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author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-21 00:43:29 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-21 00:43:29 (GMT) |
commit | db6d8c7a4027b48d797b369a53f8470aaeed7063 (patch) | |
tree | e140c104a89abc2154e1f41a7db8ebecbb6fa0b4 /net/tipc/dbg.c | |
parent | 3a533374283aea50eab3976d8a6d30532175f009 (diff) | |
parent | fb65a7c091529bfffb1262515252c0d0f6241c5c (diff) | |
download | linux-fsl-qoriq-db6d8c7a4027b48d797b369a53f8470aaeed7063.tar.xz |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (1232 commits)
iucv: Fix bad merging.
net_sched: Add size table for qdiscs
net_sched: Add accessor function for packet length for qdiscs
net_sched: Add qdisc_enqueue wrapper
highmem: Export totalhigh_pages.
ipv6 mcast: Omit redundant address family checks in ip6_mc_source().
net: Use standard structures for generic socket address structures.
ipv6 netns: Make several "global" sysctl variables namespace aware.
netns: Use net_eq() to compare net-namespaces for optimization.
ipv6: remove unused macros from net/ipv6.h
ipv6: remove unused parameter from ip6_ra_control
tcp: fix kernel panic with listening_get_next
tcp: Remove redundant checks when setting eff_sacks
tcp: options clean up
tcp: Fix MD5 signatures for non-linear skbs
sctp: Update sctp global memory limit allocations.
sctp: remove unnecessary byteshifting, calculate directly in big-endian
sctp: Allow only 1 listening socket with SO_REUSEADDR
sctp: Do not leak memory on multiple listen() calls
sctp: Support ipv6only AF_INET6 sockets.
...
Diffstat (limited to 'net/tipc/dbg.c')
-rw-r--r-- | net/tipc/dbg.c | 231 |
1 files changed, 111 insertions, 120 deletions
diff --git a/net/tipc/dbg.c b/net/tipc/dbg.c index e809d2a..29ecae8 100644 --- a/net/tipc/dbg.c +++ b/net/tipc/dbg.c @@ -2,7 +2,7 @@ * net/tipc/dbg.c: TIPC print buffer routines for debugging * * Copyright (c) 1996-2006, Ericsson AB - * Copyright (c) 2005-2006, Wind River Systems + * Copyright (c) 2005-2007, Wind River Systems * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -38,17 +38,43 @@ #include "config.h" #include "dbg.h" -static char print_string[TIPC_PB_MAX_STR]; -static DEFINE_SPINLOCK(print_lock); +/* + * 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, NULL }; -struct print_buf *TIPC_NULL = &null_buf; +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, NULL }; -struct print_buf *TIPC_CONS = &cons_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, NULL }; -struct print_buf *TIPC_LOG = &log_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) \ @@ -60,27 +86,14 @@ struct print_buf *TIPC_LOG = &log_buf; *(PTR + LEN) = '\0';\ } -/* - * Locking policy when using print buffers. - * - * 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). + * 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) @@ -88,13 +101,13 @@ void tipc_printbuf_init(struct print_buf *pb, char *raw, u32 size) pb->buf = raw; pb->crs = raw; pb->size = size; - pb->next = NULL; + pb->echo = 0; if (size < TIPC_PB_MIN_SIZE) { pb->buf = NULL; } else if (raw) { pb->buf[0] = 0; - pb->buf[size-1] = ~0; + pb->buf[size - 1] = ~0; } } @@ -105,7 +118,11 @@ void tipc_printbuf_init(struct print_buf *pb, char *raw, u32 size) void tipc_printbuf_reset(struct print_buf *pb) { - tipc_printbuf_init(pb, pb->buf, pb->size); + if (pb->buf) { + pb->crs = pb->buf; + pb->buf[0] = 0; + pb->buf[pb->size - 1] = ~0; + } } /** @@ -141,7 +158,7 @@ int tipc_printbuf_validate(struct print_buf *pb) if (pb->buf[pb->size - 1] == 0) { cp_buf = kmalloc(pb->size, GFP_ATOMIC); - if (cp_buf != NULL){ + if (cp_buf) { tipc_printbuf_init(&cb, cp_buf, pb->size); tipc_printbuf_move(&cb, pb); tipc_printbuf_move(pb, &cb); @@ -179,15 +196,16 @@ void tipc_printbuf_move(struct