From: "Ziqian SUN (Zamir)" <[email protected]>
The mmiotrace tracer cannot be enabled with ftrace=mmiotrace in
kernel commandline. With this patch, a trace_noboot_tracer_list
is implemented and will be checked during system boot. If the
tracer declares itself as not for boot up, system will print out
a message and continue booting.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=196557
Signed-off-by: Ziqian SUN (Zamir) <[email protected]>
---
kernel/trace/trace.c | 34 +++++++++++++++++++++++++++++++++-
kernel/trace/trace.h | 11 +++++++++++
kernel/trace/trace_mmiotrace.c | 4 ++++
3 files changed, 48 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 44004d8..0d25b1e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -319,6 +319,33 @@ void trace_free_pid_list(struct trace_pid_list *pid_list)
kfree(pid_list);
}
+struct mutex trace_noboot_tracer_lock;
+
+DEFINE_MUTEX(trace_noboot_tracer_lock);
+LIST_HEAD(trace_noboot_tracer_list);
+
+void trace_noboot_tracer_put(struct tracer_noboot *noboot_tracer)
+{
+ mutex_lock(&trace_noboot_tracer_lock);
+ list_add(&noboot_tracer->list, &trace_noboot_tracer_list);
+ mutex_unlock(&trace_noboot_tracer_lock);
+}
+
+bool trace_noboot_tracer_find(const char *str)
+{
+ mutex_lock(&trace_noboot_tracer_lock);
+ struct tracer_noboot *ptr = NULL;
+
+ list_for_each_entry(ptr, &trace_noboot_tracer_list, list) {
+ if (strcmp(ptr->name, str) == 0) {
+ mutex_unlock(&trace_noboot_tracer_lock);
+ return true;
+ }
+ }
+ mutex_unlock(&trace_noboot_tracer_lock);
+ return false;
+}
+
/**
* trace_find_filtered_pid - check if a pid exists in a filtered_pid list
* @filtered_pids: The list of pids to check
@@ -1641,8 +1668,13 @@ int __init register_tracer(struct tracer *type)
if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
goto out_unlock;
+ /* If the tracer should not be enabled by kernel parameter */
+ if (trace_noboot_tracer_find(type->name)) {
+ pr_warn("Tracer '%s' cannot be enabled during boot\n", type->name);
+ goto out_unlock;
+ }
+
printk(KERN_INFO "Starting tracer '%s'\n", type->name);
- /* Do we want this tracer to start on bootup? */
tracing_set_tracer(&global_trace, type->name);
default_bootup_tracer = NULL;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 490ba22..23bc668 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -502,6 +502,17 @@ enum {
TRACE_IRQ_BIT,
};
+/*
+ * For tracer that cannot be enabled during boot time.
+ */
+
+struct tracer_noboot {
+ const char *name;
+ struct list_head list;
+};
+
+void trace_noboot_tracer_put(struct tracer_noboot *noboot_tracer);
+
#define trace_recursion_set(bit) do { (current)->trace_recursion |= (1<<(bit)); } while (0)
#define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
#define trace_recursion_test(bit) ((current)->trace_recursion & (1<<(bit)))
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index cd7480d..06aa0a5 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -286,6 +286,10 @@ static enum print_line_t mmio_print_line(struct trace_iterator *iter)
__init static int init_mmio_trace(void)
{
+ struct tracer_noboot mmio_notrace;
+
+ mmio_notrace.name = "mmiotrace";
+ trace_noboot_tracer_put(&mmio_notrace);
return register_tracer(&mmio_tracer);
}
device_initcall(init_mmio_trace);
--
1.8.3.1
Hi Steve,
Is this solution acceptable? Any suggestions?
Thanks.
----- Original Message -----
> From: "Ziqian SUN (Zamir)" <[email protected]>
>
> The mmiotrace tracer cannot be enabled with ftrace=mmiotrace in
> kernel commandline. With this patch, a trace_noboot_tracer_list
> is implemented and will be checked during system boot. If the
> tracer declares itself as not for boot up, system will print out
> a message and continue booting.
