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Diffstat (limited to 'net/tipc/dbg.c')
-rw-r--r-- | net/tipc/dbg.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/net/tipc/dbg.c b/net/tipc/dbg.c new file mode 100644 index 000000000000..7ed60a1cfbb8 --- /dev/null +++ b/net/tipc/dbg.c @@ -0,0 +1,395 @@ +/* + * net/tipc/dbg.c: TIPC print buffer routines for debuggign + * + * Copyright (c) 1996-2006, Ericsson AB + * Copyright (c) 2005, 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" + +#define MAX_STRING 512 + +static char print_string[MAX_STRING]; +static spinlock_t print_lock = SPIN_LOCK_UNLOCKED; + +static struct print_buf cons_buf = { NULL, 0, NULL, NULL }; +struct print_buf *CONS = &cons_buf; + +static struct print_buf log_buf = { NULL, 0, NULL, NULL }; +struct print_buf *LOG = &log_buf; + + +#define FORMAT(PTR,LEN,FMT) \ +{\ + va_list args;\ + va_start(args, FMT);\ + LEN = vsprintf(PTR, FMT, args);\ + va_end(args);\ + *(PTR + LEN) = '\0';\ +} + +/* + * 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) TEE() uses 'print_lock' to protect its print buffer(s). + * 4) Routines of the form log_XXX() uses 'print_lock' to protect LOG. + */ + +/** + * printbuf_init - initialize print buffer to empty + */ + +void printbuf_init(struct print_buf *pb, char *raw, u32 sz) +{ + if (!pb || !raw || (sz < (MAX_STRING + 1))) + return; + + pb->crs = pb->buf = raw; + pb->size = sz; + pb->next = 0; + pb->buf[0] = 0; + pb->buf[sz-1] = ~0; +} + +/** + * printbuf_reset - reinitialize print buffer to empty state + */ + +void printbuf_reset(struct print_buf *pb) +{ + if (pb && pb->buf) + printbuf_init(pb, pb->buf, pb->size); +} + +/** + * printbuf_empty - test if print buffer is in empty state + */ + +int printbuf_empty(struct print_buf *pb) +{ + return (!pb || !pb->buf || (pb->crs == pb->buf)); +} + +/** + * printbuf_validate - check for print buffer overflow + * + * 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) + */ + +int printbuf_validate(struct print_buf *pb) +{ + char *err = " *** PRINT BUFFER WRAPPED AROUND ***\n"; + char *cp_buf; + struct print_buf cb; + + if (!pb || !pb->buf) + return 0; + + if (pb->buf[pb->size - 1] == '\0') { + cp_buf = kmalloc(pb->size, GFP_ATOMIC); + if (cp_buf != NULL){ + printbuf_init(&cb, cp_buf, pb->size); + printbuf_move(&cb, pb); + printbuf_move(pb, &cb); + kfree(cp_buf); + memcpy(pb->buf, err, strlen(err)); + } else { + printbuf_reset(pb); + tipc_printf(pb, err); + } + } + return (pb->crs - pb->buf + 1); +} + +/** + * printbuf_move - move print buffer contents to another print buffer + * + * Current contents of destination print buffer (if any) are discarded. + * Source print buffer becomes empty if a successful move occurs. + */ + +void 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 || !pb_to->buf) + return; + + if (!pb_from || !pb_from->buf) { + printbuf_reset(pb_to); + return; + } + + if (pb_to->size < pb_from->size) { + printbuf_reset(pb_to); + tipc_printf(pb_to, "*** PRINT BUFFER OVERFLOW ***"); + 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; + + printbuf_reset(pb_from); +} + +/** + * tipc_printf - append formatted output to print buffer chain + */ + +void tipc_printf(struct print_buf *pb, const char *fmt, ...) +{ + int chars_to_add; + int chars_left; + char save_char; + struct print_buf *pb_next; + + spin_lock_bh(&print_lock); + FORMAT(print_string, chars_to_add, fmt); + if (chars_to_add >= MAX_STRING) + strcpy(print_string, "*** STRING TOO LONG ***"); + + while (pb) { + if (pb == CONS) + printk(print_string); + else 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 { + 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; + } + } + pb_next = pb->next; + pb->next = 0; + pb = pb_next; + } + spin_unlock_bh(&print_lock); +} + +/** + * TEE - perform next output operation on both print buffers + */ + +struct print_buf *TEE(struct print_buf *b0, struct print_buf *b1) +{ + struct print_buf *pb = b0; + + if (!b0 || (b0 == b1)) + return b1; + if (!b1) + return b0; + + spin_lock_bh(&print_lock); + while (pb->next) { + if ((pb->next == b1) || (pb->next == b0)) + pb->next = pb->next->next; + else + pb = pb->next; + } + pb->next = b1; + spin_unlock_bh(&print_lock); + return b0; +} + +/** + * 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 < MAX_STRING ? rest : MAX_STRING; + 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; + + /* 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 + */ + +void tipc_dump(struct print_buf *pb, const char *fmt, ...) +{ + int len; + + spin_lock_bh(&print_lock); + FORMAT(CONS->buf, len, fmt); + printk(CONS->buf); + + for (; pb; pb = pb->next) { + if (pb == CONS) + continue; + printk("\n---- Start of dump,%s log ----\n\n", + (pb == LOG) ? "global" : "local"); + printbuf_dump(pb); + printbuf_reset(pb); + printk("\n-------- End of dump --------\n"); + } + spin_unlock_bh(&print_lock); +} + +/** + * log_stop - free up TIPC log print buffer + */ + +void log_stop(void) +{ + spin_lock_bh(&print_lock); + if (LOG->buf) { + kfree(LOG->buf); + LOG->buf = NULL; + } + spin_unlock_bh(&print_lock); +} + +/** + * log_reinit - set TIPC log print buffer to specified size + */ + +void log_reinit(int log_size) +{ + log_stop(); + + if (log_size) { + if (log_size <= MAX_STRING) + log_size = MAX_STRING + 1; + spin_lock_bh(&print_lock); + printbuf_init(LOG, kmalloc(log_size, GFP_ATOMIC), log_size); + spin_unlock_bh(&print_lock); + } +} + +/** + * log_resize - reconfigure size of TIPC log buffer + */ + +struct sk_buff *log_resize(const void *req_tlv_area, int req_tlv_space) +{ + u32 value; + + if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED)) + return cfg_reply_error_string(TIPC_CFG_TLV_ERROR); + + value = *(u32 *)TLV_DATA(req_tlv_area); + value = ntohl(value); + if (value != delimit(value, 0, 32768)) + return cfg_reply_error_string(TIPC_CFG_INVALID_VALUE + " (log size must be 0-32768)"); + log_reinit(value); + return cfg_reply_none(); +} + +/** + * log_dump - capture TIPC log buffer contents in configuration message + */ + +struct sk_buff *log_dump(void) +{ + struct sk_buff *reply; + + spin_lock_bh(&print_lock); + if (!LOG->buf) + reply = cfg_reply_ultra_string("log not activated\n"); + else if (printbuf_empty(LOG)) + reply = cfg_reply_ultra_string("log is empty\n"); + else { + struct tlv_desc *rep_tlv; + struct print_buf pb; + int str_len; + + str_len = min(LOG->size, 32768u); + reply = cfg_reply_alloc(TLV_SPACE(str_len)); + if (reply) { + rep_tlv = (struct tlv_desc *)reply->data; + printbuf_init(&pb, TLV_DATA(rep_tlv), str_len); + printbuf_move(&pb, LOG); + 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); + } + } + spin_unlock_bh(&print_lock); + return reply; +} + |