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tracing/syscalls: Rename variable 'nr' to 'syscall_nr'

PATCH RESEND Applied Taeung Song 2 participants 6 messages Feb 25, 2016 Tracing

v1 of 3 Applied Latest is v3 →

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#0 lore raw

PATCH RESEND 1/3 tracing/syscalls: Rename variable 'nr' to 'syscall_nr'

There is a problem about duplicated variable name
for system call number and a argument of some
system call. I found this problem when I tested
perf-script with python script as below.

    # perf record -e syscalls:*
    # perf script -g python
    # perf script -s perf-script.py
      File "perf-script.py", line 8694
        def syscalls__sys_enter_io_getevents(event_name, context, common_cpu,
    SyntaxError: duplicate argument 'nr' in function definition
    Error running python script perf-script.py

As above, problems about duplicated argument occurred when processing sys_enter_io_getevent() and sys_enter_io_submit(). Because the two system calls have a argument 'nr' as below.

    int io_getevents(aio_context_t ctx_id, long min_nr, long nr,
                     struct io_event *events, struct timespec *timeout);

    int io_submit(aio_context_t ctx_id, long nr, struct iocb **iocbpp);

So rename a variable 'nr' to 'syscall_nr' for system call number in print_syscall_enter().

Cc Thomas Gleixner <[email protected]>
Cc Lai Jiangshan <[email protected]>
---
 kernel/trace/trace.h          |  4 ++--
 kernel/trace/trace_syscalls.c | 16 ++++++++--------
 2 files changed, 10 insertions(+), 10 deletions(-)
kernel/trace/trace.h +2 -2
index 8414fa4..beddeb1 100644
@@ -88,13 +88,13 @@ enum trace_type {
  */
 struct syscall_trace_enter {
 	struct trace_entry	ent;
-	int			nr;
+	int			syscall_nr;
 	unsigned long		args[];
 };
 
 struct syscall_trace_exit {
 	struct trace_entry	ent;
-	int			nr;
+	int			syscall_nr;
 	long			ret;
 };
 
kernel/trace/trace_syscalls.c +8 -8
index 0655afb..956209f 100644
@@ -118,7 +118,7 @@ print_syscall_enter(struct trace_iterator *iter, int flags,
 	int i, syscall;
 
 	trace = (typeof(trace))ent;
-	syscall = trace->nr;
+	syscall = trace->syscall_nr;
 	entry = syscall_nr_to_meta(syscall);
 
 	if (!entry)
@@ -164,7 +164,7 @@ print_syscall_exit(struct trace_iterator *iter, int flags,
 	struct syscall_metadata *entry;
 
 	trace = (typeof(trace))ent;
-	syscall = trace->nr;
+	syscall = trace->syscall_nr;
 	entry = syscall_nr_to_meta(syscall);
 
 	if (!entry) {
@@ -261,7 +261,7 @@ static int __init syscall_enter_define_fields(struct trace_event_call *call)
 	int i;
 	int offset = offsetof(typeof(trace), args);
 
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+	ret = trace_define_field(call, SYSCALL_FIELD(int, syscall_nr), FILTER_OTHER);
 	if (ret)
 		return ret;
 
@@ -281,7 +281,7 @@ static int __init syscall_exit_define_fields(struct trace_event_call *call)
 	struct syscall_trace_exit trace;
 	int ret;
 
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+	ret = trace_define_field(call, SYSCALL_FIELD(int, syscall_nr), FILTER_OTHER);
 	if (ret)
 		return ret;
 
@@ -332,7 +332,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 		return;
 
 	entry = ring_buffer_event_data(event);
-	entry->nr = syscall_nr;
+	entry->syscall_nr = syscall_nr;
 	syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
 
 	event_trigger_unlock_commit(trace_file, buffer, event, entry,
@@ -378,7 +378,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 		return;
 
 	entry = ring_buffer_event_data(event);
-	entry->nr = syscall_nr;
+	entry->syscall_nr = syscall_nr;
 	entry->ret = syscall_get_return_value(current, regs);
 
 	event_trigger_unlock_commit(trace_file, buffer, event, entry,
@@ -579,7 +579,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
 	if (!rec)
 		return;
 
