Dynamic debug: Add more flags (8ba6ebf5) · Commits · 戴 / test

Documentation/dynamic-debug-howto.txt

+10 −2

Original line number	Diff line number	Diff line
		@@ -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

include/linux/dynamic_debug.h

+7 −1

Original line number	Diff line number	Diff line
		@@ -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)

lib/dynamic_debug.c

+51 −9

Original line number	Diff line number	Diff line
		@@ -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 '+':
		@@ -358,14 +370,15 @@ 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;
		for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
		if (*str == opt_array[i].opt_char) {
		flags \|= opt_array[i].flag;
		break;
		default:
		return -EINVAL;
		}
		}
		if (i < 0)
		return -EINVAL;
		}
		if (flags == 0)
		return -EINVAL;
		if (verbose)
		@@ -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)
		{

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