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[TIPC]: Debug print buffer enhancements and fixes

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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: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Allan Stephens 2006-10-16 21:42:04 -07:00 committed by David S. Miller
parent 065fd1772a
commit 29ede244cc
3 changed files with 110 additions and 57 deletions
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16
net/tipc/core.h
View file

@ -65,7 +65,7 @@
#define assert(i) BUG_ON(!(i)) #define assert(i) BUG_ON(!(i))
struct tipc_msg; 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 *); 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_msg_print(struct print_buf*,struct tipc_msg *,const char*);
void tipc_printf(struct print_buf *, const char *fmt, ...); 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 * here, or on a per .c file basis, by redefining these symbols. The following
* print buffer options are available: * print buffer options are available:
* *
* NULL : Output to null print buffer (i.e. print nowhere) * TIPC_NULL : null buffer (i.e. print nowhere)
* TIPC_CONS : Output to system console * TIPC_CONS : system console
* TIPC_LOG : Output to TIPC log buffer * TIPC_LOG : TIPC log buffer
* &buf : Output to user-defined buffer (struct print_buf *) * &buf : 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_TEE(&buf_a,&buf_b) : list of buffers (eg. TIPC_TEE(TIPC_CONS,TIPC_LOG))
*/ */
#ifndef TIPC_OUTPUT #ifndef TIPC_OUTPUT
@ -106,7 +106,7 @@ void tipc_dump(struct print_buf*,const char *fmt, ...);
#endif #endif
#ifndef DBG_OUTPUT #ifndef DBG_OUTPUT
#define DBG_OUTPUT NULL #define DBG_OUTPUT TIPC_NULL
#endif #endif
#else #else
@ -136,7 +136,7 @@ void tipc_dump(struct print_buf*,const char *fmt, ...);
#define TIPC_OUTPUT TIPC_CONS #define TIPC_OUTPUT TIPC_CONS
#undef DBG_OUTPUT #undef DBG_OUTPUT
#define DBG_OUTPUT NULL #define DBG_OUTPUT TIPC_NULL
#endif #endif