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=196557
> Signed-off-by: Ziqian SUN (Zamir) <[email protected]>
> ---
> kernel/trace/trace.c | 34 +++++++++++++++++++++++++++++++++-
> kernel/trace/trace.h | 11 +++++++++++
> kernel/trace/trace_mmiotrace.c | 4 ++++
> 3 files changed, 48 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 44004d8..0d25b1e 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -319,6 +319,33 @@ void trace_free_pid_list(struct trace_pid_list
> *pid_list)
> kfree(pid_list);
> }
>
> +struct mutex trace_noboot_tracer_lock;
> +
> +DEFINE_MUTEX(trace_noboot_tracer_lock);
> +LIST_HEAD(trace_noboot_tracer_list);
> +
> +void trace_noboot_tracer_put(struct tracer_noboot *noboot_tracer)
> +{
> + mutex_lock(&trace_noboot_tracer_lock);
> + list_add(&noboot_tracer->list, &trace_noboot_tracer_list);
> + mutex_unlock(&trace_noboot_tracer_lock);
> +}
> +
> +bool trace_noboot_tracer_find(const char *str)
> +{
> + mutex_lock(&trace_noboot_tracer_lock);
> + struct tracer_noboot *ptr = NULL;
> +
> + list_for_each_entry(ptr, &trace_noboot_tracer_list, list) {
> + if (strcmp(ptr->name, str) == 0) {
> + mutex_unlock(&trace_noboot_tracer_lock);
> + return true;
> + }
> + }
> + mutex_unlock(&trace_noboot_tracer_lock);
> + return false;
> +}
> +
> /**
> * trace_find_filtered_pid - check if a pid exists in a filtered_pid list
> * @filtered_pids: The list of pids to check
> @@ -1641,8 +1668,13 @@ int __init register_tracer(struct tracer *type)
> if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
> goto out_unlock;
>
> + /* If the tracer should not be enabled by kernel parameter */
> + if (trace_noboot_tracer_find(type->name)) {
> + pr_warn("Tracer '%s' cannot be enabled during boot\n", type->name);
> + goto out_unlock;
> + }
> +
> printk(KERN_INFO "Starting tracer '%s'\n", type->name);
> - /* Do we want this tracer to start on bootup? */
> tracing_set_tracer(&global_trace, type->name);
> default_bootup_tracer = NULL;
>
> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> index 490ba22..23bc668 100644
> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -502,6 +502,17 @@ enum {
> TRACE_IRQ_BIT,
> };
>
> +/*
> + * For tracer that cannot be enabled during boot time.
> + */
> +
> +struct tracer_noboot {
> + const char *name;
> + struct list_head list;
> +};
> +
> +void trace_noboot_tracer_put(struct tracer_noboot *noboot_tracer);
> +
> #define trace_recursion_set(bit) do { (current)->trace_recursion |=
> (1<<(bit)); } while (0)
> #define trace_recursion_clear(bit) do { (current)->trace_recursion &=
> ~(1<<(bit)); } while (0)
> #define trace_recursion_test(bit) ((current)->trace_recursion & (1<<(bit)))
> diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
> index cd7480d..06aa0a5 100644
> --- a/kernel/trace/trace_mmiotrace.c
> +++ b/kernel/trace/trace_mmiotrace.c
> @@ -286,6 +286,10 @@ static enum print_line_t mmio_print_line(struct
> trace_iterator *iter)
>
> __init static int init_mmio_trace(void)
> {
> + struct tracer_noboot mmio_notrace;
> +
> + mmio_notrace.name = "mmiotrace";
> + trace_noboot_tracer_put(&mmio_notrace);
> return register_tracer(&mmio_tracer);
> }
> device_initcall(init_mmio_trace);
> --
> 1.8.3.1
>
>
--
Ziqian SUN (Zamir)
Red Hat Red Hat Software (Beijing) Co.,Ltd
1D86 6D4A 49CE 4BBD 72CF FCF5 D856 6E11 F2A0 525E
On Fri, 8 Sep 2017 10:02:04 -0400 (EDT)
"Ziqian SUN (Zamir)" <[email protected]> wrote:
> Hi Steve,
>
> Is this solution acceptable? Any suggestions?
>
Sorry this patch got buried in other email. I'll take a look at it now.
-- Steve
On Wed, 30 Aug 2017 12:19:30 +0800
"Ziqian SUN (Zamir)" <[email protected]> wrote:
> From: "Ziqian SUN (Zamir)" <[email protected]>
>
> The mmiotrace tracer cannot be enabled with ftrace=mmiotrace in
> kernel commandline. With this patch, a trace_noboot_tracer_list
> is implemented and will be checked during system boot. If the
> tracer declares itself as not for boot up, system will print out
> a message and continue booting.
