[PATCH 5/6] net/core: support compiling out splice

Pieter Smith
2014-11-22T21:02:07Z

Compile out splice support from networking core when the splice-family of
syscalls is not supported by the system (i.e. CONFIG_SYSCALL_SPLICE is
undefined).

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
include/linux/skbuff.h | 9 +++++++++
net/core/skbuff.c | 9 ++++++---
2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index a59d934..8c28524 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2640,9 +2640,18 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
int len, __wsum csum);
+#ifdef CONFIG_SYSCALL_SPLICE
int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
struct pipe_inode_info *pipe, unsigned int len,
unsigned int flags);
+#else /* #ifdef CONFIG_SYSCALL_SPLICE */
+static inline int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
+ struct pipe_inode_info *pipe, unsigned int len,
+ unsigned int flags)
+{
+ return -EPERM;
+}
+#endif /* #ifdef CONFIG_SYSCALL_SPLICE */
void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 61059a0..74fad8a 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1781,9 +1781,9 @@ static bool __splice_segment(struct page *page, unsigned int poff,
* Map linear and fragment data from the skb to spd. It reports true if the
* pipe is full or if we already spliced the requested length.
*/
-static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
- unsigned int *offset, unsigned int *len,
- struct splice_pipe_desc *spd, struct sock *sk)
+static bool __maybe_unused __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
+ unsigned int *offset, unsigned int *len,
+ struct splice_pipe_desc *spd, struct sock *sk)
{
int seg;

@@ -1821,6 +1821,7 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
* the frag list, if such a thing exists. We'd probably need to recurse to
* handle that cleanly.
*/
+#ifdef CONFIG_SYSCALL_SPLICE
int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
struct pipe_inode_info *pipe, unsigned int tlen,
unsigned int flags)
@@ -1876,6 +1877,8 @@ done:

return ret;
}
+#endif /* #ifdef CONFIG_SYSCALL_SPLICE */
+

/**
* skb_store_bits - store bits from kernel buffer to skb
--
1.9.1