From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7CC1826C39B; Mon, 5 May 2025 17:33:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746466421; cv=none; b=dH2aLbLQR3iegNIYUey+8eelI3xarCiIzKYNOFkWAWCfBPcn3AZYUryWFJpN9inVAtwut2nLOpUevGz7FtJxVw35LvmIZFm24uOCTnD4gr7FLiPOmxUNDtanOtMfRnWghCr1zsxSF9ju5z4DEHlqDzOhVWtpEwtzgiKvRpimDkY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746466421; c=relaxed/simple; bh=42PvFjHDOFh9c39+Q5w0rlwI+Zk/bS3XeleGEnio6jQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=NYXVNA41Vz8YVKGpI/QWivr7VwtlADniVbOBijvVV2eHBozZ/lZo9G9cW7bwysrh1SWoNky+tRt4U8OxX19hrW/9/Q2tvHDw5Yj+snnwFgTBh6rIfKlj6ZIGEjKIg2hh085RmllaKhXtI+hgQ1HLHSZhUF635SUQ1ocHq8WArJg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Qi61bwXI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Qi61bwXI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CE2CC4CEE4; Mon, 5 May 2025 17:33:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746466421; bh=42PvFjHDOFh9c39+Q5w0rlwI+Zk/bS3XeleGEnio6jQ=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=Qi61bwXIWhN7Q5imRLB7/jxH6c1qgxj9nq/E4rrrKRs1clB+HI/4xEs/4Sah6PfNX ebKlKMZJTnHpONBvXlc5YI2SkdUXbncwzHaBz/+dvHwMNJT/ubJwIcZgOCPb2eY4s6 4Lyawvpo8ddUIEUoK9QHsuEodgjPjwc/Q0SLuggjJuDNB6RLNZ5h5zQYsQNCQy7oKY FSpmKnIbZg10ZSmZT0nWPfRDeC5HFS5wkP8cFz+9L5mpc+i7aj3tPXFoVhYLVfC7ww yV6sZwEuIu2HDtKxUu+d7IVvxgrZCQ1GYG/uQUzmcnAc1tRThcNchwxwnnK6fQ7Xdm y2Zu/GIkyE7ow== From: Jeff Layton Date: Mon, 05 May 2025 13:33:20 -0400 Subject: [PATCH v7 06/10] ref_tracker: automatically register a file in debugfs for a ref_tracker_dir Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250505-reftrack-dbgfs-v7-6-f78c5d97bcca@kernel.org> References: <20250505-reftrack-dbgfs-v7-0-f78c5d97bcca@kernel.org> In-Reply-To: <20250505-reftrack-dbgfs-v7-0-f78c5d97bcca@kernel.org> To: Andrew Morton , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin Cc: Kuniyuki Iwashima , Qasim Ijaz , Nathan Chancellor , Andrew Lunn , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, Jeff Layton X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=5380; i=jlayton@kernel.org; h=from:subject:message-id; bh=42PvFjHDOFh9c39+Q5w0rlwI+Zk/bS3XeleGEnio6jQ=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBoGPZma2GRzK5/K5200bBcueRtzZcELNBky8pAq +BcXf1vUwiJAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCaBj2ZgAKCRAADmhBGVaC FUO1D/9wXsClij4uMc41dcHChDSiaEEbveOJaASamNsqCyPr83e4jRBLhI6OXAOdMI9CTjRUoWi ld3STsZRCneIgjcVnLG1BXAPFzzOpCqauxDVGHShHu4bnBADAvwopi5XUtVqUFEsZ3QKvkPXYII Am95FrvDl3upxVh7ekSDOvq9zi1EzKRUW/OZs1QgJ8ZCpGpAzuxnsropBUa0Q953u6MPCkcS85w ZpiBkD6KakmRHI3DYDcoLbO/Ugbq0ClX9/e+E4dClwQYVvVdeE5EHcevicnanhjNZbqXKUEOnGw 8z6WvNjCG3q7QxC1PKMMGH1RCXkGyZGulup1KHMMAH4e5kCdg2A93byFt4XzabWClp+SFka7nhn hGAfsA0bbGbgU/arkerSFvzp7GoiWw/6Md0kqpdzocCxV6iN0wKmY8cPYE9qRPXBaNUycVFb1Wp a0YMqMfXHp6IZ5a8WXMjcqDlHwsToFh3fytOjCqxnxZ//LRF2GktVApb1+zbEItzDCzdMNBpCXz C8EQPuAUcTIdiI3CKZypjcVkX24dODRrV+HFVDa1NfVqxfl5u9xho2EscWgvznfWvmyRAoPNtcH egGH65U1TBCAuVrBX/fKcYRlRLzCCupxkOc5IQS3kKpWT3bsII21T4PukVzbFxzmLd1yJWZPyHD XH0WReE+VyABUdA== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 Currently, there is no convenient way to see the info that the ref_tracking infrastructure collects. Attempt to create a file in debugfs when called from ref_tracker_dir_init(). The file is given the name "class@%px", as having the unmodified address is helpful for debugging. This should be safe since this directory is only accessible by root If debugfs file creation fails, a pr_warn will be isssued. Signed-off-by: Jeff Layton --- include/linux/ref_tracker.h | 13 ++++++++ lib/ref_tracker.c | 73 +++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 84 insertions(+), 2 deletions(-) diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h index 3968f993db81e95c0d58c81454311841c1b9cd35..17d5924d595ce95bfb5d8ec6d813490499bd89d0 100644 --- a/include/linux/ref_tracker.h +++ b/include/linux/ref_tracker.h @@ -20,12 +20,17 @@ struct ref_tracker_dir { struct list_head list; /* List of active trackers */ struct list_head