regmap: Fix cache lifecycle locking and teardown

Michael Reeves <michael.reeves077@gmail.com> says:

Fix an "Invalid wait context" lockdep warning during Apple GPIO probe and
correct debugfs ordering during cache teardown.

Tested on Apple M3 MacBook Air (T8122):

- All 4 GPIO controllers probe successfully with lockdep enabled.
- The "Invalid wait context" warning no longer occurs.
- The regmap KUnit suite passes and lockdep remains enabled.

Link: https://patch.msgid.link/20261006-regcache-lifecycle-submit-v3-0-37bdd82fd47c@gmail.com

1 files changed, 11 insertions, 20 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 671c13494566..a3ff380d43f0 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1020,7 +1020,7 @@ struct sk_buff {
 #ifdef CONFIG_NET_REDIRECT
 	__u8			from_ingress:1;
 #endif
-#ifdef CONFIG_NETFILTER_SKIP_EGRESS
+#ifdef CONFIG_NET_EGRESS
 	__u8			nf_skip_egress:1;
 #endif
 #ifdef CONFIG_SKB_DECRYPTED
@@ -1834,22 +1834,6 @@ static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
 	}
 }
 
-static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val)
-{
-	skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL);
-	skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
-}
-
-static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb)
-{
-	return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL;
-}
-
-static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb)
-{
-	return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL);
-}
-
 static inline void net_zcopy_put(struct ubuf_info *uarg)
 {
 	if (uarg)
@@ -1872,8 +1856,7 @@ static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
 	struct ubuf_info *uarg = skb_zcopy(skb);
 
 	if (uarg) {
-		if (!skb_zcopy_is_nouarg(skb))
-			uarg->ops->complete(skb, uarg, zerocopy_success);
+		uarg->ops->complete(skb, uarg, zerocopy_success);
 
 		skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY;
 	}
@@ -3082,6 +3065,11 @@ static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
 	return skb->transport_header != (typeof(skb->transport_header))~0U;
 }
 
+static inline void skb_unset_transport_header(struct sk_buff *skb)
+{
+	skb->transport_header = (typeof(skb->transport_header))~0U;
+}
+
 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
 {
 	DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
@@ -4367,7 +4355,10 @@ skb_header_pointer_careful(const struct sk_buff *skb, int offset,
 static inline void * __must_check
 skb_pointer_if_linear(const struct sk_buff *skb, int offset, int len)
 {
-	if (likely(skb_headlen(skb) - offset >= len))
+	unsigned int uoffset = (unsigned int)offset;
+
+	if (likely(uoffset <= skb_headlen(skb) &&
+		   (unsigned int)len <= skb_headlen(skb) - uoffset))
 		return skb->data + offset;
 	return NULL;
 }