From: Dmitry Antipov <dmantipov@yandex.ru>
Date: Tue, 29 Aug 2023 09:43:49 +0000 (+0300)
Subject: wifi: mt76: fix clang-specific fortify warnings
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=03f0e11da7fb26db4f27e6b83a223512db9f7ca5;p=linux.git

wifi: mt76: fix clang-specific fortify warnings

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/mediatek/mt76/mt792x_core.c:4:
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);

In file included from drivers/net/wireless/mediatek/mt76/mt7915/main.c:4:
In file included from ./include/linux/etherdevice.h:20:
In file included from ./include/linux/if_ether.h:19:
In file included from ./include/linux/skbuff.h:15:
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);

In file included from drivers/net/wireless/mediatek/mt76/mt7996/main.c:6:
In file included from drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h:9:
In file included from ./include/linux/interrupt.h:8:
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 'mt7915_get_et_strings()',
'mt792x_get_et_strings()' and 'mt7996_get_et_strings()' due to the same
reason: fortification logic inteprets call to 'memcpy()' as an attempt
to copy the whole array from its 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@yandex.ru>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/main.c b/drivers/net/wireless/mediatek/mt76/mt7915/main.c
index 240483154faad..e8e02d1420fdd 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/main.c
@@ -1398,7 +1398,7 @@ void mt7915_get_et_strings(struct ieee80211_hw *hw,
 	if (sset != ETH_SS_STATS)
 		return;
 
-	memcpy(data, *mt7915_gstrings_stats, sizeof(mt7915_gstrings_stats));
+	memcpy(data, mt7915_gstrings_stats, sizeof(mt7915_gstrings_stats));
 	data += sizeof(mt7915_gstrings_stats);
 	page_pool_ethtool_stats_get_strings(data);
 }
diff --git a/drivers/net/wireless/mediatek/mt76/mt792x_core.c b/drivers/net/wireless/mediatek/mt76/mt792x_core.c
index 5648b7328b8c2..8c97ac007d9ca 100644
--- a/drivers/net/wireless/mediatek/mt76/mt792x_core.c
+++ b/drivers/net/wireless/mediatek/mt76/mt792x_core.c
@@ -358,7 +358,7 @@ void mt792x_get_et_strings(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 	if (sset != ETH_SS_STATS)
 		return;
 
-	memcpy(data, *mt792x_gstrings_stats, sizeof(mt792x_gstrings_stats));
+	memcpy(data, mt792x_gstrings_stats, sizeof(mt792x_gstrings_stats));
 
 	data += sizeof(mt792x_gstrings_stats);
 	page_pool_ethtool_stats_get_strings(data);
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/main.c b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
index fc9061e3f481d..b0f0159384d41 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
@@ -1189,7 +1189,7 @@ void mt7996_get_et_strings(struct ieee80211_hw *hw,
 			   u32 sset, u8 *data)
 {
 	if (sset == ETH_SS_STATS)
-		memcpy(data, *mt7996_gstrings_stats,
+		memcpy(data, mt7996_gstrings_stats,
 		       sizeof(mt7996_gstrings_stats));
 }