* [PATCH 1/3] tracing: Erase irqsoff trace with empty write
2017-09-20 13:29 [PATCH 0/3] [GIT PULL] tracing: Minor fixes for 4.14 (and stable) Steven Rostedt
@ 2017-09-20 13:29 ` Steven Rostedt
2017-09-20 13:29 ` [PATCH 2/3] tracing: Ignore mmiotrace from kernel commandline Steven Rostedt
2017-09-20 13:29 ` [PATCH 3/3] tracing: Fix trace_pipe behavior for instance traces Steven Rostedt
2 siblings, 0 replies; 4+ messages in thread
From: Steven Rostedt @ 2017-09-20 13:29 UTC (permalink / raw)
To: linux-kernel
Cc: Linus Torvalds, Ingo Molnar, Andrew Morton, mingo, stable, Bo Yan
[-- Attachment #1: 0001-tracing-Erase-irqsoff-trace-with-empty-write.patch --]
[-- Type: text/plain, Size: 1556 bytes --]
From: Bo Yan <byan@nvidia.com>
One convenient way to erase trace is "echo > trace". However, this
is currently broken if the current tracer is irqsoff tracer. This
is because irqsoff tracer use max_buffer as the default trace
buffer.
Set the max_buffer as the one to be cleared when it's the trace
buffer currently in use.
Link: http://lkml.kernel.org/r/1505754215-29411-1-git-send-email-byan@nvidia.com
Cc: <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 4acd4d00f ("tracing: give easy way to clear trace buffer")
Signed-off-by: Bo Yan <byan@nvidia.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5360b7aec57a..a7fb136da891 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4020,11 +4020,17 @@ static int tracing_open(struct inode *inode, struct file *file)
/* If this file was open for write, then erase contents */
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
int cpu = tracing_get_cpu(inode);
+ struct trace_buffer *trace_buf = &tr->trace_buffer;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (tr->current_trace->print_max)
+ trace_buf = &tr->max_buffer;
+#endif
if (cpu == RING_BUFFER_ALL_CPUS)
- tracing_reset_online_cpus(&tr->trace_buffer);
+ tracing_reset_online_cpus(trace_buf);
else
- tracing_reset(&tr->trace_buffer, cpu);
+ tracing_reset(trace_buf, cpu);
}
if (file->f_mode & FMODE_READ) {
--
2.13.2
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/3] tracing: Ignore mmiotrace from kernel commandline
2017-09-20 13:29 [PATCH 0/3] [GIT PULL] tracing: Minor fixes for 4.14 (and stable) Steven Rostedt
2017-09-20 13:29 ` [PATCH 1/3] tracing: Erase irqsoff trace with empty write Steven Rostedt
@ 2017-09-20 13:29 ` Steven Rostedt
2017-09-20 13:29 ` [PATCH 3/3] tracing: Fix trace_pipe behavior for instance traces Steven Rostedt
2 siblings, 0 replies; 4+ messages in thread
From: Steven Rostedt @ 2017-09-20 13:29 UTC (permalink / raw)
To: linux-kernel
Cc: Linus Torvalds, Ingo Molnar, Andrew Morton, Ziqian SUN (Zamir)
[-- Attachment #1: 0002-tracing-Ignore-mmiotrace-from-kernel-commandline.patch --]
[-- Type: text/plain, Size: 2018 bytes --]
From: "Ziqian SUN (Zamir)" <zsun@redhat.com>
The mmiotrace tracer cannot be enabled with ftrace=mmiotrace in kernel
commandline. With this patch, noboot is added to the tracer struct,
and when system boot with a tracer that has noboot=true, it will print
out a warning message and continue booting.
Link: http://lkml.kernel.org/r/1505111195-31942-1-git-send-email-zsun@redhat.com
Signed-off-by: Ziqian SUN (Zamir) <zsun@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace.c | 7 +++++++
kernel/trace/trace.h | 2 ++
kernel/trace/trace_mmiotrace.c | 1 +
3 files changed, 10 insertions(+)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a7fb136da891..d3ca35f38803 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5364,6 +5364,13 @@ static int tracing_set_tracer(struct trace_array *tr, const char *buf)
if (t == tr->current_trace)
goto out;
+ /* Some tracers won't work on kernel command line */
+ if (system_state < SYSTEM_RUNNING && t->noboot) {
+ pr_warn("Tracer '%s' is not allowed on command line, ignored\n",
+ t->name);
+ goto out;
+ }
+
/* Some tracers are only allowed for the top level buffer */
if (!trace_ok_for_array(t, tr)) {
ret = -EINVAL;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index fb5d54d0d1b3..652c682707cd 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -444,6 +444,8 @@ struct tracer {
#ifdef CONFIG_TRACER_MAX_TRACE
bool use_max_tr;
#endif
+ /* True if tracer cannot be enabled in kernel param */
+ bool noboot;
};
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index cd7480d0a201..dca78fc48439 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -282,6 +282,7 @@ static struct tracer mmio_tracer __read_mostly =
.close = mmio_close,
.read = mmio_read,
.print_line = mmio_print_line,
+ .noboot = true,
};
__init static int init_mmio_trace(void)
--
2.13.2
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 3/3] tracing: Fix trace_pipe behavior for instance traces
2017-09-20 13:29 [PATCH 0/3] [GIT PULL] tracing: Minor fixes for 4.14 (and stable) Steven Rostedt
2017-09-20 13:29 ` [PATCH 1/3] tracing: Erase irqsoff trace with empty write Steven Rostedt
2017-09-20 13:29 ` [PATCH 2/3] tracing: Ignore mmiotrace from kernel commandline Steven Rostedt
@ 2017-09-20 13:29 ` Steven Rostedt
2 siblings, 0 replies; 4+ messages in thread
From: Steven Rostedt @ 2017-09-20 13:29 UTC (permalink / raw)
To: linux-kernel
Cc: Linus Torvalds, Ingo Molnar, Andrew Morton, stable,
Tahsin Erdogan
[-- Attachment #1: 0003-tracing-Fix-trace_pipe-behavior-for-instance-traces.patch --]
[-- Type: text/plain, Size: 1428 bytes --]
From: Tahsin Erdogan <tahsin@google.com>
When reading data from trace_pipe, tracing_wait_pipe() performs a
check to see if tracing has been turned off after some data was read.
Currently, this check always looks at global trace state, but it
should be checking the trace instance where trace_pipe is located at.
Because of this bug, cat instances/i1/trace_pipe in the following
script will immediately exit instead of waiting for data:
cd /sys/kernel/debug/tracing
echo 0 > tracing_on
mkdir -p instances/i1
echo 1 > instances/i1/tracing_on
echo 1 > instances/i1/events/sched/sched_process_exec/enable
cat instances/i1/trace_pipe
Link: http://lkml.kernel.org/r/20170917102348.1615-1-tahsin@google.com
Cc: stable@vger.kernel.org
Fixes: 10246fa35d4f ("tracing: give easy way to clear trace buffer")
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d3ca35f38803..752e5daf0896 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5680,7 +5680,7 @@ static int tracing_wait_pipe(struct file *filp)
*
* iter->pos will be 0 if we haven't read anything.
*/
- if (!tracing_is_on() && iter->pos)
+ if (!tracer_tracing_is_on(iter->tr) && iter->pos)
break;
mutex_unlock(&iter->mutex);
--
2.13.2
^ permalink raw reply related [flat|nested] 4+ messages in thread