diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2018-03-30 22:50:16 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-03-30 22:50:17 +0200 |
| commit | 807ae7daf5fb9ba9ef688344ae7c0d8cbebd211c (patch) | |
| tree | 630eb9ec8764b825abe20e0457df291dd0c1f9eb /kernel/bpf | |
| parent | 1379ef828a18d8f81c526b25e4d5685caa2cfd65 (diff) | |
| parent | 6ef6d84ceee2262a8c7a4247616c7eb71268b3f9 (diff) | |
| download | linux-807ae7daf5fb9ba9ef688344ae7c0d8cbebd211c.tar.bz2 | |
Merge branch 'bpf-sockmap-sg-api-fixes'
Prashant Bhole says:
====================
These patches fix sg api usage in sockmap. Previously sockmap didn't
use sg_init_table(), which caused hitting BUG_ON in sg api, when
CONFIG_DEBUG_SG is enabled
v1: added sg_init_table() calls wherever needed.
v2:
- Patch1 adds new helper function in sg api. sg_init_marker()
- Patch2 sg_init_marker() and sg_init_table() in appropriate places
Backgroud:
While reviewing v1, John Fastabend raised a valid point about
unnecessary memset in sg_init_table() because sockmap uses sg table
which embedded in a struct. As enclosing struct is zeroed out, there
is unnecessary memset in sg_init_table.
So Daniel Borkmann suggested to define another static inline function
in scatterlist.h which only initializes sg_magic. Also this function
will be called from sg_init_table. From this suggestion I defined a
function sg_init_marker() which sets sg_magic and calls sg_mark_end()
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/sockmap.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index 9192fdbcbccc..d2bda5aa25d7 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -341,7 +341,7 @@ retry: md->sg_start++; if (md->sg_start == MAX_SKB_FRAGS) md->sg_start = 0; - memset(sg, 0, sizeof(*sg)); + sg_init_table(sg, 1); if (md->sg_start == md->sg_end) break; @@ -843,7 +843,7 @@ static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) } sg = md.sg_data; - sg_init_table(sg, MAX_SKB_FRAGS); + sg_init_marker(sg, MAX_SKB_FRAGS); rcu_read_unlock(); lock_sock(sk); @@ -950,10 +950,14 @@ static int bpf_tcp_sendpage(struct sock *sk, struct page *page, lock_sock(sk); - if (psock->cork_bytes) + if (psock->cork_bytes) { m = psock->cork; - else + sg = &m->sg_data[m->sg_end]; + } else { m = &md; + sg = m->sg_data; + sg_init_marker(sg, MAX_SKB_FRAGS); + } /* Catch case where ring is full and sendpage is stalled. */ if (unlikely(m->sg_end == m->sg_start && @@ -961,7 +965,6 @@ static int bpf_tcp_sendpage(struct sock *sk, struct page *page, goto out_err; psock->sg_size += size; - sg = &m->sg_data[m->sg_end]; sg_set_page(sg, page, size, offset); get_page(page); m->sg_copy[m->sg_end] = true; |