[PATCH] D46622: wrong usages of sem_open in the libFuzzer

[Yang Zheng via Phabricator via llvm-commits]

tomsun.0.7 created this revision.
tomsun.0.7 added reviewers: vitalybuka, krytarowski.
Herald added a subscriber: llvm-commits.

Fixed two non-standard usages of sem_open in the libFuzzer library and one NetBSD-related modification with test script.

- The return value to indicate error should be SEM_FAILED instead of (void *)-1 (please refer to "RETURN VALUE" section in this page <http://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_open.html>). Actually, SEM_FAILED != (void *)-1 holds in NetBSD.
- The SharedMemoryRegion::SecName function should return name starting with slash. Because the behaviour of name which does not start with slash is unspecified as the "DESCRIPTION" section <http://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_open.html> specified:

> If name does not begin with the <slash> character, the effect is implementation-defined.



- The length of name is limited to 14 in NetBSD, it is suggested to reduce the length of equivalence server name in the test script.




Repository:
  rCRT Compiler Runtime

https://reviews.llvm.org/D46622

Files:
  lib/fuzzer/FuzzerShmemPosix.cpp
  test/fuzzer/equivalence-signals.test


Index: test/fuzzer/equivalence-signals.test
===================================================================
--- test/fuzzer/equivalence-signals.test
+++ test/fuzzer/equivalence-signals.test
@@ -7,7 +7,7 @@
 UNSUPPORTED: darwin
 
 RUN: %cpp_compiler %S/EquivalenceATest.cpp -o %t-EquivalenceATest
-RUN: %t-EquivalenceATest -timeout=1 -run_equivalence_server=EQUIV_SIG_TEST & export APID=$!
+RUN: %t-EquivalenceATest -timeout=1 -run_equivalence_server=EQ_SIG_TEST & export APID=$!
 RUN: sleep 3
-RUN: %t-EquivalenceATest -timeout=1 -use_equivalence_server=EQUIV_SIG_TEST -runs=500000 2>&1
+RUN: %t-EquivalenceATest -timeout=1 -use_equivalence_server=EQ_SIG_TEST -runs=500000 2>&1
 RUN: kill -9 $APID
Index: lib/fuzzer/FuzzerShmemPosix.cpp
===================================================================
--- lib/fuzzer/FuzzerShmemPosix.cpp
+++ lib/fuzzer/FuzzerShmemPosix.cpp
@@ -32,6 +32,8 @@
 
 std::string SharedMemoryRegion::SemName(const char *Name, int Idx) {
   std::string Res(Name);
+  if (!Res.empty() && Res[0] != '/')
+    Res.insert(Res.begin(), '/');
   return Res + (char)('0' + Idx);
 }
 
@@ -52,7 +54,7 @@
   for (int i = 0; i < 2; i++) {
     sem_unlink(SemName(Name, i).c_str());
     Semaphore[i] = sem_open(SemName(Name, i).c_str(), O_CREAT, 0644, 0);
-    if (Semaphore[i] == (void *)-1)
+    if (Semaphore[i] == SEM_FAILED)
       return false;
   }
   IAmServer = true;
@@ -70,7 +72,7 @@
     return false;
   for (int i = 0; i < 2; i++) {
     Semaphore[i] = sem_open(SemName(Name, i).c_str(), 0);
-    if (Semaphore[i] == (void *)-1)
+    if (Semaphore[i] == SEM_FAILED)
       return false;
   }
   IAmServer = false;


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