[PATCH AUTOSEL 4.14 3/4] wifi: ath10k: fix clang-specific fortify warning

From: Sasha Levin
Date: Tue Nov 07 2023 - 07:24:58 EST


From: Dmitry Antipov <dmantipov@xxxxxxxxx>

[ Upstream commit cb4c132ebfeac5962f7258ffc831caa0c4dada1a ]

When compiling with clang 16.0.6 and CONFIG_FORTIFY_SOURCE=y, I've
noticed the following (somewhat confusing due to absence of an actual
source code location):

In file included from drivers/net/wireless/ath/ath10k/debug.c:8:
In file included from ./include/linux/module.h:13:
In file included from ./include/linux/stat.h:19:
In file included from ./include/linux/time.h:60:
In file included from ./include/linux/time32.h:13:
In file included from ./include/linux/timex.h:67:
In file included from ./arch/x86/include/asm/timex.h:5:
In file included from ./arch/x86/include/asm/processor.h:23:
In file included from ./arch/x86/include/asm/msr.h:11:
In file included from ./arch/x86/include/asm/cpumask.h:5:
In file included from ./include/linux/cpumask.h:12:
In file included from ./include/linux/bitmap.h:11:
In file included from ./include/linux/string.h:254:
./include/linux/fortify-string.h:592:4: warning: call to '__read_overflow2_field'
declared with 'warning' attribute: detected read beyond size of field (2nd
parameter); maybe use struct_group()? [-Wattribute-warning]
__read_overflow2_field(q_size_field, size);

The compiler actually complains on 'ath10k_debug_get_et_strings()' where
fortification logic inteprets call to 'memcpy()' as an attempt to copy
the whole 'ath10k_gstrings_stats' array from it's first member and so
issues an overread warning. This warning may be silenced by passing
an address of the whole array and not the first member to 'memcpy()'.

Signed-off-by: Dmitry Antipov <dmantipov@xxxxxxxxx>
Acked-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>
Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230829093652.234537-1-dmantipov@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/wireless/ath/ath10k/debug.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/debug.c b/drivers/net/wireless/ath/ath10k/debug.c
index 22003895f8548..591d0b9c0be3c 100644
--- a/drivers/net/wireless/ath/ath10k/debug.c
+++ b/drivers/net/wireless/ath/ath10k/debug.c
@@ -1411,7 +1411,7 @@ void ath10k_debug_get_et_strings(struct ieee80211_hw *hw,
u32 sset, u8 *data)
{
if (sset == ETH_SS_STATS)
- memcpy(data, *ath10k_gstrings_stats,
+ memcpy(data, ath10k_gstrings_stats,
sizeof(ath10k_gstrings_stats));
}

--
2.42.0