-	rec->nr = syscall_nr;
+	rec->syscall_nr = syscall_nr;
 	syscall_get_arguments(current, regs, 0, sys_data->nb_args,
 			       (unsigned long *)&rec->args);
 	perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
@@ -652,7 +652,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
 	if (!rec)
 		return;
 
-	rec->nr = syscall_nr;
+	rec->syscall_nr = syscall_nr;
 	rec->ret = syscall_get_return_value(current, regs);
 	perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
 }
Signature · 1 line
2.5.0
maintainer
#1 lore raw
Quoted 17 lines · On Fri, 26 Feb 2016 00:24:18 +0900 Taeung Song <[email protected]> wrote:

There is a problem about duplicated variable name
for system call number and a argument of some
system call. I found this problem when I tested
perf-script with python script as below.

    # perf record -e syscalls:*
    # perf script -g python
    # perf script -s perf-script.py
      File "perf-script.py", line 8694
        def syscalls__sys_enter_io_getevents(event_name, context, common_cpu,
    SyntaxError: duplicate argument 'nr' in function definition
    Error running python script perf-script.py

As above, problems about duplicated argument occurred when processing sys_enter_io_getevent() and sys_enter_io_submit(). Because the two system calls have a argument 'nr' as below.

Quoted 7 lines
    int io_getevents(aio_context_t ctx_id, long min_nr, long nr,
                     struct io_event *events, struct timespec *timeout);

    int io_submit(aio_context_t ctx_id, long nr, struct iocb **iocbpp);

So rename a variable 'nr' to 'syscall_nr' for system call number in print_syscall_enter().

WTF, how does changing the kernel fix a user space python generation bug?

-- Steve

Quoted 105 lines
Cc Thomas Gleixner <[email protected]>
Cc Lai Jiangshan <[email protected]>
---
 kernel/trace/trace.h          |  4 ++--
 kernel/trace/trace_syscalls.c | 16 ++++++++--------
 2 files changed, 10 insertions(+), 10 deletions(-)
kernel/trace/trace.h +2 -2
index 8414fa4..beddeb1 100644
@@ -88,13 +88,13 @@ enum trace_type {
  */
 struct syscall_trace_enter {
 	struct trace_entry	ent;
-	int			nr;
+	int			syscall_nr;
 	unsigned long		args[];
 };
 
 struct syscall_trace_exit {
 	struct trace_entry	ent;
-	int			nr;
+	int			syscall_nr;
 	long			ret;
 };
 
kernel/trace/trace_syscalls.c +8 -8
index 0655afb..956209f 100644
@@ -118,7 +118,7 @@ print_syscall_enter(struct trace_iterator *iter, int flags,
 	int i, syscall;
 
 	trace = (typeof(trace))ent;
-	syscall = trace->nr;
+	syscall = trace->syscall_nr;
 	entry = syscall_nr_to_meta(syscall);
 
 	if (!entry)
@@ -164,7 +164,7 @@ print_syscall_exit(struct trace_iterator *iter, int flags,
 	struct syscall_metadata *entry;
 
 	trace = (typeof(trace))ent;
-	syscall = trace->nr;
+	syscall = trace->syscall_nr;
 	entry = syscall_nr_to_meta(syscall);
 
 	if (!entry) {
@@ -261,7 +261,7 @@ static int __init syscall_enter_define_fields(struct trace_event_call *call)
 	int i;
 	int offset = offsetof(typeof(trace), args);
 
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+	ret = trace_define_field(call, SYSCALL_FIELD(int, syscall_nr), FILTER_OTHER);
 	if (ret)
 		return ret;
 
@@ -281,7 +281,7 @@ static int __init syscall_exit_define_fields(struct trace_event_call *call)
 	struct syscall_trace_exit trace;
 	int ret;
 
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+	ret = trace_define_field(call, SYSCALL_FIELD(int, syscall_nr), FILTER_OTHER);
 	if (ret)
 		return ret;
 
