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Commit 5ca7d2a6 authored by Jim Cromie's avatar Jim Cromie Committed by Greg Kroah-Hartman
Browse files

dynamic_debug: describe_flags with '=[pmflt_]*' 



Change describe_flags() to emit '=[pmflt_]+' for current callsite
flags, or just '=_' when they're disabled.  Having '=' in output
allows a more selective grep expression; in contrast '-' may appear
in filenames, line-ranges, and format-strings.  '=' also has better
mnemonics, saying; "the current setting is equal to <flags>".

This allows grep "=_" <dbgfs>/dynamic_debug/control to see disabled
callsites while avoiding the many occurrences of " = " seen in format
strings.

Enlarge flagsbufs to handle additional flag char, and alter
ddebug_parse_flags() to allow flags=0, so that user can turn off all
debug flags via:

  ~# echo =_ > <dbgfs>/dynamic_debug/control

Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
Signed-off-by: default avatarJason Baron <jbaron@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent d6a238d2

include/linux/dynamic_debug.h

+2 −1
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ struct _ddebug { 
 	 * The bits here are changed dynamically when the user

	 * writes commands to <debugfs>/dynamic_debug/control

	 */

#define _DPRINTK_FLAGS_NONE	0

#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)

lib/dynamic_debug.c

+10 −11
Original line number Diff line number Diff line
@@ -75,6 +75,7 @@ static struct { unsigned flag:8; char opt_char; } opt_array[] = { 
	{ _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },

	{ _DPRINTK_FLAGS_INCL_LINENO, 'l' },

	{ _DPRINTK_FLAGS_INCL_TID, 't' },

	{ _DPRINTK_FLAGS_NONE, '_' },

};



/* format a string into buf[] which describes the _ddebug's flags */
@@ -84,12 +85,12 @@ static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, 
	char *p = buf;

	int i;



	BUG_ON(maxlen < 4);

	BUG_ON(maxlen < 6);

	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++ = '_';

	*p = '\0';



	return buf;
@@ -108,7 +109,7 @@ static void ddebug_change(const struct ddebug_query *query, 
	struct ddebug_table *dt;

	unsigned int newflags;

	unsigned int nfound = 0;

	char flagbuf[8];

	char flagbuf[10];



	/* search for matching ddebugs */

	mutex_lock(&ddebug_lock);
@@ -152,7 +153,7 @@ static void ddebug_change(const struct ddebug_query *query, 
				continue;

			dp->flags = newflags;

			if (verbose)

				pr_info("changed %s:%d [%s]%s %s\n",

				pr_info("changed %s:%d [%s]%s =%s\n",

					dp->filename, dp->lineno,

					dt->mod_name, dp->function,

					ddebug_describe_flags(dp, flagbuf,
@@ -370,8 +371,6 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp, 
		if (i < 0)

			return -EINVAL;

	}

	if (flags == 0)

		return -EINVAL;

	if (verbose)

		pr_info("flags=0x%x\n", flags);
@@ -666,7 +665,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p) 
{

	struct ddebug_iter *iter = m->private;

	struct _ddebug *dp = p;

	char flagsbuf[8];

	char flagsbuf[10];



	if (verbose)

		pr_info("called m=%p p=%p\n", m, p);
@@ -677,7 +676,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p) 
		return 0;

	}



	seq_printf(m, "%s:%u [%s]%s %s \"",

	seq_printf(m, "%s:%u [%s]%s =%s \"",

		dp->filename, dp->lineno,

		iter->table->mod_name, dp->function,

		ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));