linux-kernel - [PATCH 2/2] net: of: Support adding offset to nvmem MAC addresses

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20241220-net-mac-nvmem-offset-v1-2-e9d1da2c1681@linaro.org>
Date: Fri, 20 Dec 2024 20:17:07 +0100
From: Linus Walleij <linus.walleij@...aro.org>
To: Andrew Lunn <andrew+netdev@...n.ch>, 
 "David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, 
 Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, 
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, Andrew Lunn <andrew@...n.ch>, 
 Heiner Kallweit <hkallweit1@...il.com>, 
 Russell King <linux@...linux.org.uk>, Simon Horman <horms@...nel.org>
Cc: netdev@...r.kernel.org, devicetree@...r.kernel.org, 
 linux-kernel@...r.kernel.org, Linus Walleij <linus.walleij@...aro.org>
Subject: [PATCH 2/2] net: of: Support adding offset to nvmem MAC addresses

If a lower-byte MAC address offset is encoded into the device
tree, make sure to add this to the returned address when
looking up a MAC address from NVMEM.

Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
---
 net/core/of_net.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/core/of_net.c b/net/core/of_net.c
index 93ea425b9248a23f4f95a336e9cdbf0053248e32..c98000ec13377ea4b541e182a66be8b1010edc40 100644
--- a/net/core/of_net.c
+++ b/net/core/of_net.c
@@ -64,6 +64,7 @@ int of_get_mac_address_nvmem(struct device_node *np, u8 *addr)
 	struct nvmem_cell *cell;
 	const void *mac;
 	size_t len;
+	u32 offset;
 	int ret;

 	/* Try lookup by device first, there might be a nvmem_cell_lookup
@@ -72,7 +73,7 @@ int of_get_mac_address_nvmem(struct device_node *np, u8 *addr)
 	if (pdev) {
 		ret = nvmem_get_mac_address(&pdev->dev, addr);
 		put_device(&pdev->dev);
-		return ret;
+		goto add_offset_exit;
 	}

 	cell = of_nvmem_cell_get(np, "mac-address");
@@ -92,8 +93,13 @@ int of_get_mac_address_nvmem(struct device_node *np, u8 *addr)

 	memcpy(addr, mac, ETH_ALEN);
 	kfree(mac);
+	ret = 0;

-	return 0;
+add_offset_exit:
+	if (!ret && !of_property_read_u32(np, "nvmem-mac-minor-offset", &offset))
+		addr[ETH_ALEN - 1] += offset;
+
+	return ret;
 }
 EXPORT_SYMBOL(of_get_mac_address_nvmem);

-- 
2.47.1