[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: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/core.h b/net/tipc/core.h
index 762aac2..47504ec 100644
--- a/net/tipc/core.h
+++ b/net/tipc/core.h
@@ -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 @@
* 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 @@
#endif
#ifndef DBG_OUTPUT
-#define DBG_OUTPUT NULL
+#define DBG_OUTPUT TIPC_NULL
#endif
#else
@@ -136,7 +136,7 @@
#define TIPC_OUTPUT TIPC_CONS
#undef DBG_OUTPUT
-#define DBG_OUTPUT NULL
+#define DBG_OUTPUT TIPC_NULL
#endif
diff --git a/net/tipc/dbg.c b/net/tipc/dbg.c
index 5513065..d8af4c2 100644
--- a/net/tipc/dbg.c
+++ b/net/tipc/dbg.c
@@ -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) 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 @@
/*
* Locking policy when using print buffers.
*
- * 1) Routines of the form 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.
+ * 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.
*/
/**
* 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;
- 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
+ * @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_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 @@
/**
* 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 @@
/* 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 @@
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 @@
/**
* 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 @@
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 @@
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 @@
/**
* 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 @@
if (!b0 || (b0 == b1))
return b1;
- if (!b1)
- return b0;
spin_lock_bh(&print_lock);
while (pb->next) {
@@ -256,7 +284,7 @@
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 @@
{
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",
- (pb == TIPC_LOG) ? "global" : "local");
- printbuf_dump(pb);
- tipc_printbuf_reset(pb);
- printk("\n-------- End of dump --------\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");
+ }
+ pb_next = pb->next;
+ pb->next = NULL;
+ pb = pb_next;
}
spin_unlock_bh(&print_lock);
}
@@ -324,7 +364,8 @@
}
/**
- * 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 @@
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);
}
}
diff --git a/net/tipc/dbg.h b/net/tipc/dbg.h
index 227f050..467c0bc7 100644
--- a/net/tipc/dbg.h
+++ b/net/tipc/dbg.h
@@ -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 *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);