Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753828AbbLJSxH (ORCPT ); Thu, 10 Dec 2015 13:53:07 -0500 Received: from mga14.intel.com ([192.55.52.115]:42848 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753236AbbLJSw7 (ORCPT ); Thu, 10 Dec 2015 13:52:59 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,409,1444719600"; d="scan'208";a="615998202" From: Tom Zanussi To: rostedt@goodmis.org Cc: masami.hiramatsu.pt@hitachi.com, namhyung@kernel.org, josh@joshtriplett.org, andi@firstfloor.org, mathieu.desnoyers@efficios.com, peterz@infradead.org, linux-kernel@vger.kernel.org, Tom Zanussi Subject: [PATCH v13 21/29] tracing: Remove restriction on string position in hist trigger keys Date: Thu, 10 Dec 2015 12:51:03 -0600 Message-Id: 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: 4861 Lines: 149 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. Also, cast string return values to avoid warnings on 32-bit compiles. Finally, rearrange the code without changing any functionality by moving the compound key updating code into a separate function. Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim --- kernel/trace/trace_events_hist.c | 67 ++++++++++++++++++++++------------------ 1 file changed, 37 insertions(+), 30 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 36309c1..ad6666c 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -58,14 +58,14 @@ static u64 hist_field_dynstring(struct hist_field *hist_field, void *event) int str_loc = str_item & 0xffff; char *addr = (char *)(event + str_loc); - return (u64)addr; + return (u64)(unsigned long)addr; } static u64 hist_field_pstring(struct hist_field *hist_field, void *event) { char **addr = (char **)(event + hist_field->field->offset); - return (u64)*addr; + return (u64)(unsigned long)*addr; } #define DEFINE_HIST_FIELD_FN(type) \ @@ -518,8 +518,8 @@ 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; } @@ -814,9 +814,34 @@ 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; + + 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; + + /* ensure NULL-termination */ + 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; @@ -826,8 +851,7 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec) void *key = NULL; unsigned int i; - if (hist_data->n_keys > 1) - memset(compound_key, 0, hist_data->key_size); + memset(compound_key, 0, hist_data->key_size); for_each_hist_key_field(i, hist_data) { key_field = hist_data->fields[i]; @@ -844,35 +868,18 @@ 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 *)(unsigned long)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/