llvm-project/compiler-rt
Calixte Denizet 8f46269f0c [profile] Don't dump counters when forking and don't reset when calling exec** functions
Summary:
There is no need to write out gcdas when forking because we can just reset the counters in the parent process.
Let say a counter is N before the fork, then fork and this counter is set to 0 in the child process.
In the parent process, the counter is incremented by P and in the child process it's incremented by C.
When dump is ran at exit, parent process will dump N+P for the given counter and the child process will dump 0+C, so when the gcdas are merged the resulting counter will be N+P+C.
About exec** functions, since the current process is replaced by an another one there is no need to reset the counters but just write out the gcdas since the counters are definitely lost.
To avoid to have lists in a bad state, we just lock them during the fork and the flush (if called explicitely) and lock them when an element is added.

Reviewers: marco-c

Reviewed By: marco-c

Subscribers: hiraditya, cfe-commits, #sanitizers, llvm-commits, sylvestre.ledru

Tags: #clang, #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D74953
2020-02-24 10:38:33 +01:00
..
cmake [compiler-rt] Disable building LibFuzzer for WatchOS and the corresponding simulator. 2020-02-14 13:53:54 -08:00
docs
include [compiler-rt] FuzzedDataProvider: add ConsumeData and method. 2020-02-11 13:46:24 -08:00
lib [profile] Don't dump counters when forking and don't reset when calling exec** functions 2020-02-24 10:38:33 +01:00
test [compiler-rt] [builtins] Fix logb / logbl tests 2020-02-20 10:16:03 +00:00
tools Add GWP-ASan fuzz target to compiler-rt/tools. 2019-08-27 18:28:07 +00:00
unittests [Scudo] [GWP-ASan] Add GWP-ASan to Scudo Standalone. 2019-12-13 09:09:41 -08:00
utils [compiler-rt] Fix build on NetBSD 9.99.44 2020-01-31 14:57:20 +01:00
www [www] Change URLs to HTTPS. 2019-10-24 13:25:15 -07:00
.arcconfig [compiler-rt] Set up .arcconfig to point to new Diffusion CRT repository 2017-12-06 20:55:32 +00:00
.gitignore Add .pyc files to .gitignore to compiler-rt 2017-07-24 21:51:12 +00:00
CMakeLists.txt [CMake] Enable -qfuncsect when building with IBM XL 2020-01-15 10:45:50 -05:00
CODE_OWNERS.TXT
CREDITS.TXT
LICENSE.TXT Fix typos throughout the license files that somehow I and my reviewers 2019-01-21 09:52:34 +00:00
README.txt

README.txt

Compiler-RT
================================

This directory and its subdirectories contain source code for the compiler
support routines.

Compiler-RT is open source software. You may freely distribute it under the
terms of the license agreement found in LICENSE.txt.

================================