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 F23B41AC45C; Tue, 9 Jul 2024 16:21:00 +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=1720542061; cv=none; b=XY/DXp1sRjpkV7dM1qQ9HH9lMYFU+/m2xJ6P2oLp3dfB15XqVEdnSjRtYinrcwk2kM8H9xizo5oP56LxXpQV1Av30/CcxkNA6KZO4JCXjkV9L5Sl/eR9T7Jf6lSOdNJeNdpQp7nFEAgqKamVGCXt9kEEsJbgkqKh7EyRZqaM/40= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720542061; c=relaxed/simple; bh=1P3Npn3mh2RmgZy5z8jWNbyPq/9BixdfLRnEu8Vc2QA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=stoXZdbnJzzorC88XNk9m7Bkb3jR+KdXrXQl04Q+LZHd3/NG2+vsDh3+k+GFsbRhqFc9khJnpmdjsT7tautAM7ynpPwlcKrDN0NAVmx5I8LOBXR/BB/M+7mxryPMk2qM+ci2I58WIZl3yrKPg5IIDRWMuR90xxghGQsYhGr2CdI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ooNJP2cK; 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="ooNJP2cK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9969AC3277B; Tue, 9 Jul 2024 16:20:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720542060; bh=1P3Npn3mh2RmgZy5z8jWNbyPq/9BixdfLRnEu8Vc2QA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ooNJP2cKXLQCkMuaOh4ClcPUkv6xfVLC0QSdCayrA/ev9Oscwj/BPZ7eNGaXyYVBX IclpRd1CPp/4Mkdb4e+ErYgeduWBth3yRLPAGiyv20UyPQczFoapwfqOtHW8rf5pFR 7UFhDnIIrYn1oNongetL0hcrvh/SGo2psp/3CC6q06wiAMgPYYdxbTzK3QOKzbVbm+ f6usCDvcqjKMRb+klznIAp/tZmhLHlRfnbr/0aUAfzTxaDUTf5NxrUvEOlrr83yLqr CP9LtqsK8GjI7RQejyp4QZJDv6dUiY9Aj2FaTHCER5saIGrV1yV//9EhIL/Divfd8w SSegq855zZaGA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ian Ray , Bartosz Golaszewski , Sasha Levin , linus.walleij@linaro.org, brgl@bgdev.pl, linux-gpio@vger.kernel.org Subject: [PATCH AUTOSEL 6.9 23/40] gpio: pca953x: fix pca953x_irq_bus_sync_unlock race Date: Tue, 9 Jul 2024 12:19:03 -0400 Message-ID: <20240709162007.30160-23-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240709162007.30160-1-sashal@kernel.org> References: <20240709162007.30160-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.9.8 Content-Transfer-Encoding: 8bit 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 00ffa168e4056..f2f40393e3695 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -758,6 +758,8 @@ static void pca953x_irq_bus_sync_unlock(struct irq_data *d) int level; 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