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 4F3591C6896; Tue, 9 Jul 2024 16:23:06 +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=1720542186; cv=none; b=i4HbuU4ogIPBNYY2axhIJiUA7MLrEZegT1bqvq8X7W3jgcTlv6T72YH0+lDxrh/kLea3MNyVbX4kcaLER5xsS7U3qu5jcstsjHWkNLwZCyR34GyQJjAQZSdAqIT59dELe2oqAaYdFQCE1hvrPn1XNb/v/vcvcMoVNfOGzgp9jmM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720542186; c=relaxed/simple; bh=JQ8rH6L0UG56rgymtQj7bFKqC8XdJrsYxqZhDSzY9f4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YpXCF9bfvJvFDYsjfCuDNAN9a7fOWKoSz5zrUt3IosQ6QkZfennDFHg3w4BLEBi666JEe3eKLuB8pAOvp+YodN88PfwmMKu1hTLe9v4uc4YxcGeDtQC0bpaDZVY9tEaaOTbxCubuGto9La4tQFtfUOouoPgDBkFZM+krU0hTaeE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=plDWqSQe; 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="plDWqSQe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9054AC4AF0B; Tue, 9 Jul 2024 16:23:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720542185; bh=JQ8rH6L0UG56rgymtQj7bFKqC8XdJrsYxqZhDSzY9f4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=plDWqSQewncF1pKOIyZyAy1E0T0ckGFcq6qCT7aKwTWUfunBJarR4Le6b53T0QlWn XtvtGVxbiLAiP+gq7PFO7XVWVnTmcTP5J4ktESco7GlPaqpm3mmPNjDIaxZwXMSN/q IJMHLc9kg7oWEkRDfum1FDZ6ud2pkaLoLaPyZmCOCy7aeJqOTOXrJHxuyYO0AL/0Q3 UorSzjdeAf0Lj5rHttHbi33S6RPDn3cmpEp+COi4wcEoNLV0YzNT6rcnegHTz3MqFT 4HHkUGRIt2kTQTuwmRokpktiP3+gprkhXmG3RTLhEIEQKmUEeNA+aL9YPoIfBvm22g 6w6VLkS7ci5Eg== 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 6.6 18/33] gpio: pca953x: fix pca953x_irq_bus_sync_unlock race Date: Tue, 9 Jul 2024 12:21:44 -0400 Message-ID: <20240709162224.31148-18-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240709162224.31148-1-sashal@kernel.org> References: <20240709162224.31148-1-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 6.6.38 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 bdd50a78e4142..ce9a94e332801 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -766,6 +766,8 @@ 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