| Message ID | 1454447641-29153-3-git-send-email-mathieu.poirier@linaro.org |
|---|---|
| State | Accepted |
| Commit | a9ddc71f5840c2711e530f2e055b278f79948b29 |
| Headers | show
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[2001:1868:205::9]) by mx.google.com with ESMTPS id d66si4038326pfj.173.2016.02.02.13.16.25 for <patch@linaro.org> (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Feb 2016 13:16:25 -0800 (PST) Received-SPF: pass (google.com: domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) client-ip=2001:1868:205::9; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) smtp.mailfrom=linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org; dkim=neutral (body hash did not verify) header.i=@linaro.org Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aQiIG-0002cv-1T; Tue, 02 Feb 2016 21:15:24 +0000 Received: from mail-pf0-x22c.google.com ([2607:f8b0:400e:c00::22c]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aQiHV-0001BP-4k for linux-arm-kernel@lists.infradead.org; Tue, 02 Feb 2016 21:14:39 +0000 Received: by mail-pf0-x22c.google.com with SMTP id 65so565991pfd.2 for <linux-arm-kernel@lists.infradead.org>; Tue, 02 Feb 2016 13:14:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=MM9vJbZFAXhL/HsVhAGA8vuQuqxlGZ8QVclww/ElCNM=; b=YCjIag1+scZKgfn6jrVMptS1Kq1B6Rn49KkRo1EJ4cxh1K5Lfx7BoTqwWpkvx8egHA XAkb4v3hxF0fdpcapNKbHB/6TMocDE4bF0qOSz0RUudmLkajrEq/cTElc+Jvo4IsbWvl 96tUV83CpsQPGW3qd1/PVaTHijNx24xYInstc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=MM9vJbZFAXhL/HsVhAGA8vuQuqxlGZ8QVclww/ElCNM=; b=e6gl6//D+bgCQSqT2GCWl1TY3An7Z4iW1VGLPyMnNlycIlJqmkzoOZPnN01e6lEeWU D6jMKA1EtZd8QE7rSr6hCzeDRlG+q/dLiy82K8G12RS9X3NUh3LIMJI9kx5SaCRKFwsQ WdaPgeWbVXMs9B9gyXGbDGXG9KGkpFcUqwaWX8yu6+eDsGZZ3oLIc/vg9Bx9bs3xtmOD XIbsM4IH1QEDQCr30Ln+CAwOUYGdkr9RtuGX3pBLBMbB2V+swoYUhdLQNMJofJSTyeVI zp1cFAIgmckpztk5hTqdfr9T+3Dx2xdnCeAEMJCY0kuolTs/e8Ip/icovwm/sX65xzwe Sx/Q== X-Gm-Message-State: AG10YOQg7yd0QZij4cxgCgr0T4VmGv01/o04o19a5YanPwvSYHyoXVyMe2fsOvhgcp6Pwi4Z X-Received: by 10.98.2.150 with SMTP id 144mr50630372pfc.11.1454447656414; Tue, 02 Feb 2016 13:14:16 -0800 (PST) Received: from t430.cg.shawcable.net ([184.64.168.246]) by smtp.gmail.com with ESMTPSA id 79sm4769141pfr.22.2016.02.02.13.14.15 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 02 Feb 2016 13:14:15 -0800 (PST) From: Mathieu Poirier <mathieu.poirier@linaro.org> To: gregkh@linuxfoundation.org Subject: [PATCH 2/7] coresight: fixing lockdep error Date: Tue, 2 Feb 2016 14:13:56 -0700 Message-Id: <1454447641-29153-3-git-send-email-mathieu.poirier@linaro.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1454447641-29153-1-git-send-email-mathieu.poirier@linaro.org> References: <1454447641-29153-1-git-send-email-mathieu.poirier@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160202_131437_370289_6B6A674F X-CRM114-Status: GOOD ( 20.52 ) X-Spam-Score: -2.7 (--) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-2.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [2607:f8b0:400e:c00:0:0:0:22c listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: <linux-arm-kernel.lists.infradead.org> List-Unsubscribe: <http://lists.infradead.org/mailman/options/linux-arm-kernel>, <mailto:linux-arm-kernel-request@lists.infradead.org?subject=unsubscribe> List-Archive: <http://lists.infradead.org/pipermail/linux-arm-kernel/> List-Post: <mailto:linux-arm-kernel@lists.infradead.org> List-Help: <mailto:linux-arm-kernel-request@lists.infradead.org?subject=help> List-Subscribe: <http://lists.infradead.org/mailman/listinfo/linux-arm-kernel>, <mailto:linux-arm-kernel-request@lists.infradead.org?subject=subscribe> Cc: linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org |
