Support multi-buffer on uprobe-based dynamic events by
using ftrace_event_file.
This patch is based kprobe-based dynamic events multibuffer
support work initially, commited by Masami(commit 41a7dd420c),
but revised as below:
Oleg changed the kprobe-based multibuffer design from
array-pointers of ftrace_event_file into simple list,
so this patch also change to the list design.
rcu_read_lock/unlock added into uprobe_trace_func/uretprobe_trace_func,
to synchronize with ftrace_event_file list add and delete.
Even though we allow multi-uprobes instances now,
but TP_FLAG_PROFILE/TP_FLAG_TRACE are still mutually exclusive
in probe_event_enable currently, this means we cannot allow
one user is using uprobe-tracer, and another user is using
perf-probe on same uprobe concurrently.
(Perhaps this will be fix in future, kprobe dont't have this
limitation now)
Signed-off-by: zhangwei(Jovi) <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Srikar Dronamraju <[email protected]>
---
kernel/trace/trace_uprobe.c | 119 ++++++++++++++++++++++++++++++++++++-------
1 file changed, 100 insertions(+), 19 deletions(-)
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 32494fb0..2fc9931 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -53,6 +53,7 @@ struct trace_uprobe {
struct list_head list;
struct ftrace_event_class class;
struct ftrace_event_call call;
+ struct list_head files;
struct trace_uprobe_filter filter;
struct uprobe_consumer consumer;
struct inode *inode;
@@ -65,6 +66,11 @@ struct trace_uprobe {
struct probe_arg args[];
};
+struct event_file_link {
+ struct ftrace_event_file *file;
+ struct list_head list;
+};
+
#define SIZEOF_TRACE_UPROBE(n) \
(offsetof(struct trace_uprobe, args) + \
(sizeof(struct probe_arg) * (n)))
@@ -124,6 +130,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
goto error;
INIT_LIST_HEAD(&tu->list);
+ INIT_LIST_HEAD(&tu->files);
tu->consumer.handler = uprobe_dispatcher;
if (is_ret)
tu->consumer.ret_handler = uretprobe_dispatcher;
@@ -511,7 +518,8 @@ static const struct file_operations uprobe_profile_ops = {
};
static void uprobe_trace_print(struct trace_uprobe *tu,
- unsigned long func, struct pt_regs *regs)
+ unsigned long func, struct pt_regs *regs,
+ struct ftrace_event_file *ftrace_file)
{
struct uprobe_trace_entry_head *entry;
struct ring_buffer_event *event;
@@ -520,9 +528,12 @@ static void uprobe_trace_print(struct trace_uprobe *tu,
int size, i;
struct ftrace_event_call *call = &tu->call;
+ WARN_ON(call != ftrace_file->event_call);
+
size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
- event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
- size + tu->size, 0, 0);
+ event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
+ call->event.type,
+ size + tu->size, 0, 0);
if (!event)
return;
@@ -546,15 +557,28 @@ static void uprobe_trace_print(struct trace_uprobe *tu,
/* uprobe handler */
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
{
- if (!is_ret_probe(tu))
- uprobe_trace_print(tu, 0, regs);
+ struct event_file_link *link;
+
+ if (is_ret_probe(tu))
+ return 0;
+
+ rcu_read_lock();
+ list_for_each_entry(link, &tu->files, list)
+ uprobe_trace_print(tu, 0, regs, link->file);
+ rcu_read_unlock();
+
return 0;
}
static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
struct pt_regs *regs)
{
- uprobe_trace_print(tu, func, regs);
+ struct event_file_link *link;
+
+ rcu_read_lock();
+ list_for_each_entry(link, &tu->files, list)
+ uprobe_trace_print(tu, func, regs, link->file);
+ rcu_read_unlock();
}
/* Event entry printers */
@@ -605,33 +629,89 @@ typedef bool (*filter_func_t)(struct uprobe_consumer *self,