@@ -332,7 +332,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 		return;
 
 	entry = ring_buffer_event_data(event);
-	entry->nr = syscall_nr;
+	entry->syscall_nr = syscall_nr;
 	syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
 
 	event_trigger_unlock_commit(trace_file, buffer, event, entry,
@@ -378,7 +378,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 		return;
 
 	entry = ring_buffer_event_data(event);
-	entry->nr = syscall_nr;
+	entry->syscall_nr = syscall_nr;
 	entry->ret = syscall_get_return_value(current, regs);
 
 	event_trigger_unlock_commit(trace_file, buffer, event, entry,
@@ -579,7 +579,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
 	if (!rec)
 		return;
 
-	rec->nr = syscall_nr;
+	rec->syscall_nr = syscall_nr;
 	syscall_get_arguments(current, regs, 0, sys_data->nb_args,
 			       (unsigned long *)&rec->args);
 	perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
@@ -652,7 +652,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
 	if (!rec)
 		return;
 
-	rec->nr = syscall_nr;
+	rec->syscall_nr = syscall_nr;
 	rec->ret = syscall_get_return_value(current, regs);
 	perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
 }
#2 lore raw

Hi, Steven

Quoted 23 lines · Steven Rostedt
Quoted 20 lines · On Fri, 26 Feb 2016 00:24:18 +0900 Taeung Song <[email protected]> wrote:

There is a problem about duplicated variable name
for system call number and a argument of some
system call. I found this problem when I tested
perf-script with python script as below.

     # perf record -e syscalls:*
     # perf script -g python
     # perf script -s perf-script.py
       File "perf-script.py", line 8694
         def syscalls__sys_enter_io_getevents(event_name, context, common_cpu,
     SyntaxError: duplicate argument 'nr' in function definition
     Error running python script perf-script.py

As above, problems about duplicated argument occurred when processing sys_enter_io_getevent() and sys_enter_io_submit(). Because the two system calls have a argument 'nr' as below.

int io_getevents(aio_context_t ctx_id, long min_nr, long nr,
struct io_event *events, struct timespec *timeout);

Quoted 8 lines
Quoted 4 lines
     int io_submit(aio_context_t ctx_id, long nr, struct iocb **iocbpp);

So rename a variable 'nr' to 'syscall_nr' for system call number in print_syscall_enter().

WTF, how does changing the kernel fix a user space python generation bug?

The underlying cause of this problem is not because of the python script. This problem have relevance to tracing/syscalls as below.

# cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
name: sys_enter_io_getevents
ID: 739
format:
       field:unsigned short common_type; offset:0;size:2;signed:0;
       field:unsigned char common_flags; offset:2;size:1;signed:0;
       field:unsigned char common_preempt_count; offset:3;size:1;signed:0;
       field:int common_pid;             offset:4;size:4;signed:1;
       field:int nr;                     offset:8;size:4;signed:1;
       field:aio_context_t ctx_id;       offset:16;size:8;signed:0;
       field:long min_nr;                offset:24;size:8;signed:0;
       field:long nr;                    offset:32;size:8;signed:0;
       field:struct io_event * events;   offset:40;size:8;signed:0;
       field:struct timespec * timeout;  offset:48;size:8;signed:0;

print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events: 0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned long)(REC->events)), ((unsigned long)(REC->timeout))

As you see, there are duplicated variable name among fields. So I renamed the variable name 'nr' to 'syscall_nr' to avoid this duplication. As you know 'nr' in print_syscall_enter() mean system call number so, I changed 'nr' to 'syscall_nr'(IMHO).

