07 17:27:10 -07:00
Julian Lettner 0a9667b0f5 [Sanitizer][Darwin] Cleanup MaybeReexec() function and usage
While investigating another issue, I noticed that `MaybeReexec()` never
actually "re-executes via `execv()`" anymore.  `DyldNeedsEnvVariable()`
only returned true on macOS 10.10 and below.

Usually, I try to avoid "unnecessary" cleanups (it's hard to be certain
that there truly is no fallout), but I decided to do this one because:

* I initially tricked myself into thinking that `MaybeReexec()` was
  relevant to my original investigation (instead of being dead code).
* The deleted code itself is quite complicated.
* Over time a few other things were mushed into `MaybeReexec()`:
  initializing `MonotonicNanoTime()`, verifying interceptors are
  working, and stripping the `DYLD_INSERT_LIBRARIES` env var to avoid
  problems when forking.
* This platform-specific thing leaked into `sanitizer_common.h`.
* The `ReexecDisabled()` config nob relies on the "strong overrides weak
  pattern", which is now problematic and can be completely removed.
* `ReexecDisabled()` actually hid another issue with interceptors not
  working in unit tests.  I added an explicit `verify_interceptors`
  (defaults to `true`) option instead.

Differential Revision: https://reviews.llvm.org/D129157
2022-07-07 16:39:27 -07:00
Florian Mayer d49aaaf44f [memprof] Fix UB.
An infinite loop without any effects is illegal C++ and can be optimized
away by the compiler.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D119575
2022-02-11 13:01:14 -08:00
Florian Mayer 11b0506c08 [Sanitizers] Fix build broken by missing import. 2022-02-11 11:43:00 -08:00
Vitaly Buka 6318001209 [sanitizer] Support IsRssLimitExceeded in all sanitizers
Reviewed By: kstoimenov

Differential Revision: https://reviews.llvm.org/D115000
2021-12-03 12:45:44 -08:00
Vitaly Buka 36e6a259c8 [NFC][sanitizer] Remove SetSoftRssLimitExceededCallback
According comments on D44404, something like that was the goal.

Reviewed By: morehouse, kstoimenov

Differential Revision: https://reviews.llvm.org/D114991
2021-12-02 14:37:02 -08:00
Teresa Johnson 0d8bdc1786 [MemProf] Record accesses for all words touched in mem intrinsic
Previously for mem* intrinsics we only incremented the access count for
the first word in the range. However, after thinking it through I think
it makes more sense to record an access for every word in the range.
This better matches the behavior of inlined memory intrinsics, and also
allows better analysis of utilization at a future date.

Differential Revision: https://reviews.llvm.org/D110799
2021-09-30 15:07:55 -07:00
Dmitry Vyukov 2721e27c3a sanitizer_common: deduplicate CheckFailed
We have some significant amount of duplication around
CheckFailed functionality. Each sanitizer copy-pasted
a chunk of code. Some got random improvements like
dealing with recursive failures better. These improvements
could benefit all sanitizers, but they don't.

Deduplicate CheckFailed logic across sanitizers and let each
sanitizer only print the current stack trace.
I've tried to dedup stack printing as well,
but this got me into cmake hell. So let's keep this part
duplicated in each sanitizer for now.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D102221
2021-05-12 08:50:53 +02:00
Nico Weber 0e92cbd6a6 Revert "[sanitizer] Simplify GetTls with dl_iterate_phdr on Linux"
This reverts commit ec575e3b0a.
Still doesn't work, see https://crbug.com/1196037
2021-04-05 19:00:18 -04:00
Fangrui Song ec575e3b0a [sanitizer] Simplify GetTls with dl_iterate_phdr on Linux
This was reverted by f176803ef1 due to
Ubuntu 16.04 x86-64 glibc 2.23 problems.
This commit additionally calls `__tls_get_addr({modid,0})` to work around the
dlpi_tls_data==NULL issues for glibc<2.25
(https://sourceware.org/bugzilla/show_bug.cgi?id=19826)

GetTls is the range of

* thread control block and optional TLS_PRE_TCB_SIZE
* static TLS blocks plus static TLS surplus

On glibc, lsan requires the range to include
`pthread::{specific_1stblock,specific}` so that allocations only referenced by
`pthread_setspecific` can be scanned.

This patch uses `dl_iterate_phdr` to collect TLS blocks. Find the one
with `dlpi_tls_modid==1` as one of the initially loaded module, then find
consecutive ranges. The boundaries give us addr and size.

This allows us to drop the glibc internal `_dl_get_tls_static_info` and
`InitTlsSize` entirely. Use the simplified method with non-Android Linux for
now, but in theory this can be used with *BSD and potentially other ELF OSes.

This simplification enables D99566 for TLS Variant I architectures.

See https://reviews.llvm.org/D93972#2480556 for analysis on GetTls usage
across various sanitizers.

