[PATCH 1/3] tracing: add ftrace_trace_stack into __trace_puts/__trace_bputs

zhangwei(Jovi)
2013-07-18T08:33:15Z

Currently trace option stacktrace is not applicable for
trace_printk with constant string argument, the reason is
there missed ftrace_trace_stack in __trace_puts/__trace_bputs.

In contrast, when using trace_printk with not constant string
argument(will call into __trace_printk/__trace_bprintk), then
trace option stacktrace is workable, this inconstant result
will confusing user a lot.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
---
kernel/trace/trace.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 3d5a931..4d70cc5 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -363,13 +363,16 @@ int __trace_puts(unsigned long ip, const char *str, int size)
struct print_entry *entry;
unsigned long irq_flags;
int alloc;
+ int pc;
+
+ pc = preempt_count();

alloc = sizeof(*entry) + size + 2; /* possible \n added */

local_save_flags(irq_flags);
buffer = global_trace.trace_buffer.buffer;
event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
- irq_flags, preempt_count());
+ irq_flags, pc);
if (!event)
return 0;

@@ -386,6 +389,7 @@ int __trace_puts(unsigned long ip, const char *str, int size)
entry->buf[size] = '\0';

__buffer_unlock_commit(buffer, event);
+ ftrace_trace_stack(buffer, irq_flags, 4, pc);

return size;
}
@@ -403,11 +407,14 @@ int __trace_bputs(unsigned long ip, const char *str)
struct bputs_entry *entry;
unsigned long irq_flags;
int size = sizeof(struct bputs_entry);
+ int pc;
+
+ pc = preempt_count();

local_save_flags(irq_flags);
buffer = global_trace.trace_buffer.buffer;
event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
- irq_flags, preempt_count());
+ irq_flags, pc);
if (!event)
return 0;

@@ -416,6 +423,7 @@ int __trace_bputs(unsigned long ip, const char *str)
entry->str = str;

__buffer_unlock_commit(buffer, event);
+ ftrace_trace_stack(buffer, irq_flags, 4, pc);

return 1;
}
--
1.7.9.7