Thanks,
Taeung

Quoted 106 lines
Quoted 105 lines
Cc Thomas Gleixner <[email protected]>
Cc Lai Jiangshan <[email protected]>
---
  kernel/trace/trace.h          |  4 ++--
  kernel/trace/trace_syscalls.c | 16 ++++++++--------
  2 files changed, 10 insertions(+), 10 deletions(-)
kernel/trace/trace.h +2 -2
index 8414fa4..beddeb1 100644
@@ -88,13 +88,13 @@ enum trace_type {
   */
  struct syscall_trace_enter {
  	struct trace_entry	ent;
-	int			nr;
+	int			syscall_nr;
  	unsigned long		args[];
  };
 
  struct syscall_trace_exit {
  	struct trace_entry	ent;
-	int			nr;
+	int			syscall_nr;
  	long			ret;
  };
 
kernel/trace/trace_syscalls.c +8 -8
index 0655afb..956209f 100644
@@ -118,7 +118,7 @@ print_syscall_enter(struct trace_iterator *iter, int flags,
  	int i, syscall;
 
  	trace = (typeof(trace))ent;
-	syscall = trace->nr;
+	syscall = trace->syscall_nr;
  	entry = syscall_nr_to_meta(syscall);
 
  	if (!entry)
@@ -164,7 +164,7 @@ print_syscall_exit(struct trace_iterator *iter, int flags,
  	struct syscall_metadata *entry;
 
  	trace = (typeof(trace))ent;
-	syscall = trace->nr;
+	syscall = trace->syscall_nr;
  	entry = syscall_nr_to_meta(syscall);
 
  	if (!entry) {
@@ -261,7 +261,7 @@ static int __init syscall_enter_define_fields(struct trace_event_call *call)
  	int i;
  	int offset = offsetof(typeof(trace), args);
 
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+	ret = trace_define_field(call, SYSCALL_FIELD(int, syscall_nr), FILTER_OTHER);
  	if (ret)
  		return ret;
 
@@ -281,7 +281,7 @@ static int __init syscall_exit_define_fields(struct trace_event_call *call)
  	struct syscall_trace_exit trace;
  	int ret;
 
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+	ret = trace_define_field(call, SYSCALL_FIELD(int, syscall_nr), FILTER_OTHER);
  	if (ret)
  		return ret;
 
@@ -332,7 +332,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
  		return;
 
  	entry = ring_buffer_event_data(event);
-	entry->nr = syscall_nr;
+	entry->syscall_nr = syscall_nr;
  	syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
 
  	event_trigger_unlock_commit(trace_file, buffer, event, entry,
@@ -378,7 +378,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
  		return;
 
  	entry = ring_buffer_event_data(event);
-	entry->nr = syscall_nr;
+	entry->syscall_nr = syscall_nr;
  	entry->ret = syscall_get_return_value(current, regs);
 
  	event_trigger_unlock_commit(trace_file, buffer, event, entry,
@@ -579,7 +579,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
  	if (!rec)
  		return;
 
-	rec->nr = syscall_nr;
+	rec->syscall_nr = syscall_nr;
  	syscall_get_arguments(current, regs, 0, sys_data->nb_args,
  			       (unsigned long *)&rec->args);
  	perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
@@ -652,7 +652,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
  	if (!rec)
  		return;
 
-	rec->nr = syscall_nr;
+	rec->syscall_nr = syscall_nr;
  	rec->ret = syscall_get_return_value(current, regs);
  	perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
  }
maintainer
#3 lore raw
Quoted 27 lines · On Fri, 26 Feb 2016 01:53:47 +0900 Taeung Song <[email protected]> wrote:

The underlying cause of this problem is not because of the python script. This problem have relevance to tracing/syscalls as below.

# cat 
/sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
name: sys_enter_io_getevents
ID: 739
format:
        field:unsigned short common_type; offset:0;size:2;signed:0;
        field:unsigned char common_flags; offset:2;size:1;signed:0;
        field:unsigned char common_preempt_count; offset:3;size:1;signed:0;
        field:int common_pid;             offset:4;size:4;signed:1;
        field:int nr;                     offset:8;size:4;signed:1;
        field:aio_context_t ctx_id;       offset:16;size:8;signed:0;
        field:long min_nr;                offset:24;size:8;signed:0;
        field:long nr;                    offset:32;size:8;signed:0;
        field:struct io_event * events;   offset:40;size:8;signed:0;
        field:struct timespec * timeout;  offset:48;size:8;signed:0;

print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events:
0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned long)(REC->events)), ((unsigned long)(REC->timeout))

Quoted 5 lines

As you see, there are duplicated variable name among fields. So I renamed the variable name 'nr' to 'syscall_nr' to avoid this duplication. As you know 'nr' in print_syscall_enter() mean system call number so, I changed 'nr' to 'syscall_nr'(IMHO).

