net: b44: use ethtool_puts

There's a subtle error with the memcpy here, where b44_gstrings should
not be dereferenced. Dereferening causes the following error with W=1:

In file included from drivers/net/ethernet/broadcom/b44.c:17:
In file included from ./include/linux/module.h:18:
In file included from ./include/linux/kmod.h:9:
In file included from ./include/linux/umh.h:4:
In file included from ./include/linux/gfp.h:7:
In file included from ./include/linux/mmzone.h:8:
In file included from ./include/linux/spinlock.h:56:
In file included from ./include/linux/preempt.h:79:
In file included from ./arch/powerpc/include/asm/preempt.h:5:
In file included from ./include/asm-generic/preempt.h:5:
In file included from ./include/linux/thread_info.h:23:
In file included from ./arch/powerpc/include/asm/current.h:13:
In file included from ./arch/powerpc/include/asm/paca.h:16:
In file included from ./include/linux/string.h:386:
./include/linux/fortify-string.h:578:4: error: call to
'__read_overflow2_field' declared with 'warning' attribute: detected read
beyond size of field (2nd parameter); maybe use>
  578 |                        __read_overflow2_field(q_size_field, size);
      |                         ^

Instead of fixing the memcpy, use ethtool_puts, which is the proper
helper for printing ethtool gstrings.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20260531000334.388351-1-rosenp@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/broadcom/b44.c b/drivers/net/ethernet/broadcom/b44.c
index 90df02e0039cbacc57df1de0d9e0b564672da53d..f994636fbd5f1a5420cdbd98cae2a172c946a7ef 100644 (file)
--- a/drivers/net/ethernet/broadcom/b44.c
+++ b/drivers/net/ethernet/broadcom/b44.c
@@ -2031,11 +2031,11 @@ static int b44_set_pauseparam(struct net_device *dev,
 
 static void b44_get_strings(struct net_device *dev, u32 stringset, u8 *data)
 {
-       switch(stringset) {
-       case ETH_SS_STATS:
-               memcpy(data, *b44_gstrings, sizeof(b44_gstrings));
-               break;
-       }
+       if (stringset != ETH_SS_STATS)
+               return;
+
+       for (int i = 0; i < ARRAY_SIZE(b44_gstrings); i++)
+               ethtool_puts(&data, b44_gstrings[i]);
 }
 
 static int b44_get_sset_count(struct net_device *dev, int sset)