Commit 29ede244 authored by Allan Stephens's avatar Allan Stephens Committed by David S. Miller
Browse files

[TIPC]: Debug print buffer enhancements and fixes 



This change modifies TIPC's print buffer code as follows:
1) Now supports small print buffers (min. size reduced from 512 bytes to 64)
2) Now uses TIPC_NULL print buffer structure to indicate null device
   instead of NULL pointer (this simplified error handling)
3) Fixed misuse of console buffer structure by tipc_dump()
4) Added and corrected comments in various places

Signed-off-by: default avatarAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: default avatarPer Liden <per.liden@ericsson.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 065fd177

net/tipc/core.h

+8 −8
Original line number Diff line number Diff line
@@ -65,7 +65,7 @@ 
#define assert(i)  BUG_ON(!(i))



struct tipc_msg;

extern struct print_buf *TIPC_CONS, *TIPC_LOG;

extern struct print_buf *TIPC_NULL, *TIPC_CONS, *TIPC_LOG;

extern struct print_buf *TIPC_TEE(struct print_buf *, struct print_buf *);

void tipc_msg_print(struct print_buf*,struct tipc_msg *,const char*);

void tipc_printf(struct print_buf *, const char *fmt, ...);
@@ -94,11 +94,11 @@ void tipc_dump(struct print_buf*,const char *fmt, ...); 
 * here, or on a per .c file basis, by redefining these symbols.  The following

 * print buffer options are available:

 *

 * NULL				: Output to null print buffer (i.e. print nowhere)

 * TIPC_CONS			: Output to system console

 * TIPC_LOG			: Output to TIPC log buffer 

 * &buf				: Output to user-defined buffer (struct print_buf *)

 * TIPC_TEE(&buf_a,&buf_b)	: Output to two print buffers (eg. TIPC_TEE(TIPC_CONS,TIPC_LOG) )

 * TIPC_NULL		   : null buffer (i.e. print nowhere)

 * TIPC_CONS		   : system console

 * TIPC_LOG		   : TIPC log buffer

 * &buf			   : user-defined buffer (struct print_buf *)

 * TIPC_TEE(&buf_a,&buf_b) : list of buffers (eg. TIPC_TEE(TIPC_CONS,TIPC_LOG))

 */



#ifndef TIPC_OUTPUT
@@ -106,7 +106,7 @@ void tipc_dump(struct print_buf*,const char *fmt, ...); 
#endif



#ifndef DBG_OUTPUT

#define DBG_OUTPUT NULL

#define DBG_OUTPUT TIPC_NULL

#endif



#else
@@ -136,7 +136,7 @@ void tipc_dump(struct print_buf*,const char *fmt, ...); 
#define TIPC_OUTPUT TIPC_CONS



#undef  DBG_OUTPUT

#define DBG_OUTPUT NULL

#define DBG_OUTPUT TIPC_NULL



#endif

net/tipc/dbg.c

+89 −47
Original line number Diff line number Diff line 
/*

 * net/tipc/dbg.c: TIPC print buffer routines for debuggign

 * net/tipc/dbg.c: TIPC print buffer routines for debugging

 * 

 * Copyright (c) 1996-2006, Ericsson AB

 * Copyright (c) 2005, Wind River Systems

 * Copyright (c) 2005-2006, Wind River Systems

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without
@@ -38,11 +38,12 @@ 
#include "config.h"

#include "dbg.h"



#define MAX_STRING 512



static char print_string[MAX_STRING];

static char print_string[TIPC_PB_MAX_STR];

static DEFINE_SPINLOCK(print_lock);



static struct print_buf null_buf = { NULL, 0, NULL, NULL };

struct print_buf *TIPC_NULL = &null_buf;



static struct print_buf cons_buf = { NULL, 0, NULL, NULL };

struct print_buf *TIPC_CONS = &cons_buf;
@@ -62,68 +63,83 @@ struct print_buf *TIPC_LOG = &log_buf; 
/*

 * Locking policy when using print buffers.

