From 29ede244cc4cfb11432a0bffd158ba09e7b2c167 Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Mon, 16 Oct 2006 21:42:04 -0700 Subject: [PATCH] [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 Signed-off-by: Per Liden Signed-off-by: David S. Miller --- net/tipc/core.h | 16 +++--- net/tipc/dbg.c | 136 +++++++++++++++++++++++++++++++----------------- net/tipc/dbg.h | 15 +++++- 3 files changed, 110 insertions(+), 57 deletions(-) diff --git a/net/tipc/core.h b/net/tipc/core.h index 762aac2572..47504ec15d 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 @@ 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 diff --git a/net/tipc/dbg.c b/net/tipc/dbg.c index 55130655e1..d8af4c2869 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 @@ 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 - * 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 @@ 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", - (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 @@ 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); } } diff --git a/net/tipc/dbg.h b/net/tipc/dbg.h index 227f050d2a..467c0bc78a 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 { 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); -- 2.39.5