Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2018-03-21

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add a BPF hook for sendmsg and sendfile by reusing the ULP infrastructure
   and sockmap. Three helpers are added along with this, bpf_msg_apply_bytes(),
   bpf_msg_cork_bytes(), and bpf_msg_pull_data(). The first is used to tell
   for how many bytes the verdict should be applied to, the second to tell
   that x bytes need to be queued first to retrigger the BPF program for a
   verdict, and the third helper is mainly for the sendfile case to pull in
   data for making it private for reading and/or writing, from John.

2) Improve address to symbol resolution of user stack traces in BPF stackmap.
   Currently, the latter stores the address for each entry in the call trace,
   however to map these addresses to user space files, it is necessary to
   maintain the mapping from these virtual addresses to symbols in the binary
   which is not practical for system-wide profiling. Instead, this option for
   the stackmap rather stores the ELF build id and offset for the call trace
   entries, from Song.

3) Add support that allows BPF programs attached to perf events to read the
   address values recorded with the perf events. They are requested through
   PERF_SAMPLE_ADDR via perf_event_open(). Main motivation behind it is to
   support building memory or lock access profiling and tracing tools with
   the help of BPF, from Teng.

4) Several improvements to the tools/bpf/ Makefiles. The 'make bpf' in the
   tools directory does not provide the standard quiet output except for
   bpftool and it also does not respect specifying a build output directory.
   'make bpf_install' command neither respects specified destination nor
   prefix, all from Jiri. In addition, Jakub fixes several other minor issues
   in the Makefiles on top of that, e.g. fixing dependency paths, phony
   targets and more.

5) Various doc updates e.g. add a comment for BPF fs about reserved names
   to make the dentry lookup from there a bit more obvious, and a comment
   to the bpf_devel_QA file in order to explain the diff between native
   and bpf target clang usage with regards to pointer size, from Quentin
   and Daniel.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 61 insertions, 0 deletions

diff --git a/net/core/sock.c b/net/core/sock.c
index a8962d912895..f704324d1219 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2237,6 +2237,67 @@ bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
 }
 EXPORT_SYMBOL(sk_page_frag_refill);
 
+int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg,
+		int sg_start, int *sg_curr_index, unsigned int *sg_curr_size,
+		int first_coalesce)
+{
+	int sg_curr = *sg_curr_index, use = 0, rc = 0;
+	unsigned int size = *sg_curr_size;
+	struct page_frag *pfrag;
+	struct scatterlist *sge;
+
+	len -= size;
+	pfrag = sk_page_frag(sk);
+
+	while (len > 0) {
+		unsigned int orig_offset;
+
+		if (!sk_page_frag_refill(sk, pfrag)) {
+			rc = -ENOMEM;
+			goto out;
+		}
+
+		use = min_t(int, len, pfrag->size - pfrag->offset);
+
+		if (!sk_wmem_schedule(sk, use)) {
+			rc = -ENOMEM;
+			goto out;
+		}
+
+		sk_mem_charge(sk, use);
+		size += use;
+		orig_offset = pfrag->offset;
+		pfrag->offset += use;
+
+		sge = sg + sg_curr - 1;
+		if (sg_curr > first_coalesce && sg_page(sg) == pfrag->page &&
+		    sg->offset + sg->length == orig_offset) {
+			sg->length += use;
+		} else {
+			sge = sg + sg_curr;
+			sg_unmark_end(sge);
+			sg_set_page(sge, pfrag->page, use, orig_offset);
+			get_page(pfrag->page);
+			sg_curr++;
+
+			if (sg_curr == MAX_SKB_FRAGS)
+				sg_curr = 0;
+
+			if (sg_curr == sg_start) {
+				rc = -ENOSPC;
+				break;
+			}
+		}
+
+		len -= use;
+	}
+out:
+	*sg_curr_size = size;
+	*sg_curr_index = sg_curr;
+	return rc;
+}
+EXPORT_SYMBOL(sk_alloc_sg);
+
 static void __lock_sock(struct sock *sk)
 	__releases(&sk->sk_lock.slock)
 	__acquires(&sk->sk_lock.slock)