From patchwork Tue Aug 23 22:09:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Rogers X-Patchwork-Id: 12952653 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EC00C32772 for ; Tue, 23 Aug 2022 22:12:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233219AbiHWWMm (ORCPT ); Tue, 23 Aug 2022 18:12:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233051AbiHWWMG (ORCPT ); Tue, 23 Aug 2022 18:12:06 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0DCD77AC3C for ; Tue, 23 Aug 2022 15:11:05 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-335ff2ef600so261881307b3.18 for ; Tue, 23 Aug 2022 15:11:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:from:to:cc; bh=oBQ8fNk49ilPWpXTVU4R9YnuRnoXvu3xuE3Ff0vlliw=; b=ZtQXSc3nLMgidV0RkXHAnNfb+wLDHFqtJ2m2CLNTkr9/mk1Pb2lwWkDQDUIRWunlg+ JiLUE2TGYDpGiLgCmsBuVaVEg1BcTU5heky1RUQMVhyxvVDnaw00zccMmaCPs8/Ydk3o RcGVndc2p39zpI5Ai5vGpaTxsKlv/L3zgINK+6jbONVRdMRxTmm28HFq9/6vHIJGzl+i c52JNYUJjH7z2noWJjC8TFLzblNOHBxhyqaYt3CPSgiJNGkZvPuxbWJPYQ2tYJL2kaAq uvEClhlGisibgw2+5AV1jT+xjgGe7vw33oSqWtBSsX3Rllh1pIbzBIeDCtsqXAgUpbuu PKdg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:x-gm-message-state:from:to:cc; bh=oBQ8fNk49ilPWpXTVU4R9YnuRnoXvu3xuE3Ff0vlliw=; b=R2KFKvuU+gR2u0QlM8UpDC0RgeypKmi2tf9wIrCXCEAxsUOM6oPWZEeDXC9KUgp1Nj dy6sGHm/MbgjffbJHbrLK2fpf1gBAUlO4k0s1nXKIPQA7u01uKxbex/mbH702xu7UEEI Cj1N9PeoKz8qtJZi0Qz2AlOLvSV8xIxC3cXE3iuH6CrBcynhzBxyZZsW8Tgbdc+p+3YG jvnwvAjL4G64KCu8jtRxhUjHMXbtA7A9iHlCrl0XBaGloxUydy9JtjXOF+nx9MebcmjH z25khLVCmR4mJA6sJv5DwxQg6MwdMzzVl6qcf3Kc4E3oMh/POX7Qy6DA+zSWmsVzFdpN C4/Q== X-Gm-Message-State: ACgBeo1wkZ4m+YIyxVXsaRohTkCRt0jx+439E2z698wJrJkIzOOfTJB7 qakj8c+2ybA0rZGCCDMqUg8f53L/6wQk X-Google-Smtp-Source: AA6agR4b/l59aAfX2CCgdljg/llF2RNbdpziMN0iJsvjeCzIe3p/c4gad5OdNLA9Z/E64+34TQ87ZO+tJ3li X-Received: from irogers.svl.corp.google.com ([2620:15c:2d4:203:7dbd:c08f:de81:c2a3]) (user=irogers job=sendgmr) by 2002:a0d:dcc7:0:b0:325:314c:9a30 with SMTP id f190-20020a0ddcc7000000b00325314c9a30mr28547074ywe.121.1661292664801; Tue, 23 Aug 2022 15:11:04 -0700 (PDT) Date: Tue, 23 Aug 2022 15:09:19 -0700 In-Reply-To: <20220823220922.256001-1-irogers@google.com> Message-Id: <20220823220922.256001-16-irogers@google.com> Mime-Version: 1.0 References: <20220823220922.256001-1-irogers@google.com> X-Mailer: git-send-email 2.37.2.609.g9ff673ca1a-goog Subject: [PATCH v2 15/18] perf mutex: Add thread safety annotations From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Darren Hart , Davidlohr Bueso , " =?utf-8?q?Andr=C3=A9_Almeida?= " , Nathan Chancellor , Nick Desaulniers , Tom Rix , Weiguo Li , Athira Rajeev , Thomas Richter , Ravi Bangoria , Dario Petrillo , Hewenliang , yaowenbin , Wenyu Liu , Song Liu , Andrii Nakryiko , Dave Marchevsky , Leo Yan , Kim Phillips , Pavithra Gurushankar , Alexandre Truong , Quentin Monnet , William Cohen , Andres Freund , Adrian Hunter , " =?utf-8?q?Martin_Li=C5=A1ka?= " , Colin Ian King , James Clark , Fangrui Song , Stephane Eranian , Kajol Jain , Alexey Bayduraev , Riccardo Mancini , Andi Kleen , Masami Hiramatsu , Zechuan Chen , Jason Wang , Christophe JAILLET , Remi Bernon , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, bpf@vger.kernel.org, llvm@lists.linux.dev Cc: Ian Rogers Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add thread safety annotations to struct mutex so that when compiled with clang's -Wthread-safety warnings are generated for erroneous lock patterns. NO_THREAD_SAFETY_ANALYSIS is needed for mutex_lock/mutex_unlock as the analysis doesn't under pthread calls. Signed-off-by: Ian Rogers --- tools/perf/util/mutex.c | 2 ++ tools/perf/util/mutex.h | 72 ++++++++++++++++++++++++++++++++++++++--- 2 files changed, 69 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/mutex.c b/tools/perf/util/mutex.c index d12cf0714268..c936557d8bbb 100644 --- a/tools/perf/util/mutex.c +++ b/tools/perf/util/mutex.c @@ -40,11 +40,13 @@ void mutex_destroy(struct mutex *mtx) } void mutex_lock(struct mutex *mtx) + NO_THREAD_SAFETY_ANALYSIS { CHECK_ERR(pthread_mutex_lock(&mtx->lock)); } void mutex_unlock(struct mutex *mtx) + NO_THREAD_SAFETY_ANALYSIS { CHECK_ERR(pthread_mutex_unlock(&mtx->lock)); } diff --git a/tools/perf/util/mutex.h b/tools/perf/util/mutex.h index 952276ad83bd..6c2062d41a4e 100644 --- a/tools/perf/util/mutex.h +++ b/tools/perf/util/mutex.h @@ -5,11 +5,73 @@ #include #include +/* + * A function-like feature checking macro that is a wrapper around + * `__has_attribute`, which is defined by GCC 5+ and Clang and evaluates to a + * nonzero constant integer if the attribute is supported or 0 if not. + */ +#ifdef __has_attribute +#define HAVE_ATTRIBUTE(x) __has_attribute(x) +#else +#define HAVE_ATTRIBUTE(x) 0 +#endif + + +#if HAVE_ATTRIBUTE(guarded_by) && HAVE_ATTRIBUTE(pt_guarded_by) && \ + HAVE_ATTRIBUTE(lockable) && HAVE_ATTRIBUTE(exclusive_lock_function) && \ + HAVE_ATTRIBUTE(exclusive_trylock_function) && HAVE_ATTRIBUTE(exclusive_locks_required) && \ + HAVE_ATTRIBUTE(no_thread_safety_analysis) + +/* Documents if a shared field or global variable needs to be protected by a mutex. */ +#define GUARDED_BY(x) __attribute__((guarded_by(x))) + +/* + * Documents if the memory location pointed to by a pointer should be guarded by + * a mutex when dereferencing the pointer. + */ +#define PT_GUARDED_BY(x) __attribute__((pt_guarded_by(x))) + +/* Documents if a type is a lockable type. */ +#define LOCKABLE __attribute__((capability("lockable"))) + +/* Documents functions that acquire a lock in the body of a function, and do not release it. */ +#define EXCLUSIVE_LOCK_FUNCTION(...) __attribute__((exclusive_lock_function(__VA_ARGS__))) + +/* + * Documents functions that expect a lock to be held on entry to the function, + * and release it in the body of the function. + */ +#define UNLOCK_FUNCTION(...) __attribute__((unlock_function(__VA_ARGS__))) + +/* Documents functions that try to acquire a lock, and return success or failure. */ +#define EXCLUSIVE_TRYLOCK_FUNCTION(...) \ + __attribute__((exclusive_trylock_function(__VA_ARGS__))) + + +/* Documents a function that expects a mutex to be held prior to entry. */ +#define EXCLUSIVE_LOCKS_REQUIRED(...) __attribute__((exclusive_locks_required(__VA_ARGS__))) + +/* Turns off thread safety checking within the body of a particular function. */ +#define NO_THREAD_SAFETY_ANALYSIS __attribute__((no_thread_safety_analysis)) + +#else + +#define GUARDED_BY(x) +#define PT_GUARDED_BY(x) +#define LOCKABLE +#define EXCLUSIVE_LOCK_FUNCTION(...) +#define UNLOCK_FUNCTION(...) +#define EXCLUSIVE_TRYLOCK_FUNCTION(...) +#define EXCLUSIVE_LOCKS_REQUIRED(...) +#define NO_THREAD_SAFETY_ANALYSIS + +#endif + /* * A wrapper around the mutex implementation that allows perf to error check * usage, etc. */ -struct mutex { +struct LOCKABLE mutex { pthread_mutex_t lock; }; @@ -25,9 +87,9 @@ struct cond { void mutex_init(struct mutex *mtx, bool pshared); void mutex_destroy(struct mutex *mtx); -void mutex_lock(struct mutex *mtx); -void mutex_unlock(struct mutex *mtx); -bool mutex_trylock(struct mutex *mtx); +void mutex_lock(struct mutex *mtx) EXCLUSIVE_LOCK_FUNCTION(*mtx); +void mutex_unlock(struct mutex *mtx) UNLOCK_FUNCTION(*mtx); +bool mutex_trylock(struct mutex *mtx) EXCLUSIVE_TRYLOCK_FUNCTION(true, *mtx); /* * Initialize the cond struct, if pshared is set then specify the process-shared @@ -36,7 +98,7 @@ bool mutex_trylock(struct mutex *mtx); void cond_init(struct cond *cnd, bool pshared); void cond_destroy(struct cond *cnd); -void cond_wait(struct cond *cnd, struct mutex *mtx); +void cond_wait(struct cond *cnd, struct mutex *mtx) EXCLUSIVE_LOCKS_REQUIRED(mtx); void cond_signal(struct cond *cnd); void cond_broadcast(struct cond *cnd);