[PATCH AUTOSEL 4.14 2/4] wifi: ath9k: fix clang-specific fortify warnings

[Sasha Levin]

From: Dmitry Antipov <dmantipov@xxxxxxxxx>

[ Upstream commit 95f97fe0ac974467ab4da215985a32b2fdf48af0 ]

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/ath9k/debug.c:17:
In file included from ./include/linux/slab.h:16:
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/x86/include/asm/preempt.h:9:
In file included from ./include/linux/thread_info.h:60:
In file included from ./arch/x86/include/asm/thread_info.h:53:
In file included from ./arch/x86/include/asm/cpufeature.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);

In file included from drivers/net/wireless/ath/ath9k/htc_drv_debug.c:17:
In file included from drivers/net/wireless/ath/ath9k/htc.h:20:
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 'ath9k_get_et_strings()' and
'ath9k_htc_get_et_strings()' due to the same reason: fortification logic
inteprets call to 'memcpy()' as an attempt to copy the whole array from
it's first member and so issues an overread warning. These warnings 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: Toke Høiland-Jørgensen <toke@xxxxxxx>
Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230829093856.234584-1-dmantipov@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/wireless/ath/ath9k/debug.c         | 2 +-
 drivers/net/wireless/ath/ath9k/htc_drv_debug.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
index e05be0eb3f349..efaac08cd0caa 100644
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -1297,7 +1297,7 @@ void ath9k_get_et_strings(struct ieee80211_hw *hw,
 			  u32 sset, u8 *data)
 {
 	if (sset == ETH_SS_STATS)
-		memcpy(data, *ath9k_gstrings_stats,
+		memcpy(data, ath9k_gstrings_stats,
 		       sizeof(ath9k_gstrings_stats));
 }
 
diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_debug.c b/drivers/net/wireless/ath/ath9k/htc_drv_debug.c
index b711b2e1ce93e..957d818b16cfc 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_debug.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_debug.c
@@ -428,7 +428,7 @@ void ath9k_htc_get_et_strings(struct ieee80211_hw *hw,
 			      u32 sset, u8 *data)
 {
 	if (sset == ETH_SS_STATS)
-		memcpy(data, *ath9k_htc_gstrings_stats,
+		memcpy(data, ath9k_htc_gstrings_stats,
 		       sizeof(ath9k_htc_gstrings_stats));
 }
 
-- 
2.42.0