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tracing: Fix irqs-off tag display in syscall tracing

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All syscall tracing irqs-off tags are wrong, the syscall enter entry doesn't
disable irqs.

 [root@jovi tracing]#echo "syscalls:sys_enter_open" > set_event
 [root@jovi tracing]# cat trace
 # tracer: nop
 #
 # entries-in-buffer/entries-written: 13/13   #P:2
 #
 #                              _-----=> irqs-off
 #                             / _----=> need-resched
 #                            | / _---=> hardirq/softirq
 #                            || / _--=> preempt-depth
 #                            ||| /     delay
 #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
 #              | |       |   ||||       |         |
       irqbalance-513   [000] d... 56115.496766: sys_open(filename: 804e1a6, flags: 0, mode: 1b6)
       irqbalance-513   [000] d... 56115.497008: sys_open(filename: 804e1bb, flags: 0, mode: 1b6)
         sendmail-771   [000] d... 56115.827982: sys_open(filename: b770e6d1, flags: 0, mode: 1b6)

The reason is syscall tracing doesn't record irq_flags into buffer.
The proper display is:

 [root@jovi tracing]#echo "syscalls:sys_enter_open" > set_event
 [root@jovi tracing]# cat trace
 # tracer: nop
 #
 # entries-in-buffer/entries-written: 14/14   #P:2
 #
 #                              _-----=> irqs-off
 #                             / _----=> need-resched
 #                            | / _---=> hardirq/softirq
 #                            || / _--=> preempt-depth
 #                            ||| /     delay
 #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
 #              | |       |   ||||       |         |
       irqbalance-514   [001] ....    46.213921: sys_open(filename: 804e1a6, flags: 0, mode: 1b6)
       irqbalance-514   [001] ....    46.214160: sys_open(filename: 804e1bb, flags: 0, mode: 1b6)
            <...>-920   [001] ....    47.307260: sys_open(filename: 4e82a0c5, flags: 80000, mode: 0)

Link: http://lkml.kernel.org/r/1365564393-10972-3-git-send-email-jovi.zhangwei@huawei.com

Cc: stable@vger.kernel.org # 2.6.35
Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
zhangwei(Jovi) 2013-04-10 11:26:23 +08:00 committed by Steven Rostedt
parent fa44063f9e
commit 11034ae9c2
1 changed files with 17 additions and 4 deletions
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21
kernel/trace/trace_syscalls.c
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@ -306,6 +306,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
unsigned long irq_flags;
int pc;
int syscall_nr;
int size;
@ -321,9 +323,12 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
local_save_flags(irq_flags);
pc = preempt_count();
buffer = tr->trace_buffer.buffer;
event = trace_buffer_lock_reserve(buffer,
sys_data->enter_event->event.type, size, 0, 0);
sys_data->enter_event->event.type, size, irq_flags, pc);
if (!event)
return;
@ -333,7 +338,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
if (!filter_current_check_discard(buffer, sys_data->enter_event,
entry, event))
trace_current_buffer_unlock_commit(buffer, event, 0, 0);
trace_current_buffer_unlock_commit(buffer, event,
irq_flags, pc);
}
static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
@ -343,6 +349,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
unsigned long irq_flags;
int pc;
int syscall_nr;
syscall_nr = trace_get_syscall_nr(current, regs);
@ -355,9 +363,13 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
if (!sys_data)
return;
local_save_flags(irq_flags);
pc = preempt_count();
buffer = tr->trace_buffer.buffer;
event = trace_buffer_lock_reserve(buffer,
sys_data->exit_event->event.type, sizeof(*entry), 0, 0);
sys_data->exit_event->event.type, sizeof(*entry),
irq_flags, pc);
if (!event)
return;
@ -367,7 +379,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
if (!filter_current_check_discard(buffer, sys_data->exit_event,
entry, event))
trace_current_buffer_unlock_commit(buffer, event, 0, 0);
trace_current_buffer_unlock_commit(buffer, event,
irq_flags, pc);
}
static int reg_event_syscall_enter(struct ftrace_event_file *file,