From nobody Sun Feb 8 06:22:12 2026 Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (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 6D5552C11FE for ; Wed, 12 Nov 2025 07:43:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762933397; cv=none; b=MhHOh8es7V9sDvRAudxgJvT8EiAEZ+Y2EDs3ETpeiu+SAVQFnDURq43EsgCZiVkNFuRgrWPIgXN03yAzruo4qgNnHeheT5imXYWDS736d691Dz9Cu7Zc+t1h71HN9FHuTUIpnjhZs6kxIkSBGrI2SInZtVrH5bw0mcX/4s3fkWU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762933397; c=relaxed/simple; bh=QZumcc+aGuEyWSU11cBF1Lm2JEA58vA2/+jRiRWwFsM=; h=Date:Mime-Version:Message-ID:Subject:From:To:Content-Type; b=mNtMuXXDaHRGE45kMTH5WkIXC17rj1cERnrVjn04CF5cCA4XRt53UbvdeXs4pVKfQAAXxwg0jDiBw91yeH3NcosnHuDWd2WQELWqgPncd0429ij5PghF6noy9i2EOj5n39lpFo3tp0CF4KgYG4Tqd+6CJIB2b7r8P8lksVFkm6s= 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=e/39kuo1; arc=none smtp.client-ip=209.85.215.201 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="e/39kuo1" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-ba265ee0e34so479830a12.2 for ; Tue, 11 Nov 2025 23:43:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1762933396; x=1763538196; darn=vger.kernel.org; h=to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=iDxlg3rjq7IUfgkqdF3QzT2vSrqjrpZ2K7ERAvuReQE=; b=e/39kuo1C1lGdvfxoN0gl8F6uTFSZt4e7U9TS2Vd2sELFIfULh2ZIq+VzwP+xe0s55 SQgY/4068kWD/yakY0b5ZQL6g/cLnkY21QMaH46M0SWv/czamM7z2j/+ygi0FVS2zHMk nG/skQ/NgXFKKgEWxaZIuZvo0bhQnDH0a0fblDHB7ZRLFToe54D3/5t8USDeNd+Xbjci pxvVd1V4FYEDgcSMJ4yeEezC6lK+6UOdNK8NjbphiSIDYsNWXZjSflNYABXq+uoC0/vC l7R3U3TFIRr/X8qAMVsqyWg4HAX3bWradXz+JeLfAPa0VJ6qci/9b1g3kSt4ktkWP3xS kZbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762933396; x=1763538196; h=to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=iDxlg3rjq7IUfgkqdF3QzT2vSrqjrpZ2K7ERAvuReQE=; b=gUoIwwqvA3X7/aOywfgEwB+78u5lV6MlO/pqedb9waLhb8V+y+9nLaulnYlBVsWZ9x iHDBA5+gl3sXlrmJxzvRQA5Hft/qwF0KiiE6ioCl9O80SATzDNU+NHwWaEhAsAUGH5XJ 2G8c18CLTxQ6wrkOreEL8BRRCz3NXinrrc1AphrEegdg4V5gLVJQwmmxa1+p2o7ZqdT1 VEflHRvOEsCg0aOe6pU5f9soslRbb/dTS77zJCLWyq7taNhmZgzTm2zx2VK1YTwjknZ1 lp8ZybkaYWggjuzGvHn4i9QkDoFTBZmflIW7cWdfKIn3HZV4OGj/J5UClBZkWwxaSeje xxVQ== X-Forwarded-Encrypted: i=1; AJvYcCXshd85c5Vflp6J+/Jek7eLc22urpdCHSn0F771XNxh8n+17t1GwnJJoxnAFtcOkxgM+9P4beYgDj5k414=@vger.kernel.org X-Gm-Message-State: AOJu0Yya28ae7vaBb+1lXL2nhmSLoK28QnUHe73Xg7GfIc8fElzKGJ5Z L35ap2aEyqbyXbjfhkOJPooU4bf8uDWGU0w2zfJpGOIkcnHpHbSu6Cy2Eky1C2mkfUq2yzeDs+L sf1UHFjnVjA== X-Google-Smtp-Source: AGHT+IFlCJoHl4U0qhCyKZm/cv+eMqTRrwx9eTjHB4ufjp5u24z+RJZmtmB6/nLtuNj70VwaJ52q87cSYoOs X-Received: from dlbdx18.prod.google.com ([2002:a05:7022:e12:b0:119:49ca:6b96]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:3c8d:b0:34e:cc0a:40b2 with SMTP id adf61e73a8af0-3590b02ad56mr2632422637.30.1762933395749; Tue, 11 Nov 2025 23:43:15 -0800 (PST) Date: Tue, 11 Nov 2025 23:43:11 -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: <20251112074311.1440101-1-irogers@google.com> Subject: [PATCH v2] 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 --- v2: Remove unneeded unistd.h include. --- tools/perf/util/libbfd.c | 38 ++++++++++++++++++++++++++++++++++++++ tools/perf/util/mutex.c | 14 ++++++++++---- tools/perf/util/mutex.h | 2 ++ 3 files changed, 50 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/libbfd.c b/tools/perf/util/libbfd.c index 01147fbf73b3..6434c2dccd4a 100644 --- a/tools/perf/util/libbfd.c +++ b/tools/perf/util/libbfd.c @@ -38,6 +38,39 @@ 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 +165,7 @@ 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 +322,7 @@ 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 +428,7 @@ 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 +457,7 @@ 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 +517,7 @@ 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