From: Alison Schofield <alison.schofield@intel.com>
To: Dave Jiang <dave.jiang@intel.com>
Cc: <linux-acpi@vger.kernel.org>, <linux-cxl@vger.kernel.org>,
<rafael@kernel.org>, <tony.luck@intel.com>, <bp@alien8.de>,
<guohanjun@huawei.com>, <mchehab@kernel.org>,
<xueshuai@linux.alibaba.com>, <terry.bowman@amd.com>,
<sashiko-bot@kernel.org>
Subject: Re: [PATCH v3 06/10] ACPI: extlog: Defer CXL protocol error handling to avoid lock inversion
Date: Mon, 20 Jul 2026 09:26:59 -0700 [thread overview]
Message-ID: <al5MU5B8M60GiiRK@aschofie-mobl2.lan> (raw)
In-Reply-To: <20260717161647.1493259-7-dave.jiang@intel.com>
On Fri, Jul 17, 2026 at 09:16:43AM -0700, Dave Jiang wrote:
> sashiko-bot flagged an AB-BA deadlock between the PCI device_lock and
> the MCE decoder chain rwsem.
>
> extlog_print() calls cxl_cper_handle_prot_err() synchronously while the
> MCE notifier chain rwsem is held, and that path takes the PCI device_lock
> via guard(device)(). The probe path takes the locks in the opposite
> order (device_lock held while mce_register_decode_chain() takes the
> rwsem), so the two form an AB-BA deadlock.
>
> ghes.c already avoids this by posting protocol errors to a kfifo and
> handling them from a workqueue via cxl_cper_post_prot_err(). Export that
> function and use it from acpi_extlog.c instead of calling
> cxl_cper_handle_prot_err() directly.
>
> Reported-by: sashiko-bot@kernel.org
> Link: https://lore.kernel.org/linux-cxl/20260709165457.8BA181F000E9@smtp.kernel.org/
> Assisted-by: Claude:claude-sonnet-4-6
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
next prev parent reply other threads:[~2026-07-20 16:27 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-17 16:16 [PATCH v3 00/10] ACPI: APEI: GHES: Collection of fixes for issues reported by sashiko Dave Jiang
2026-07-17 16:16 ` [PATCH v3 01/10] ACPI: APEI: GHES: Bound CXL event record copy to the firmware section length Dave Jiang
2026-07-17 17:09 ` sashiko-bot
2026-07-20 12:21 ` Hanjun Guo
2026-07-20 16:15 ` Dave Jiang
2026-07-20 16:23 ` Alison Schofield
2026-08-12 12:10 ` Shuai Xue
2026-07-17 16:16 ` [PATCH v3 02/10] efi/cper: Reject CPER records with an out-of-range error_data_length Dave Jiang
2026-07-17 17:26 ` sashiko-bot
2026-07-20 16:24 ` Alison Schofield
2026-08-12 12:23 ` Shuai Xue
2026-07-17 16:16 ` [PATCH v3 03/10] ACPI: APEI: GHES: Validate CXL protocol error section length before RAS cap copy Dave Jiang
2026-07-17 17:41 ` sashiko-bot
2026-07-20 16:25 ` Alison Schofield
2026-08-12 12:30 ` Shuai Xue
2026-07-17 16:16 ` [PATCH v3 04/10] ACPI: extlog: Avoid populating software AER metadata from raw hardware buffer Dave Jiang
2026-07-17 17:58 ` sashiko-bot
2026-07-20 16:25 ` Alison Schofield
2026-08-12 12:32 ` Shuai Xue
2026-07-17 16:16 ` [PATCH v3 05/10] ACPI: extlog: Validate PCIe error section length before payload access Dave Jiang
2026-07-17 18:29 ` sashiko-bot
2026-07-20 16:26 ` Alison Schofield
2026-08-12 12:59 ` Shuai Xue
2026-07-17 16:16 ` [PATCH v3 06/10] ACPI: extlog: Defer CXL protocol error handling to avoid lock inversion Dave Jiang
2026-07-17 18:44 ` sashiko-bot
2026-07-20 16:26 ` Alison Schofield [this message]
2026-08-12 13:06 ` Shuai Xue
2026-07-17 16:16 ` [PATCH v3 07/10] ACPI: extlog: Fix CONFIG_ACPI_APEI_PCIEAER guard typo Dave Jiang
2026-07-17 19:07 ` sashiko-bot
2026-07-17 21:24 ` Dave Jiang
2026-07-20 16:27 ` Alison Schofield
2026-08-12 13:10 ` Shuai Xue
2026-07-17 16:16 ` [PATCH v3 08/10] ACPI: APEI: GHES: Validate memory error section length before payload access Dave Jiang
2026-07-17 19:23 ` sashiko-bot
2026-07-20 16:28 ` Alison Schofield
2026-08-12 13:14 ` Shuai Xue
2026-07-17 16:16 ` [PATCH v3 09/10] ACPI: APEI: GHES: Bound AER info copy and sanitize software metadata Dave Jiang
2026-07-17 19:39 ` sashiko-bot
2026-07-20 16:28 ` Alison Schofield
2026-08-12 13:16 ` Shuai Xue
2026-07-17 16:16 ` [PATCH v3 10/10] ACPI: extlog: Validate elog record length before walking sections Dave Jiang
2026-07-17 19:57 ` sashiko-bot
2026-07-20 16:29 ` Alison Schofield
2026-08-12 13:18 ` Shuai Xue
2026-07-21 11:33 ` [PATCH v3 00/10] ACPI: APEI: GHES: Collection of fixes for issues reported by sashiko Rafael J. Wysocki (Intel)
2026-07-21 15:06 ` Dave Jiang
2026-08-14 20:16 ` Rafael J. Wysocki (Intel)
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