Received-SPF: pass (google.com: domain of linux-kernel+bounces-164589-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Date: Tue, 30 Apr 2024 11:32:27 -0700
From: Tony Luck <tony.luck@intel.com>
To: Ira Weiny <ira.weiny@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Jonathan Cameron <jonathan.cameron@huawei.com>,
	Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>,
	Shiju Jose <shiju.jose@huawei.com>,
	Dan Carpenter <dan.carpenter@linaro.org>,
	Yazen Ghannam <yazen.ghannam@amd.com>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Alison Schofield <alison.schofield@intel.com>,
	Vishal Verma <vishal.l.verma@intel.com>,
	Ard Biesheuvel <ardb@kernel.org>, linux-efi@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Borislav Petkov <bp@alien8.de>
Subject: Re: [PATCH v4 1/2] acpi/ghes: Process CXL Component Events
Message-ID: <ZjE5O87IxxMAoaFz@agluck-desk3>
References: <20240426-cxl-cper3-v4-0-58076cce1624@intel.com>
 <20240426-cxl-cper3-v4-1-58076cce1624@intel.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20240426-cxl-cper3-v4-1-58076cce1624@intel.com>

On Fri, Apr 26, 2024 at 08:34:00PM -0700, Ira Weiny wrote:
> @@ -707,6 +805,18 @@ static bool ghes_do_proc(struct ghes *ghes,
>  		}
>  		else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) {
>  			queued = ghes_handle_arm_hw_error(gdata, sev, sync);
> +		} else if (guid_equal(sec_type, &CPER_SEC_CXL_GEN_MEDIA_GUID)) {
> +			struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
> +
> +			cxl_cper_post_event(CXL_CPER_EVENT_GEN_MEDIA, rec);
> +		} else if (guid_equal(sec_type, &CPER_SEC_CXL_DRAM_GUID)) {
> +			struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
> +
> +			cxl_cper_post_event(CXL_CPER_EVENT_DRAM, rec);
> +		} else if (guid_equal(sec_type, &CPER_SEC_CXL_MEM_MODULE_GUID)) {
> +			struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
> +
> +			cxl_cper_post_event(CXL_CPER_EVENT_MEM_MODULE, rec);
>  		} else {
>  			void *err = acpi_hest_get_payload(gdata);

You pass "rec" to cxl_cper_post_event() in all these cases for later
processing in context where you can sleep to get locks. But that's
just a pointer somewhere into the "gdata" error record received from
BIOS.

What's the lifetime of that record? Can it be re-used/overwritten
before that other kernel thread gets around to looking at it?

-Tony