From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792773934; b=Wj7iO8IdYwpAkEFrzQTj6MPTGDlJ69d5NoI1bFMOe4oYTg772ipWBKoIxvJ/cpJ2yYMR 0xAerc1C3qe85FGEGtwEQ90UwKJc3JHtEeG5oJEmpQLwbYVZFNudwooHPFWwMNn/56i6K FNmO7ifAvga8kQtTJZXTnx3SVzFT2hSllkmz5kcTgyPv1pef0m3L++mW5O1n+2ohRFb56 SNYh7DHu4elK+Vgm0kcGdAxyFHOV0bIrRPchhxAarAsyY2IAc0ZvPIGSjkKBhhgr2q0VB RFOO2eCd5dYgCYImw0ddv6sqXX4ObJmncj69WBxUlABuFZzxLFiLeXR2Fj2lF67OgNg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792773934; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=jKoKvMdULdHrmFrMxYntDYwx6CW5w9VvQA0PJ3nu4Pk=; b=ukj87JCTxzvc06dzfHiyeRaBq0epsV2ExaEH2xH01W61ly76eMQvhE44o051LlAHl+dy PMzqpJ05NiPzzQWkrP7TeggVrOQK6RTdI80pyUAKe5m6ja3vNiRPHdJXuZN83x+9vu3SQ P86fqhK0Yl+dGuBJWNWlE6sR+NQ2/galKi6cMGkEMEMpzWH9ScwJKtO/YUaYGhHeK7L/G 7OHC7+GTifhOFFGnpuxfR4iFGGxzU3WcEjvXCUUeLJLX5Y/K0vIzg6WiU1j4PdaEZVEJ/ OtXPg0mP84Ivu16V7GjMgRQ/VJc28bJ5MJBUMEcc1cYk2q2AX2ZSx7pjMvM5AGtHaew== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=z8UWJe3g; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F051D606A31A; Fri, 23 Oct 2026 16:45:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=z8UWJe3g Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C16E1F01825; Fri, 23 Oct 2026 16:45:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792773933; bh=jKoKvMdULdHrmFrMxYntDYwx6CW5w9VvQA0PJ3nu4Pk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=z8UWJe3gypI05FkJKZnnrkECO/KKCa6e03X1GwaIqXDD2a27AKdROicHC3O+7W8FF D+85Z2MVRTTD9bQJBo6EHeYwNZn/l1uSwdeVa3nbl4hmcY1gf5zAdrLk6VRuxLFh0X QTEbTr04Y5Ril50OTR/J+z7tDxvJHkVJK+wZhD00= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Frank Li , Peng Fan , Andy Shevchenko , Bartosz Golaszewski , Sasha Levin Subject: [PATCH 6.18 066/193] gpio: mxc: fix wakeup_pads bit operations Date: Fri, 23 Oct 2026 18:35:43 +0200 Message-ID: <20261023163715.765338121@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261023163714.201276352@linuxfoundation.org> References: <20261023163714.201276352@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peng Fan [ Upstream commit 170aeff46fb54f41545c85a72aec525aebc79d44 ] gpio_set_wake_irq() can be called concurrently for different pins on the same port. The writer-vs-writer race is the concern: two concurrent gpio_set_wake_irq() calls for different pins on the same port both do a non-atomic read-modify-write on the same wakeup_pads word. The old |= and &= compile to separate load/modify/store instructions that can interleave, losing one CPU's update. assign_bit() uses an atomic RMW instruction, so concurrent writers to different bits in the same word are safe. The reader side (for_each_set_bit in noirq_suspend, wakeup_pads > 0) runs in noirq context where no concurrent writer can execute, so reader atomicity is not needed. wakeup_pads is a u32, while assign_bit() operates on unsigned long pointers. On 64-bit platforms, this causes an 8-byte read-modify-write on a 4-byte field, corrupting the adjacent is_pad_wakeup. So change wakeup_pads to unsigned long and reorder to avoid wasting words. And fix the enable/disable path unconditionally sets/clears the wakeup_pads bit even when enable_irq_wake()/disable_irq_wake() fails. Only update the bit on success. Fixes: f60c9eac54af ("gpio: mxc: enable pad wakeup on i.MX8x platforms") Assisted-by: LLM Reviewed-by: Frank Li Signed-off-by: Peng Fan Reviewed-by: Andy Shevchenko Link: https://patch.msgid.link/20261013-gpio-mxc-cleanup-v7-3-c4d769587d3e@nxp.com Signed-off-by: Bartosz Golaszewski Signed-off-by: Sasha Levin --- drivers/gpio/gpio-mxc.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c index 7e17d7668980d..e3a80f17d0412 100644 --- a/drivers/gpio/gpio-mxc.c +++ b/drivers/gpio/gpio-mxc.c @@ -72,8 +72,8 @@ struct mxc_gpio_port { unsigned long both_edges; struct mxc_gpio_reg_saved gpio_saved_reg; bool power_off; - u32 wakeup_pads; bool is_pad_wakeup; + unsigned long wakeup_pads; u32 pad_type[32]; const struct mxc_gpio_hwdata *hwdata; }; @@ -331,16 +331,18 @@ static int gpio_set_wake_irq(struct irq_data *d, u32 enable) ret = enable_irq_wake(port->irq_high); else ret = enable_irq_wake(port->irq); - port->wakeup_pads |= BIT(gpio_idx); } else { if (port->irq_high && (gpio_idx >= 16)) ret = disable_irq_wake(port->irq_high); else ret = disable_irq_wake(port->irq); - port->wakeup_pads &= ~BIT(gpio_idx); } + if (ret) + return ret; - return ret; + assign_bit(gpio_idx, &port->wakeup_pads, enable); + + return 0; } static int mxc_gpio_init_gc(struct mxc_gpio_port *port, int irq_base) -- 2.53.0