Messages in this thread Patch in this message | | | From | Jim Cromie <> | Subject | [PATCH 09/21] dynamic_debug: save_pending() saves non-matching queries for later. | Date | Mon, 11 Jul 2011 01:46:44 -0600 |
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When a query/rule doesnt match, 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.
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 added on the boot-line which do not match (because module is not built-in, and thus not present yet) are added to pending_queries.
IE, with these boot-line additions: dynamic_debug.verbose=1 ddebug_query="module scx200_hrt +p"
Kernel will log the following:
ddebug_exec_queries: query 0: "module scx200_hrt +p" ddebug_tokenize: split into words: "module" "scx200_hrt" "+p" ddebug_parse_query: parsed q->function="(null)" q->filename="(null)" \ q->module="scx200_hrt" q->format="(null)" q->lineno=0-0 ddebug_parse_flags: op='+' ddebug_parse_flags: flags=0x1 ddebug_parse_flags: *flagsp=0x1 *maskp=0xffffffff ddebug_exec_query: nfound 0 on q->function="(null)" q->filename="(null)" \ q->module="scx200_hrt" q->format="(null)" q->lineno=0-0 ddebug_save_pending: add to pending: q->function="(null)" q->filename="(null)"\ q->module="scx200_hrt" q->format="(null)" q->lineno=0-0 ddebug_save_pending: ddebug: query saved as pending 1
Signed-off-by: Jim Cromie <jim.cromie@gmail.com> --- lib/dynamic_debug.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 56 insertions(+), 0 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 81268e2..b049ef2 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) { @@ -421,6 +436,42 @@ 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; + + if (verbose) + pr_info("add to pending: %s\n", show_ddebug_query(query)); + + pending_ct++; + 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) + pq->query.module = strcpy(pq->module, query->module); + if (query->function) + pq->query.function = strcpy(pq->function, query->function); + if (query->filename) + pq->query.filename = strcpy(pq->filename, query->filename); + if (query->format) + pq->query.format = strcpy(pq->format, query->format); + + pq->flags = flags; + pq->mask = mask; + + mutex_lock(&ddebug_lock); + list_add(&pq->link, &pending_queries); + mutex_unlock(&ddebug_lock); + + if (verbose) + pr_info("query saved as pending %d\n", pending_ct); + return 0; +} + static int ddebug_exec_query(char *query_string) { unsigned int flags = 0, mask = 0; @@ -440,6 +491,11 @@ static int ddebug_exec_query(char *query_string) /* actually go and implement the change */ nfound = ddebug_change(&query, flags, mask); + + pr_info("nfound %d on %s\n", nfound, show_ddebug_query(&query)); + if (!nfound) + return ddebug_save_pending(&query, flags, mask); + return 0; } -- 1.7.4.1
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