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 56EB21B23A4; Tue, 9 Jul 2024 16:27:08 +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=1720542428; cv=none; b=Qz/dMs+O0Q8EQWsq5K4wbZlKuU5vLYnHjaigld6lyLHO+U6rL9nnLwjqw0LYpqgunlJTYZ2/09LzMOCavIHe7+v7E0J7yO8kgIdowsayDH9GQpmi0a2bZm+ebeBtt3WNclwTKwr2O8oL2r3z7a8/hko1c1Wy8gC5tkqBADcXJns= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720542428; c=relaxed/simple; bh=PB2N1eX+pov5VJqR3NyzDSn32fREMRxdp5mlsLtGc3Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tjwqLSg6V61PV5Qqp66kefJW1mD4MELSPxxz5+zNY2kRL5fZHU78KrszmsK9T827HZi8rffBXST3QAlheG9b+Dt7X1w+tXovIDHSd2bcmn3YQYITDxHsZB7LLRJg3sXQMEXncgQvTcLMrl4FK2aWCtmiuAw6OKHl7FIfLPfRBKE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CuG1yyHa; 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="CuG1yyHa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4802BC32782; Tue, 9 Jul 2024 16:27:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720542428; bh=PB2N1eX+pov5VJqR3NyzDSn32fREMRxdp5mlsLtGc3Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CuG1yyHaDUE1C/P164wpER1CzzJ988T6ipW29ldSEBrNpUqM+5gT126ei06td+4Oh 8gHgaDG359SLgqvXYEap5fnD5AiGX8i53KR75hR8TKMiXY+U1RzwF7moBddtjPMOwR 3h9tcTsrrabhKeVP9H/z7v15zFkXlms5R7aiFgBSMpGQiblXvkPdzTv0dI8elS+5XL CUfWGIEJl+5Dr5M2uitB5ojz1xIMMHK/0AHGSWTgP2S1tYWmjqqc6K1rej3GPCWd9/ I4DwHM9gSbXAl5eD1HZ+3s0QH4/P17nDC055NHi+Sm2PtxERxHe1868dXnNYgmebro YuAcATDGV2sow== 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 5.4 06/11] gpio: pca953x: fix pca953x_irq_bus_sync_unlock race Date: Tue, 9 Jul 2024 12:26:39 -0400 Message-ID: <20240709162654.33343-6-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240709162654.33343-1-sashal@kernel.org> References: <20240709162654.33343-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.4.279 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 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