struct mm_struct *mm);
static int
-probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter)
+probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
+ filter_func_t filter)
{
- int ret = 0;
+ bool enabled = is_trace_uprobe_enabled(tu);
+ struct event_file_link *link;
+ int ret;
+
+ if (file) {
+ if (tu->flags & TP_FLAG_PROFILE)
+ return -EINTR;
- if (is_trace_uprobe_enabled(tu))
- return -EINTR;
+ link = kmalloc(sizeof(*link), GFP_KERNEL);
+ if (!link)
+ return -ENOMEM;
+
+ link->file = file;
+ list_add_tail_rcu(&link->list, &tu->files);
+
+ tu->flags |= TP_FLAG_TRACE;
+ } else {
+ if (tu->flags & TP_FLAG_TRACE)
+ return -EINTR;
+
+ tu->flags |= TP_FLAG_PROFILE;
+ }
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
- tu->flags |= flag;
+ if (enabled)
+ return;
+
tu->consumer.filter = filter;
ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
- if (ret)
- tu->flags &= ~flag;
+ if (ret) {
+ if (file) {
+ list_del(&link->list);
+ kfree(link);
+ tu->flags &= ~TP_FLAG_TRACE;
+ } else
+ tu->flags &= ~TP_FLAG_PROFILE;
+ }
return ret;
}
-static void probe_event_disable(struct trace_uprobe *tu, int flag)
+static struct event_file_link *
+find_event_file_link(struct trace_uprobe *tu, struct ftrace_event_file *file)
+{
+ struct event_file_link *link;
+
+ list_for_each_entry(link, &tu->files, list)
+ if (link->file == file)
+ return link;
+
+ return NULL;
+}
+
+static void
+probe_event_disable(struct trace_uprobe *tu, struct ftrace_event_file *file)
{
if (!is_trace_uprobe_enabled(tu))
return;
+ if (file) {
+ struct event_file_link *link;
+
+ link = find_event_file_link(tu, file);
+ if (!link)
+ return;
+
+ list_del_rcu(&link->list);
+ /* synchronize with uprobe_trace_func/uretprobe_trace_func */
+ synchronize_sched();
+ kfree(link);
+
+ if (!list_empty(&tu->files))
+ return;
+ }
+
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
- tu->flags &= ~flag;
+ tu->flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
}
static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
@@ -867,21 +947,22 @@ static
int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)
{
struct trace_uprobe *tu = event->data;
+ struct ftrace_event_file *file = data;
switch (type) {
case TRACE_REG_REGISTER:
- return probe_event_enable(tu, TP_FLAG_TRACE, NULL);
+ return probe_event_enable(tu, file, NULL);
case TRACE_REG_UNREGISTER:
- probe_event_disable(tu, TP_FLAG_TRACE);
+ probe_event_disable(tu, file);
return 0;
#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
- return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter);
+ return probe_event_enable(tu, NULL, uprobe_perf_filter);
case TRACE_REG_PERF_UNREGISTER:
- probe_event_disable(tu, TP_FLAG_PROFILE);
+ probe_event_disable(tu, NULL);
return 0;
case TRACE_REG_PERF_OPEN:
--
1.7.9.7
Support multi-buffer on uprobe-based dynamic events by
using ftrace_event_file.
This patch is based kprobe-based dynamic events multibuffer
support work initially, commited by Masami(commit 41a7dd420c),
but revised as below:
Oleg changed the kprobe-based multibuffer design from
array-pointers of ftrace_event_file into simple list,
so this patch also change to the list design.
rcu_read_lock/unlock added into uprobe_trace_func/uretprobe_trace_func,
to synchronize with ftrace_event_file list add and delete.
Even though we allow multi-uprobes instances now,
but TP_FLAG_PROFILE/TP_FLAG_TRACE are still mutually exclusive
in probe_event_enable currently, this means we cannot allow
one user is using uprobe-tracer, and another user is using
perf-probe on same uprobe concurrently.