print_buf *pb_to, struct print_buf *pb_from) } if (pb_to->size < pb_from->size) { - tipc_printbuf_reset(pb_to); - tipc_printf(pb_to, "*** PRINT BUFFER MOVE ERROR ***"); + 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)) { + 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 @@ -203,8 +221,8 @@ 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) + * tipc_printf - append formatted output to print buffer + * @pb: pointer to print buffer * @fmt: formatted info to be printed */ @@ -213,68 +231,40 @@ 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 >= TIPC_PB_MAX_STR) strcpy(print_string, "*** PRINT BUFFER STRING TOO LONG ***"); - while (pb) { - if (pb == TIPC_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 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->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; } - pb_next = pb->next; - pb->next = NULL; - pb = pb_next; } - spin_unlock_bh(&print_lock); -} -/** - * 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. - */ + if (pb->echo) + printk(print_string); -struct print_buf *TIPC_TEE(struct print_buf *b0, struct print_buf *b1) -{ - struct print_buf *pb = b0; - - if (!b0 || (b0 == b1)) - return b1; - - 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; } +#ifdef CONFIG_TIPC_DEBUG + /** * print_to_console - write string of bytes to console in multiple chunks */ @@ -321,72 +311,66 @@ static void printbuf_dump(struct print_buf *pb) } /** - * tipc_dump - dump non-console print buffer(s) to console - * @pb: pointer to chain of print buffers + * tipc_dump_dbg - dump (non-console) print buffer to console + * @pb: pointer to print buffer */ -void tipc_dump(struct print_buf *pb, const char *fmt, ...) +void tipc_dump_dbg(struct print_buf *pb, const char *fmt, ...) { - struct print_buf *pb_next; int len; + if (pb == TIPC_CONS) + return; + spin_lock_bh(&print_lock); + FORMAT(print_string, len, fmt); printk(print_string); - for (; pb; pb = pb->next) { - 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; - } + 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_stop - free up TIPC log print buffer + * tipc_log_resize - change the size of the TIPC log buffer + * @log_size: print buffer size to use */ -void tipc_log_stop(void) +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; } - spin_unlock_bh(&print_lock); -} - -/** - * tipc_log_reinit - (re)initialize TIPC log print buffer - * @log_size: print buffer size to use - */ - -void tipc_log_reinit(int log_size) -{ - tipc_log_stop(); - if (log_size) { if (log_size < TIPC_PB_MIN_SIZE) log_size = TIPC_PB_MIN_SIZE; - spin_lock_bh(&print_lock); + res = TIPC_LOG->echo; tipc_printbuf_init(TIPC_LOG, kmalloc(log_size, GFP_ATOMIC), log_size); - spin_unlock_bh(&print_lock); + TIPC_LOG->echo = res; + res = !TIPC_LOG->buf; } + spin_unlock_bh(&print_lock); + + return res; } /** - * tipc_log_resize - reconfigure size of TIPC log buffer + * tipc_log_resize_cmd - reconfigure size of TIPC log buffer */ -struct sk_buff *tipc_log_resize(const void *req_tlv_area, int req_tlv_space) +struct sk_buff *tipc_log_resize_cmd(const void *req_tlv_area, int req_tlv_space) { u32 value; @@ -397,7 +381,9 @@ struct sk_buff *tipc_log_resize(const void *req_tlv_area, int req_tlv_space) if (value != delimit(value, 0, 32768)) return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE " (log size must be 0-32768)"); - tipc_log_reinit(value); + 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(); } @@ -410,27 +396,32 @@ struct sk_buff *tipc_log_dump(void) struct sk_buff *reply; spin_lock_bh(&print_lock); - if (!TIPC_LOG->buf) + 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)) + } 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); } } - spin_unlock_bh(&print_lock); return reply; } |