2019-05-10 09:37:00

by Petr Štetiar

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Subject: [PATCH net 3/5] powerpc: tsi108: fix similar warning reported by kbuild test robot

This patch fixes following (similar) warning reported by kbuild test robot:

In function ‘memcpy’,
inlined from ‘smsc75xx_init_mac_address’ at drivers/net/usb/smsc75xx.c:778:3,
inlined from ‘smsc75xx_bind’ at drivers/net/usb/smsc75xx.c:1501:2:
./include/linux/string.h:355:9: warning: argument 2 null where non-null expected [-Wnonnull]
return __builtin_memcpy(p, q, size);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/usb/smsc75xx.c: In function ‘smsc75xx_bind’:
./include/linux/string.h:355:9: note: in a call to built-in function ‘__builtin_memcpy’

I've replaced the offending memcpy with ether_addr_copy, because I'm
100% sure, that of_get_mac_address can't return NULL as it returns valid
pointer or ERR_PTR encoded value, nothing else.

I'm hesitant to just change IS_ERR into IS_ERR_OR_NULL check, as this
would make the warning disappear also, but it would be confusing to
check for impossible return value just to make a compiler happy.

I'm now changing all occurencies of memcpy to ether_addr_copy after the
of_get_mac_address call, as it's very likely, that we're going to get
similar reports from kbuild test robot in the future.

Fixes: ea168cdf1299 ("powerpc: tsi108: support of_get_mac_address new ERR_PTR error")
Reported-by: kbuild test robot <[email protected]>
Signed-off-by: Petr Štetiar <[email protected]>
---
arch/powerpc/sysdev/tsi108_dev.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/sysdev/tsi108_dev.c b/arch/powerpc/sysdev/tsi108_dev.c
index c92dcac85231..026619c9a8cb 100644
--- a/arch/powerpc/sysdev/tsi108_dev.c
+++ b/arch/powerpc/sysdev/tsi108_dev.c
@@ -18,6 +18,7 @@
#include <linux/irq.h>
#include <linux/export.h>
#include <linux/device.h>
+#include <linux/etherdevice.h>
#include <linux/platform_device.h>
#include <linux/of_net.h>
#include <asm/tsi108.h>
@@ -106,7 +107,7 @@ static int __init tsi108_eth_of_init(void)

mac_addr = of_get_mac_address(np);
if (!IS_ERR(mac_addr))
- memcpy(tsi_eth_data.mac_addr, mac_addr, 6);
+ ether_addr_copy(tsi_eth_data.mac_addr, mac_addr);

ph = of_get_property(np, "mdio-handle", NULL);
mdio = of_find_node_by_phandle(*ph);
--
1.9.1