(Perhaps this will be fix in future, kprobe dont't have this
limitation now)
Signed-off-by: zhangwei(Jovi) <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Srikar Dronamraju <[email protected]>
---
kernel/trace/trace_uprobe.c | 119 ++++++++++++++++++++++++++++++++++++-------
1 file changed, 100 insertions(+), 19 deletions(-)
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 32494fb0..2fc9931 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -53,6 +53,7 @@ struct trace_uprobe {
struct list_head list;
struct ftrace_event_class class;
struct ftrace_event_call call;
+ struct list_head files;
struct trace_uprobe_filter filter;
struct uprobe_consumer consumer;
struct inode *inode;
@@ -65,6 +66,11 @@ struct trace_uprobe {
struct probe_arg args[];
};
+struct event_file_link {
+ struct ftrace_event_file *file;
+ struct list_head list;
+};
+
#define SIZEOF_TRACE_UPROBE(n) \
(offsetof(struct trace_uprobe, args) + \
(sizeof(struct probe_arg) * (n)))
@@ -124,6 +130,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
goto error;
INIT_LIST_HEAD(&tu->list);
+ INIT_LIST_HEAD(&tu->files);
tu->consumer.handler = uprobe_dispatcher;
if (is_ret)
tu->consumer.ret_handler = uretprobe_dispatcher;
@@ -511,7 +518,8 @@ static const struct file_operations uprobe_profile_ops = {
};
static void uprobe_trace_print(struct trace_uprobe *tu,
- unsigned long func, struct pt_regs *regs)
+ unsigned long func, struct pt_regs *regs,
+ struct ftrace_event_file *ftrace_file)
{
struct uprobe_trace_entry_head *entry;
struct ring_buffer_event *event;
@@ -520,9 +528,12 @@ static void uprobe_trace_print(struct trace_uprobe *tu,
int size, i;
struct ftrace_event_call *call = &tu->call;
+ WARN_ON(call != ftrace_file->event_call);
+
size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
- event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
- size + tu->size, 0, 0);
+ event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
+ call->event.type,
+ size + tu->size, 0, 0);
if (!event)
return;
@@ -546,15 +557,28 @@ static void uprobe_trace_print(struct trace_uprobe *tu,
/* uprobe handler */
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
{
- if (!is_ret_probe(tu))
- uprobe_trace_print(tu, 0, regs);
+ struct event_file_link *link;
+
+ if (is_ret_probe(tu))
+ return 0;
+
+ rcu_read_lock();
+ list_for_each_entry(link, &tu->files, list)
+ uprobe_trace_print(tu, 0, regs, link->file);
+ rcu_read_unlock();
+
return 0;
}
static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
struct pt_regs *regs)
{
- uprobe_trace_print(tu, func, regs);
+ struct event_file_link *link;
+
+ rcu_read_lock();
+ list_for_each_entry(link, &tu->files, list)
+ uprobe_trace_print(tu, func, regs, link->file);
+ rcu_read_unlock();
}
/* Event entry printers */
@@ -605,33 +629,89 @@ typedef bool (*filter_func_t)(struct uprobe_consumer *self,
struct mm_struct *mm);
static int
-probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter)
+probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
+ filter_func_t filter)
{
- int ret = 0;
+ bool enabled = is_trace_uprobe_enabled(tu);
+ struct event_file_link *link;
+ int ret;
+
+ if (file) {
+ if (tu->flags & TP_FLAG_PROFILE)
+ return -EINTR;
- if (is_trace_uprobe_enabled(tu))
- return -EINTR;
+ link = kmalloc(sizeof(*link), GFP_KERNEL);
+ if (!link)
+ return -ENOMEM;
+
+ link->file = file;
+ list_add_tail_rcu(&link->list, &tu->files);
+
+ tu->flags |= TP_FLAG_TRACE;
+ } else {
+ if (tu->flags & TP_FLAG_TRACE)
+ return -EINTR;
+
+ tu->flags |= TP_FLAG_PROFILE;
+ }
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
- tu->flags |= flag;
+ if (enabled)
+ return 0;
+
tu->consumer.filter = filter;
ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
