Commit Graph

5 Commits

Author SHA1 Message Date
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