diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index a828cf99c5215..2d01b2bbb7465 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -4150,6 +4150,9 @@ enum skb_ext_id {
#endif
#if IS_ENABLED(CONFIG_MPTCP)
SKB_EXT_MPTCP,
+#endif
+#if IS_ENABLED(CONFIG_KCOV)
+ SKB_EXT_KCOV_HANDLE,
#endif
SKB_EXT_NUM, /* must be last */
};
@@ -4605,5 +4608,35 @@ static inline void skb_reset_redirect(struct sk_buff *skb)
#endif
}
+#ifdef CONFIG_KCOV
+static inline void skb_set_kcov_handle(struct sk_buff *skb,
+ const u64 kcov_handle)
+{
+ /* Do not allocate skb extensions only to set kcov_handle to zero
+ * (as it is zero by default). However, if the extensions are
+ * already allocated, update kcov_handle anyway since
+ * skb_set_kcov_handle can be called to zero a previously set
+ * value.
+ */
+ if (skb_has_extensions(skb) || kcov_handle) {
+ u64 *kcov_handle_ptr = skb_ext_add(skb, SKB_EXT_KCOV_HANDLE);
+
+ if (kcov_handle_ptr)
+ *kcov_handle_ptr = kcov_handle;
+ }
+}
+
+static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
+{
+ u64 *kcov_handle = skb_ext_find(skb, SKB_EXT_KCOV_HANDLE);
+
+ return kcov_handle ? *kcov_handle : 0;
+}
+#else
+static inline void skb_set_kcov_handle(struct sk_buff *skb,
+ const u64 kcov_handle) { }
+static inline u64 skb_get_kcov_handle(struct sk_buff *skb) { return 0; }
+#endif /* CONFIG_KCOV */
+
#endif /* __KERNEL__ */
#endif /* _LINUX_SKBUFF_H */
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 6b8368be89c8e..80bfe71bbe13e 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -1023,6 +1023,8 @@ EXPORT_SYMBOL(kcov_remote_stop);
/* See the comment before kcov_remote_start() for usage details. */
u64 kcov_common_handle(void)
{
+ if (!in_task())
+ return 0;
return current->kcov_handle;
}
EXPORT_SYMBOL(kcov_common_handle);
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d7a7bc3b60982..d171a032db78d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1870,6 +1870,7 @@ config KCOV
depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
select DEBUG_FS
select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
+ select SKB_EXTENSIONS
help
KCOV exposes kernel code coverage information in a form suitable
for coverage-guided fuzzing (randomized testing).
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 1ba8f01637441..c5e6c0b83a926 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -249,6 +249,9 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
fclones->skb2.fclone = SKB_FCLONE_CLONE;
}
+
+ skb_set_kcov_handle(skb, kcov_common_handle());
+
out:
return skb;
nodata:
@@ -282,6 +285,8 @@ static struct sk_buff *__build_skb_around(struct sk_buff *skb,
memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
atomic_set(&shinfo->dataref, 1);
+ skb_set_kcov_handle(skb, kcov_common_handle());
+
return skb;
}
@@ -4203,6 +4208,9 @@ static const u8 skb_ext_type_len[] = {
#if IS_ENABLED(CONFIG_MPTCP)
[SKB_EXT_MPTCP] = SKB_EXT_CHUNKSIZEOF(struct mptcp_ext),
#endif
+#if IS_ENABLED(CONFIG_KCOV)
+ [SKB_EXT_KCOV_HANDLE] = SKB_EXT_CHUNKSIZEOF(u64),
+#endif
};
static __always_inline unsigned int skb_ext_total_length(void)
@@ -4219,6 +4227,9 @@ static __always_inline unsigned int skb_ext_total_length(void)
#endif
#if IS_ENABLED(CONFIG_MPTCP)
skb_ext_type_len[SKB_EXT_MPTCP] +
+#endif
+#if IS_ENABLED(CONFIG_KCOV)
+ skb_ext_type_len[SKB_EXT_KCOV_HANDLE] +
#endif
0;
}
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 1be775979132c..56a1bcea2c1ce 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1356,6 +1356,7 @@ static void ieee80211_iface_work(struct work_struct *work)
while ((skb = skb_dequeue(&sdata->skb_queue))) {
struct ieee80211_mgmt *mgmt = (void *)skb->data;
+ kcov_remote_start_common(skb_get_kcov_handle(skb));
if (ieee80211_is_action(mgmt->frame_control) &&
mgmt->u.action.category == WLAN_CATEGORY_BACK) {
int len = skb->len;
@@ -1465,6 +1466,7 @@ static void ieee80211_iface_work(struct work_struct *work)
}
kfree_skb(skb);
+ kcov_remote_stop();
}
/* then other type-dependent work */
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 1e2e5a406d587..09d1c9fb88724 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -4742,6 +4742,8 @@ void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
status->rx_flags = 0;
+ kcov_remote_start_common(skb_get_kcov_handle(skb));
+
/*
* Frames with failed FCS/PLCP checksum are not returned,
* all other frames are returned without radiotap header
@@ -4749,15 +4751,15 @@ void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
* Also, frames with less than 16 bytes are dropped.
*/
skb = ieee80211_rx_monitor(local, skb, rate);
- if (!skb)
- return;
-
- ieee80211_tpt_led_trig_rx(local,
- ((struct ieee80211_hdr *)skb->data)->frame_control,
- skb->len);
+ if (skb) {
+ ieee80211_tpt_led_trig_rx(local,
+ ((struct ieee80211_hdr *)skb->data)->frame_control,
+ skb->len);
- __ieee80211_rx_handle_packet(hw, pubsta, skb, list);
+ __ieee80211_rx_handle_packet(hw, pubsta, skb, list);
+ }
+ kcov_remote_stop();
return;
drop:
kfree_skb(skb);