- if (ret)
- tu->flags &= ~flag;
+ if (ret) {
+ if (file) {
+ list_del(&link->list);
+ kfree(link);
+ tu->flags &= ~TP_FLAG_TRACE;
+ } else
+ tu->flags &= ~TP_FLAG_PROFILE;
+ }
return ret;
}
-static void probe_event_disable(struct trace_uprobe *tu, int flag)
+static struct event_file_link *
+find_event_file_link(struct trace_uprobe *tu, struct ftrace_event_file *file)
+{
+ struct event_file_link *link;
+
+ list_for_each_entry(link, &tu->files, list)
+ if (link->file == file)
+ return link;
+
+ return NULL;
+}
+
+static void
+probe_event_disable(struct trace_uprobe *tu, struct ftrace_event_file *file)
{
if (!is_trace_uprobe_enabled(tu))
return;
+ if (file) {
+ struct event_file_link *link;
+
+ link = find_event_file_link(tu, file);
+ if (!link)
+ return;
+
+ list_del_rcu(&link->list);
+ /* synchronize with uprobe_trace_func/uretprobe_trace_func */
+ synchronize_sched();
+ kfree(link);
+
+ if (!list_empty(&tu->files))
+ return;
+ }
+
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
- tu->flags &= ~flag;
+ tu->flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
}
static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
@@ -867,21 +947,22 @@ static
int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)
{
struct trace_uprobe *tu = event->data;
+ struct ftrace_event_file *file = data;
switch (type) {
case TRACE_REG_REGISTER:
- return probe_event_enable(tu, TP_FLAG_TRACE, NULL);
+ return probe_event_enable(tu, file, NULL);
case TRACE_REG_UNREGISTER:
- probe_event_disable(tu, TP_FLAG_TRACE);
+ probe_event_disable(tu, file);
return 0;
#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
- return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter);
+ return probe_event_enable(tu, NULL, uprobe_perf_filter);
case TRACE_REG_PERF_UNREGISTER:
- probe_event_disable(tu, TP_FLAG_PROFILE);
+ probe_event_disable(tu, NULL);
return 0;
case TRACE_REG_PERF_OPEN:
-- 1.7.9.7
Hi Jovi,
Just a few of dummy questions..
On Thu, 4 Jul 2013 15:01:10 +0800, zhangwei wrote:
> Support multi-buffer on uprobe-based dynamic events by
> using ftrace_event_file.
>
> This patch is based kprobe-based dynamic events multibuffer
> support work initially, commited by Masami(commit 41a7dd420c),
> but revised as below:
>
> Oleg changed the kprobe-based multibuffer design from
> array-pointers of ftrace_event_file into simple list,
> so this patch also change to the list design.
>
> rcu_read_lock/unlock added into uprobe_trace_func/uretprobe_trace_func,
> to synchronize with ftrace_event_file list add and delete.
>
> Even though we allow multi-uprobes instances now,
> but TP_FLAG_PROFILE/TP_FLAG_TRACE are still mutually exclusive
> in probe_event_enable currently, this means we cannot allow
> one user is using uprobe-tracer, and another user is using
> perf-probe on same uprobe concurrently.
> (Perhaps this will be fix in future, kprobe dont't have this
> limitation now)
So why does this limitation exist? Didn't we support this kind of thing
in the original code?
>
> Signed-off-by: zhangwei(Jovi) <[email protected]>
> Cc: Masami Hiramatsu <[email protected]>
> Cc: Frederic Weisbecker <[email protected]>
> Cc: Oleg Nesterov <[email protected]>
> Cc: Srikar Dronamraju <[email protected]>
> ---
[SNIP]
> + rcu_read_lock();
> + list_for_each_entry(link, &tu->files, list)
list_for_each_entry_rcu() ?
> + uprobe_trace_print(tu, 0, regs, link->file);
> + rcu_read_unlock();
> +
> return 0;
> }
>
> static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
> struct pt_regs *regs)
> {
> - uprobe_trace_print(tu, func, regs);
> + struct event_file_link *link;
> +
> + rcu_read_lock();
> + list_for_each_entry(link, &tu->files, list)
Ditto.
