tracing: Add generic tracing_lseek() function

Trace event triggers added a lseek that uses the ftrace_filter_lseek()
function. Unfortunately, when function tracing is not configured in
that function is not defined and the kernel fails to build.

This is the second time that function was added to a file ops and
it broke the build due to requiring special config dependencies.

Make a generic tracing_lseek() that all the tracing utilities may
use.

Also, modify the old ftrace_filter_lseek() to return 0 instead of
1 on WRONLY. Not sure why it was a 1 as that does not make sense.

This also changes the old tracing_seek() to modify the file pos
pointer on WRONLY as well.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Red Hat) 2013-12-21 17:39:40 -05:00 committed by Steven Rostedt
parent ac38fb8582
commit 098c879e1f
6 changed files with 19 additions and 28 deletions

View File

@ -570,8 +570,6 @@ static inline int
ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
#endif /* CONFIG_DYNAMIC_FTRACE */
loff_t ftrace_filter_lseek(struct file *file, loff_t offset, int whence);
/* totally disable ftrace - can not re-enable after this */
void ftrace_kill(void);

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@ -1082,19 +1082,6 @@ static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
static struct pid * const ftrace_swapper_pid = &init_struct_pid;
loff_t
ftrace_filter_lseek(struct file *file, loff_t offset, int whence)
{
loff_t ret;
if (file->f_mode & FMODE_READ)
ret = seq_lseek(file, offset, whence);
else
file->f_pos = ret = 1;
return ret;
}
#ifdef CONFIG_DYNAMIC_FTRACE
#ifndef CONFIG_FTRACE_MCOUNT_RECORD
@ -2739,7 +2726,7 @@ static void ftrace_filter_reset(struct ftrace_hash *hash)
* routine, you can use ftrace_filter_write() for the write
* routine if @flag has FTRACE_ITER_FILTER set, or
* ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
* ftrace_filter_lseek() should be used as the lseek routine, and
* tracing_lseek() should be used as the lseek routine, and
* release must call ftrace_regex_release().
*/
int
@ -3767,7 +3754,7 @@ static const struct file_operations ftrace_filter_fops = {
.open = ftrace_filter_open,
.read = seq_read,
.write = ftrace_filter_write,
.llseek = ftrace_filter_lseek,
.llseek = tracing_lseek,
.release = ftrace_regex_release,
};
@ -3775,7 +3762,7 @@ static const struct file_operations ftrace_notrace_fops = {
.open = ftrace_notrace_open,
.read = seq_read,
.write = ftrace_notrace_write,
.llseek = ftrace_filter_lseek,
.llseek = tracing_lseek,
.release = ftrace_regex_release,
};
@ -4038,7 +4025,7 @@ static const struct file_operations ftrace_graph_fops = {
.open = ftrace_graph_open,
.read = seq_read,
.write = ftrace_graph_write,
.llseek = ftrace_filter_lseek,
.llseek = tracing_lseek,
.release = ftrace_graph_release,
};
@ -4046,7 +4033,7 @@ static const struct file_operations ftrace_graph_notrace_fops = {
.open = ftrace_graph_notrace_open,
.read = seq_read,
.write = ftrace_graph_write,
.llseek = ftrace_filter_lseek,
.llseek = tracing_lseek,
.release = ftrace_graph_release,
};
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
@ -4719,7 +4706,7 @@ static const struct file_operations ftrace_pid_fops = {
.open = ftrace_pid_open,
.write = ftrace_pid_write,
.read = seq_read,
.llseek = ftrace_filter_lseek,
.llseek = tracing_lseek,
.release = ftrace_pid_release,
};

View File

@ -3183,19 +3183,23 @@ tracing_write_stub(struct file *filp, const char __user *ubuf,
return count;
}
static loff_t tracing_seek(struct file *file, loff_t offset, int origin)
loff_t tracing_lseek(struct file *file, loff_t offset, int whence)
{
int ret;
if (file->f_mode & FMODE_READ)
return seq_lseek(file, offset, origin);
ret = seq_lseek(file, offset, whence);
else
return 0;
file->f_pos = ret = 0;
return ret;
}
static const struct file_operations tracing_fops = {
.open = tracing_open,
.read = seq_read,
.write = tracing_write_stub,
.llseek = tracing_seek,
.llseek = tracing_lseek,
.release = tracing_release,
};
@ -4940,7 +4944,7 @@ static const struct file_operations snapshot_fops = {
.open = tracing_snapshot_open,
.read = seq_read,
.write = tracing_snapshot_write,
.llseek = tracing_seek,
.llseek = tracing_lseek,
.release = tracing_snapshot_release,
};

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@ -588,6 +588,8 @@ void tracing_start_sched_switch_record(void);
int register_tracer(struct tracer *type);
int is_tracing_stopped(void);
loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
extern cpumask_var_t __read_mostly tracing_buffer_mask;
#define for_each_tracing_cpu(cpu) \

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@ -281,7 +281,7 @@ const struct file_operations event_trigger_fops = {
.open = event_trigger_open,
.read = seq_read,
.write = event_trigger_write,
.llseek = ftrace_filter_lseek,
.llseek = tracing_lseek,
.release = event_trigger_release,
};

View File

@ -382,7 +382,7 @@ static const struct file_operations stack_trace_filter_fops = {
.open = stack_trace_filter_open,
.read = seq_read,
.write = ftrace_filter_write,
.llseek = ftrace_filter_lseek,
.llseek = tracing_lseek,
.release = ftrace_regex_release,
};