[igt-dev] [PATCH i-g-t 1/3] lib: Add hooks for enabling ftrace
Ashutosh Dixit
ashutosh.dixit at intel.com
Tue Apr 2 02:44:19 UTC 2019
From: Chris Wilson <chris at chris-wilson.co.uk>
If the kernel has tracing support builtin, we can enable around
troublesome tests to obtain greater detail from the kernel that may
prove invaluable in debugging the problem.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
lib/Makefile.sources | 2 +
lib/igt_core.c | 28 ++----
lib/igt_ftrace.c | 204 +++++++++++++++++++++++++++++++++++++++++++
lib/igt_ftrace.h | 46 ++++++++++
lib/meson.build | 1 +
5 files changed, 258 insertions(+), 23 deletions(-)
create mode 100644 lib/igt_ftrace.c
create mode 100644 lib/igt_ftrace.h
diff --git a/lib/Makefile.sources b/lib/Makefile.sources
index e00347f9..e45f1a19 100644
--- a/lib/Makefile.sources
+++ b/lib/Makefile.sources
@@ -26,6 +26,8 @@ lib_source_list = \
igt_color_encoding.c \
igt_color_encoding.h \
igt_edid_template.h \
+ igt_ftrace.c \
+ igt_ftrace.h \
igt_gpu_power.c \
igt_gpu_power.h \
igt_gt.c \
diff --git a/lib/igt_core.c b/lib/igt_core.c
index 6eb4798e..3e69cf66 100644
--- a/lib/igt_core.c
+++ b/lib/igt_core.c
@@ -62,6 +62,7 @@
#include "intel_io.h"
#include "igt_debugfs.h"
#include "igt_dummyload.h"
+#include "igt_ftrace.h"
#include "version.h"
#include "config.h"
@@ -490,31 +491,11 @@ void __igt_fixture_end(void)
siglongjmp(igt_subtest_jmpbuf, 1);
}
-/*
- * If the test takes out the machine, in addition to the usual dmesg
- * spam, the kernel may also emit a "death rattle" -- extra debug
- * information that is overkill for normal successful tests, but
- * vital for post-mortem analysis.
- */
-static void ftrace_dump_on_oops(bool enable)
-{
- int fd;
-
- fd = open("/proc/sys/kernel/ftrace_dump_on_oops", O_WRONLY);
- if (fd < 0)
- return;
-
- /*
- * If we fail, we do not get the death rattle we wish, but we
- * still want to run the tests anyway.
- */
- igt_ignore_warn(write(fd, enable ? "1\n" : "0\n", 2));
- close(fd);
-}
-
bool igt_exit_called;
static void common_exit_handler(int sig)
{
+ igt_ftrace_close();
+
if (!igt_only_list_subtests()) {
bind_fbcon(true);
}
@@ -812,7 +793,8 @@ out:
sync();
oom_adjust_for_doom();
- ftrace_dump_on_oops(true);
+
+ igt_ftrace_open();
}
/* install exit handler, to ensure we clean up */
diff --git a/lib/igt_ftrace.c b/lib/igt_ftrace.c
new file mode 100644
index 00000000..43f396d6
--- /dev/null
+++ b/lib/igt_ftrace.c
@@ -0,0 +1,204 @@
+/*
+ * Copyright © 2019 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "igt.h"
+#include "igt_ftrace.h"
+#include "igt_debugfs.h"
+#include "igt_sysfs.h"
+
+#define BIT(x) (1ul << (x))
+
+/* Only a single tracer in the kernel, so we can use a singleton */
+struct igt_ftrace {
+ int dir;
+
+ unsigned long flags;
+#define PID_SET BIT(0)
+#define INCLUDE_SET BIT(1)
+#define EXCLUDE_SET BIT(2)
+
+} igt_ftrace = { -1 };
+
+/*
+ * If the test takes out the machine, in addition to the usual dmesg
+ * spam, the kernel may also emit a "death rattle" -- extra debug
+ * information that is overkill for normal successful tests, but
+ * vital for post-mortem analysis.
+ */
+static void ftrace_dump_on_oops(bool enable)
+{
+ int fd;
+
+ fd = open("/proc/sys/kernel/ftrace_dump_on_oops", O_WRONLY);
+ if (fd < 0)
+ return;
+
+ /*
+ * If we fail, we do not get the death rattle we wish, but we
+ * still want to run the tests anyway.