> + uprobe_trace_print(tu, func, regs, link->file);
> + rcu_read_unlock();
> }
[SNIP]
> -static void probe_event_disable(struct trace_uprobe *tu, int flag)
> +static struct event_file_link *
> +find_event_file_link(struct trace_uprobe *tu, struct ftrace_event_file *file)
> +{
> + struct event_file_link *link;
> +
> + list_for_each_entry(link, &tu->files, list)
Not sure of this case. ;)
Thanks,
Namhyung
> + if (link->file == file)
> + return link;
> +
> + return NULL;
> +}
> +
> +static void
> +probe_event_disable(struct trace_uprobe *tu, struct ftrace_event_file *file)
> {
> if (!is_trace_uprobe_enabled(tu))
> return;
>
> + if (file) {
> + struct event_file_link *link;
> +
> + link = find_event_file_link(tu, file);
> + if (!link)
> + return;
> +
> + list_del_rcu(&link->list);
> + /* synchronize with uprobe_trace_func/uretprobe_trace_func */
> + synchronize_sched();
> + kfree(link);
> +
> + if (!list_empty(&tu->files))
> + return;
> + }
> +
> WARN_ON(!uprobe_filter_is_empty(&tu->filter));
>
> uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
> - tu->flags &= ~flag;
> + tu->flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
> }
>
> static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
> @@ -867,21 +947,22 @@ static
> int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)
> {
> struct trace_uprobe *tu = event->data;
> + struct ftrace_event_file *file = data;
>
> switch (type) {
> case TRACE_REG_REGISTER:
> - return probe_event_enable(tu, TP_FLAG_TRACE, NULL);
> + return probe_event_enable(tu, file, NULL);
>
> case TRACE_REG_UNREGISTER:
> - probe_event_disable(tu, TP_FLAG_TRACE);
> + probe_event_disable(tu, file);
> return 0;
>
> #ifdef CONFIG_PERF_EVENTS
> case TRACE_REG_PERF_REGISTER:
> - return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter);
> + return probe_event_enable(tu, NULL, uprobe_perf_filter);
>
> case TRACE_REG_PERF_UNREGISTER:
> - probe_event_disable(tu, TP_FLAG_PROFILE);
> + probe_event_disable(tu, NULL);
> return 0;
>
> case TRACE_REG_PERF_OPEN:
> -- 1.7.9.7
On 2013/7/4 15:41, Namhyung Kim wrote:
> Hi Jovi,
>
> Just a few of dummy questions..
>
>
> On Thu, 4 Jul 2013 15:01:10 +0800, zhangwei wrote:
>> Support multi-buffer on uprobe-based dynamic events by
>> using ftrace_event_file.
>>
>> This patch is based kprobe-based dynamic events multibuffer
>> support work initially, commited by Masami(commit 41a7dd420c),
>> but revised as below:
>>
>> Oleg changed the kprobe-based multibuffer design from
>> array-pointers of ftrace_event_file into simple list,
>> so this patch also change to the list design.
>>
>> rcu_read_lock/unlock added into uprobe_trace_func/uretprobe_trace_func,
>> to synchronize with ftrace_event_file list add and delete.
>>
>> Even though we allow multi-uprobes instances now,
>> but TP_FLAG_PROFILE/TP_FLAG_TRACE are still mutually exclusive
>> in probe_event_enable currently, this means we cannot allow
>> one user is using uprobe-tracer, and another user is using
>> perf-probe on same uprobe concurrently.
>> (Perhaps this will be fix in future, kprobe dont't have this
>> limitation now)
>
> So why does this limitation exist? Didn't we support this kind of thing
> in the original code?
>
Yes, it existed(maybe not exist before uprobe pre-filter work), because uprobe filter
is associated with trace_uprobe tightly at present, so we cannot assign
TP_FLAG_PROFILE/TP_FLAG_TRACE for same trace_uprobe with different filter.
Perhaps we need to remove the limitation in future.
>>
>> Signed-off-by: zhangwei(Jovi) <[email protected]>
>> Cc: Masami Hiramatsu <[email protected]>
>> Cc: Frederic Weisbecker <[email protected]>
>> Cc: Oleg Nesterov <[email protected]>
>> Cc: Srikar Dronamraju <[email protected]>
>> ---
> [SNIP]
>> + rcu_read_lock();
>> + list_for_each_entry(link, &tu->files, list)
>
> list_for_each_entry_rcu() ?
>
I haven't noticed this, thanks, I will update it.