136
net/tipc/dbg.c
View file

@ -1,8 +1,8 @@
/* /*
* 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) 1996-2006, Ericsson AB
* Copyright (c) 2005, Wind River Systems * Copyright (c) 2005-2006, Wind River Systems
* All rights reserved. * All rights reserved.
* *
* Redistribution and use in source and binary forms, with or without * Redistribution and use in source and binary forms, with or without
@ -38,11 +38,12 @@
#include "config.h" #include "config.h"
#include "dbg.h" #include "dbg.h"
#define MAX_STRING 512 static char print_string[TIPC_PB_MAX_STR];
static char print_string[MAX_STRING];
static DEFINE_SPINLOCK(print_lock); 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 }; static struct print_buf cons_buf = { NULL, 0, NULL, NULL };
struct print_buf *TIPC_CONS = &cons_buf; struct print_buf *TIPC_CONS = &cons_buf;
@ -62,68 +63,83 @@ struct print_buf *TIPC_LOG = &log_buf;
/* /*
* Locking policy when using print buffers. * 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:
* simultaneous use of the print buffer(s) being manipulated. * 1) tipc_printf() - to protect its print buffer(s) and 'print_string'
* 2) tipc_printf() uses 'print_lock' to prevent simultaneous use of * 2) TIPC_TEE() - to protect its print buffer(s)
* 'print_string' and to protect its print buffer(s). * 3) tipc_dump() - to protect its print buffer(s) and 'print_string'
* 3) TIPC_TEE() uses 'print_lock' to protect its print buffer(s). * 4) tipc_log_XXX() - to protect TIPC_LOG
* 4) Routines of the form log_XXX() uses 'print_lock' 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.
*/ */
/** /**
* tipc_printbuf_init - initialize print buffer to empty * 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))) pb->buf = raw;
return; pb->crs = raw;
pb->size = size;
pb->crs = pb->buf = raw;
pb->size = sz;
pb->next = NULL; pb->next = NULL;
pb->buf[0] = 0;
pb->buf[sz-1] = ~0; if (size < TIPC_PB_MIN_SIZE) {
pb->buf = NULL;
} else if (raw) {
pb->buf[0] = 0;
pb->buf[size-1] = ~0;
}
} }
/** /**
* tipc_printbuf_reset - reinitialize print buffer to empty state * tipc_printbuf_reset - reinitialize print buffer to empty state
* @pb: pointer to print buffer structure
*/ */
void tipc_printbuf_reset(struct print_buf *pb) void tipc_printbuf_reset(struct print_buf *pb)
{ {
if (pb && pb->buf) tipc_printbuf_init(pb, pb->buf, pb->size);
tipc_printbuf_init(pb, pb->buf, pb->size);
} }
/** /**
* tipc_printbuf_empty - test if print buffer is in empty state * 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) 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 * 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. * Verifies that a print buffer has captured all data written to it.
* If data has been lost, linearize buffer and prepend an error message * 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) 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; char *cp_buf;
struct print_buf cb; struct print_buf cb;
if (!pb || !pb->buf) if (!pb->buf)
return 0; return 0;
if (pb->buf[pb->size - 1] == '\0') { if (pb->buf[pb->size - 1] == 0) {
cp_buf = kmalloc(pb->size, GFP_ATOMIC); cp_buf = kmalloc(pb->size, GFP_ATOMIC);
if (cp_buf != NULL){ if (cp_buf != NULL){
tipc_printbuf_init(&cb, cp_buf, pb->size); 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 * 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. * Current contents of destination print buffer (if any) are discarded.
* Source print buffer becomes empty if a successful move occurs. * 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 */ /* Handle the cases where contents can't be moved */
if (!pb_to || !pb_to->buf) if (!pb_to->buf)
return; return;
if (!pb_from || !pb_from->buf) { if (!pb_from->buf) {
tipc_printbuf_reset(pb_to); tipc_printbuf_reset(pb_to);
return; return;
} }
if (pb_to->size < pb_from->size) { if (pb_to->size < pb_from->size) {
tipc_printbuf_reset(pb_to); tipc_printbuf_reset(pb_to);
tipc_printf(pb_to, "*** PRINT BUFFER OVERFLOW ***"); tipc_printf(pb_to, "*** PRINT BUFFER MOVE ERROR ***");
return; return;
} }
/* Copy data from char after cursor to end (if used) */ /* Copy data from char after cursor to end (if used) */
len = pb_from->buf + pb_from->size - pb_from->crs - 2; len = pb_from->buf + pb_from->size - pb_from->crs - 2;
if ((pb_from->buf[pb_from->size-1] == 0) && (len > 0)) { if ((pb_from->buf[pb_from->size-1] == 0) && (len > 0)) {
strcpy(pb_to->buf, pb_from->crs + 1); 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; pb_to->crs = pb_to->buf;
/* Copy data from start to cursor (always) */ /* Copy data from start to cursor (always) */
len = pb_from->crs - pb_from->buf; len = pb_from->crs - pb_from->buf;