+ */
+ igt_ignore_warn(write(fd, enable ? "1\n" : "0\n", 2));
+ close(fd);
+}
+
+int igt_ftrace_open(void)
+{
+ int dir;
+ int err;
+
+ dir = open(igt_debugfs_mount(), O_RDONLY);
+ if (dir < 0)
+ return -errno;
+
+ igt_ftrace.dir = openat(dir, "tracing", O_RDONLY);
+ close(dir);
+ if (igt_ftrace.dir < 0)
+ return -errno;
+
+ err = igt_ftrace_disable();
+ if (err)
+ goto ft_close;
+
+ ftrace_dump_on_oops(true);
+ return 0;
+
+ft_close:
+ close(igt_ftrace.dir);
+ igt_ftrace.dir = -1;
+ return err;
+}
+
+int __igt_ftrace_enable(const char *mode,
+ const struct igt_ftrace_options *opts)
+{
+ int err;
+
+ if (igt_ftrace.dir < 0)
+ return -ENODEV;
+
+ if (!mode)
+ return -EINVAL;
+
+ err = igt_sysfs_set(igt_ftrace.dir, "current_tracer", mode);
+ if (err < 0)
+ return err;
+
+ if (opts && opts->pid) {
+ err = igt_sysfs_printf(igt_ftrace.dir,
+ "set_ftrace_pid", "%d",
+ opts->pid);
+ if (err < 0)
+ goto disable;
+
+ igt_ftrace.flags |= PID_SET;
+ }
+
+ if (opts && opts->include) {
+ err = igt_sysfs_set(igt_ftrace.dir,
+ "set_ftrace_filter",
+ opts->include);
+ if (err < 0)
+ goto disable;
+
+ igt_ftrace.flags |= INCLUDE_SET;
+ }
+
+ if (opts && opts->exclude) {
+ err = igt_sysfs_set(igt_ftrace.dir,
+ "set_ftrace_notrace",
+ opts->exclude);
+ if (err < 0)
+ goto disable;
+
+ igt_ftrace.flags |= EXCLUDE_SET;
+ }
+
+ err = igt_sysfs_set(igt_ftrace.dir, "tracer_on", "1");
+ if (err < 0)
+ return err;
+
+ return 0;
+
+disable:
+ igt_ftrace_disable();
+ return err;
+}
+
+int igt_ftrace_disable(void)
+{
+ int err;
+
+ if (igt_ftrace.dir < 0)
+ return -ENODEV;
+
+ err = igt_sysfs_set(igt_ftrace.dir, "tracer_on", "0");
+ if (err < 0)
+ return err;
+
+ if (igt_ftrace.flags & PID_SET) {
+ igt_sysfs_set(igt_ftrace.dir, "set_ftrace_pid", "");
+ igt_ftrace.flags &= ~PID_SET;
+ }
+
+ if (igt_ftrace.flags & INCLUDE_SET) {
+ igt_sysfs_set(igt_ftrace.dir, "set_ftrace_filter", "");
+ igt_ftrace.flags &= ~INCLUDE_SET;
+ }
+
+ if (igt_ftrace.flags & EXCLUDE_SET) {
+ igt_sysfs_set(igt_ftrace.dir, "set_ftrace_notrace", "");
+ igt_ftrace.flags &= ~EXCLUDE_SET;
+ }
+
+ return 0;
+}
+
+void igt_ftrace_dump(const char *header)
+{
+ char *txt;
+
+ if (igt_ftrace.dir < 0)
+ return;
+
+ txt = igt_sysfs_get(igt_ftrace.dir, "trace");
+ if (!txt)
+ return;
+
+ igt_info("%s:\n%s", header, txt);
+ free(txt);
+}
+
+void igt_ftrace_close(void)
+{
+ if (igt_ftrace.dir < 0)
+ return;
+
+ close(igt_ftrace.dir);
+ igt_ftrace.dir = -1;
+}
diff --git a/lib/igt_ftrace.h b/lib/igt_ftrace.h
new file mode 100644
index 00000000..9aceeca9
--- /dev/null
+++ b/lib/igt_ftrace.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright © 2019 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef IGT_FTRACE_H
+#define IGT_FTRACE_H
+
+int igt_ftrace_open(void);
+
+struct igt_ftrace_options {
+ int pid;
+ const char *include;
+ const char *exclude;
+};
+
+int __igt_ftrace_enable(const char *mode,
+ const struct igt_ftrace_options *opts);
+#define igt_ftrace_enable() __igt_ftrace_enable("function_graph", NULL)
+
+int igt_ftrace_disable(void);
+
+void igt_ftrace_dump(const char *header);
+
+void igt_ftrace_close(void);
+
+#endif /* IGT_FTRACE_H */
diff --git a/lib/meson.build b/lib/meson.build
index 89de06e6..99438235 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -9,6 +9,7 @@ lib_sources = [
'igt_debugfs.c',
'igt_device.c',
'igt_aux.c',
+ 'igt_ftrace.c',
'igt_gpu_power.c',
'igt_gt.c',
'igt_gvt.c',
--
2.21.0
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