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index 4236a02cdab2..41b42018b660 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -713,12 +713,8 @@ EXPORT_SYMBOL_GPL(coresight_register); void coresight_unregister(struct coresight_device *csdev) { - mutex_lock(&coresight_mutex); - kfree(csdev->conns); device_unregister(&csdev->dev); - - mutex_unlock(&coresight_mutex); } EXPORT_SYMBOL_GPL(coresight_unregister);
On some platform the following lockdep error occurs when doing simple manipulations: [ 23.197021] [ 23.198608] ====================================================== [ 23.205078] [ INFO: possible circular locking dependency detected ] [ 23.211639] 4.4.0-rc8-00025-gbbf360b #172 Not tainted [ 23.216918] ------------------------------------------------------- [ 23.223480] sh/858 is trying to acquire lock: [ 23.228057] (coresight_mutex){+.+.+.}, at: [<c0415d40>] coresight_enable+0x1c/0x1b4 [ 23.236206] [ 23.236206] but task is already holding lock: [ 23.242309] (s_active#52){++++.+}, at: [<c01d4b40>] kernfs_fop_write+0x5c/0x1c0 [ 23.250122] [ 23.250122] which lock already depends on the new lock. [ 23.250122] [ 23.258697] [ 23.258697] the existing dependency chain (in reverse order) is: [ 23.266510] -> #1 (s_active#52){++++.+}: [ 23.270843] [<c01d30ec>] __kernfs_remove+0x294/0x35c [ 23.276672] [<c01d3e44>] kernfs_remove_by_name_ns+0x44/0x8c [ 23.283172] [<c01d6318>] remove_files+0x3c/0x84 [ 23.288543] [<c01d66b4>] sysfs_remove_group+0x48/0x9c [ 23.294494] [<c01d6734>] sysfs_remove_groups+0x2c/0x3c [ 23.300506] [<c030b658>] device_remove_attrs+0x5c/0x74 [ 23.306549] [<c030c290>] device_del+0x110/0x218 [ 23.311950] [<c030c3c4>] device_unregister+0x2c/0x6c [ 23.317779] [<c04156d8>] coresight_unregister+0x30/0x40 [ 23.323883] [<c041a290>] etm_probe+0x228/0x2e8 [ 23.329193] [<c02bc760>] amba_probe+0xe4/0x160 [ 23.334503] [<c0310540>] driver_probe_device+0x23c/0x480 [ 23.340728] [<c0310820>] __driver_attach+0x9c/0xa0 [ 23.346374] [<c030e400>] bus_for_each_dev+0x70/0xa4 [ 23.352142] [<c030fcf4>] driver_attach+0x24/0x28 [ 23.357604] [<c030f86c>] bus_add_driver+0x1e0/0x278 [ 23.363372] [<c0310d48>] driver_register+0x80/0x100 [ 23.369110] [<c02bc508>] amba_driver_register+0x58/0x5c [ 23.375244] [<c0749514>] etm_driver_init+0x18/0x1c [ 23.380889] [<c0009918>] do_one_initcall+0xc4/0x20c [ 23.386657] [<c0715e7c>] kernel_init_freeable+0x160/0x208 [ 23.392974] [<c052d7fc>] kernel_init+0x18/0xf0 [ 23.398254] [<c0010850>] ret_from_fork+0x14/0x24 [ 23.403747] -> #0 (coresight_mutex){+.+.+.}: [ 23.408447] [<c008ed60>] lock_acquire+0xe4/0x210 [ 23.413909] [<c0530a30>] mutex_lock_nested+0x74/0x450 [ 23.419860] [<c0415d40>] coresight_enable+0x1c/0x1b4 [ 23.425689] [<c0416030>] enable_source_store+0x58/0x68 [ 23.431732] [<c030b358>] dev_attr_store+0x20/0x2c [ 23.437286] [<c01d55e8>] sysfs_kf_write+0x50/0x54 [ 23.442871] [<c01d4ba8>] kernfs_fop_write+0xc4/0x1c0 [ 23.448699] [<c015b60c>] __vfs_write+0x34/0xe4 [ 23.454040] [<c015bf38>] vfs_write+0x98/0x174 [ 23.459228] [<c015c7a8>] SyS_write+0x4c/0xa8 [ 23.464355] [<c00107c0>] ret_fast_syscall+0x0/0x1c [ 23.470031] [ 23.470031] other info that might help us debug this: [ 23.470031] [ 23.478393] Possible unsafe locking scenario: [ 23.478393] [ 23.484619] CPU0 CPU1 [ 23.489349] ---- ---- [ 23.494079] lock(s_active#52); [ 23.497497] lock(coresight_mutex); [ 23.503906] lock(s_active#52); [ 23.509918] lock(coresight_mutex); [ 23.513702] [ 23.513702] *** DEADLOCK *** [ 23.513702] [ 23.519897] 3 locks held by sh/858: [ 23.523529] #0: (sb_writers#7){.