Re: [PATCH v4 1/2] acpi/ghes: Process CXL Component Events

[Tony Luck]

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