>
>> + uprobe_trace_print(tu, 0, regs, link->file);
>> + rcu_read_unlock();
>> +
>> return 0;
>> }
>>
>> static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
>> struct pt_regs *regs)
>> {
>> - uprobe_trace_print(tu, func, regs);
>> + struct event_file_link *link;
>> +
>> + rcu_read_lock();
>> + list_for_each_entry(link, &tu->files, list)
>
> Ditto.
>
>
>> + uprobe_trace_print(tu, func, regs, link->file);
>> + rcu_read_unlock();
>> }
> [SNIP]
>> -static void probe_event_disable(struct trace_uprobe *tu, int flag)
>> +static struct event_file_link *
>> +find_event_file_link(struct trace_uprobe *tu, struct ftrace_event_file *file)
>> +{
>> + struct event_file_link *link;
>> +
>> + list_for_each_entry(link, &tu->files, list)
>
> Not sure of this case. ;)
>
Yes, _rcu is not needed in here, it's only called in event disable serialized case.
> Thanks,
> Namhyung
>
>> + if (link->file == file)
>> + return link;
>> +
>> + return NULL;
>> +}
>> +
>> +static void
>> +probe_event_disable(struct trace_uprobe *tu, struct ftrace_event_file *file)
>> {
>> if (!is_trace_uprobe_enabled(tu))
>> return;
>>
>> + if (file) {
>> + struct event_file_link *link;
>> +
>> + link = find_event_file_link(tu, file);
>> + if (!link)
>> + return;
>> +
>> + list_del_rcu(&link->list);
>> + /* synchronize with uprobe_trace_func/uretprobe_trace_func */
>> + synchronize_sched();
>> + kfree(link);
>> +
>> + if (!list_empty(&tu->files))
>> + return;
>> + }
>> +
>> WARN_ON(!uprobe_filter_is_empty(&tu->filter));
>>
>> uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
>> - tu->flags &= ~flag;
>> + tu->flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
>> }
>>
>> static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
>> @@ -867,21 +947,22 @@ static
>> int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)
>> {
>> struct trace_uprobe *tu = event->data;
>> + struct ftrace_event_file *file = data;
>>
>> switch (type) {
>> case TRACE_REG_REGISTER:
>> - return probe_event_enable(tu, TP_FLAG_TRACE, NULL);
>> + return probe_event_enable(tu, file, NULL);
>>
>> case TRACE_REG_UNREGISTER:
>> - probe_event_disable(tu, TP_FLAG_TRACE);
>> + probe_event_disable(tu, file);
>> return 0;
>>
>> #ifdef CONFIG_PERF_EVENTS
>> case TRACE_REG_PERF_REGISTER:
>> - return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter);
>> + return probe_event_enable(tu, NULL, uprobe_perf_filter);
>>
>> case TRACE_REG_PERF_UNREGISTER:
>> - probe_event_disable(tu, TP_FLAG_PROFILE);
>> + probe_event_disable(tu, NULL);
>> return 0;
>>
>> case TRACE_REG_PERF_OPEN:
>> -- 1.7.9.7
>
> .
>
On 07/04, zhangwei(Jovi) wrote:
>
> On 2013/7/4 15:41, Namhyung Kim wrote:
> >>
> >> Even though we allow multi-uprobes instances now,
> >> but TP_FLAG_PROFILE/TP_FLAG_TRACE are still mutually exclusive
> >> in probe_event_enable currently, this means we cannot allow
> >> one user is using uprobe-tracer, and another user is using
> >> perf-probe on same uprobe concurrently.
> >> (Perhaps this will be fix in future, kprobe dont't have this
> >> limitation now)
> >
> > So why does this limitation exist? Didn't we support this kind of thing
> > in the original code?
For no reason.
> Yes, it existed(maybe not exist before uprobe pre-filter work),
No, it was always here and I never understood it.
> because uprobe filter
> is associated with trace_uprobe tightly at present, so we cannot assign
> TP_FLAG_PROFILE/TP_FLAG_TRACE for same trace_uprobe with different filter.
More precisely, TRACE_REG_REGISTER should participate (inc/dec nr_systemwide)
if CONFIG_PERF_EVENTS.
> Perhaps we need to remove the limitation in future.
Yes, I'll remove it.
Oleg.