The above should have been in the change log. That makes much more sense.

Thanks!

-- Steve

maintainer
#4 lore raw
Quoted 30 lines · On Thu, 25 Feb 2016 12:05:01 -0500 Steven Rostedt <[email protected]> wrote:
Quoted 27 lines · On Fri, 26 Feb 2016 01:53:47 +0900 Taeung Song <[email protected]> wrote:

The underlying cause of this problem is not because of the python script. This problem have relevance to tracing/syscalls as below.

# cat 
/sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
name: sys_enter_io_getevents
ID: 739
format:
        field:unsigned short common_type; offset:0;size:2;signed:0;
        field:unsigned char common_flags; offset:2;size:1;signed:0;
        field:unsigned char common_preempt_count; offset:3;size:1;signed:0;
        field:int common_pid;             offset:4;size:4;signed:1;
        field:int nr;                     offset:8;size:4;signed:1;
        field:aio_context_t ctx_id;       offset:16;size:8;signed:0;
        field:long min_nr;                offset:24;size:8;signed:0;
        field:long nr;                    offset:32;size:8;signed:0;
        field:struct io_event * events;   offset:40;size:8;signed:0;
        field:struct timespec * timeout;  offset:48;size:8;signed:0;

print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events:
0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned long)(REC->events)), ((unsigned long)(REC->timeout))

Quoted 9 lines
Quoted 5 lines

As you see, there are duplicated variable name among fields. So I renamed the variable name 'nr' to 'syscall_nr' to avoid this duplication. As you know 'nr' in print_syscall_enter() mean system call number so, I changed 'nr' to 'syscall_nr'(IMHO).

The above should have been in the change log. That makes much more sense.

I'm a bit nervous about this change though. Because it is an ABI change. Hopefully there's no tools that parse the syscall tracepoints and expect to find a 'nr' in there.

-- Steve

#5 lore raw
Quoted 39 lines · Steven Rostedt
Quoted 36 lines · On Thu, 25 Feb 2016 12:05:01 -0500 Steven Rostedt <[email protected]> wrote:
Quoted 32 lines · On Fri, 26 Feb 2016 01:53:47 +0900 Taeung Song <[email protected]> wrote:

The underlying cause of this problem is not because of the python script. This problem have relevance to tracing/syscalls as below.

# cat
/sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
name: sys_enter_io_getevents
ID: 739
format:
         field:unsigned short common_type; offset:0;size:2;signed:0;
         field:unsigned char common_flags; offset:2;size:1;signed:0;
         field:unsigned char common_preempt_count; offset:3;size:1;signed:0;
         field:int common_pid;             offset:4;size:4;signed:1;
         field:int nr;                     offset:8;size:4;signed:1;
         field:aio_context_t ctx_id;       offset:16;size:8;signed:0;
         field:long min_nr;                offset:24;size:8;signed:0;
         field:long nr;                    offset:32;size:8;signed:0;
         field:struct io_event * events;   offset:40;size:8;signed:0;
         field:struct timespec * timeout;  offset:48;size:8;signed:0;

print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events:
0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned long)(REC->events)), ((unsigned long)(REC->timeout))

As you see, there are duplicated variable name among fields. So I renamed the variable name 'nr' to 'syscall_nr' to avoid this duplication. As you know 'nr' in print_syscall_enter() mean system call number so, I changed 'nr' to 'syscall_nr'(IMHO).

Quoted 3 lines
Quoted 3 lines

The above should have been in the change log. That makes much more sense.

Sorry, this change log is misinterpretable.
So I'm rewriting change log for this patch.
I will resend it soon.

Quoted 5 lines

I'm a bit nervous about this change though. Because it is an ABI change. Hopefully there's no tools that parse the syscall tracepoints and expect to find a 'nr' in there.

AFIAIK, I think so but resend this modified patch.

Thanks,
Taeung