Commit Graph

18 Commits

Author SHA1 Message Date
Dmitry Vyukov 92a3a2dc3e sanitizer_common: introduce kInvalidTid/kMainTid
Currently we have a bit of a mess related to tids:
 - sanitizers re-declare kInvalidTid multiple times
 - some call it kUnknownTid
 - implicit assumptions that main tid is 0
 - asan/memprof claim their tids need to fit into 24 bits,
   but this does not seem to be true anymore
 - inconsistent use of u32/int to store tids

Introduce kInvalidTid/kMainTid in sanitizer_common
and use them consistently.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D101428
2021-04-30 15:58:05 +02:00
Jianzhou Zhao 75be3681d1 [msan] Remove dead function/fields
To see how to extract a shared allocator interface for D101204,
found some unused code. Tests passed. Are they safe to remove?

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D101559
2021-04-29 23:08:39 +00:00
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
Vitaly Buka e0dadf3de2 [sanitizer] Remove max_len parameter from InternalScopedString
InternalScopedString uses InternalMmapVector internally
so it can be resized dynamically as needed.

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D98751
2021-03-17 16:57:09 -07:00
Alex Richardson ad294e572b [sanitizers] Fix interception of GLibc regexec
Previously, on GLibc systems, the interceptor was calling __compat_regexec
(regexec@GLIBC_2.2.5) insead of the newer __regexec (regexec@GLIBC_2.3.4).
The __compat_regexec strips the REG_STARTEND flag but does not report an
error if other flags are present. This can result in infinite loops for
programs that use REG_STARTEND to find all matches inside a buffer (since
ignoring REG_STARTEND means that the search always starts from the first
character).

The underlying issue is that GLibc's dlsym(RTLD_NEXT, ...) appears to
always return the oldest versioned symbol instead of the default. This
means it does not match the behaviour of dlsym(RTLD_DEFAULT, ...) or the
behaviour documented in the manpage.

It appears a similar issue was encountered with realpath and worked around
in 77ef78a0a5.

See also https://sourceware.org/bugzilla/show_bug.cgi?id=14932 and
https://sourceware.org/bugzilla/show_bug.cgi?id=1319.

Fixes https://github.com/google/sanitizers/issues/1371

Reviewed By: #sanitizers, vitalybuka, marxin

Differential Revision: https://reviews.llvm.org/D96348
2021-03-08 10:53:55 +00:00
Fangrui Song fde3ae88ee [asan][memprof] Declare _DYNAMIC and fix -Wparentheses
Declare `extern ElfW(Dyn) _DYNAMIC[];` so that it will trivially work on musl.
2020-12-27 20:28:59 -08:00
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
Teresa Johnson a75b2e87e6 [MemProf] Add interface to dump profile
Add an interface so that the profile can be dumped on demand.

Differential Revision: https://reviews.llvm.org/D91768
2020-11-19 10:21:53 -08:00
Vitaly Buka 4cd0927306 [memprof] Don't protect destructor in final 2020-11-03 11:33:33 -08:00
Vitaly Buka d48f2d7c02 [sanitizer] Cleanup -Wnon-virtual-dtor warnings 2020-11-02 20:30:50 -08:00
Vitaly Buka 8b37a4e6ca [sanitizer] Make destructors protected 2020-11-02 18:00:43 -08:00
Petr Hosek 6db314e86b [CMake] Remove cxx-headers from runtime deps
Part of D88922
2020-10-30 20:03:38 -07:00
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