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=196557
> Signed-off-by: Ziqian SUN (Zamir) <[email protected]>
> ---
> kernel/trace/trace.c | 34 +++++++++++++++++++++++++++++++++-
> kernel/trace/trace.h | 11 +++++++++++
> kernel/trace/trace_mmiotrace.c | 4 ++++
> 3 files changed, 48 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 44004d8..0d25b1e 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -319,6 +319,33 @@ void trace_free_pid_list(struct trace_pid_list *pid_list)
> kfree(pid_list);
> }
>
> +struct mutex trace_noboot_tracer_lock;
> +
> +DEFINE_MUTEX(trace_noboot_tracer_lock);
> +LIST_HEAD(trace_noboot_tracer_list);
> +
> +void trace_noboot_tracer_put(struct tracer_noboot *noboot_tracer)
> +{
> + mutex_lock(&trace_noboot_tracer_lock);
> + list_add(&noboot_tracer->list, &trace_noboot_tracer_list);
> + mutex_unlock(&trace_noboot_tracer_lock);
> +}
> +
> +bool trace_noboot_tracer_find(const char *str)
> +{
> + mutex_lock(&trace_noboot_tracer_lock);
> + struct tracer_noboot *ptr = NULL;
> +
> + list_for_each_entry(ptr, &trace_noboot_tracer_list, list) {
> + if (strcmp(ptr->name, str) == 0) {
> + mutex_unlock(&trace_noboot_tracer_lock);
> + return true;
> + }
> + }
> + mutex_unlock(&trace_noboot_tracer_lock);
> + return false;
> +}
> +
> /**
> * trace_find_filtered_pid - check if a pid exists in a filtered_pid list
> * @filtered_pids: The list of pids to check
> @@ -1641,8 +1668,13 @@ int __init register_tracer(struct tracer *type)
> if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
> goto out_unlock;
>
> + /* If the tracer should not be enabled by kernel parameter */
> + if (trace_noboot_tracer_find(type->name)) {
> + pr_warn("Tracer '%s' cannot be enabled during boot\n", type->name);
> + goto out_unlock;
> + }
> +
> printk(KERN_INFO "Starting tracer '%s'\n", type->name);
> - /* Do we want this tracer to start on bootup? */
> tracing_set_tracer(&global_trace, type->name);
> default_bootup_tracer = NULL;
>
> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> index 490ba22..23bc668 100644
> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -502,6 +502,17 @@ enum {
> TRACE_IRQ_BIT,
> };
>
> +/*
> + * For tracer that cannot be enabled during boot time.
> + */
> +
> +struct tracer_noboot {
> + const char *name;
> + struct list_head list;
> +};
> +
> +void trace_noboot_tracer_put(struct tracer_noboot *noboot_tracer);
> +
> #define trace_recursion_set(bit) do { (current)->trace_recursion |= (1<<(bit)); } while (0)
> #define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
> #define trace_recursion_test(bit) ((current)->trace_recursion & (1<<(bit)))
> diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
> index cd7480d..06aa0a5 100644
> --- a/kernel/trace/trace_mmiotrace.c
> +++ b/kernel/trace/trace_mmiotrace.c
> @@ -286,6 +286,10 @@ static enum print_line_t mmio_print_line(struct trace_iterator *iter)
>
> __init static int init_mmio_trace(void)
> {
> + struct tracer_noboot mmio_notrace;
> +
> + mmio_notrace.name = "mmiotrace";
> + trace_noboot_tracer_put(&mmio_notrace);
> return register_tracer(&mmio_tracer);
> }
> device_initcall(init_mmio_trace);
This is way overkill. Just add
bool noboot;
to struct tracer in trace.h and then to the mmiotracer:
struct tracer mmio_tracer = {
[..]
.noboot = true,
};
And then in tracing_set_tracer() add after:
if (t == tr->current_trace)
goto out;
this:
if (system_state < SYSTEM_RUNNING && t->noboot) {
WARN(1, "Tracer %s not allowed on command line",
t->name);
goto out;
}
That's it. No need for locking or anything else.
-- Steve
> On Wed, 30 Aug 2017 12:19:30 +0800
> "Ziqian SUN (Zamir)" <[email protected]> wrote:
>
> > From: "Ziqian SUN (Zamir)" <[email protected]>
> >
> > The mmiotrace tracer cannot be enabled with ftrace=mmiotrace in
> > kernel commandline. With this patch, a trace_noboot_tracer_list
> > is implemented and will be checked during system boot. If the
> > tracer declares itself as not for boot up, system will print out
> > a message and continue booting.
