X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=net%2Ftipc%2Fdbg.c;h=1885a7edb0c8014831e3e6f2a9f9a91ba326674d;hb=735eb93ae267f0b5638045b86dbc1e0b7019e3e8;hp=55130655e1edbe306a484f552c2a20080496cb15;hpb=34af946a22724c4e2b204957f2b24b22a0fb121c;p=safe%2Fjmp%2Flinux-2.6

diff --git a/net/tipc/dbg.c b/net/tipc/dbg.c
index 5513065..1885a7e 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) 2005-2007, Wind River Systems
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -38,16 +38,43 @@
 #include "config.h"
 #include "dbg.h"
 
-#define MAX_STRING 512
+/*
+ * 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 char print_string[MAX_STRING];
-static DEFINE_SPINLOCK(print_lock);
+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) \
@@ -59,89 +86,97 @@ struct print_buf *TIPC_LOG = &log_buf;
        *(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) 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.
- */
-
 /**
  * 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 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->next = NULL;
-	pb->buf[0] = 0;
-	pb->buf[sz-1] = ~0;
+	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 && pb->buf)
-		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;
+	}
 }
 
 /**
  * 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
- * 
- * Verifies that a print buffer has captured all data written to it. 
+ * @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 *cp_buf;
-        struct print_buf cb;
+	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') {
-                cp_buf = kmalloc(pb->size, GFP_ATOMIC);
-                if (cp_buf != NULL){
-                        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);
-                }
+	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.
  */
@@ -152,29 +187,32 @@ 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 ***");
+		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
 		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;
@@ -183,7 +221,9 @@ void tipc_printbuf_move(struct print_buf *pb_to, struct print_buf *pb_from)
 }
 
 /**
- * tipc_printf - append formatted output to print buffer chain
+ * 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, ...)
@@ -191,62 +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 >= MAX_STRING)
-		strcpy(print_string, "*** 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 {
-				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;
+	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;
+		}
 	}
-	spin_unlock_bh(&print_lock);
-}
 
-/**
- * TIPC_TEE - perform next output operation on both print buffers  
- */
-
-struct print_buf *TIPC_TEE(struct print_buf *b0, struct print_buf *b1)
-{
-	struct print_buf *pb = b0;
-
-	if (!b0 || (b0 == b1))
-		return b1;
-	if (!b1)
-		return b0;
+	if (pb->echo)
+		printk("%s", print_string);
 
-	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
  */
@@ -256,7 +274,7 @@ 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;
@@ -275,88 +293,97 @@ 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
+ * 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, ...)
 {
 	int len;
 
+	if (pb == TIPC_CONS)
+		return;
+
 	spin_lock_bh(&print_lock);
-	FORMAT(TIPC_CONS->buf, len, fmt);
-	printk(TIPC_CONS->buf);
-
-	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");
-	}
+
+	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_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 - set TIPC log print buffer to specified size
- */
-
-void tipc_log_reinit(int log_size)
-{
-	tipc_log_stop();
-
 	if (log_size) {
-		if (log_size <= MAX_STRING)
-			log_size = MAX_STRING + 1;
-		spin_lock_bh(&print_lock);
-		tipc_printbuf_init(TIPC_LOG, kmalloc(log_size, GFP_ATOMIC), log_size);
-		spin_unlock_bh(&print_lock);
+		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 - 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;
 
 	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
 		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 
-	value = *(u32 *)TLV_DATA(req_tlv_area);
-	value = ntohl(value);
+	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)");
-	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();
 }
 
@@ -369,27 +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;
 }