Thread (48 messages) 48 messages, 6 authors, 2026-01-29

Re: [PATCH v2 net-next 01/15] net: mdio-regmap: permit working with non-MMIO regmaps

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: 2026-01-22 14:38:44
Also in: linux-devicetree, lkml

On Thu, Jan 22, 2026 at 03:47:04PM +0200, Vladimir Oltean wrote:
On Thu, Jan 22, 2026 at 02:13:01PM +0200, Vladimir Oltean wrote:
...
quoted
quoted
quoted
+	unsigned int base;
Hmm... resource_size_t ?
quoted
Well, regmap_read() takes "unsigned int reg".
https://elixir.bootlin.com/linux/v6.18.6/source/include/linux/regmap.h#L1297
So in practice, a truncation will be done somewhere if the register base
exceeds unsigned int storage capacity. But I didn't feel that it's worth
handling that.
Would this address your feedback?
Yes and no. See my remarks below.
quoted hunk ↗ jump to hunk
diff --git a/drivers/net/mdio/mdio-regmap.c b/drivers/net/mdio/mdio-regmap.c
index 2a0e9c519fa3..416ff4e13e8f 100644
--- a/drivers/net/mdio/mdio-regmap.c
+++ b/drivers/net/mdio/mdio-regmap.c
@@ -67,8 +67,15 @@ struct mii_bus *devm_mdio_regmap_register(struct device *dev,
 	mr = mii->priv;
 	mr->regmap = config->regmap;
 	mr->valid_addr = config->valid_addr;
-	if (config->resource)
+	if (config->resource) {
Btw, this might be not enough, one should check size and flags as well
before use. There was a discussion about this recently. Maybe we should
just move to a simple unsigned int in the config for now? Because handling
resources maybe considered as over engineering in this case.
+		if (config->resource->start > U32_MAX ||
+		    config->resource->end > U32_MAX) {
Ideally it should be resource_overlaps() check. But see above.
+			dev_err(config->parent,
+				"Resource exceeds regmap API addressing possibilities\n");
+			return ERR_PTR(-EINVAL);
+		}
 		mr->base = config->resource->start;
+	}
-- 
With Best Regards,
Andy Shevchenko

Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help