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Dynamic debug: Add more flags

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Add flags that allow the user to specify via debugfs whether or not the
module name, function name, line number and/or thread ID have to be
included in the printed message.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Greg Banks <gnb@fmeh.org>
Cc: Konrad Rzeszutek Wilk <konrad@darnok.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Bart Van Assche 2011-01-23 17:17:24 +01:00 committed by Greg Kroah-Hartman
parent 9b99b7f84e
commit 8ba6ebf583
3 changed files with 68 additions and 12 deletions
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12
Documentation/dynamic-debug-howto.txt
View File

@ -205,12 +205,20 @@ of the characters:
The flags are:
f
Include the function name in the printed message
l
Include line number in the printed message
m
Include module name in the printed message
p
Causes a printk() message to be emitted to dmesg
t
Include thread ID in messages not generated from interrupt context
Note the regexp ^[-+=][scp]+$ matches a flags specification.
Note the regexp ^[-+=][flmpt]+$ matches a flags specification.
Note also that there is no convenient syntax to remove all
the flags at once, you need to use "-psc".
the flags at once, you need to use "-flmpt".
Debug messages during boot process

8
include/linux/dynamic_debug.h
View File

@ -31,6 +31,10 @@ struct _ddebug {
* writes commands to <debugfs>/dynamic_debug/control
*/
#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */
#define _DPRINTK_FLAGS_INCL_MODNAME (1<<1)
#define _DPRINTK_FLAGS_INCL_FUNCNAME (1<<2)
#define _DPRINTK_FLAGS_INCL_LINENO (1<<3)
#define _DPRINTK_FLAGS_INCL_TID (1<<4)
#define _DPRINTK_FLAGS_DEFAULT 0
unsigned int flags:8;
char enabled;
@ -42,6 +46,8 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n,
#if defined(CONFIG_DYNAMIC_DEBUG)
extern int ddebug_remove_module(const char *mod_name);
extern int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
__attribute__ ((format (printf, 2, 3)));
#define dynamic_pr_debug(fmt, ...) do { \
static struct _ddebug descriptor \
@ -50,7 +56,7 @@ extern int ddebug_remove_module(const char *mod_name);
{ KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \
_DPRINTK_FLAGS_DEFAULT }; \
if (unlikely(descriptor.enabled)) \
printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
__dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__); \
} while (0)

60
lib/dynamic_debug.c
View File

@ -7,6 +7,7 @@
* Copyright (C) 2008 Jason Baron <jbaron@redhat.com>
* By Greg Banks <gnb@melbourne.sgi.com>
* Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved.
* Copyright (C) 2011 Bart Van Assche. All Rights Reserved.
*/
#include <linux/kernel.h>
@ -27,6 +28,7 @@
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/jump_label.h>
#include <linux/hardirq.h>
extern struct _ddebug __start___verbose[];
extern struct _ddebug __stop___verbose[];
@ -63,15 +65,25 @@ static inline const char *basename(const char *path)
return tail ? tail+1 : path;
}
static struct { unsigned flag:8; char opt_char; } opt_array[] = {
{ _DPRINTK_FLAGS_PRINT, 'p' },
{ _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
{ _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
{ _DPRINTK_FLAGS_INCL_LINENO, 'l' },
{ _DPRINTK_FLAGS_INCL_TID, 't' },
};
/* format a string into buf[] which describes the _ddebug's flags */
static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
size_t maxlen)
{
char *p = buf;
int i;
BUG_ON(maxlen < 4);
if (dp->flags & _DPRINTK_FLAGS_PRINT)
*p++ = 'p';
for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
if (dp->flags & opt_array[i].flag)
*p++ = opt_array[i].opt_char;
if (p == buf)
*p++ = '-';
*p = '\0';
@ -343,7 +355,7 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
unsigned int *maskp)
{
unsigned flags = 0;
int op = '=';
int op = '=', i;
switch (*str) {
case '+':
@ -358,13 +370,14 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
printk(KERN_INFO "%s: op='%c'\n", __func__, op);
for ( ; *str ; ++str) {
switch (*str) {
case 'p':
flags |= _DPRINTK_FLAGS_PRINT;
break;
default:
return -EINVAL;
for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
if (*str == opt_array[i].opt_char) {
flags |= opt_array[i].flag;
break;
}
}
if (i < 0)
return -EINVAL;
}
if (flags == 0)
return -EINVAL;
@ -413,6 +426,35 @@ static int ddebug_exec_query(char *query_string)
return 0;
}
int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
{
va_list args;
int res;
BUG_ON(!descriptor);
BUG_ON(!fmt);
va_start(args, fmt);
res = printk(KERN_DEBUG);
if (descriptor->flags & _DPRINTK_FLAGS_INCL_TID) {
if (in_interrupt())
res += printk(KERN_CONT "<intr> ");
else
res += printk(KERN_CONT "[%d] ", task_pid_vnr(current));
}
if (descriptor->flags & _DPRINTK_FLAGS_INCL_MODNAME)
res += printk(KERN_CONT "%s:", descriptor->modname);
if (descriptor->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
res += printk(KERN_CONT "%s:", descriptor->function);
if (descriptor->flags & _DPRINTK_FLAGS_INCL_LINENO)
res += printk(KERN_CONT "%d ", descriptor->lineno);
res += vprintk(fmt, args);
va_end(args);
return res;
}
EXPORT_SYMBOL(__dynamic_pr_debug);
static __initdata char ddebug_setup_string[1024];
static __init int ddebug_setup_query(char *str)
{