 *

 * 1) Routines of the form printbuf_XXX() rely on the caller to prevent

 * The following routines use 'print_lock' for protection:

 * 1) tipc_printf()  - to protect its print buffer(s) and 'print_string'

 * 2) TIPC_TEE()     - to protect its print buffer(s)

 * 3) tipc_dump()    - to protect its print buffer(s) and 'print_string'

 * 4) tipc_log_XXX() - to protect TIPC_LOG

 *

 * All routines of the form tipc_printbuf_XXX() rely on the caller to prevent

 * simultaneous use of the print buffer(s) being manipulated.

 * 2) tipc_printf() uses 'print_lock' to prevent simultaneous use of

 *    'print_string' and to protect its print buffer(s).

 * 3) TIPC_TEE() uses 'print_lock' to protect its print buffer(s).

 * 4) Routines of the form log_XXX() uses 'print_lock' to protect TIPC_LOG.

 */



/**

 * tipc_printbuf_init - initialize print buffer to empty

 * @pb: pointer to print buffer structure

 * @raw: pointer to character array used by print buffer

 * @size: size of character array

 *

 * Makes the print buffer a null device that discards anything written to it

 * if the character array is too small (or absent).

 */



void tipc_printbuf_init(struct print_buf *pb, char *raw, u32 sz)

void tipc_printbuf_init(struct print_buf *pb, char *raw, u32 size)

{

	if (!pb || !raw || (sz < (MAX_STRING + 1)))

		return;



	pb->crs = pb->buf = raw;

	pb->size = sz;

	pb->buf = raw;

	pb->crs = raw;

	pb->size = size;

	pb->next = NULL;



	if (size < TIPC_PB_MIN_SIZE) {

		pb->buf = NULL;

	} else if (raw) {

		pb->buf[0] = 0;

	pb->buf[sz-1] = ~0;

		pb->buf[size-1] = ~0;

	}

}



/**

 * tipc_printbuf_reset - reinitialize print buffer to empty state

 * @pb: pointer to print buffer structure

 */



void tipc_printbuf_reset(struct print_buf *pb)

{

	if (pb && pb->buf)

	tipc_printbuf_init(pb, pb->buf, pb->size);

}



/**

 * tipc_printbuf_empty - test if print buffer is in empty state

 * @pb: pointer to print buffer structure

 *

 * Returns non-zero if print buffer is empty.

 */



int tipc_printbuf_empty(struct print_buf *pb)

{

	return (!pb || !pb->buf || (pb->crs == pb->buf));

	return (!pb->buf || (pb->crs == pb->buf));

}



/**

 * tipc_printbuf_validate - check for print buffer overflow

 * @pb: pointer to print buffer structure

 * 

 * Verifies that a print buffer has captured all data written to it. 

 * If data has been lost, linearize buffer and prepend an error message

 * 

 * Returns length of print buffer data string (including trailing NULL)

 * Returns length of print buffer data string (including trailing NUL)

 */



int tipc_printbuf_validate(struct print_buf *pb)

{

        char *err = "             *** PRINT BUFFER WRAPPED AROUND ***\n";

        char *err = "\n\n*** PRINT BUFFER OVERFLOW ***\n\n";

        char *cp_buf;

        struct print_buf cb;



	if (!pb || !pb->buf)

	if (!pb->buf)

		return 0;



	if (pb->buf[pb->size - 1] == '\0') {

	if (pb->buf[pb->size - 1] == 0) {

                cp_buf = kmalloc(pb->size, GFP_ATOMIC);

                if (cp_buf != NULL){

                        tipc_printbuf_init(&cb, cp_buf, pb->size);
@@ -141,6 +157,8 @@ int tipc_printbuf_validate(struct print_buf *pb) 


/**

 * tipc_printbuf_move - move print buffer contents to another print buffer

 * @pb_to: pointer to destination print buffer structure

 * @pb_from: pointer to source print buffer structure

 * 

 * Current contents of destination print buffer (if any) are discarded.

