From: "zhangwei(Jovi)" <jovi.zhang...@huawei.com>
Now all syscall tracing irqs-off tag is wrong,
syscall enter entry doesn't disable irq.
[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.
Fix this after this patch:
[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)
Signed-off-by: zhangwei(Jovi) <jovi.zhang...@huawei.com>
---
kernel/trace/trace_syscalls.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 8f2ac73..322e164 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -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,
--
1.7.9.7
--
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