| /* |
| * net/tipc/dbg.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 "dbg.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 }; |
| 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); |
| |
| |
| #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 |
| */ |
| |
| 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. |
| */ |
| |
| 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. |
| */ |
| |
| 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(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); |
| if (TIPC_LOG->buf) { |
| 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; |
| } |
| |