+.+.+}, at: [<c015ec38>] __sb_start_write+0xa8/0xd4 [ 23.531799] #1: (&of->mutex){+.+...}, at: [<c01d4b38>] kernfs_fop_write+0x54/0x1c0 [ 23.539916] #2: (s_active#52){++++.+}, at: [<c01d4b40>] kernfs_fop_write+0x5c/0x1c0 [ 23.548156] [ 23.548156] stack backtrace: [ 23.552734] CPU: 0 PID: 858 Comm: sh Not tainted 4.4.0-rc8-00025-gbbf360b #172 [ 23.560302] Hardware name: Generic OMAP4 (Flattened Device Tree) [ 23.566589] Backtrace: [ 23.569152] [<c00154d4>] (dump_backtrace) from [<c00156d0>] (show_stack+0x18/0x1c) [ 23.577087] r7:ed4b8570 r6:c0936400 r5:c07ae71c r4:00000000 [ 23.583038] [<c00156b8>] (show_stack) from [<c027e69c>] (dump_stack+0x98/0xc0) [ 23.590606] [<c027e604>] (dump_stack) from [<c008a750>] (print_circular_bug+0x21c/0x33c) [ 23.599090] r5:c0939d60 r4:c0936400 [ 23.602874] [<c008a534>] (print_circular_bug) from [<c008e370>] (__lock_acquire+0x1c98/0x1d88) [ 23.611877] r10:00000003 r9:c0fd7a5c r8:ed4b8550 r7:ed4b8570 r6:ed4b8000 r5:c0ff69e4 [ 23.620117] r4:c0936400 r3:ed4b8550 [ 23.623901] [<c008c6d8>] (__lock_acquire) from [<c008ed60>] (lock_acquire+0xe4/0x210) [ 23.632080] r10:00000000 r9:00000000 r8:60000013 r7:c07cb7b4 r6:00000001 r5:00000000 [ 23.640350] r4:00000000 [ 23.643005] [<c008ec7c>] (lock_acquire) from [<c0530a30>] (mutex_lock_nested+0x74/0x450) [ 23.651458] r10:ecc0bf80 r9:edbe7dcc r8:ed4b8000 r7:c0fd7a5c r6:c0415d40 r5:00000000 [ 23.659729] r4:c07cb780 [ 23.662384] [<c05309bc>] (mutex_lock_nested) from [<c0415d40>] (coresight_enable+0x1c/0x1b4) [ 23.671234] r10:ecc0bf80 r9:edbe7dcc r8:ed733c00 r7:00000000 r6:ed733c00 r5:00000002 [ 23.679473] r4:ed762140 [ 23.682128] [<c0415d24>] (coresight_enable) from [<c0416030>] (enable_source_store+0x58/0x68) [ 23.691070] r7:00000000 r6:ed733c00 r5:00000002 r4:ed762160 [ 23.697052] [<c0415fd8>] (enable_source_store) from [<c030b358>] (dev_attr_store+0x20/0x2c) [ 23.705780] r5:edbe7dc0 r4:c0415fd8 [ 23.709533] [<c030b338>] (dev_attr_store) from [<c01d55e8>] (sysfs_kf_write+0x50/0x54) [ 23.717834] r5:edbe7dc0 r4:c030b338 [ 23.721618] [<c01d5598>] (sysfs_kf_write) from [<c01d4ba8>] (kernfs_fop_write+0xc4/0x1c0) [ 23.730163] r7:00000000 r6:00000000 r5:00000002 r4:edbe7dc0 [ 23.736145] [<c01d4ae4>] (kernfs_fop_write) from [<c015b60c>] (__vfs_write+0x34/0xe4) [ 23.744323] r10:00000000 r9:ecc0a000 r8:c0010964 r7:ecc0bf80 r6:00000002 r5:c01d4ae4 [ 23.752593] r4:ee385a40 [ 23.755249] [<c015b5d8>] (__vfs_write) from [<c015bf38>] (vfs_write+0x98/0x174) [ 23.762908] r9:ecc0a000 r8:c0010964 r7:ecc0bf80 r6:000ab0d8 r5:00000002 r4:ee385a40 [ 23.771057] [<c015bea0>] (vfs_write) from [<c015c7a8>] (SyS_write+0x4c/0xa8) [ 23.778442] r8:c0010964 r7:00000002 r6:000ab0d8 r5:ee385a40 r4:ee385a40 [ 23.785522] [<c015c75c>] (SyS_write) from [<c00107c0>] (ret_fast_syscall+0x0/0x1c) [ 23.793457] r7:00000004 r6:00000001 r5:000ab0d8 r4:00000002 [ 23.799652] coresight-etb10 54162000.etb: ETB enabled [ 23.805084] coresight-funnel 54164000.funnel: FUNNEL inport 0 enabled [ 23.811859] coresight-replicator 44000000.ocp:replicator: REPLICATOR enabled [ 23.819335] coresight-funnel 54158000.funnel: FUNNEL inport 0 enabled [ 23.826110] coresight-etm3x 5414c000.ptm: ETM tracing enabled The locking in coresight_unregister() is not required as the only customers of the function are drivers themselves when an initialisation failure has been encoutered. Reported-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> --- drivers/hwtracing/coresight/coresight.c | 4 ---- 1 file changed, 4 deletions(-) -- 2.1.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel