Merge tag 'perf-tools-fixes-for-v5.12-2020-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tooling fixes from Arnaldo Carvalho de Melo:

 - Avoid write of uninitialized memory when generating PERF_RECORD_MMAP*
   records.

 - Fix 'perf top' BPF support related crash with perf_event_paranoid=3 +
   kptr_restrict.

 - Validate raw event with sysfs exported format bits.

 - Fix waipid on SIGCHLD delivery bugs in 'perf daemon'.

 - Change to use bash for daemon test on Debian, where the default is
   dash and thus fails for use of bashisms in this test.

 - Fix memory leak in vDSO found using ASAN.

 - Remove now useless (due to the fact that BPF now supports static
   vars) failing sub test "BPF relocation checker".

 - Fix auxtrace queue conflict.

 - Sync linux/kvm.h with the kernel sources.

* tag 'perf-tools-fixes-for-v5.12-2020-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf test: Change to use bash for daemon test
  perf record: Fix memory leak in vDSO found using ASAN
  perf test: Remove now useless failing sub test "BPF relocation checker"
  perf daemon: Return from kill functions
  perf daemon: Force waipid for all session on SIGCHLD delivery
  perf top: Fix BPF support related crash with perf_event_paranoid=3 + kptr_restrict
  perf pmu: Validate raw event with sysfs exported format bits
  perf synthetic events: Avoid write of uninitialized memory when generating PERF_RECORD_MMAP* records
  tools headers UAPI: Sync linux/kvm.h with the kernel sources
  perf synthetic-events: Fix uninitialized 'kernel_thread' variable
  perf auxtrace: Fix auxtrace queue conflict

1 files changed, 33 insertions, 24 deletions

diff --git a/tools/perf/builtin-daemon.c b/tools/perf/builtin-daemon.c
index ace8772a4f03..7c4a9d424a64 100644
--- a/tools/perf/builtin-daemon.c
+++ b/tools/perf/builtin-daemon.c
@@ -402,35 +402,42 @@ static pid_t handle_signalfd(struct daemon *daemon)
 	int status;
 	pid_t pid;
 
+	/*
+	 * Take signal fd data as pure signal notification and check all
+	 * the sessions state. The reason is that multiple signals can get
+	 * coalesced in kernel and we can receive only single signal even
+	 * if multiple SIGCHLD were generated.
+	 */
 	err = read(daemon->signal_fd, &si, sizeof(struct signalfd_siginfo));
-	if (err != sizeof(struct signalfd_siginfo))
+	if (err != sizeof(struct signalfd_siginfo)) {
+		pr_err("failed to read signal fd\n");
 		return -1;
+	}
 
 	list_for_each_entry(session, &daemon->sessions, list) {
+		if (session->pid == -1)
+			continue;
 
-		if (session->pid != (int) si.ssi_pid)
+		pid = waitpid(session->pid, &status, WNOHANG);
+		if (pid <= 0)
 			continue;
 
-		pid = waitpid(session->pid, &status, 0);
-		if (pid == session->pid) {
-			if (WIFEXITED(status)) {
-				pr_info("session '%s' exited, status=%d\n",
-					session->name, WEXITSTATUS(status));
-			} else if (WIFSIGNALED(status)) {
-				pr_info("session '%s' killed (signal %d)\n",
-					session->name, WTERMSIG(status));
-			} else if (WIFSTOPPED(status)) {
-				pr_info("session '%s' stopped (signal %d)\n",
-					session->name, WSTOPSIG(status));
-			} else {
-				pr_info("session '%s' Unexpected status (0x%x)\n",
-					session->name, status);
-			}
+		if (WIFEXITED(status)) {
+			pr_info("session '%s' exited, status=%d\n",
+				session->name, WEXITSTATUS(status));
+		} else if (WIFSIGNALED(status)) {
+			pr_info("session '%s' killed (signal %d)\n",
+				session->name, WTERMSIG(status));
+		} else if (WIFSTOPPED(status)) {
+			pr_info("session '%s' stopped (signal %d)\n",
+				session->name, WSTOPSIG(status));
+		} else {
+			pr_info("session '%s' Unexpected status (0x%x)\n",
+				session->name, status);
 		}
 
 		session->state = KILL;
 		session->pid = -1;
-		return pid;
 	}
 
 	return 0;
@@ -443,7 +450,6 @@ static int daemon_session__wait(struct daemon_session *session, struct daemon *d
 		.fd	= daemon->signal_fd,
 		.events	= POLLIN,
 	};
-	pid_t wpid = 0, pid = session->pid;
 	time_t start;
 
 	start = time(NULL);
@@ -452,7 +458,7 @@ static int daemon_session__wait(struct daemon_session *session, struct daemon *d
 		int err = poll(&pollfd, 1, 1000);
 
 		if (err > 0) {
-			wpid = handle_signalfd(daemon);
+			handle_signalfd(daemon);
 		} else if (err < 0) {
 			perror("failed: poll\n");
 			return -1;
@@ -460,7 +466,7 @@ static int daemon_session__wait(struct daemon_session *session, struct daemon *d
 
 		if (start + secs < time(NULL))
 			return -1;
-	} while (wpid != pid);
+	} while (session->pid != -1);
 
 	return 0;
 }
@@ -902,7 +908,9 @@ static void daemon_session__kill(struct daemon_session *session,
 			daemon_session__signal(session, SIGKILL);
 			break;
 		default:
-			break;
+			pr_err("failed to wait for session %s\n",
+			       session->name);
+			return;
 		}
 		how++;
 
@@ -955,7 +963,8 @@ static void daemon__kill(struct daemon *daemon)
 			daemon__signal(daemon, SIGKILL);
 			break;
 		default:
-			break;
+			pr_err("failed to wait for sessions\n");
+			return;
 		}
 		how++;
 
@@ -1344,7 +1353,7 @@ out:
 		close(sock_fd);
 	if (conf_fd != -1)
 		close(conf_fd);
-	if (conf_fd != -1)
+	if (signal_fd != -1)
 		close(signal_fd);
 
 	pr_info("daemon exited\n");