* [PATCH 1/3] tracing/ftrace: alloc the started cpumask for the trace file
2009-04-07 2:22 [PATCH 0/3] [GIT PULL] more updates to tip/tracing/core Steven Rostedt
@ 2009-04-07 2:22 ` Steven Rostedt
2009-04-07 2:22 ` [PATCH 2/3] Update /debug/tracing/README Steven Rostedt
2009-04-07 2:22 ` [PATCH 3/3] ftrace: Correct a text align for event format output Steven Rostedt
2 siblings, 0 replies; 4+ messages in thread
From: Steven Rostedt @ 2009-04-07 2:22 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Frederic Weisbecker
[-- Attachment #1: 0001-tracing-ftrace-alloc-the-started-cpumask-for-the-tr.patch --]
[-- Type: text/plain, Size: 3657 bytes --]
From: Frederic Weisbecker <fweisbec@gmail.com>
Impact: fix a crash while cat trace file
Currently we are using a cpumask to remind each cpu where a
trace occured. It lets us notice the user that a cpu just had
its first trace.
But on latest -tip we have the following crash once we cat the trace
file:
IP: [<c0270c4a>] print_trace_fmt+0x45/0xe7
*pde = 00000000
Oops: 0000 [#1] PREEMPT SMP
last sysfs file: /sys/class/net/eth0/carrier
Pid: 3897, comm: cat Not tainted (2.6.29-tip-02825-g0f22972-dirty #81)
EIP: 0060:[<c0270c4a>] EFLAGS: 00010297 CPU: 0
EIP is at print_trace_fmt+0x45/0xe7
EAX: 00000000 EBX: 00000000 ECX: c12d9e98 EDX: ccdb7010
ESI: d31f4000 EDI: 00322401 EBP: d31f3f10 ESP: d31f3efc
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process cat (pid: 3897, ti=d31f2000 task=d3b3cf20 task.ti=d31f2000)
Stack:
d31f4080 ccdb7010 d31f4000 d691fe70 ccdb7010 d31f3f24 c0270e5c d31f4000
d691fe70 d31f4000 d31f3f34 c02718e8 c12d9e98 d691fe70 d31f3f70 c02bfc33
00001000 09130000 d3b46e00 d691fe98 00000000 00000079 00000001 00000000
Call Trace:
[<c0270e5c>] ? print_trace_line+0x170/0x17c
[<c02718e8>] ? s_show+0xa7/0xbd
[<c02bfc33>] ? seq_read+0x24a/0x327
[<c02bf9e9>] ? seq_read+0x0/0x327
[<c02ab18b>] ? vfs_read+0x86/0xe1
[<c02ab289>] ? sys_read+0x40/0x65
[<c0202d8f>] ? sysenter_do_call+0x12/0x3c
Code: 00 00 00 89 45 ec f7 c7 00 20 00 00 89 55 f0 74 4e f6 86 98 10 00 00 02 74 45 8b 86 8c 10 00 00 8b 9e a8 10 00 00 e8 52 f3 ff ff <0f> a3 03 19 c0 85 c0 75 2b 8b 86 8c 10 00 00 8b 9e a8 10 00 00
EIP: [<c0270c4a>] print_trace_fmt+0x45/0xe7 SS:ESP 0068:d31f3efc
CR2: 0000000000000000
---[ end trace aa9cf38e5ebed9dd ]---
This is because we alloc the iter->started cpumask on tracing_pipe_open but
not on tracing_open.
It hadn't been noticed until now because we need to have ring buffer overruns
to activate the starting of cpu buffer detection.
Also, we need a check to not print the messagge for the first trace on the file.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1238619188-6109-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/trace/trace.c | 13 ++++++++++++-
1 files changed, 12 insertions(+), 1 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d64a162..b0cec4c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1623,7 +1623,11 @@ static void test_cpu_buff_start(struct trace_iterator *iter)
return;
cpumask_set_cpu(iter->cpu, iter->started);
- trace_seq_printf(s, "##### CPU %u buffer started ####\n", iter->cpu);
+
+ /* Don't print started cpu buffer for the first entry of the trace */
+ if (iter->idx > 1)
+ trace_seq_printf(s, "##### CPU %u buffer started ####\n",
+ iter->cpu);
}
static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
@@ -1858,6 +1862,11 @@ __tracing_open(struct inode *inode, struct file *file)
if (current_trace)
*iter->trace = *current_trace;
+ if (!alloc_cpumask_var(&iter->started, GFP_KERNEL))
+ goto fail;
+
+ cpumask_clear(iter->started);
+
if (current_trace && current_trace->print_max)
iter->tr = &max_tr;
else
@@ -1908,6 +1917,7 @@ __tracing_open(struct inode *inode, struct file *file)
if (iter->buffer_iter[cpu])
ring_buffer_read_finish(iter->buffer_iter[cpu]);
}
+ free_cpumask_var(iter->started);
fail:
mutex_unlock(&trace_types_lock);
kfree(iter->trace);
@@ -1951,6 +1961,7 @@ static int tracing_release(struct inode *inode, struct file *file)
seq_release(inode, file);
mutex_destroy(&iter->mutex);
+ free_cpumask_var(iter->started);
kfree(iter->trace);
kfree(iter);
return 0;
--
1.6.2.1
--
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 3/3] ftrace: Correct a text align for event format output
2009-04-07 2:22 [PATCH 0/3] [GIT PULL] more updates to tip/tracing/core Steven Rostedt
2009-04-07 2:22 ` [PATCH 1/3] tracing/ftrace: alloc the started cpumask for the trace file Steven Rostedt
2009-04-07 2:22 ` [PATCH 2/3] Update /debug/tracing/README Steven Rostedt
@ 2009-04-07 2:22 ` Steven Rostedt
2 siblings, 0 replies; 4+ messages in thread
From: Steven Rostedt @ 2009-04-07 2:22 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Zhao Lei
[-- Attachment #1: 0003-ftrace-Correct-a-text-align-for-event-format-output.patch --]
[-- Type: text/plain, Size: 1347 bytes --]
From: Zhaolei <zhaolei@cn.fujitsu.com>
If we cat debugfs/tracing/events/ftrace/bprint/format, we'll see:
name: bprint
ID: 6
format:
field:unsigned char common_type; offset:0; size:1;
field:unsigned char common_flags; offset:1; size:1;
field:unsigned char common_preempt_count; offset:2; size:1;
field:int common_pid; offset:4; size:4;
field:int common_tgid; offset:8; size:4;
field:unsigned long ip; offset:12; size:4;
field:char * fmt; offset:16; size:4;
field: char buf; offset:20; size:0;
print fmt: "%08lx (%d) fmt:%p %s"
There is an inconsistent blank before char buf.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
LKML-Reference: <49D5E3EE.70201@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/trace/trace_export.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index 4d9952d..07a22c3 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -40,7 +40,7 @@
#undef TRACE_FIELD_ZERO_CHAR
#define TRACE_FIELD_ZERO_CHAR(item) \
- ret = trace_seq_printf(s, "\tfield: char " #item ";\t" \
+ ret = trace_seq_printf(s, "\tfield:char " #item ";\t" \
"offset:%u;\tsize:0;\n", \
(unsigned int)offsetof(typeof(field), item)); \
if (!ret) \
--
1.6.2.1
--
^ permalink raw reply related [flat|nested] 4+ messages in thread