From f5e75269f59f7c3816f23314b924895e4ecf8409 Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Fri, 31 Dec 2010 18:59:24 +0000 Subject: tipc: rename dbg.[ch] to log.[ch] As the first step in removing obsolete debugging code from TIPC the files that implement TIPC's non-debug-related log buffer subsystem are renamed to better reflect their true nature. Signed-off-by: Allan Stephens Signed-off-by: Paul Gortmaker Signed-off-by: David S. Miller --- net/tipc/log.c | 428 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 428 insertions(+) create mode 100644 net/tipc/log.c (limited to 'net/tipc/log.c') diff --git a/net/tipc/log.c b/net/tipc/log.c new file mode 100644 index 000000000000..9d99f7097d2d --- /dev/null +++ b/net/tipc/log.c @@ -0,0 +1,428 @@ +/* + * net/tipc/log.c: TIPC print buffer routines for debugging + * + * Copyright (c) 1996-2006, Ericsson AB + * Copyright (c) 2005-2007, Wind River Systems + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the names of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2 as published by the Free + * Software Foundation. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include "core.h" +#include "config.h" +#include "log.h" + +/* + * TIPC pre-defines the following print buffers: + * + * TIPC_NULL : null buffer (i.e. print nowhere) + * TIPC_CONS : system console + * TIPC_LOG : TIPC log buffer + * + * Additional user-defined print buffers are also permitted. + */ + +static struct print_buf null_buf = { NULL, 0, NULL, 0 }; +struct print_buf *const TIPC_NULL = &null_buf; + +static struct print_buf cons_buf = { NULL, 0, NULL, 1 }; +static struct print_buf *const TIPC_CONS = &cons_buf; + +static struct print_buf log_buf = { NULL, 0, NULL, 1 }; +struct print_buf *const TIPC_LOG = &log_buf; + +/* + * Locking policy when using print buffers. + * + * 1) tipc_printf() uses 'print_lock' to protect against concurrent access to + * 'print_string' when writing to a print buffer. This also protects against + * concurrent writes to the print buffer being written to. + * + * 2) tipc_dump() and tipc_log_XXX() leverage the aforementioned + * use of 'print_lock' to protect against all types of concurrent operations + * on their associated print buffer (not just write operations). + * + * Note: All routines of the form tipc_printbuf_XXX() are lock-free, and rely + * on the caller to prevent simultaneous use of the print buffer(s) being + * manipulated. + */ + +static char print_string[TIPC_PB_MAX_STR]; +static DEFINE_SPINLOCK(print_lock); + +static void tipc_printbuf_reset(struct print_buf *pb); +static int tipc_printbuf_empty(struct print_buf *pb); +static void tipc_printbuf_move(struct print_buf *pb_to, + struct print_buf *pb_from); + +#define FORMAT(PTR, LEN, FMT) \ +{\ + va_list args;\ + va_start(args, FMT);\ + LEN = vsprintf(PTR, FMT, args);\ + va_end(args);\ + *(PTR + LEN) = '\0';\ +} + +/** + * 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 + * + * Note: If the character array is too small (or absent), the print buffer + * becomes a null device that discards anything written to it. + */ + +void tipc_printbuf_init(struct print_buf *pb, char *raw, u32 size) +{ + pb->buf = raw; + pb->crs = raw; + pb->size = size; + pb->echo = 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 + */ + +static void tipc_printbuf_reset(struct print_buf *pb) +{ + if (pb->buf) { + pb->crs = pb->buf; + pb->buf[0] = 0; + pb->buf[pb->size - 1] = ~0; + } +} + +/** + * 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. + */ + +static int tipc_printbuf_empty(struct print_buf *pb) +{ + 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 NUL) + */ + +int tipc_printbuf_validate(struct print_buf *pb) +{ + char *err = "\n\n*** PRINT BUFFER OVERFLOW ***\n\n"; + char *cp_buf; + struct print_buf cb; + + if (!pb->buf) + return 0; + + if (pb->buf[pb->size - 1] == 0) { + cp_buf = kmalloc(pb->size, GFP_ATOMIC); + if (cp_buf) { + tipc_printbuf_init(&cb, cp_buf, pb->size); + tipc_printbuf_move(&cb, pb); + tipc_printbuf_move(pb, &cb); + kfree(cp_buf); + memcpy(pb->buf, err, strlen(err)); + } else { + tipc_printbuf_reset(pb); + tipc_printf(pb, err); + } + } + return pb->crs - pb->buf + 1; +} + +/** + * 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. + */ + +static void tipc_printbuf_move(struct print_buf *pb_to, + struct print_buf *pb_from) +{ + int len; + + /* Handle the cases where contents can't be moved */ + + if (!pb_to->buf) + return; + + if (!pb_from->buf) { + tipc_printbuf_reset(pb_to); + return; + } + + if (pb_to->size < pb_from->size) { + strcpy(pb_to->buf, "*** PRINT BUFFER MOVE ERROR ***"); + pb_to->buf[pb_to->size - 1] = ~0; + pb_to->crs = strchr(pb_to->buf, 0); + 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); + pb_to->crs = pb_to->buf + len; + } else + 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; + + tipc_printbuf_reset(pb_from); +} + +/** + * tipc_printf - append formatted output to print buffer + * @pb: pointer to print buffer + * @fmt: formatted info to be printed + */ + +void tipc_printf(struct print_buf *pb, const char *fmt, ...) +{ + int chars_to_add; + int chars_left; + char save_char; + + spin_lock_bh(&print_lock); + + FORMAT(print_string, chars_to_add, fmt); + if (chars_to_add >= TIPC_PB_MAX_STR) + strcpy(print_string, "*** PRINT BUFFER STRING TOO LONG ***"); + + if (pb->buf) { + chars_left = pb->buf + pb->size - pb->crs - 1; + 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]; + print_string[chars_left] = 0; + strcpy(pb->crs, print_string); + print_string[chars_left] = save_char; + pb->crs = pb->buf + chars_to_add - chars_left; + } + } + + if (pb->echo) + printk("%s", print_string); + + spin_unlock_bh(&print_lock); +} + +#ifdef CONFIG_TIPC_DEBUG + +/** + * print_to_console - write string of bytes to console in multiple chunks + */ + +static void print_to_console(char *crs, int len) +{ + int rest = len; + + while (rest > 0) { + int sz = rest < TIPC_PB_MAX_STR ? rest : TIPC_PB_MAX_STR; + char c = crs[sz]; + + crs[sz] = 0; + printk((const char *)crs); + crs[sz] = c; + rest -= sz; + crs += sz; + } +} + +/** + * printbuf_dump - write print buffer contents to console + */ + +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_dbg - dump (non-console) print buffer to console + * @pb: pointer to print buffer + */ + +void tipc_dump_dbg(struct print_buf *pb, const char *fmt, ...) +{ + int len; + + if (pb == TIPC_CONS) + return; + + spin_lock_bh(&print_lock); + + FORMAT(print_string, len, fmt); + printk(print_string); + + 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"); + + spin_unlock_bh(&print_lock); +} + +#endif + +/** + * tipc_log_resize - change the size of the TIPC log buffer + * @log_size: print buffer size to use + */ + +int tipc_log_resize(int log_size) +{ + int res = 0; + + spin_lock_bh(&print_lock); + kfree(TIPC_LOG->buf); + TIPC_LOG->buf = NULL; + if (log_size) { + if (log_size < TIPC_PB_MIN_SIZE) + log_size = TIPC_PB_MIN_SIZE; + res = TIPC_LOG->echo; + tipc_printbuf_init(TIPC_LOG, kmalloc(log_size, GFP_ATOMIC), + log_size); + TIPC_LOG->echo = res; + res = !TIPC_LOG->buf; + } + spin_unlock_bh(&print_lock); + + return res; +} + +/** + * tipc_log_resize_cmd - reconfigure size of TIPC log buffer + */ + +struct sk_buff *tipc_log_resize_cmd(const void *req_tlv_area, int req_tlv_space) +{ + u32 value; + + if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED)) + return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); + + value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area)); + if (value != delimit(value, 0, 32768)) + return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE + " (log size must be 0-32768)"); + if (tipc_log_resize(value)) + return tipc_cfg_reply_error_string( + "unable to create specified log (log size is now 0)"); + return tipc_cfg_reply_none(); +} + +/** + * tipc_log_dump - capture TIPC log buffer contents in configuration message + */ + +struct sk_buff *tipc_log_dump(void) +{ + struct sk_buff *reply; + + spin_lock_bh(&print_lock); + if (!TIPC_LOG->buf) { + spin_unlock_bh(&print_lock); + reply = tipc_cfg_reply_ultra_string("log not activated\n"); + } else if (tipc_printbuf_empty(TIPC_LOG)) { + spin_unlock_bh(&print_lock); + reply = tipc_cfg_reply_ultra_string("log is empty\n"); + } else { + struct tlv_desc *rep_tlv; + struct print_buf pb; + int str_len; + + str_len = min(TIPC_LOG->size, 32768u); + spin_unlock_bh(&print_lock); + reply = tipc_cfg_reply_alloc(TLV_SPACE(str_len)); + if (reply) { + rep_tlv = (struct tlv_desc *)reply->data; + tipc_printbuf_init(&pb, TLV_DATA(rep_tlv), str_len); + spin_lock_bh(&print_lock); + tipc_printbuf_move(&pb, TIPC_LOG); + spin_unlock_bh(&print_lock); + str_len = strlen(TLV_DATA(rep_tlv)) + 1; + skb_put(reply, TLV_SPACE(str_len)); + TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len); + } + } + return reply; +} -- cgit v1.2.3-58-ga151