Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754615AbZIXTtv (ORCPT ); Thu, 24 Sep 2009 15:49:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754223AbZIXTtt (ORCPT ); Thu, 24 Sep 2009 15:49:49 -0400 Received: from mail-ew0-f211.google.com ([209.85.219.211]:54837 "EHLO mail-ew0-f211.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753845AbZIXTtr (ORCPT ); Thu, 24 Sep 2009 15:49:47 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=ds96oNcqCPoXejTNUO+552G8z9GHz2OeX113xGlM1kv5CUXiQSydzAHIGCCJRur9g4 3HWpIshr//O5SFBRkkJs+QZKsyAhJu9YWfkJn2CN2ccfai8XZeQrRmlTUA4i6hH7nijS 7GSXx7GMx3s2SbV5U+O92451SbO98wdp9qABk= From: Frederic Weisbecker To: Ingo Molnar Cc: LKML , Frederic Weisbecker , Steven Rostedt , Tom Zanussi , Li Zefan Subject: [PATCH 4/5 v2] tracing/filters: Provide basic regex support Date: Thu, 24 Sep 2009 21:49:34 +0200 Message-Id: <1253821775-8618-5-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.6.2.3 In-Reply-To: <1253821775-8618-1-git-send-email-fweisbec@gmail.com> References: <1253821775-8618-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7932 Lines: 307 This patch provides basic support for regular expressions in filters. It supports the following types of regexp: - *match_beginning - *match_middle* - match_end* - !don't match Example: cd /debug/tracing/events/bkl/lock_kernel echo 'file == "*reiserfs*"' > filter echo 1 > enable gedit-4941 [000] 457.735437: lock_kernel: depth: 0, fs/reiserfs/namei.c:334 reiserfs_lookup() sync_supers-227 [001] 461.379985: lock_kernel: depth: 0, fs/reiserfs/super.c:69 reiserfs_sync_fs() sync_supers-227 [000] 461.383096: lock_kernel: depth: 0, fs/reiserfs/journal.c:1069 flush_commit_list() reiserfs/1-1369 [001] 461.479885: lock_kernel: depth: 0, fs/reiserfs/journal.c:3509 flush_async_commits() Every string is now handled as a regexp in the filter framework, which helps to factorize the code for handling both simple strings and regexp comparisons. (The regexp parsing code has been wildly cherry picked from ftrace.c written by Steve.) v2: Simplify the whole and drop the filter_regex file Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Tom Zanussi Cc: Li Zefan --- kernel/trace/trace.h | 27 ++++-- kernel/trace/trace_events_filter.c | 155 ++++++++++++++++++++++++++++++++---- 2 files changed, 157 insertions(+), 25 deletions(-) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 86bcff9..8d0db60 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -702,20 +702,29 @@ struct event_subsystem { }; struct filter_pred; +struct regex; typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event, int val1, int val2); +typedef int (*regex_match_func)(char *str, struct regex *r, int len); + +struct regex { + char pattern[MAX_FILTER_STR_VAL]; + int len; + int field_len; + regex_match_func match; +}; + struct filter_pred { - filter_pred_fn_t fn; - u64 val; - char str_val[MAX_FILTER_STR_VAL]; - int str_len; - char *field_name; - int offset; - int not; - int op; - int pop_n; + filter_pred_fn_t fn; + u64 val; + struct regex regex; + char *field_name; + int offset; + int not; + int op; + int pop_n; }; extern void print_event_filter(struct ftrace_event_call *call, diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 189663d..d3c94c1 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -195,9 +195,9 @@ static int filter_pred_string(struct filter_pred *pred, void *event, char *addr = (char *)(event + pred->offset); int cmp, match; - cmp = strncmp(addr, pred->str_val, pred->str_len); + cmp = pred->regex.match(addr, &pred->regex, pred->regex.field_len); - match = (!cmp) ^ pred->not; + match = cmp ^ pred->not; return match; } @@ -209,9 +209,9 @@ static int filter_pred_pchar(struct filter_pred *pred, void *event, char **addr = (char **)(event + pred->offset); int cmp, match; - cmp = strncmp(*addr, pred->str_val, pred->str_len); + cmp = pred->regex.match(*addr, &pred->regex, pred->regex.field_len); - match = (!cmp) ^ pred->not; + match = cmp ^ pred->not; return match; } @@ -235,9 +235,9 @@ static int filter_pred_strloc(struct filter_pred *pred, void *event, char *addr = (char *)(event + str_loc); int cmp, match; - cmp = strncmp(addr, pred->str_val, str_len); + cmp = pred->regex.match(addr, &pred->regex, str_len); - match = (!cmp) ^ pred->not; + match = cmp ^ pred->not; return match; } @@ -248,6 +248,126 @@ static int filter_pred_none(struct filter_pred *pred, void *event, return 0; } +/* Basic regex callbacks */ +static int regex_match_full(char *str, struct regex *r, int len) +{ + if (strncmp(str, r->pattern, len) == 0) + return 1; + return 0; +} + +static int regex_match_front(char *str, struct regex *r, int len) +{ + if (strncmp(str, r->pattern, len) == 0) + return 1; + return 0; +} + +static int regex_match_middle(char *str, struct regex *r, int len) +{ + if (strstr(str, r->pattern)) + return 1; + return 0; +} + +static int regex_match_end(char *str, struct regex *r, int len) +{ + char *ptr = strstr(str, r->pattern); + + if (ptr && (ptr[r->len] == 0)) + return 1; + return 0; +} + +enum regex_type { + MATCH_FULL, + MATCH_FRONT_ONLY, + MATCH_MIDDLE_ONLY, + MATCH_END_ONLY, +}; + +/* + * Pass in a buffer containing a regex and this function will + * set search to point to the search part of the buffer and + * return the type of search it is (see enum above). + * This does modify buff. + * + * Returns enum type. + * search returns the pointer to use for comparison. + * not returns 1 if buff started with a '!' + * 0 otherwise. + */ +static enum regex_type +filter_parse_regex(char *buff, int len, char **search, int *not) +{ + int type = MATCH_FULL; + int i; + + if (buff[0] == '!') { + *not = 1; + buff++; + len--; + } else + *not = 0; + + *search = buff; + + for (i = 0; i < len; i++) { + if (buff[i] == '*') { + if (!i) { + *search = buff + 1; + type = MATCH_END_ONLY; + } else { + if (type == MATCH_END_ONLY) + type = MATCH_MIDDLE_ONLY; + else + type = MATCH_FRONT_ONLY; + buff[i] = 0; + break; + } + } + } + + return type; +} + +static int filter_build_regex(struct filter_pred *pred) +{ + struct regex *r = &pred->regex; + char *search, *dup; + enum regex_type type; + int not; + + type = filter_parse_regex(r->pattern, r->len, &search, ¬); + dup = kstrdup(search, GFP_KERNEL); + if (!dup) + return -ENOMEM; + + strcpy(r->pattern, dup); + kfree(dup); + + r->len = strlen(r->pattern); + + switch (type) { + case MATCH_FULL: + r->match = regex_match_full; + break; + case MATCH_FRONT_ONLY: + r->match = regex_match_front; + break; + case MATCH_MIDDLE_ONLY: + r->match = regex_match_middle; + break; + case MATCH_END_ONLY: + r->match = regex_match_end; + break; + } + + pred->not ^= not; + + return 0; +} + /* return 1 if event matches, 0 otherwise (discard) */ int filter_match_preds(struct ftrace_event_call *call, void *rec) { @@ -394,7 +514,7 @@ static void filter_clear_pred(struct filter_pred *pred) { kfree(pred->field_name); pred->field_name = NULL; - pred->str_len = 0; + pred->regex.len = 0; } static int filter_set_pred(struct filter_pred *dest, @@ -658,21 +778,24 @@ static int filter_add_pred(struct filter_parse_state *ps, } if (is_string_field(field)) { - pred->str_len = field->size; + ret = filter_build_regex(pred); + if (ret) + return ret; - if (field->filter_type == FILTER_STATIC_STRING) + if (field->filter_type == FILTER_STATIC_STRING) { fn = filter_pred_string; - else if (field->filter_type == FILTER_DYN_STRING) - fn = filter_pred_strloc; + pred->regex.field_len = field->size; + } else if (field->filter_type == FILTER_DYN_STRING) + fn = filter_pred_strloc; else { fn = filter_pred_pchar; - pred->str_len = strlen(pred->str_val); + pred->regex.field_len = strlen(pred->regex.pattern); } } else { if (field->is_signed) - ret = strict_strtoll(pred->str_val, 0, &val); + ret = strict_strtoll(pred->regex.pattern, 0, &val); else - ret = strict_strtoull(pred->str_val, 0, &val); + ret = strict_strtoull(pred->regex.pattern, 0, &val); if (ret) { parse_error(ps, FILT_ERR_ILLEGAL_INTVAL, 0); return -EINVAL; @@ -1042,8 +1165,8 @@ static struct filter_pred *create_pred(int op, char *operand1, char *operand2) return NULL; } - strcpy(pred->str_val, operand2); - pred->str_len = strlen(operand2); + strcpy(pred->regex.pattern, operand2); + pred->regex.len = strlen(pred->regex.pattern); pred->op = op; -- 1.6.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/