On 03/29/2018 05:21 PM, Prashant Bhole wrote:

When CONFIG_DEBUG_SG is set, sg->sg_magic is initialized in
sg_init_table() and it is verified in sg api while navigating. We hit
BUG_ON when magic check is failed.

In functions sg_tcp_sendpage and sg_tcp_sendmsg, the struct containing
the scatterlist is already zeroed out. So to avoid extra memset, we
use sg_init_marker() to initialize sg_magic.

Fixed following things:
- In bpf_tcp_sendpage: initialize sg using sg_init_marker
- In bpf_tcp_sendmsg: Replace sg_init_table with sg_init_marker
- In bpf_tcp_push: Replace memset with sg_init_table where consumed
  sg entry needs to be re-initialized.

Signed-off-by: Prashant Bhole <redacted>
---
 kernel/bpf/sockmap.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

Acked-by: John Fastabend <john.fastabend@gmail.com>