From nobody Sun Feb 8 00:26:47 2026 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8429C2C2357 for ; Wed, 12 Nov 2025 07:40:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762933238; cv=none; b=o+CksdM41WDi23hqqF0Q1tx0ED/uTb6kUMWkE9YneeuHLb6a9KKII3EAjlaRKtuWIM1GI6ZcRprDx+TtDjfyh1q9stfp3BTTSO6PkAfsXLvNey87FKy1uIfDsbO1RD0UTXoUYCDeAall3F+cnV9cFZjgU/t+MkjhwnFRd80uaDY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762933238; c=relaxed/simple; bh=4SALSKbCmgX/8BOof2Zi1l+NvRGR0X15IZnZc2+XiB4=; h=Date:Mime-Version:Message-ID:Subject:From:To:Content-Type; b=KMoruYVAm59G/pCeGxsaGH+qnFYlzitP+Wabrqp3W643M7/yps7vVC/llC0E1Z1QEffo2UJarkuVeC2yFUrOeNwbNyzv6rsopdsqfrH3gMAlmvSfqr9cP51rVrWJwhn1ymNsRt0dHNU5iZhKZVN9wvacJBo6q1sNoxaWPCLwOpA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=dPRMm8Ie; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="dPRMm8Ie" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2958c80fcabso13658645ad.0 for ; Tue, 11 Nov 2025 23:40:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1762933236; x=1763538036; darn=vger.kernel.org; h=to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=b4j12ALBms7hTL30MK6vG9oB8izvbJzE18Mhy1cM3lQ=; b=dPRMm8IeM8v7ZHg44ZxHO9eBhYxqB6CKGQSO0x52AtARpoJTX1LJ+hl3kD5qzUW5Pw Nl9OW4DOKBuX87Qi0hUeQJkqzEdGT6U7E7jpqdyY7kRc6GSfEd8q6TjF+7t49LHAM2eg Dk2ZwKnRsOyK3i8iYwQBBJu2wZoPRMXnOUv2pTqxIP/XCjwt4MHTGffXpixIkR1PagDC 1cE8jPM4NEX7AJrkPZ6STXG4/IoZOHqz9GSEepIIj/gF+rJtvVASQxt/BHFvoCTjvrHe s35pu9NJ33Jmi07d9vXYjEsBtKr2G6SJ70xkUuagqFYSahnUTx9UooiUkLPnV1KuoJDo eUtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762933236; x=1763538036; h=to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=b4j12ALBms7hTL30MK6vG9oB8izvbJzE18Mhy1cM3lQ=; b=ZKF6qJUM6ws3IotxXUYK7TYksn7Q3tpb38H2HpE8IlKyTEJFEq52kXGjWRyrVQWw4g hpnHpkWRBI7KFWYR7tDfbWm7GQpTlK/hyG/xXmBvjevsuANwfCG7A+3WF+RvtqdNBg0f x8laubQIH0OTgudGwCdkZxWsrwzVk83tC4jWCAeQe14v7KU3hDTIT2ADkRJ5BxMzmqhQ 5+JL5UxXe1jdpALigO1VKmV2/kGrTgUKkr14RT38WtLDE1gRDNJ0R4UTV3VALIStodnn qUV81+7OnTwejoVOGJK1BpJwwKLP/VwKXS6f67GyKq4SN1blXMM3ZwyH3EUpbuEWpPZI SFwg== X-Forwarded-Encrypted: i=1; AJvYcCVuqwIIfDq/FLXU2x3p6B+cpv/xFeKm+9BAt1esYnPT5dHM2DDaIYwcdnkbvcB6MGw2Okq9Ym/UmXQaZtQ=@vger.kernel.org X-Gm-Message-State: AOJu0YzLCR79gVIPiPx5miEUMYQyfRpwyfqH+ozziykCXKbJHEH24b/O y8UO4bZiYYosoibA91laM2KkyAl/ThCAHdjmUAIjVZ8UYCGRtKSedO7duUmUTRXXnOBObKM8k/o 5gUCUEJgMbA== X-Google-Smtp-Source: AGHT+IHfhIMW+Y2tjkl213sKicyatqbA81t/2MTS7BpCHBXOS8ZJ+7k32EHIntIqbQvPQ9zP1brPBmH33+Sg X-Received: from dycrq20.prod.google.com ([2002:a05:693c:2c14:b0:2a4:74cb:b0ad]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:e788:b0:295:70b1:edc8 with SMTP id d9443c01a7336-2984ed79fd7mr28105145ad.2.1762933235823; Tue, 11 Nov 2025 23:40:35 -0800 (PST) Date: Tue, 11 Nov 2025 23:40:31 -0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.51.2.1041.gc1ab5b90ca-goog Message-ID: <20251112074031.1436415-1-irogers@google.com> Subject: [PATCH v1] perf libbfd: Ensure libbfd is initialized prior to use From: Ian Rogers To: Guilherme Amadio , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Multiple threads may be creating and destroying BFD objects in situations like `perf top`. Without appropriate initialization crashes may occur during libbfd's cache management. BFD's locks require recursive mutexes, add support for these. Reported-by: Guilherme Amadio Closes: https://lore.kernel.org/lkml/aQt66zhfxSA80xwt@gentoo.org/ Fixes: 95931d9a594d ("perf libbfd: Move libbfd functionality to its own fil= e") Signed-off-by: Ian Rogers --- tools/perf/util/libbfd.c | 39 +++++++++++++++++++++++++++++++++++++++ tools/perf/util/mutex.c | 14 ++++++++++---- tools/perf/util/mutex.h | 2 ++ 3 files changed, 51 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/libbfd.c b/tools/perf/util/libbfd.c index 01147fbf73b3..42edb3191d7d 100644 --- a/tools/perf/util/libbfd.c +++ b/tools/perf/util/libbfd.c @@ -19,6 +19,7 @@ #include #include #include +#include #define PACKAGE "perf" #include =20 @@ -38,6 +39,39 @@ struct a2l_data { asymbol **syms; }; =20 +static bool perf_bfd_lock(void *bfd_mutex) +{ + mutex_lock(bfd_mutex); + return true; +} + +static bool perf_bfd_unlock(void *bfd_mutex) +{ + mutex_unlock(bfd_mutex); + return true; +} + +static void perf_bfd_init(void) +{ + static struct mutex bfd_mutex; + + mutex_init_recursive(&bfd_mutex); + + if (bfd_init() !