shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

[libFuzzer] always install signal handler with SA_ONSTACK (#147422)

Browse Source 
SA_ONSTACK is required for certain runtimes that use small stacks, for
instance the Go runtime.
See https://github.com/golang/go/issues/49075
SA_ONSTACK is a no-op unless someone also calls sigaltstack.
This commit is contained in:
Keith Randall 2025-08-09 11:45:41 -07:00 committed by GitHub
parent 62735d26b1
commit aee4f2bacc
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
1 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
compiler-rt/lib/fuzzer/FuzzerUtilPosix.cpp
View File

@ -78,10 +78,14 @@ static void SetSigaction(int signum,
}
struct sigaction new_sigact = {};
// Address sanitizer needs SA_ONSTACK (causing the signal handler to run on a
// dedicated stack) in order to be able to detect stack overflows; keep the
// flag if it's set.
new_sigact.sa_flags = SA_SIGINFO | (sigact.sa_flags & SA_ONSTACK);
// SA_ONSTACK is required for certain runtimes that use small stacks, for
// instance the Go runtime.
// See https://github.com/golang/go/issues/49075
// Address sanitizer also wants SA_ONSTACK, and the fuzzer and sanitizer
// often run together.
// SA_ONSTACK is a no-op unless someone also calls sigaltstack. That is left
// up to code that needs it.
new_sigact.sa_flags = SA_SIGINFO | SA_ONSTACK;
new_sigact.sa_sigaction = callback;
if (sigaction(signum, &new_sigact, nullptr)) {
Printf("libFuzzer: sigaction failed with %d\n", errno);