Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932502AbbGPRZJ (ORCPT ); Thu, 16 Jul 2015 13:25:09 -0400 Received: from mga11.intel.com ([192.55.52.93]:41789 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932394AbbGPRYG (ORCPT ); Thu, 16 Jul 2015 13:24:06 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,488,1432623600"; d="scan'208";a="525475493" From: Tom Zanussi To: rostedt@goodmis.org Cc: daniel.wagner@bmw-carit.de, masami.hiramatsu.pt@hitachi.com, namhyung@kernel.org, josh@joshtriplett.org, andi@firstfloor.org, linux-kernel@vger.kernel.org, Tom Zanussi Subject: [PATCH v9 20/22] tracing: Remove restriction on string position in hist trigger keys Date: Thu, 16 Jul 2015 12:22:53 -0500 Message-Id: <226f0a817bd72c2fd78c3b72c0fa79e9e8f394b1.1437066836.git.tom.zanussi@linux.intel.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4194 Lines: 130 If we assume the maximum size for a string field, we don't have to worry about its position. Since we only allow two keys in a compound key and having more than one string key in a given compound key doesn't make much sense anyway, trading a bit of extra space instead of introducing an arbitrary restriction makes more sense. We also need to use the event field size for static strings when copying the contents, otherwise we get random garbage in the key. Finally, rearrange the code without changing any functionality by moving the compound key updating code into a separate function. Signed-off-by: Tom Zanussi --- kernel/trace/trace_events_hist.c | 65 +++++++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 28 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 67fffee..4ba7645 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -508,8 +508,8 @@ static int create_key_field(struct hist_trigger_data *hist_data, goto out; } - if (is_string_field(field)) /* should be last key field */ - key_size = HIST_KEY_SIZE_MAX - key_offset; + if (is_string_field(field)) + key_size = MAX_FILTER_STR_VAL; else key_size = field->size; } @@ -781,9 +781,36 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, } } +static inline void add_to_key(char *compound_key, void *key, + struct hist_field *key_field, void *rec) +{ + size_t size = key_field->size; + + if (key_field->flags & HIST_FIELD_STRING) { + struct ftrace_event_field *field; + + /* ensure NULL-termination */ + size--; + + field = key_field->field; + if (field->filter_type == FILTER_DYN_STRING) + size = *(u32 *)(rec + field->offset) >> 16; + else if (field->filter_type == FILTER_PTR_STRING) + size = strlen(key); + else if (field->filter_type == FILTER_STATIC_STRING) + size = field->size; + + if (size > key_field->size - 1) + size = key_field->size - 1; + } + + memcpy(compound_key + key_field->offset, key, size); +} + static void event_hist_trigger(struct event_trigger_data *data, void *rec) { struct hist_trigger_data *hist_data = data->private_data; + bool use_compound_key = (hist_data->n_keys > 1); unsigned long entries[HIST_STACKTRACE_DEPTH]; char compound_key[HIST_KEY_SIZE_MAX]; struct stack_trace stacktrace; @@ -798,8 +825,7 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec) return; } - if (hist_data->n_keys > 1) - memset(compound_key, 0, hist_data->key_size); + memset(compound_key, 0, hist_data->key_size); for (i = hist_data->n_vals; i < hist_data->n_fields; i++) { key_field = hist_data->fields[i]; @@ -816,35 +842,18 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec) key = entries; } else { field_contents = key_field->fn(key_field, rec); - if (key_field->flags & HIST_FIELD_STRING) + if (key_field->flags & HIST_FIELD_STRING) { key = (void *)field_contents; - else + use_compound_key = true; + } else key = (void *)&field_contents; - - if (hist_data->n_keys > 1) { - /* ensure NULL-termination */ - size_t size = key_field->size - 1; - - if (key_field->flags & HIST_FIELD_STRING) { - struct ftrace_event_field *field; - - field = key_field->field; - if (field->filter_type == FILTER_DYN_STRING) - size = *(u32 *)(rec + field->offset) >> 16; - else if (field->filter_type == FILTER_PTR_STRING) - size = strlen(key); - - if (size > key_field->size - 1) - size = key_field->size - 1; - } - - memcpy(compound_key + key_field->offset, key, - size); - } } + + if (use_compound_key) + add_to_key(compound_key, key, key_field, rec); } - if (hist_data->n_keys > 1) + if (use_compound_key) key = compound_key; elt = tracing_map_insert(hist_data->map, key); -- 1.9.3 -- 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/