Differential Revision: https://reviews.llvm.org/D98926
2021-04-04 15:35:53 -07:00
Nico Weber f176803ef1 Revert "[sanitizer] Simplify GetTls with dl_iterate_phdr"
This reverts commit 9be8f8b34d.
This breaks tsan on Ubuntu 16.04:

    $ cat tiny_race.c
    #include <pthread.h>
    int Global;
    void *Thread1(void *x) {
      Global = 42;
      return x;
    }
    int main() {
      pthread_t t;
      pthread_create(&t, NULL, Thread1, NULL);
      Global = 43;
      pthread_join(t, NULL);
      return Global;
    }
    $ out/gn/bin/clang -fsanitize=thread -g -O1 tiny_race.c --sysroot ~/src/chrome/src/build/linux/debian_sid_amd64-sysroot/
    $ docker run -v $PWD:/foo ubuntu:xenial /foo/a.out
    FATAL: ThreadSanitizer CHECK failed: ../../compiler-rt/lib/tsan/rtl/tsan_platform_linux.cpp:447 "((thr_beg)) >= ((tls_addr))" (0x7fddd76beb80, 0xfffffffffffff980)
        #0 <null> <null> (a.out+0x4960b6)
        #1 <null> <null> (a.out+0x4b677f)
        #2 <null> <null> (a.out+0x49cf94)
        #3 <null> <null> (a.out+0x499bd2)
        #4 <null> <null> (a.out+0x42aaf1)
        #5 <null> <null> (libpthread.so.0+0x76b9)
        #6 <null> <null> (libc.so.6+0x1074dc)

(Get the sysroot from here: https://commondatastorage.googleapis.com/chrome-linux-sysroot/toolchain/500976182686961e34974ea7bdc0a21fca32be06/debian_sid_amd64_sysroot.tar.xz)

Also reverts follow-on commits:
This reverts commit 58c62fd976.
This reverts commit 31e541e375.
2021-04-02 18:19:17 -04:00
Fangrui Song 9be8f8b34d [sanitizer] Simplify GetTls with dl_iterate_phdr
GetTls is the range of

* thread control block and optional TLS_PRE_TCB_SIZE
* static TLS blocks plus static TLS surplus

On glibc, lsan requires the range to include
`pthread::{specific_1stblock,specific}` so that allocations only referenced by
`pthread_setspecific` can be scanned.

This patch uses `dl_iterate_phdr` to collect TLS ranges. Find the one
with `dlpi_tls_modid==1` as one of the initially loaded module, then find
consecutive ranges. The boundaries give us addr and size.

This allows us to drop the glibc internal `_dl_get_tls_static_info` and
`InitTlsSize` entirely. Use the simplified method with non-Android Linux for
now, but in theory this can be used with *BSD and potentially other ELF OSes.

In the future, we can move `ThreadDescriptorSize` code to lsan (and consider
intercepting `pthread_setspecific`) to avoid hacks in generic code.

See https://reviews.llvm.org/D93972#2480556 for analysis on GetTls usage
across various sanitizers.

Differential Revision: https://reviews.llvm.org/D98926
2021-03-25 21:55:27 -07:00
Jeroen Dobbelaere d7e71b5db8 [compiler-rt santizer] Use clock_gettime instead of timespec_get
On RH66, timespec_get is not available. Use clock_gettime instead.

This problem was introduced with D87120

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D91687
2020-12-08 10:10:17 -08:00
Petr Hosek ed4fbe6d9c [CMake] Replace ctime with time.h in memprof
Part of D88922
2020-10-30 20:02:53 -07:00
Teresa Johnson 5c20d7db9f [MemProf] Allow the binary to specify the profile output filename
This will allow the output directory to be specified by a build time
option, similar to the directory specified for regular PGO profiles via
-fprofile-generate=. The memory profiling instrumentation pass will
set up the variable. This is the same mechanism used by the PGO
instrumentation and runtime.

Depends on D87120 and D89629.

Differential Revision: https://reviews.llvm.org/D89086
2020-10-22 08:30:19 -07:00
Teresa Johnson 3d4bba302d [MemProf] Memory profiling runtime support
See RFC for background:
http://lists.llvm.org/pipermail/llvm-dev/2020-June/142744.html

Follow on companion to the clang/llvm instrumentation support in D85948
and committed earlier.

This patch adds the compiler-rt runtime support for the memory
profiling.

Note that much of this support was cloned from asan (and then greatly
simplified and renamed). For example the interactions with the
sanitizer_common allocators, error handling, interception, etc.

The bulk of the memory profiling specific code can be found in the
MemInfoBlock, MemInfoBlockCache, and related classes defined and used
in memprof_allocator.cpp.

For now, the memory profile is dumped to text (stderr by default, but
honors the sanitizer_common log_path flag). It is dumped in either a
default verbose format, or an optional terse format.

This patch also adds a set of tests for the core functionality.

Differential Revision: https://reviews.llvm.org/D87120
2020-10-16 09:47:02 -07:00