Re: [PATCH net-next] drivers: net: sky2: Fix -Wstringop-truncation with W=1
From: Jakub Kicinski <kuba@kernel.org>
Date: 2020-11-03 00:01:09
On Sat, 31 Oct 2020 18:40:28 +0100 Andrew Lunn wrote:
quoted hunk ↗ jump to hunk
In function ‘strncpy’, inlined from ‘sky2_name’ at drivers/net/ethernet/marvell/sky2.c:4903:3, inlined from ‘sky2_probe’ at drivers/net/ethernet/marvell/sky2.c:5049:2: ./include/linux/string.h:297:30: warning: ‘__builtin_strncpy’ specified bound 16 equals destination size [-Wstringop-truncation] None of the device names are 16 characters long, so it was never an issue, but reduce the length of the buffer size by one to avoid the warning. Signed-off-by: Andrew Lunn <andrew@lunn.ch> --- drivers/net/ethernet/marvell/sky2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/net/ethernet/marvell/sky2.c b/drivers/net/ethernet/marvell/sky2.c index 25981a7a43b5..35b0ec5afe13 100644 --- a/drivers/net/ethernet/marvell/sky2.c +++ b/drivers/net/ethernet/marvell/sky2.c@@ -4900,7 +4900,7 @@ static const char *sky2_name(u8 chipid, char *buf, int sz) }; if (chipid >= CHIP_ID_YUKON_XL && chipid <= CHIP_ID_YUKON_OP_2) - strncpy(buf, name[chipid - CHIP_ID_YUKON_XL], sz); + strncpy(buf, name[chipid - CHIP_ID_YUKON_XL], sz - 1);
Hm. This irks the eye a little. AFAIK the idiomatic code would be: strncpy(buf, name..., sz - 1); buf[sz - 1] = '\0'; Perhaps it's easier to convert to strscpy()/strscpy_pad()?
else snprintf(buf, sz, "(chip %#x)", chipid); return buf;