From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 B3CA737EFE3; Mon, 24 Aug 2026 17:49:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787593785; cv=none; b=LDgtf3uSOtqG+jGrNu6S8D2cuD1gZ8Afsrv/LUqvmIRv9UexvTjI+dhPKs8Zko7WBLorOElKGbJRmlVgBPUMb9lgMVLrwSGkmp/iH7rwozRN0xQo1B7xspz650EDnSS69OQ4WdqIRJ9hDDuBm5Vvpy1qZkdBLKh1+lwJMiyIIeA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787593785; c=relaxed/simple; bh=KIKSIiU318yLehVOQuUmyyakuVIan2KSnuIBrMUYD5w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=L0Lgw23aaVxhVyB22lrtdExS64lkBhoMxMvaHb5kbHZReCm/RbaEABxb02xMwp3igRI26diTv7t3dBYv6wAjQt4CRgB4hwfkU0Crg9r2pWtXBz/LmdgVrJ6358Swt52XMbR4m/GWqcHHZuYSUYt4oy67Dl/gajYEqxj4BetXrPc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 484431F00A3A; Mon, 24 Aug 2026 17:49:44 +0000 (UTC) From: Dave Jiang To: linux-acpi@vger.kernel.org, linux-cxl@vger.kernel.org Cc: rafael@kernel.org, tony.luck@intel.com, bp@alien8.de, guohanjun@huawei.com, mchehab@kernel.org, xueshuai@linux.alibaba.com, terry.bowman@amd.com, benjamin.cheatham@amd.com, alison.schofield@intel.com, sashiko-bot@kernel.org Subject: [PATCH v4 04/13] ACPI: extlog: Defer CXL protocol error handling to avoid lock inversion Date: Mon, 24 Aug 2026 10:49:27 -0700 Message-ID: <20260824174936.939059-5-dave.jiang@intel.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260824174936.939059-1-dave.jiang@intel.com> References: <20260824174936.939059-1-dave.jiang@intel.com> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 two in the opposite order, holding device_lock while mce_register_decode_chain() takes the rwsem, so they can deadlock AB-BA. 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 call it instead. Declare it with the other CONFIG_ACPI_APEI_GHES exports rather than at the end of the header. No #else stub: ACPI_EXTLOG selects ACPI_APEI_GHES, so the only caller cannot exist without it. Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/linux-cxl/20260709165457.8BA181F000E9@smtp.kernel.org/ Reviewed-by: Alison Schofield Reviewed-by: Shuai Xue Assisted-by: Claude:claude-sonnet-4-6 Signed-off-by: Dave Jiang --- v4: - Moved the cxl_cper_post_prot_err() declaration inside the CONFIG_ACPI_APEI_GHES block (Shuai Xue). --- drivers/acpi/acpi_extlog.c | 21 ++------------------- drivers/acpi/apei/ghes.c | 5 +++-- include/acpi/ghes.h | 4 ++++ 3 files changed, 9 insertions(+), 21 deletions(-) diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c index 9ad0052aa20c..f6e3da4e13e7 100644 --- a/drivers/acpi/acpi_extlog.c +++ b/drivers/acpi/acpi_extlog.c @@ -163,23 +163,6 @@ static void extlog_print_pcie(struct cper_sec_pcie *pcie_err, #endif } -static void -extlog_cxl_cper_handle_prot_err(struct cxl_cper_sec_prot_err *prot_err, - int severity) -{ -#ifdef ACPI_APEI_PCIEAER - struct cxl_cper_prot_err_work_data wd; - - if (cxl_cper_sec_prot_err_valid(prot_err)) - return; - - if (cxl_cper_setup_prot_err_work_data(&wd, prot_err, severity)) - return; - - cxl_cper_handle_prot_err(&wd); -#endif -} - static int extlog_print(struct notifier_block *nb, unsigned long val, void *data) { @@ -239,8 +222,8 @@ static int extlog_print(struct notifier_block *nb, unsigned long val, struct cxl_cper_sec_prot_err *prot_err = acpi_hest_get_payload(gdata); - extlog_cxl_cper_handle_prot_err(prot_err, - gdata->error_severity); + cxl_cper_post_prot_err(prot_err, + gdata->error_severity); } else if (guid_equal(sec_type, &CPER_SEC_PCIE)) { struct cper_sec_pcie *pcie_err = acpi_hest_get_payload(gdata); diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 3236a3ce79d6..a382aabf9835 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -752,8 +752,8 @@ static DEFINE_KFIFO(cxl_cper_prot_err_fifo, struct cxl_cper_prot_err_work_data, static DEFINE_SPINLOCK(cxl_cper_prot_err_work_lock); struct work_struct *cxl_cper_prot_err_work; -static void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err, - int severity) +void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err, + int severity) { #ifdef CONFIG_ACPI_APEI_PCIEAER struct cxl_cper_prot_err_work_data wd; @@ -777,6 +777,7 @@ static void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err, schedule_work(cxl_cper_prot_err_work); #endif } +EXPORT_SYMBOL_FOR_MODULES(cxl_cper_post_prot_err, "acpi_extlog"); int cxl_cper_register_prot_err_work(struct work_struct *work) { diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h index 8d7e5caef3f1..be496bc0386f 100644 --- a/include/acpi/ghes.h +++ b/include/acpi/ghes.h @@ -85,6 +85,10 @@ int devm_ghes_register_vendor_record_notifier(struct device *dev, struct list_head *ghes_get_devices(void); void ghes_estatus_pool_region_free(unsigned long addr, u32 size); + +struct cxl_cper_sec_prot_err; +void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err, + int severity); #else static inline struct list_head *ghes_get_devices(void) { return NULL; } -- 2.54.0