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-rw-r--r--include/linux/skbuff.h33
-rw-r--r--lib/Kconfig.debug1
-rw-r--r--net/core/skbuff.c11
3 files changed, 45 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index a828cf99c521..2d01b2bbb746 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -4151,6 +4151,9 @@ enum skb_ext_id {
#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/lib/Kconfig.debug b/lib/Kconfig.debug
index d7a7bc3b6098..d171a032db78 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 1ba8f0163744..c5e6c0b83a92 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)
@@ -4220,6 +4228,9 @@ static __always_inline unsigned int skb_ext_total_length(void)
#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;
}