 * Source print buffer becomes empty if a successful move occurs.
@@ -152,21 +170,22 @@ void tipc_printbuf_move(struct print_buf *pb_to, struct print_buf *pb_from) 


	/* Handle the cases where contents can't be moved */



	if (!pb_to || !pb_to->buf)

	if (!pb_to->buf)

		return;



	if (!pb_from || !pb_from->buf) {

	if (!pb_from->buf) {

		tipc_printbuf_reset(pb_to);

		return;

	}



	if (pb_to->size < pb_from->size) {

		tipc_printbuf_reset(pb_to);

		tipc_printf(pb_to, "*** PRINT BUFFER OVERFLOW ***");

		tipc_printf(pb_to, "*** PRINT BUFFER MOVE ERROR ***");

		return;

	}



	/* Copy data from char after cursor to end (if used) */



	len = pb_from->buf + pb_from->size - pb_from->crs - 2;

	if ((pb_from->buf[pb_from->size-1] == 0) && (len > 0)) {

		strcpy(pb_to->buf, pb_from->crs + 1);
@@ -175,6 +194,7 @@ void tipc_printbuf_move(struct print_buf *pb_to, struct print_buf *pb_from) 
		pb_to->crs = pb_to->buf;



	/* Copy data from start to cursor (always) */



	len = pb_from->crs - pb_from->buf;

	strcpy(pb_to->crs, pb_from->buf);

	pb_to->crs += len;
@@ -184,6 +204,8 @@ void tipc_printbuf_move(struct print_buf *pb_to, struct print_buf *pb_from) 


/**

 * tipc_printf - append formatted output to print buffer chain

 * @pb: pointer to chain of print buffers (may be NULL)

 * @fmt: formatted info to be printed

 */



void tipc_printf(struct print_buf *pb, const char *fmt, ...)
@@ -195,8 +217,8 @@ void tipc_printf(struct print_buf *pb, const char *fmt, ...) 


	spin_lock_bh(&print_lock);

	FORMAT(print_string, chars_to_add, fmt);

	if (chars_to_add >= MAX_STRING)

		strcpy(print_string, "*** STRING TOO LONG ***");

	if (chars_to_add >= TIPC_PB_MAX_STR)

		strcpy(print_string, "*** PRINT BUFFER STRING TOO LONG ***");



	while (pb) {

		if (pb == TIPC_CONS)
@@ -206,6 +228,10 @@ void tipc_printf(struct print_buf *pb, const char *fmt, ...) 
			if (chars_to_add <= chars_left) {

				strcpy(pb->crs, print_string);

				pb->crs += chars_to_add;

			} else if (chars_to_add >= (pb->size - 1)) {

				strcpy(pb->buf, print_string + chars_to_add + 1

				       - pb->size);

				pb->crs = pb->buf + pb->size - 1;

			} else {

				strcpy(pb->buf, print_string + chars_left);

                                save_char = print_string[chars_left];
@@ -224,6 +250,10 @@ void tipc_printf(struct print_buf *pb, const char *fmt, ...) 


/**

 * TIPC_TEE - perform next output operation on both print buffers  

 * @b0: pointer to chain of print buffers (may be NULL)

 * @b1: pointer to print buffer to add to chain

 *

 * Returns pointer to print buffer chain.

 */



struct print_buf *TIPC_TEE(struct print_buf *b0, struct print_buf *b1)
@@ -232,8 +262,6 @@ struct print_buf *TIPC_TEE(struct print_buf *b0, struct print_buf *b1) 


	if (!b0 || (b0 == b1))

		return b1;

	if (!b1)

		return b0;



	spin_lock_bh(&print_lock);

	while (pb->next) {
@@ -256,7 +284,7 @@ static void print_to_console(char *crs, int len) 
	int rest = len;



	while (rest > 0) {

		int sz = rest < MAX_STRING ? rest : MAX_STRING;

		int sz = rest < TIPC_PB_MAX_STR ? rest : TIPC_PB_MAX_STR;

		char c = crs[sz];



		crs[sz] = 0;
@@ -275,36 +303,48 @@ static void printbuf_dump(struct print_buf *pb) 
{

	int len;



	if (!pb->buf) {

		printk("*** PRINT BUFFER NOT ALLOCATED ***");

		return;