quarantine; /* List of dead trackers */ const char *class; /* object classname */ +#ifdef CONFIG_DEBUG_FS + struct dentry *dentry; +#endif char name[32]; #endif }; #ifdef CONFIG_REF_TRACKER +void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir); + static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir, unsigned int quarantine_count, const char *class, @@ -39,7 +44,11 @@ static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir, refcount_set(&dir->untracked, 1); refcount_set(&dir->no_tracker, 1); dir->class = class; +#ifdef CONFIG_DEBUG_FS + dir->dentry = NULL; +#endif strscpy(dir->name, name, sizeof(dir->name)); + ref_tracker_dir_debugfs(dir); stack_depot_init(); } @@ -68,6 +77,10 @@ static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir, { } +static inline void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir) +{ +} + static inline void ref_tracker_dir_exit(struct ref_tracker_dir *dir) { } diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c index 66a765cdfc471968fd6434dafc5b654962f20667..723df31321242d6af267986cc56a9d80b6e5ad18 100644 --- a/lib/ref_tracker.c +++ b/lib/ref_tracker.c @@ -31,6 +31,14 @@ struct ref_tracker_dir_stats { } stacks[]; }; +#ifdef CONFIG_DEBUG_FS +static void ref_tracker_debugfs_remove(struct ref_tracker_dir *dir); +#else +static inline void ref_tracker_debugfs_remove(struct ref_tracker_dir *dir) +{ +} +#endif + static struct ref_tracker_dir_stats * ref_tracker_get_stats(struct ref_tracker_dir *dir, unsigned int limit) { @@ -195,6 +203,7 @@ void ref_tracker_dir_exit(struct ref_tracker_dir *dir) bool leak = false; dir->dead = true; + ref_tracker_debugfs_remove(dir); spin_lock_irqsave(&dir->lock, flags); list_for_each_entry_safe(tracker, n, &dir->quarantine, head) { list_del(&tracker->head); @@ -311,8 +320,7 @@ EXPORT_SYMBOL_GPL(ref_tracker_free); #ifdef CONFIG_DEBUG_FS #include -static __maybe_unused int -ref_tracker_dir_seq_print(struct ref_tracker_dir *dir, struct seq_file *seq) +static int ref_tracker_dir_seq_print(struct ref_tracker_dir *dir, struct seq_file *seq) { struct ostream os = { .func = pr_ostream_seq, .prefix = "", @@ -326,6 +334,67 @@ ref_tracker_dir_seq_print(struct ref_tracker_dir *dir, struct seq_file *seq) return os.used; } +static int ref_tracker_debugfs_show(struct seq_file *f, void *v) +{ + struct ref_tracker_dir *dir = f->private; + + return ref_tracker_dir_seq_print(dir, f); +} + +static int ref_tracker_debugfs_open(struct inode *inode, struct file *filp) +{ + struct ref_tracker_dir *dir = inode->i_private; + + return single_open(filp, ref_tracker_debugfs_show, dir); +} + +static const struct file_operations ref_tracker_debugfs_fops = { + .owner = THIS_MODULE, + .open = ref_tracker_debugfs_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +/** + * ref_tracker_dir_debugfs - create debugfs file for ref_tracker_dir + * @dir: ref_tracker_dir to be associated with debugfs file + * + * In most cases, a debugfs file will be created automatically for every + * ref_tracker_dir. If the object was created before debugfs is brought up + * then that may fail. In those cases, it is safe to call this at a later + * time to create the file. + */ +void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir) +{ + char name[NAME_MAX + 1]; + int ret; + + /* No-op if already created */ + if (!IS_ERR_OR_NULL(dir->dentry)) + return; + + ret = snprintf(name, sizeof(name), "%s@%px", dir->class, dir); + name[sizeof(name) - 1] = '\0'; + + if (ret < sizeof(name)) + dir->dentry = debugfs_create_file(name, S_IFREG | 0400, + ref_tracker_debug_dir, dir, + &ref_tracker_debugfs_fops); + else + dir->dentry = ERR_PTR(-ENAMETOOLONG); + + if (IS_ERR(dir->dentry)) + pr_warn("ref_tracker: unable to create debugfs file for %s: %pe\n", + name, dir->dentry); +} +EXPORT_SYMBOL(ref_tracker_dir_debugfs); + +static void ref_tracker_debugfs_remove(struct ref_tracker_dir *dir) +{ + debugfs_remove(dir->dentry); +} + static int __init ref_tracker_debugfs_init(void) { ref_tracker_debug_dir = debugfs_create_dir("ref_tracker", NULL); -- 2.49.0