Re: [PATCH v5 0/2] Incorporate DRAM address in EDAC messages

[Borislav Petkov]

On Thu, Jun 04, 2026 at 11:48:56AM -0400, Yazen Ghannam wrote:
> I think the issue is having concurrent updates to mci->error_desc. EDAC
> assumes a single owner for the MCIs. The fake_inject interface basically
> acts as a second module/owner.

Ok, something like this. Ugly but it should show the intent. It probably needs
more auditing whether we have copied all the fields we need down the
edac_mc_handle_error() path...

diff --git a/drivers/edac/debugfs.c b/drivers/edac/debugfs.c
index 8195fc9c9354..034b9b3f9cf5 100644
--- a/drivers/edac/debugfs.c
+++ b/drivers/edac/debugfs.c
@@ -14,28 +14,38 @@ static ssize_t edac_fake_inject_write(struct file *file,
 	struct mem_ctl_info *mci = to_mci(dev);
 	static enum hw_event_mc_err_type type;
 	u16 errcount = mci->fake_inject_count;
+	struct mem_ctl_info *imci;
+
+	imci = kmalloc(sizeof(struct mem_ctl_info), GFP_KERNEL);
+	if (!imci)
+		return -ENOMEM;
+
+	/* use a local copy and copy the struct */
+	*imci = *mci;
 
 	if (!errcount)
 		errcount = 1;
 
-	type = mci->fake_inject_ue ? HW_EVENT_ERR_UNCORRECTED
-				   : HW_EVENT_ERR_CORRECTED;
+	type = imci->fake_inject_ue ? HW_EVENT_ERR_UNCORRECTED
+				    : HW_EVENT_ERR_CORRECTED;
 
 	printk(KERN_DEBUG
 	       "Generating %d %s fake error%s to %d.%d.%d to test core handling. NOTE: this won't test the driver-specific decoding logic.\n",
 		errcount,
 		(type == HW_EVENT_ERR_UNCORRECTED) ? "UE" : "CE",
 		str_plural(errcount),
-		mci->fake_inject_layer[0],
-		mci->fake_inject_layer[1],
-		mci->fake_inject_layer[2]
+		imci->fake_inject_layer[0],
+		imci->fake_inject_layer[1],
+		imci->fake_inject_layer[2]
 	       );
-	edac_mc_handle_error(type, mci, errcount, 0, 0, 0,
-			     mci->fake_inject_layer[0],
-			     mci->fake_inject_layer[1],
-			     mci->fake_inject_layer[2],
+	edac_mc_handle_error(type, imci, errcount, 0, 0, 0,
+			     imci->fake_inject_layer[0],
+			     imci->fake_inject_layer[1],
+			     imci->fake_inject_layer[2],
 			     "FAKE ERROR", "for EDAC testing only");
 
+	kfree(imci);
+
 	return count;
 }
 


-- 
Regards/Gruss,
    Boris.

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