Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753180AbZDQF1W (ORCPT ); Fri, 17 Apr 2009 01:27:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751610AbZDQF1N (ORCPT ); Fri, 17 Apr 2009 01:27:13 -0400 Received: from mail-gx0-f160.google.com ([209.85.217.160]:47282 "EHLO mail-gx0-f160.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751078AbZDQF1M (ORCPT ); Fri, 17 Apr 2009 01:27:12 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:content-type:date:message-id:mime-version :x-mailer:content-transfer-encoding; b=kkQa805bzKKsypup0RVUh2LGjdEHBIjThNt/SfhNKZCGpOLxjpgcV7heFswfhsMeFG uMD8pWA44n4jnfC5FmH2y0yVc6bzSNJMxeh7jCIe4/nwBlVxnt3w5BA124Rp1GMwqwUn 4Iqw3dG1+xcBPSFosI6373x9Vv1HApWzo8+Rk= Subject: [PATCH v2] tracing/filters: add filter_mutex to protect filter predicates From: Tom Zanussi To: Li Zefan Cc: Frederic Weisbecker , LKML , Ingo Molnar , Steven Rostedt , paulmck@linux.vnet.ibm.com Content-Type: text/plain Date: Fri, 17 Apr 2009 00:27:08 -0500 Message-Id: <1239946028.6639.13.camel@tropicana> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8172 Lines: 278 This patch adds a filter_mutex to prevent the filter predicates from being accessed concurrently by various external functions. It's based on a previous patch by Li Zefan: "[PATCH 7/7] tracing/filters: make filter preds RCU safe" v2 changes: - fixed wrong value returned in a add_subsystem_pred() failure case noticed by Li Zefan. Signed-off-by: Tom Zanussi --- kernel/trace/trace.h | 4 +- kernel/trace/trace_events.c | 4 +- kernel/trace/trace_events_filter.c | 90 ++++++++++++++++++++++++++++-------- 3 files changed, 75 insertions(+), 23 deletions(-) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index eb92307..8750e83 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -759,13 +759,15 @@ struct filter_pred { }; extern void filter_free_pred(struct filter_pred *pred); -extern void filter_print_preds(struct filter_pred **preds, int n_preds, +extern void filter_print_preds(struct ftrace_event_call *call, struct trace_seq *s); extern int filter_parse(char **pbuf, struct filter_pred *pred); extern int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred); extern void filter_disable_preds(struct ftrace_event_call *call); extern void filter_free_subsystem_preds(struct event_subsystem *system); +extern void filter_print_subsystem_preds(struct event_subsystem *system, + struct trace_seq *s); extern int filter_add_subsystem_pred(struct event_subsystem *system, struct filter_pred *pred); diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 8af3534..e6d6404 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -488,7 +488,7 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt, trace_seq_init(s); - filter_print_preds(call->preds, call->n_preds, s); + filter_print_preds(call, s); r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); kfree(s); @@ -558,7 +558,7 @@ subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt, trace_seq_init(s); - filter_print_preds(system->preds, system->n_preds, s); + filter_print_subsystem_preds(system, s); r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); kfree(s); diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index f8e5eab..e0fcfd2 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -22,10 +22,13 @@ #include #include #include +#include #include "trace.h" #include "trace_output.h" +static DEFINE_MUTEX(filter_mutex); + static int filter_pred_64(struct filter_pred *pred, void *event) { u64 *addr = (u64 *)(event + pred->offset); @@ -112,8 +115,8 @@ int filter_match_preds(struct ftrace_event_call *call, void *rec) } EXPORT_SYMBOL_GPL(filter_match_preds); -void filter_print_preds(struct filter_pred **preds, int n_preds, - struct trace_seq *s) +static void __filter_print_preds(struct filter_pred **preds, int n_preds, + struct trace_seq *s) { char *field_name; struct filter_pred *pred; @@ -138,6 +141,21 @@ void filter_print_preds(struct filter_pred **preds, int n_preds, } } +void filter_print_preds(struct ftrace_event_call *call, struct trace_seq *s) +{ + mutex_lock(&filter_mutex); + __filter_print_preds(call->preds, call->n_preds, s); + mutex_unlock(&filter_mutex); +} + +void