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
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
Vitaly Buka