Messages in this thread | | | Subject | Re: [PATCH RESEND 1/3] tracing/syscalls: Rename variable 'nr' to 'syscall_nr' | From | Taeung Song <> | Date | Fri, 26 Feb 2016 01:53:47 +0900 |
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Hi, Steven
On 02/26/2016 12:47 AM, Steven Rostedt wrote: > On Fri, 26 Feb 2016 00:24:18 +0900 > Taeung Song <treeze.taeung@gmail.com> 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); >> >> 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
>> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: Lai Jiangshan <jiangshanlai@gmail.com> >> Signed-off-by: Taeung Song <treeze.taeung@gmail.com> >> --- >> kernel/trace/trace.h | 4 ++-- >> kernel/trace/trace_syscalls.c | 16 ++++++++-------- >> 2 files changed, 10 insertions(+), 10 deletions(-) >> >> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h >> index 8414fa4..beddeb1 100644 >> --- a/kernel/trace/trace.h >> +++ b/kernel/trace/trace.h >> @@ -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; >> }; >> >> diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c >> index 0655afb..956209f 100644 >> --- a/kernel/trace/trace_syscalls.c >> +++ b/kernel/trace/trace_syscalls.c >> @@ -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); >> } >
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