filter_print_subsystem_preds(struct event_subsystem *system, + struct trace_seq *s) +{ + mutex_lock(&filter_mutex); + __filter_print_preds(system->preds, system->n_preds, s); + mutex_unlock(&filter_mutex); +} + static struct ftrace_event_field * find_event_field(struct ftrace_event_call *call, char *name) { @@ -180,7 +198,7 @@ static int filter_set_pred(struct filter_pred *dest, return 0; } -void filter_disable_preds(struct ftrace_event_call *call) +static void __filter_disable_preds(struct ftrace_event_call *call) { int i; @@ -190,6 +208,13 @@ void filter_disable_preds(struct ftrace_event_call *call) call->preds[i]->fn = filter_pred_none; } +void filter_disable_preds(struct ftrace_event_call *call) +{ + mutex_lock(&filter_mutex); + __filter_disable_preds(call); + mutex_unlock(&filter_mutex); +} + int init_preds(struct ftrace_event_call *call) { struct filter_pred *pred; @@ -223,7 +248,7 @@ oom: } EXPORT_SYMBOL_GPL(init_preds); -void filter_free_subsystem_preds(struct event_subsystem *system) +static void __filter_free_subsystem_preds(struct event_subsystem *system) { struct ftrace_event_call *call; int i; @@ -241,18 +266,25 @@ void filter_free_subsystem_preds(struct event_subsystem *system) continue; if (!strcmp(call->system, system->name)) - filter_disable_preds(call); + __filter_disable_preds(call); } } -static int __filter_add_pred(struct ftrace_event_call *call, - struct filter_pred *pred, - filter_pred_fn_t fn) +void filter_free_subsystem_preds(struct event_subsystem *system) +{ + mutex_lock(&filter_mutex); + __filter_free_subsystem_preds(system); + mutex_unlock(&filter_mutex); +} + +static int filter_add_pred_fn(struct ftrace_event_call *call, + struct filter_pred *pred, + filter_pred_fn_t fn) { int idx, err; if (call->n_preds && !pred->compound) - filter_disable_preds(call); + __filter_disable_preds(call); if (call->n_preds == MAX_FILTER_PRED) return -ENOSPC; @@ -276,7 +308,8 @@ static int is_string_field(const char *type) return 0; } -int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred) +static int __filter_add_pred(struct ftrace_event_call *call, + struct filter_pred *pred) { struct ftrace_event_field *field; filter_pred_fn_t fn; @@ -293,7 +326,7 @@ int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred) return -EINVAL; fn = filter_pred_string; pred->str_len = field->size; - return __filter_add_pred(call, pred, fn); + return filter_add_pred_fn(call, pred, fn); } else { if (pred->str_len) return -EINVAL; @@ -316,7 +349,18 @@ int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred) return -EINVAL; } - return __filter_add_pred(call, pred, fn); + return filter_add_pred_fn(call, pred, fn); +} + +int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred) +{ + int err; + + mutex_lock(&filter_mutex); + err = __filter_add_pred(call, pred); + mutex_unlock(&filter_mutex); + + return err; } int filter_add_subsystem_pred(struct event_subsystem *system, @@ -324,20 +368,27 @@ int filter_add_subsystem_pred(struct event_subsystem *system, { struct ftrace_event_call *call; + mutex_lock(&filter_mutex); + if (system->n_preds && !pred->compound) - filter_free_subsystem_preds(system); + __filter_free_subsystem_preds(system); if (!system->n_preds) { system->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL); - if (!system->preds) + if (!system->preds) { + mutex_unlock(&filter_mutex); return -ENOMEM; + } } - if (system->n_preds == MAX_FILTER_PRED) + if (system->n_preds == MAX_FILTER_PRED) { + mutex_unlock(&filter_mutex); return -ENOSPC; + } system->preds[system->n_preds] = pred; + system->n_preds++; list_for_each_entry(call, &ftrace_events, list) { int err; @@ -348,17 +399,16 @@ int filter_add_subsystem_pred(struct event_subsystem *system, if (strcmp(call->system, system->name)) continue; - if (!find_event_field(call, pred->field_name)) - continue; - - err = filter_add_pred(call, pred); + err = __filter_add_pred(call, pred); if (err == -ENOMEM) { system->preds[system->n_preds] = NULL; + system->n_preds--; + mutex_unlock(&filter_mutex); return err; } } - system->n_preds++; + mutex_unlock(&filter_mutex); return 0; } -- 1.5.6.3 -- 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/