	}



	/* Dump print buffer from char after cursor to end (if used) */



	len = pb->buf + pb->size - pb->crs - 2;

	if ((pb->buf[pb->size - 1] == 0) && (len > 0))

		print_to_console(pb->crs + 1, len);



	/* Dump print buffer from start to cursor (always) */



	len = pb->crs - pb->buf;

	print_to_console(pb->buf, len);

}



/**

 * tipc_dump - dump non-console print buffer(s) to console

 * @pb: pointer to chain of print buffers

 */



void tipc_dump(struct print_buf *pb, const char *fmt, ...)

{

	struct print_buf *pb_next;

	int len;



	spin_lock_bh(&print_lock);

	FORMAT(TIPC_CONS->buf, len, fmt);

	printk(TIPC_CONS->buf);

	FORMAT(print_string, len, fmt);

	printk(print_string);



	for (; pb; pb = pb->next) {

		if (pb == TIPC_CONS)

			continue;

		printk("\n---- Start of dump,%s log ----\n\n", 

		if (pb != TIPC_CONS) {

			printk("\n---- Start of %s log dump ----\n\n",

			       (pb == TIPC_LOG) ? "global" : "local");

			printbuf_dump(pb);

			tipc_printbuf_reset(pb);

		printk("\n-------- End of dump --------\n");

			printk("\n---- End of dump ----\n");

		}

		pb_next = pb->next;

		pb->next = NULL;

		pb = pb_next;

	}

	spin_unlock_bh(&print_lock);

}
@@ -324,7 +364,8 @@ void tipc_log_stop(void) 
}



/**

 * tipc_log_reinit - set TIPC log print buffer to specified size

 * tipc_log_reinit - (re)initialize TIPC log print buffer

 * @log_size: print buffer size to use

 */



void tipc_log_reinit(int log_size)
@@ -332,10 +373,11 @@ void tipc_log_reinit(int log_size) 
	tipc_log_stop();



	if (log_size) {

		if (log_size <= MAX_STRING)

			log_size = MAX_STRING + 1;

		if (log_size < TIPC_PB_MIN_SIZE)

			log_size = TIPC_PB_MIN_SIZE;

		spin_lock_bh(&print_lock);

		tipc_printbuf_init(TIPC_LOG, kmalloc(log_size, GFP_ATOMIC), log_size);

		tipc_printbuf_init(TIPC_LOG, kmalloc(log_size, GFP_ATOMIC),

				   log_size);

		spin_unlock_bh(&print_lock);

	}

}

net/tipc/dbg.h

+13 −2
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
 * net/tipc/dbg.h: Include file for TIPC print buffer routines

 * 

 * Copyright (c) 1997-2006, Ericsson AB

 * Copyright (c) 2005, Wind River Systems

 * Copyright (c) 2005-2006, Wind River Systems

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without
@@ -37,6 +37,14 @@ 
#ifndef _TIPC_DBG_H

#define _TIPC_DBG_H



/**

 * struct print_buf - TIPC print buffer structure

 * @buf: pointer to character array containing print buffer contents

 * @size: size of character array

 * @crs: pointer to first unused space in character array (i.e. final NUL)

 * @next: used to link print buffers when printing to more than one at a time

 */



struct print_buf {

	char *buf;

	u32 size;
@@ -44,7 +52,10 @@ struct print_buf { 
	struct print_buf *next;

};



void tipc_printbuf_init(struct print_buf *pb, char *buf, u32 sz);

#define TIPC_PB_MIN_SIZE 64	/* minimum size for a print buffer's array */

#define TIPC_PB_MAX_STR 512	/* max printable string (with trailing NUL) */



void tipc_printbuf_init(struct print_buf *pb, char *buf, u32 size);

void tipc_printbuf_reset(struct print_buf *pb);

int  tipc_printbuf_empty(struct print_buf *pb);

int  tipc_printbuf_validate(struct print_buf *pb);

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