From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753232Ab1GYVrB (ORCPT ); Mon, 25 Jul 2011 17:47:01 -0400 Received: from mail-pz0-f42.google.com ([209.85.210.42]:39747 "EHLO mail-pz0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753111Ab1GYVne (ORCPT ); Mon, 25 Jul 2011 17:43:34 -0400 From: Jim Cromie To: jbaron@redhat.com Cc: bvanassche@acm.org, joe@perches.com, gregkh@suse.de, linux-kernel@vger.kernel.org, gnb@fmeh.org, Jim Cromie Subject: [PATCH 12/25] dynamic_debug: save non-matching queries to pending-list for later application. Date: Mon, 25 Jul 2011 15:42:37 -0600 Message-Id: <1311630170-26057-13-git-send-email-jim.cromie@gmail.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1311630170-26057-1-git-send-email-jim.cromie@gmail.com> References: <1311630170-26057-1-git-send-email-jim.cromie@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When a query/rule doesnt match against current callsites, call save_pending(new function) to copy the query off the stack, into a (new) struct pending_query, and add to pending_queries (new) list. Alter ddebug_change to return number of matches found for query/rule. Patch adds: /sys/module/dynamic_debug/parameters/ verbose - rw, added previously, here for completeness pending_ct - ro, shows current count of pending queries With this and previous patches, queries submitted (on the boot-line for example) which do not match (because module is not built-in, and thus not present yet) are added to pending_queries. Clear pending list in ddebug_remove_all_tables(). Note that latter is currently only used for init-error path, its not called during cleanup. Signed-off-by: Jim Cromie --- lib/dynamic_debug.c | 108 +++++++++++++++++++++++++++++++++++++++++++++++--- 1 files changed, 101 insertions(+), 7 deletions(-) diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 5774a6f..4135bf5 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -53,6 +53,16 @@ struct ddebug_query { unsigned int first_lineno, last_lineno; }; +struct pending_query { + struct list_head link; + struct ddebug_query query; + char filename[100]; + char module[30]; + char function[50]; + char format[200]; + unsigned int flags, mask; +}; + struct ddebug_iter { struct ddebug_table *table; unsigned int idx; @@ -63,6 +73,11 @@ static LIST_HEAD(ddebug_tables); static int verbose = 0; module_param(verbose, int, 0644); +/* legal but inapplicable queries, save and test against new modules */ +static LIST_HEAD(pending_queries); +static int pending_ct; +module_param(pending_ct, int, 0444); + /* Return the last part of a pathname */ static inline const char *basename(const char *path) { @@ -111,14 +126,31 @@ static char *show_ddebug_query(const struct ddebug_query *q) return p; } +static char *show_pending_query(struct pending_query *pq) +{ + struct ddebug_query *q = &pq->query; + + char *p = kasprintf(GFP_KERNEL, + "func=\"%s\" file=\"%s\" " + "module=\"%s\" format=\"%s\" lineno=%u-%u" + " flags=0x%x mask=0x%x", + q->function ? q->function : "", + q->filename ? q->filename : "", + q->module ? q->module : "", + q->format ? q->format : "", + q->first_lineno, q->last_lineno, + pq->flags, pq->mask); + return p; +} + /* * Search the tables for _ddebug's which match the given * `query' and apply the `flags' and `mask' to them. Tells * the user which ddebug's were changed, or whether none * were matched. */ -static void ddebug_change(const struct ddebug_query *query, - unsigned int flags, unsigned int mask) +static int ddebug_change(const struct ddebug_query *query, + unsigned int flags, unsigned int mask) { int i; struct ddebug_table *dt; @@ -181,8 +213,7 @@ static void ddebug_change(const struct ddebug_query *query, } mutex_unlock(&ddebug_lock); - if (!nfound) - pr_debug("no matches for query\n"); + return nfound; } /* @@ -421,13 +452,58 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp, return 0; } +/* copy query off stack, save flags & mask, and store in pending-list */ +static int ddebug_save_pending(struct ddebug_query *query, + unsigned int flags, unsigned int mask) +{ + struct pending_query *pq; + char *qstr; + + qstr = show_ddebug_query(query); + pr_debug("add to pending: %s\n", qstr); + kfree(qstr); + + pq = kzalloc(sizeof(struct pending_query), GFP_KERNEL); + if (pq == NULL) + return -ENOMEM; + + /* copy non-null match-specs into allocd mem, update pointers */ + if (query->module) { + strlcpy(pq->module, query->module, sizeof(pq->module)); + pq->query.module = pq->module; + } + if (query->function) { + strlcpy(pq->function, query->function, sizeof(pq->function)); + pq->query.function = pq->function; + } + if (query->filename) { + strlcpy(pq->filename, query->filename, sizeof(pq->filename)); + pq->query.filename = pq->filename; + } + if (query->format) { + strlcpy(pq->format, query->format, sizeof(pq->format)); + pq->query.format = pq->format; + } + pq->flags = flags; + pq->mask = mask; + + mutex_lock(&ddebug_lock); + list_add(&pq->link, &pending_queries); + pending_ct++; + mutex_unlock(&ddebug_lock); + + pr_debug("query saved as pending %d\n", pending_ct); + return 0; +} + static int ddebug_exec_query(char *query_string) { unsigned int flags = 0, mask = 0; struct ddebug_query query; #define MAXWORDS 9 int nwords; - char *words[MAXWORDS]; + char *words[MAXWORDS], *qstr; + int nfound, rc = 0; nwords = ddebug_tokenize(query_string, words, MAXWORDS); if (nwords <= 0) @@ -438,8 +514,17 @@ static int ddebug_exec_query(char *query_string) return -EINVAL; /* actually go and implement the change */ - ddebug_change(&query, flags, mask); - return 0; + nfound = ddebug_change(&query, flags, mask); + qstr = show_ddebug_query(&query); + pr_debug("nfound %d on %s\n", nfound, qstr); + if (!nfound) { + if (flags & _DPRINTK_FLAGS_APPEND) + rc = ddebug_save_pending(&query, flags, mask); + else + pr_warn("no match on: %s\n", qstr); + } + kfree(qstr); + return rc; } /* handle multiple queries, continue on error, return last error */ @@ -845,6 +930,8 @@ EXPORT_SYMBOL_GPL(ddebug_remove_module); static void ddebug_remove_all_tables(void) { + struct pending_query *pq, *pqnext; + mutex_lock(&ddebug_lock); while (!list_empty(&ddebug_tables)) { struct ddebug_table *dt = list_entry(ddebug_tables.next, @@ -852,6 +939,13 @@ static void ddebug_remove_all_tables(void) link); ddebug_table_free(dt); } + list_for_each_entry_safe(pq, pqnext, &pending_queries, link) { + char *qstr = show_pending_query(pq); + pr_debug("delete pending: %s\n", qstr); + kfree(qstr); + list_del_init(&pq->link); + kfree(pq); + } mutex_unlock(&ddebug_lock); } -- 1.7.4.1