strcpy(pb_to->crs, pb_from->buf); strcpy(pb_to->crs, pb_from->buf);
pb_to->crs += len; 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 * 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, ...) 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); spin_lock_bh(&print_lock);
FORMAT(print_string, chars_to_add, fmt); FORMAT(print_string, chars_to_add, fmt);
if (chars_to_add >= MAX_STRING) if (chars_to_add >= TIPC_PB_MAX_STR)
strcpy(print_string, "*** STRING TOO LONG ***"); strcpy(print_string, "*** PRINT BUFFER STRING TOO LONG ***");
while (pb) { while (pb) {
if (pb == TIPC_CONS) if (pb == TIPC_CONS)
@ -206,6 +228,10 @@ void tipc_printf(struct print_buf *pb, const char *fmt, ...)
if (chars_to_add <= chars_left) { if (chars_to_add <= chars_left) {
strcpy(pb->crs, print_string); strcpy(pb->crs, print_string);
pb->crs += chars_to_add; 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 { } else {
strcpy(pb->buf, print_string + chars_left); strcpy(pb->buf, print_string + chars_left);
save_char = 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 * 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) 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)) if (!b0 || (b0 == b1))
return b1; return b1;
if (!b1)
return b0;
spin_lock_bh(&print_lock); spin_lock_bh(&print_lock);
while (pb->next) { while (pb->next) {
@ -256,7 +284,7 @@ static void print_to_console(char *crs, int len)
int rest = len; int rest = len;
while (rest > 0) { 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]; char c = crs[sz];
crs[sz] = 0; crs[sz] = 0;
@ -275,36 +303,48 @@ static void printbuf_dump(struct print_buf *pb)
{ {
int len; int len;
if (!pb->buf) {
printk("*** PRINT BUFFER NOT ALLOCATED ***");
return;
}
/* Dump print buffer from char after cursor to end (if used) */ /* Dump print buffer from char after cursor to end (if used) */
len = pb->buf + pb->size - pb->crs - 2; len = pb->buf + pb->size - pb->crs - 2;
if ((pb->buf[pb->size - 1] == 0) && (len > 0)) if ((pb->buf[pb->size - 1] == 0) && (len > 0))
print_to_console(pb->crs + 1, len); print_to_console(pb->crs + 1, len);
/* Dump print buffer from start to cursor (always) */ /* Dump print buffer from start to cursor (always) */
len = pb->crs - pb->buf; len = pb->crs - pb->buf;
print_to_console(pb->buf, len); print_to_console(pb->buf, len);
} }
/** /**
* tipc_dump - dump non-console print buffer(s) to console * 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, ...) void tipc_dump(struct print_buf *pb, const char *fmt, ...)
{ {
struct print_buf *pb_next;
int len; int len;
spin_lock_bh(&print_lock); spin_lock_bh(&print_lock);
FORMAT(TIPC_CONS->buf, len, fmt); FORMAT(print_string, len, fmt);
printk(TIPC_CONS->buf); printk(print_string);
for (; pb; pb = pb->next) { for (; pb; pb = pb->next) {
if (pb == TIPC_CONS) if (pb != TIPC_CONS) {
continue; printk("\n---- Start of %s log dump ----\n\n",
printk("\n---- Start of dump,%s log ----\n\n", (pb == TIPC_LOG) ? "global" : "local");
(pb == TIPC_LOG) ? "global" : "local"); printbuf_dump(pb);
printbuf_dump(pb); tipc_printbuf_reset(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); 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) void tipc_log_reinit(int log_size)
@ -332,10 +373,11 @@ void tipc_log_reinit(int log_size)
tipc_log_stop(); tipc_log_stop();
if (log_size) { if (log_size) {
if (log_size <= MAX_STRING) if (log_size < TIPC_PB_MIN_SIZE)
log_size = MAX_STRING + 1; log_size = TIPC_PB_MIN_SIZE;
spin_lock_bh(&print_lock); 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); spin_unlock_bh(&print_lock);
} }
} }

15
net/tipc/dbg.h
View file

@ -2,7 +2,7 @@
* net/tipc/dbg.h: Include file for TIPC print buffer routines * net/tipc/dbg.h: Include file for TIPC print buffer routines
* *
* Copyright (c) 1997-2006, Ericsson AB * Copyright (c) 1997-2006, Ericsson AB
* Copyright (c) 2005, Wind River Systems * Copyright (c) 2005-2006, Wind River Systems
* All rights reserved. * All rights reserved.
* *
* Redistribution and use in source and binary forms, with or without * Redistribution and use in source and binary forms, with or without
@ -37,6 +37,14 @@
#ifndef _TIPC_DBG_H #ifndef _TIPC_DBG_H
#define _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 { struct print_buf {
char *buf; char *buf;
u32 size; u32 size;
@ -44,7 +52,10 @@ struct print_buf {
struct print_buf *next; 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); void tipc_printbuf_reset(struct print_buf *pb);
int tipc_printbuf_empty(struct print_buf *pb); int tipc_printbuf_empty(struct print_buf *pb);
int tipc_printbuf_validate(struct print_buf *pb); int tipc_printbuf_validate(struct print_buf *pb);