From patchwork Wed Aug 24 15:38:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Rogers X-Patchwork-Id: 12953759 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 5CF1CC32796 for ; Wed, 24 Aug 2022 15:41:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239681AbiHXPlk (ORCPT ); Wed, 24 Aug 2022 11:41:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52578 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239788AbiHXPlP (ORCPT ); Wed, 24 Aug 2022 11:41:15 -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 C038F5A8A1 for ; Wed, 24 Aug 2022 08:41:02 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-33931a5c133so211742107b3.17 for ; Wed, 24 Aug 2022 08:41:02 -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=LjukWJTxiUbmz3A955PSO/1CFVXOcF8enTwdO4bv+2k=; b=AGSry0S7tLFAWkzxbedRzYiJ9ysP6HAmKoQ8SfJ3YEkyGo2TykPqcLB8gslpUmglD6 yxwQd7uIU1M2oHNuJOY5EZ0xObY5kpB3e530ycd+xsLBWoOFyEZuTLbG8jmR6os91JjH D+96tYCm31TZ8CCEJBT1P6Zn4CGVjytQkAzPlfhZplSdJ5OoO0tiEjnpL0I0hCScExzJ +rLkeID3K/OyKmT9cihkb+7WLd+mezzRp7wO/FLiT0/Mg1wup5UkdbLx1GdniZvEnhfX l5c8Eo0GalmpR2KHbyuWUFEPDfKjc3xk+No/YYKOC7O+BofO2zcNY54PpGSL0uZ8Q39Y 5RpA== 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=LjukWJTxiUbmz3A955PSO/1CFVXOcF8enTwdO4bv+2k=; b=Wd2Rg9OvpvyoT2+n9/dlhEDIC2oCZDZXYMA07GTqfzG+7RwED5AkclQS3HspkcQ3mr Dj4378Uwpbnke5wEd4UO14lB6/SHfuF3zsn6c1ADix1BQqFvPLxuRG/B86VU1Wg/yhA2 66neXmXb9j9MEXrupqJRqWiIDzr47W/dVYx/xHiRlJggFgAERvnzxcpgmXESznrfzUar EgjRDc1WY/9Yn9i5Femy08jI9ls1TuZFqcBtAirGeYZzib5Ed1yBcuoNEss4cj1J45Mr pH+xH2AD2cp2Jdtrutg3BMQD+YoJayQgHolZYZck3izEq9nMd7FUn++bhYOZ/wEqRY6n vMVA== X-Gm-Message-State: ACgBeo0sAc2FdEXUt+SUOBsi7q7HzL8UHbZn5pcI4IMJztLkhEuWCpmd j2OozSc1/do6KdE0Qaiyy2VCVJT/6XTS X-Google-Smtp-Source: AA6agR737oV5Dv6Pucv6QEva05ChhkiOkZrwXPlgfZWxhjXq71+F4fdz6wLE3EkpCdimbdquZbhFaPgx4R9r X-Received: from irogers.svl.corp.google.com ([2620:15c:2d4:203:ab82:a348:500d:1fc4]) (user=irogers job=sendgmr) by 2002:a25:f85:0:b0:696:144b:ebd8 with SMTP id 127-20020a250f85000000b00696144bebd8mr4698286ybp.123.1661355662085; Wed, 24 Aug 2022 08:41:02 -0700 (PDT) Date: Wed, 24 Aug 2022 08:38:58 -0700 In-Reply-To: <20220824153901.488576-1-irogers@google.com> Message-Id: <20220824153901.488576-16-irogers@google.com> Mime-Version: 1.0 References: <20220824153901.488576-1-irogers@google.com> X-Mailer: git-send-email 2.37.2.609.g9ff673ca1a-goog Subject: [PATCH v3 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 892294ac1769..ec813093276d 100644 --- a/tools/perf/util/mutex.c +++ b/tools/perf/util/mutex.c @@ -50,11 +50,13 @@ 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 c9e110a2b55e..48a2d87598f0 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; }; @@ -27,9 +89,9 @@ void mutex_init(struct mutex *mtx); void mutex_init_pshared(struct mutex *mtx); 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); /* Default initialize the cond struct. */ void cond_init(struct cond *cnd); @@ -40,7 +102,7 @@ void cond_init(struct cond *cnd); void cond_init_pshared(struct cond *cnd); 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);