linux-kselftest-fixes-6.6-rc2

This kselftest fixes update for Linux 6.6-rc2 consists of important
 fixes to user_events test and ftrace test.
 
 user_events test has been enabled for default run in Linux 6.6-rc1. The
 following fixes are for bugs found since then:
 
 - adds checks for dependencies and skips the test. user_events test
   requires root access, and tracefs and user_events enabled. It leaves
   tracefs mounted and a fix is in progress for that missing piece.
 
 - creates user_events test-specific Kconfig fragments.
 
 ftrace test fixes:
 
 - unmounts tracefs for recovering environment. Fix identified during the
   above mentioned user_events dependencies fix.
 
 - adds softlink to latest log directory improving usage.
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Merge tag 'linux-kselftest-fixes-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull more kselftest fixes from Shuah Khan
 "Fixes to user_events test and ftrace test.

  The user_events test was enabled by default in Linux 6.6-rc1. The
  following fixes are for bugs found since then:

   - add checks for dependencies and skip the test if they aren't met.

     The user_events test requires root access, and tracefs and
     user_events enabled. It leaves tracefs mounted and a fix is in
     progress for that missing piece.

   - create user_events test-specific Kconfig fragments

  ftrace test fixes:

   - unmount tracefs for recovering environment. Fix identified during
     the above mentioned user_events dependencies fix.

   - adds softlink to latest log directory improving usage"

* tag 'linux-kselftest-fixes-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: tracing: Fix to unmount tracefs for recovering environment
  selftests: user_events: create test-specific Kconfig fragments
  ftrace/selftests: Add softlink to latest log directory
  selftests/user_events: Fix failures when user_events is not installed

tools/testing/selftests/ftrace/ftracetest

@@ -31,6 +31,9 @@ err_ret=1
 # kselftest skip code is 4
 err_skip=4
 
+# umount required
+UMOUNT_DIR=""
+
 # cgroup RT scheduling prevents chrt commands from succeeding, which
 # induces failures in test wakeup tests.  Disable for the duration of
 # the tests.
@@ -45,6 +48,9 @@ setup() {
 
 cleanup() {
   echo $sched_rt_runtime_orig > $sched_rt_runtime
+  if [ -n "${UMOUNT_DIR}" ]; then
+    umount ${UMOUNT_DIR} ||:
+  fi
 }
 
 errexit() { # message
@@ -124,6 +130,7 @@ parse_opts() { # opts
     ;;
     --logdir|-l)
       LOG_DIR=$2
+      LINK_PTR=
       shift 2
     ;;
     *.tc)
@@ -160,11 +167,13 @@ if [ -z "$TRACING_DIR" ]; then
 	    mount -t tracefs nodev /sys/kernel/tracing ||
 	      errexit "Failed to mount /sys/kernel/tracing"
 	    TRACING_DIR="/sys/kernel/tracing"
+	    UMOUNT_DIR=${TRACING_DIR}
 	# If debugfs exists, then so does /sys/kernel/debug
 	elif [ -d "/sys/kernel/debug" ]; then
 	    mount -t debugfs nodev /sys/kernel/debug ||
 	      errexit "Failed to mount /sys/kernel/debug"
 	    TRACING_DIR="/sys/kernel/debug/tracing"
+	    UMOUNT_DIR=${TRACING_DIR}
 	else
 	    err_ret=$err_skip
 	    errexit "debugfs and tracefs are not configured in this kernel"
@@ -181,7 +190,10 @@ fi
 TOP_DIR=`absdir $0`
 TEST_DIR=$TOP_DIR/test.d
 TEST_CASES=`find_testcases $TEST_DIR`
-LOG_DIR=$TOP_DIR/logs/`date +%Y%m%d-%H%M%S`/
+LOG_TOP_DIR=$TOP_DIR/logs
+LOG_DATE=`date +%Y%m%d-%H%M%S`
+LOG_DIR=$LOG_TOP_DIR/$LOG_DATE/
+LINK_PTR=$LOG_TOP_DIR/latest
 KEEP_LOG=0
 KTAP=0
 DEBUG=0
@@ -207,6 +219,10 @@ else
   LOG_FILE=$LOG_DIR/ftracetest.log
   mkdir -p $LOG_DIR || errexit "Failed to make a log directory: $LOG_DIR"
   date > $LOG_FILE
+  if [ "x-$LINK_PTR" != "x-" ]; then
+    unlink $LINK_PTR
+    ln -fs $LOG_DATE $LINK_PTR
+  fi
 fi
 
 # Define text colors

tools/testing/selftests/user_events/abi_test.c

@@ -19,6 +19,7 @@
 #include <asm/unistd.h>
 
 #include "../kselftest_harness.h"
+#include "user_events_selftests.h"
 
 const char *data_file = "/sys/kernel/tracing/user_events_data";
 const char *enable_file = "/sys/kernel/tracing/events/user_events/__abi_event/enable";
@@ -93,6 +94,8 @@ FIXTURE(user) {
 };
 
