From 001f56735f831f836fb002a77097b509f0cdb7f7 Mon Sep 17 00:00:00 2001 From: Kostya Serebryany Date: Fri, 27 Jan 2017 22:41:30 +0000 Subject: [PATCH] [libFuzzer] make shmem more robust in the presence of signals git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293339 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Fuzzer/FuzzerShmemPosix.cpp | 10 +++++++--- lib/Fuzzer/test/equivalence.test | 10 ++++++++++ 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/lib/Fuzzer/FuzzerShmemPosix.cpp b/lib/Fuzzer/FuzzerShmemPosix.cpp index 820d64d07c1b..d5f4aabc4269 100644 --- a/lib/Fuzzer/FuzzerShmemPosix.cpp +++ b/lib/Fuzzer/FuzzerShmemPosix.cpp @@ -86,9 +86,13 @@ void SharedMemoryRegion::Post(int Idx) { void SharedMemoryRegion::Wait(int Idx) { assert(Idx == 0 || Idx == 1); - if (sem_wait((sem_t*)Semaphore[Idx])) { - Printf("ERROR: sem_wait failed\n"); - exit(1); + for (int i = 0; i < 10 && sem_wait((sem_t*)Semaphore[Idx]); i++) { + // sem_wait may fail if interrupted by a signal. + sleep(i); + if (i) + Printf("%s: sem_wait[%d] failed %s\n", i < 9 ? "WARNING" : "ERROR", i, + strerror(errno)); + if (i == 9) abort(); } } diff --git a/lib/Fuzzer/test/equivalence.test b/lib/Fuzzer/test/equivalence.test index 8c8b9ba15541..6c9d87888e07 100644 --- a/lib/Fuzzer/test/equivalence.test +++ b/lib/Fuzzer/test/equivalence.test @@ -4,3 +4,13 @@ RUN: not LLVMFuzzer-EquivalenceBTest -use_equivalence_server=EQUIV_TEST 2>&1 | F CHECK: ERROR: libFuzzer: equivalence-mismatch. Sizes: {{.*}}; offset 2 CHECK: SUMMARY: libFuzzer: equivalence-mismatch RUN: kill -9 $APID + + +# Run EquivalenceATest against itself with a small timeout +# to stress the signal handling and ensure that shmem doesn't mind +# the signals. + +RUN: LLVMFuzzer-EquivalenceATest -timeout=1 -run_equivalence_server=EQUIV_TEST & export APID=$! +RUN: sleep 3 +RUN: LLVMFuzzer-EquivalenceATest -timeout=1 -use_equivalence_server=EQUIV_TEST -runs=500000 2>&1 +RUN: kill -9 $APID