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 E4CF519A29C; Thu, 25 Jul 2024 14:42:41 +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=1721918562; cv=none; b=gtq/KB6RtnvzUYYMR63ZQ8WARC5qAws1K3JuooYbW55xR9ngk/gekEKiq9/E/aF74O0uj0a+VYSgmrUwDdC23wYqSuLCS2kiIHeKUJFSZguMMarKySWVFlhACIiS7Fu5OR2yEPTReidmtUIx4cIl0H8594Ag1qjwjSvz91i60Ag= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721918562; c=relaxed/simple; bh=lmg3xzFI82KttQK9Ffh3dvH2RfjfVPkYJ5cSrCXt1S8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LL/w8fpMDtlVlFhVBzb/DKy5ctwRwgR2xp4JjZqCRI4e9dgmH4lDvYVW8rku6XNzWjudF1hZjRnbZXIwAgZtdpaw3lirZ7PyTqL5I8sfyucW8t9q10OIuBMSYr0ednw6rIvdKhEVlxxMBf5DPGc9tYyim17wlH/9G+ioDC4myTo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KrK5/T4+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="KrK5/T4+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B875C116B1; Thu, 25 Jul 2024 14:42:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1721918561; bh=lmg3xzFI82KttQK9Ffh3dvH2RfjfVPkYJ5cSrCXt1S8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KrK5/T4+QiMSgTAosK2K7OBq4bvL4qhIzK55nfsnLKGByzYjblfrSKH5UcrtjurdX r05YgFeNQ/XrfEONFtDYxoxv3wj0q5RZwJVXDuSpjZQ5MSmu6oGIcI1ZF5avaDDiOG buDljsqeDm88sOscXHnvWDbndUaGpYFA/4L8a7/M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ian Ray , Bartosz Golaszewski , Sasha Levin Subject: [PATCH 5.4 23/43] gpio: pca953x: fix pca953x_irq_bus_sync_unlock race Date: Thu, 25 Jul 2024 16:36:46 +0200 Message-ID: <20240725142731.349817406@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240725142730.471190017@linuxfoundation.org> References: <20240725142730.471190017@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ian Ray [ Upstream commit bfc6444b57dc7186b6acc964705d7516cbaf3904 ] Ensure that `i2c_lock' is held when setting interrupt latch and mask in pca953x_irq_bus_sync_unlock() in order to avoid races. The other (non-probe) call site pca953x_gpio_set_multiple() ensures the lock is held before calling pca953x_write_regs(). The problem occurred when a request raced against irq_bus_sync_unlock() approximately once per thousand reboots on an i.MX8MP based system. * Normal case 0-0022: write register AI|3a {03,02,00,00,01} Input latch P0 0-0022: write register AI|49 {fc,fd,ff,ff,fe} Interrupt mask P0 0-0022: write register AI|08 {ff,00,00,00,00} Output P3 0-0022: write register AI|12 {fc,00,00,00,00} Config P3 * Race case 0-0022: write register AI|08 {ff,00,00,00,00} Output P3 0-0022: write register AI|08 {03,02,00,00,01} *** Wrong register *** 0-0022: write register AI|12 {fc,00,00,00,00} Config P3 0-0022: write register AI|49 {fc,fd,ff,ff,fe} Interrupt mask P0 Signed-off-by: Ian Ray Link: https://lore.kernel.org/r/20240620042915.2173-1-ian.ray@gehealthcare.com Signed-off-by: Bartosz Golaszewski Signed-off-by: Sasha Levin --- drivers/gpio/gpio-pca953x.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c index c81d73d5e0159..d4c81373929af 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -696,6 +696,8 @@ static void pca953x_irq_bus_sync_unlock(struct irq_data *d) pca953x_read_regs(chip, chip->regs->direction, reg_direction); if (chip->driver_data & PCA_PCAL) { + guard(mutex)(&chip->i2c_lock); + /* Enable latch on interrupt-enabled inputs */ pca953x_write_regs(chip, PCAL953X_IN_LATCH, chip->irq_mask); -- 2.43.0