=3D BFD_INIT_MAGIC) { + pr_err("Error initializing libbfd\n"); + return; + } + if (!bfd_thread_init(perf_bfd_lock, perf_bfd_unlock, &bfd_mutex)) + pr_err("Error initializing libbfd threading\n"); +} + +static void ensure_bfd_init(void) +{ + static pthread_once_t bfd_init_once =3D PTHREAD_ONCE_INIT; + + pthread_once(&bfd_init_once, perf_bfd_init); +} + static int bfd_error(const char *string) { const char *errmsg; @@ -132,6 +166,7 @@ static struct a2l_data *addr2line_init(const char *path) bfd *abfd; struct a2l_data *a2l =3D NULL; =20 + ensure_bfd_init(); abfd =3D bfd_openr(path, NULL); if (abfd =3D=3D NULL) return NULL; @@ -288,6 +323,7 @@ int dso__load_bfd_symbols(struct dso *dso, const char *= debugfile) bfd *abfd; u64 start, len; =20 + ensure_bfd_init(); abfd =3D bfd_openr(debugfile, NULL); if (!abfd) return -1; @@ -393,6 +429,7 @@ int libbfd__read_build_id(const char *filename, struct = build_id *bid, bool block if (fd < 0) return -1; =20 + ensure_bfd_init(); abfd =3D bfd_fdopenr(filename, /*target=3D*/NULL, fd); if (!abfd) return -1; @@ -421,6 +458,7 @@ int libbfd_filename__read_debuglink(const char *filenam= e, char *debuglink, asection *section; bfd *abfd; =20 + ensure_bfd_init(); abfd =3D bfd_openr(filename, NULL); if (!abfd) return -1; @@ -480,6 +518,7 @@ int symbol__disassemble_bpf_libbfd(struct symbol *sym _= _maybe_unused, memset(tpath, 0, sizeof(tpath)); perf_exe(tpath, sizeof(tpath)); =20 + ensure_bfd_init(); bfdf =3D bfd_openr(tpath, NULL); if (bfdf =3D=3D NULL) abort(); diff --git a/tools/perf/util/mutex.c b/tools/perf/util/mutex.c index bca7f0717f35..7aa1f3f55a7d 100644 --- a/tools/perf/util/mutex.c +++ b/tools/perf/util/mutex.c @@ -17,7 +17,7 @@ static void check_err(const char *fn, int err) =20 #define CHECK_ERR(err) check_err(__func__, err) =20 -static void __mutex_init(struct mutex *mtx, bool pshared) +static void __mutex_init(struct mutex *mtx, bool pshared, bool recursive) { pthread_mutexattr_t attr; =20 @@ -27,21 +27,27 @@ static void __mutex_init(struct mutex *mtx, bool pshare= d) /* In normal builds enable error checking, such as recursive usage. */ CHECK_ERR(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK)); #endif + if (recursive) + CHECK_ERR(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)); if (pshared) CHECK_ERR(pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED)); - CHECK_ERR(pthread_mutex_init(&mtx->lock, &attr)); CHECK_ERR(pthread_mutexattr_destroy(&attr)); } =20 void mutex_init(struct mutex *mtx) { - __mutex_init(mtx, /*pshared=3D*/false); + __mutex_init(mtx, /*pshared=3D*/false, /*recursive=3D*/false); } =20 void mutex_init_pshared(struct mutex *mtx) { - __mutex_init(mtx, /*pshared=3D*/true); + __mutex_init(mtx, /*pshared=3D*/true, /*recursive=3D*/false); +} + +void mutex_init_recursive(struct mutex *mtx) +{ + __mutex_init(mtx, /*pshared=3D*/false, /*recursive=3D*/true); } =20 void mutex_destroy(struct mutex *mtx) diff --git a/tools/perf/util/mutex.h b/tools/perf/util/mutex.h index 38458f00846f..70232d8d094f 100644 --- a/tools/perf/util/mutex.h +++ b/tools/perf/util/mutex.h @@ -104,6 +104,8 @@ void mutex_init(struct mutex *mtx); * process-private attribute. */ void mutex_init_pshared(struct mutex *mtx); +/* Initializes a mutex that may be recursively held on the same thread. */ +void mutex_init_recursive(struct mutex *mtx); void mutex_destroy(struct mutex *mtx); =20 void mutex_lock(struct mutex *mtx) EXCLUSIVE_LOCK_FUNCTION(*mtx); --=20 2.51.2.1041.gc1ab5b90ca-goog