 FIXTURE_SETUP(user) {
+	USER_EVENT_FIXTURE_SETUP(return);
+
 	change_event(false);
 	self->check = 0;
 }

tools/testing/selftests/user_events/config

@@ -0,0 +1 @@
+CONFIG_USER_EVENTS=y

tools/testing/selftests/user_events/dyn_test.c

@@ -15,6 +15,7 @@
 #include <unistd.h>
 
 #include "../kselftest_harness.h"
+#include "user_events_selftests.h"
 
 const char *abi_file = "/sys/kernel/tracing/user_events_data";
 const char *enable_file = "/sys/kernel/tracing/events/user_events/__test_event/enable";
@@ -146,6 +147,7 @@ FIXTURE(user) {
 };
 
 FIXTURE_SETUP(user) {
+	USER_EVENT_FIXTURE_SETUP(return);
 }
 
 FIXTURE_TEARDOWN(user) {

tools/testing/selftests/user_events/ftrace_test.c

@@ -16,6 +16,7 @@
 #include <unistd.h>
 
 #include "../kselftest_harness.h"
+#include "user_events_selftests.h"
 
 const char *data_file = "/sys/kernel/tracing/user_events_data";
 const char *status_file = "/sys/kernel/tracing/user_events_status";
@@ -206,6 +207,8 @@ FIXTURE(user) {
 };
 
 FIXTURE_SETUP(user) {
+	USER_EVENT_FIXTURE_SETUP(return);
+
 	self->status_fd = open(status_file, O_RDONLY);
 	ASSERT_NE(-1, self->status_fd);
 

tools/testing/selftests/user_events/perf_test.c

@@ -17,6 +17,7 @@
 #include <asm/unistd.h>
 
 #include "../kselftest_harness.h"
+#include "user_events_selftests.h"
 
 const char *data_file = "/sys/kernel/tracing/user_events_data";
 const char *id_file = "/sys/kernel/tracing/events/user_events/__test_event/id";
@@ -113,6 +114,8 @@ FIXTURE(user) {
 };
 
 FIXTURE_SETUP(user) {
+	USER_EVENT_FIXTURE_SETUP(return);
+
 	self->data_fd = open(data_file, O_RDWR);
 	ASSERT_NE(-1, self->data_fd);
 }

tools/testing/selftests/user_events/user_events_selftests.h

@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _USER_EVENTS_SELFTESTS_H
+#define _USER_EVENTS_SELFTESTS_H
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/mount.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "../kselftest.h"
+
+static inline bool tracefs_enabled(char **message, bool *fail)
+{
+	struct stat buf;
+	int ret;
+
+	*message = "";
+	*fail = false;
+
+	/* Ensure tracefs is installed */
+	ret = stat("/sys/kernel/tracing", &buf);
+
+	if (ret == -1) {
+		*message = "Tracefs is not installed";
+		return false;
+	}
+
+	/* Ensure mounted tracefs */
+	ret = stat("/sys/kernel/tracing/README", &buf);
+
+	if (ret == -1 && errno == ENOENT) {
+		if (mount(NULL, "/sys/kernel/tracing", "tracefs", 0, NULL) != 0) {
+			*message = "Cannot mount tracefs";
+			*fail = true;
+			return false;
+		}
+
+		ret = stat("/sys/kernel/tracing/README", &buf);
+	}
+
+	if (ret == -1) {
+		*message = "Cannot access tracefs";
+		*fail = true;
+		return false;
+	}
+
+	return true;
+}
+
+static inline bool user_events_enabled(char **message, bool *fail)
+{
+	struct stat buf;
+	int ret;
+
+	*message = "";
+	*fail = false;
+
+	if (getuid() != 0) {
+		*message = "Must be run as root";
+		*fail = true;
+		return false;
+	}
+
+	if (!tracefs_enabled(message, fail))
+		return false;
+
+	/* Ensure user_events is installed */
+	ret = stat("/sys/kernel/tracing/user_events_data", &buf);
+
+	if (ret == -1) {
+		switch (errno) {
+		case ENOENT:
+			*message = "user_events is not installed";
+			return false;
+
+		default:
+			*message = "Cannot access user_events_data";
+			*fail = true;
+			return false;
+		}
+	}
+
+	return true;
+}
+
+#define USER_EVENT_FIXTURE_SETUP(statement) do { \
+	char *message; \
+	bool fail; \
+	if (!user_events_enabled(&message, &fail)) { \
+		if (fail) { \
+			TH_LOG("Setup failed due to: %s", message); \
+			ASSERT_FALSE(fail); \
+		} \
+		SKIP(statement, "Skipping due to: %s", message); \
+	} \
+} while (0)
+
+#endif /* _USER_EVENTS_SELFTESTS_H */