posix: check wait events in a loop

2 files changed, 54 insertions, 40 deletions

diff --git a/honggfuzz.c b/honggfuzz.c
index 4ecf345c..eb8eaa47 100644
--- a/honggfuzz.c
+++ b/honggfuzz.c
@@ -197,7 +197,7 @@ static void printSummary(honggfuzz_t* hfuzz) {
 
 static void pingThreads(honggfuzz_t* hfuzz) {
     for (size_t i = 0; i < hfuzz->threads.threadsMax; i++) {
-        if (pthread_kill(hfuzz->threads.threads[i], SIGUSR1) != 0) {
+        if (pthread_kill(hfuzz->threads.threads[i], SIGUSR1) != 0 && errno != EINTR) {
             PLOG_W("pthread_kill(thread=%zu, SIGUSR1)", i);
         }
     }
@@ -215,13 +215,15 @@ static void* signalThread(void* arg) {
 
     for (;;) {
         int sig;
-        if (sigwait(&ss, &sig) != 0) {
+        if (sigwait(&ss, &sig) != 0 && errno != EINTR) {
             PLOG_F("sigwait(SIGCHLD)");
         }
         if (fuzz_isTerminating()) {
             break;
         }
-        pingThreads(hfuzz);
+        if (sig == SIGCHLD) {
+            pingThreads(hfuzz);
+        }
     }
 
     return NULL;
@@ -321,11 +323,11 @@ int main(int argc, char** argv) {
 
     fuzz_setTerminating();
 
-    /* Ping threads one last time */
     void* retval;
     if (pthread_join(sigthread, &retval) != 0) {
         PLOG_W("Couldn't stop the signal thread");
     }
+    /* Ping threads one last time */
     pingThreads(&hfuzz);
     fuzz_threadsStop(&hfuzz);
 
diff --git a/posix/arch.c b/posix/arch.c
index 2aafac29..cdc14293 100644
--- a/posix/arch.c
+++ b/posix/arch.c
@@ -80,12 +80,12 @@ struct {
  * Returns true if a process exited (so, presumably, we can delete an input
  * file)
  */
-static bool arch_analyzeSignal(run_t* run, int status) {
+static void arch_analyzeSignal(run_t* run, int status) {
     /*
      * Resumed by delivery of SIGCONT
      */
     if (WIFCONTINUED(status)) {
-        return false;
+        return;
     }
 
     /*
@@ -93,7 +93,7 @@ static bool arch_analyzeSignal(run_t* run, int status) {
      */
     if (WIFEXITED(status)) {
         LOG_D("Process (pid %d) exited normally with status %d", run->pid, WEXITSTATUS(status));
-        return true;
+        return;
     }
 
     /*
@@ -102,14 +102,14 @@ static bool arch_analyzeSignal(run_t* run, int status) {
     if (!WIFSIGNALED(status)) {
         LOG_E("Process (pid %d) exited with the following status %d, please report that as a bug",
             run->pid, status);
-        return false;
+        return;
     }
 
     int termsig = WTERMSIG(status);
     LOG_D("Process (pid %d) killed by signal %d '%s'", run->pid, termsig, strsignal(termsig));
     if (!arch_sigs[termsig].important) {
         LOG_D("It's not that important signal, skipping");
-        return true;
+        return;
     }
 
     char localtmstr[PATH_MAX];
@@ -137,8 +137,6 @@ static bool arch_analyzeSignal(run_t* run, int status) {
             newname, run->dynamicFile, run->dynamicFileSz, O_CREAT | O_EXCL | O_WRONLY) == false) {
         LOG_E("Couldn't save crash to '%s'", run->crashFileName);
     }
-
-    return true;
 }
 
 pid_t arch_fork(run_t* fuzzer HF_ATTR_UNUSED) {
@@ -186,6 +184,48 @@ void arch_prepareParent(run_t* fuzzer HF_ATTR_UNUSED) {
 void arch_prepareParentAfterFork(run_t* fuzzer HF_ATTR_UNUSED) {
 }
 
+static bool arch_checkWait(run_t* run) {
+    /* All queued wait events must be tested when SIGCHLD was delivered */
+    for (;;) {
+        int status;
+        int wflags = WNOHANG;
+#if defined(__WNOTHREAD)
+        wflags |= __WNOTHREAD;
+#endif /* defined(__WNOTHREAD) */
+#if defined(__WALL)
+        wflags |= __WALL;
+#endif /* defined(__WALL) */
+
+        pid_t pid = TEMP_FAILURE_RETRY(waitpid(run->pid, &status, wflags));
+        if (pid == 0) {
+            return false;
+        }
+        if (pid == -1 && errno == ECHILD) {
+            LOG_D("No more processes to track");
+            return true;
+        }
+        if (pid == -1) {
+            PLOG_F("waitpid() failed");
+        }
+
+        char statusStr[4096];
+        LOG_D("pid=%d returned with status: %s", pid,
+            subproc_StatusToStr(status, statusStr, sizeof(statusStr)));
+
+        arch_analyzeSignal(run, status);
+
+        if (pid == run->pid && (WIFEXITED(status) || WIFSIGNALED(status))) {
+            if (run->global->exe.persistent) {
+                if (!fuzz_isTerminating()) {
+                    LOG_W("Persistent mode: pid=%d exited with status: %s", (int)run->pid,
+                        subproc_StatusToStr(status, statusStr, sizeof(statusStr)));
+                }
+            }
+            return true;
+        }
+    }
+}
+
 void arch_reapChild(run_t* run) {
     for (;;) {
         if (subproc_persistentModeStateMachine(run)) {
@@ -216,35 +256,7 @@ void arch_reapChild(run_t* run) {
             }
         }
 
-        int status;
-        int ret = waitpid(run->pid, &status, WNOHANG);
-        if (ret == 0) {
-            continue;
-        }
-        if (ret == -1 && errno == EINTR) {
-            continue;
-        }
-        if (ret == -1) {
-            PLOG_W("waitpid(pid=%d)", run->pid);
-            continue;
-        }
-        if (ret != run->pid) {
-            continue;
-        }
-
-        char strStatus[4096];
-        if (run->global->exe.persistent && ret == run->pid &&
-            (WIFEXITED(status) || WIFSIGNALED(status))) {
-            if (!fuzz_isTerminating()) {
-                LOG_W("Persistent mode: PID %d exited with status: %s", ret,
-                    subproc_StatusToStr(status, strStatus, sizeof(strStatus)));
-            }
-        }
-
-        LOG_D("Process (pid %d) came back with status: %s", run->pid,
-            subproc_StatusToStr(status, strStatus, sizeof(strStatus)));
-
-        if (arch_analyzeSignal(run, status)) {
+        if (arch_checkWait(run)) {
             run->pid = 0;
             break;
         }