> >
> > Link: https://bugzilla.kernel.org/show_bug.cgi?id=196557
> > Signed-off-by: Ziqian SUN (Zamir) <[email protected]>
> > ---
> > kernel/trace/trace.c | 34 +++++++++++++++++++++++++++++++++-
> > kernel/trace/trace.h | 11 +++++++++++
> > kernel/trace/trace_mmiotrace.c | 4 ++++
> > 3 files changed, 48 insertions(+), 1 deletion(-)
> >
> > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> > index 44004d8..0d25b1e 100644
> > --- a/kernel/trace/trace.c
> > +++ b/kernel/trace/trace.c
> > @@ -319,6 +319,33 @@ void trace_free_pid_list(struct trace_pid_list
> > *pid_list)
> > kfree(pid_list);
> > }
> >
> > +struct mutex trace_noboot_tracer_lock;
> > +
> > +DEFINE_MUTEX(trace_noboot_tracer_lock);
> > +LIST_HEAD(trace_noboot_tracer_list);
> > +
> > +void trace_noboot_tracer_put(struct tracer_noboot *noboot_tracer)
> > +{
> > + mutex_lock(&trace_noboot_tracer_lock);
> > + list_add(&noboot_tracer->list, &trace_noboot_tracer_list);
> > + mutex_unlock(&trace_noboot_tracer_lock);
> > +}
> > +
> > +bool trace_noboot_tracer_find(const char *str)
> > +{
> > + mutex_lock(&trace_noboot_tracer_lock);
> > + struct tracer_noboot *ptr = NULL;
> > +
> > + list_for_each_entry(ptr, &trace_noboot_tracer_list, list) {
> > + if (strcmp(ptr->name, str) == 0) {
> > + mutex_unlock(&trace_noboot_tracer_lock);
> > + return true;
> > + }
> > + }
> > + mutex_unlock(&trace_noboot_tracer_lock);
> > + return false;
> > +}
> > +
> > /**
> > * trace_find_filtered_pid - check if a pid exists in a filtered_pid list
> > * @filtered_pids: The list of pids to check
> > @@ -1641,8 +1668,13 @@ int __init register_tracer(struct tracer *type)
> > if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
> > goto out_unlock;
> >
> > + /* If the tracer should not be enabled by kernel parameter */
> > + if (trace_noboot_tracer_find(type->name)) {
> > + pr_warn("Tracer '%s' cannot be enabled during boot\n", type->name);
> > + goto out_unlock;
> > + }
> > +
> > printk(KERN_INFO "Starting tracer '%s'\n", type->name);
> > - /* Do we want this tracer to start on bootup? */
> > tracing_set_tracer(&global_trace, type->name);
> > default_bootup_tracer = NULL;
> >
> > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> > index 490ba22..23bc668 100644
> > --- a/kernel/trace/trace.h
> > +++ b/kernel/trace/trace.h
> > @@ -502,6 +502,17 @@ enum {
> > TRACE_IRQ_BIT,
> > };
> >
> > +/*
> > + * For tracer that cannot be enabled during boot time.
> > + */
> > +
> > +struct tracer_noboot {
> > + const char *name;
> > + struct list_head list;
> > +};
> > +
> > +void trace_noboot_tracer_put(struct tracer_noboot *noboot_tracer);
> > +
> > #define trace_recursion_set(bit) do { (current)->trace_recursion |=
> > (1<<(bit)); } while (0)
> > #define trace_recursion_clear(bit) do { (current)->trace_recursion &=
> > ~(1<<(bit)); } while (0)
> > #define trace_recursion_test(bit) ((current)->trace_recursion &
> > (1<<(bit)))
> > diff --git a/kernel/trace/trace_mmiotrace.c
> > b/kernel/trace/trace_mmiotrace.c
> > index cd7480d..06aa0a5 100644
> > --- a/kernel/trace/trace_mmiotrace.c
> > +++ b/kernel/trace/trace_mmiotrace.c
> > @@ -286,6 +286,10 @@ static enum print_line_t mmio_print_line(struct
> > trace_iterator *iter)
> >
> > __init static int init_mmio_trace(void)
> > {
> > + struct tracer_noboot mmio_notrace;
> > +
> > + mmio_notrace.name = "mmiotrace";
> > + trace_noboot_tracer_put(&mmio_notrace);
> > return register_tracer(&mmio_tracer);
> > }
> > device_initcall(init_mmio_trace);
>
> This is way overkill. Just add
>
> bool noboot;
>
> to struct tracer in trace.h and then to the mmiotracer:
>
> struct tracer mmio_tracer = {
> [..]
> .noboot = true,
> };
>
>
> And then in tracing_set_tracer() add after:
>
> if (t == tr->current_trace)
> goto out;
>
> this:
>
> if (system_state < SYSTEM_RUNNING && t->noboot) {
> WARN(1, "Tracer %s not allowed on command line",
> t->name);
> goto out;
> }
>
> That's it. No need for locking or anything else.
>
Thanks for the suggestions. I will send a patch v3 after testing.
> -- Steve
>
>
>
--
Ziqian SUN