Summary:
When ASan reports an issue the contents of the system log buffer
(`error_message_buffer`) get flushed to the system log (via
`LogFullErrorReport()`). After this happens the buffer is not cleared
but this is usually fine because the process usually exits soon after
reporting the issue.
However, when ASan runs in `halt_on_error=0` mode execution continues
without clearing the buffer. This leads to problems if more ASan
issues are found and reported.
1. Duplicate ASan reports in the system log. The Nth (start counting from 1)
ASan report will be duplicated (M - N) times in the system log if M is the
number of ASan issues reported.
2. Lost ASan reports. Given a sufficient
number of reports the buffer will fill up and consequently cannot be appended
to. This means reports can be lost.
The fix here is to reset `error_message_buffer_pos` to 0 which
effectively clears the system log buffer.
A test case is included but unfortunately it is Darwin specific because
querying the system log is an OS specific activity.
rdar://problem/55986279
Reviewers: kubamracek, yln, vitalybuka, kcc, filcab
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D76749
AddressSanitizer RT
================================
This directory contains sources of the AddressSanitizer (ASan) runtime library.
Directory structure:
README.txt : This file.
Makefile.mk : File for make-based build.
CMakeLists.txt : File for cmake-based build.
asan_*.{cc,h} : Sources of the asan runtime library.
scripts/* : Helper scripts.
tests/* : ASan unit tests.
Also ASan runtime needs the following libraries:
lib/interception/ : Machinery used to intercept function calls.
lib/sanitizer_common/ : Code shared between various sanitizers.
ASan runtime currently also embeds part of LeakSanitizer runtime for
leak detection (lib/lsan/lsan_common.{cc,h}).
ASan runtime can only be built by CMake. You can run ASan tests
from the root of your CMake build tree:
make check-asan
For more instructions see:
https://github.com/google/sanitizers/wiki/AddressSanitizerHowToBuild
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