Hi,
Can you elaborate a bit on that, If session index is 64, if we do not
increase by 1, it will only make one 64B vec for the bitmap, which may not
hold the session index.
Florin Coras <fcoras.li...@gmail.com> 于2022年10月25日周二 01:14写道：
> Hi,
>
> Could you replace s->session_index by s->session_index ? : 1 in the patch?
>
> Regards,
> Florin
>
> On Oct 24, 2022, at 12:23 AM, Zhang Dongya <fortitude.zh...@gmail.com>
> wrote:
>
> Hi list,
>
> Recently I am testing my TCP application in a plugin, what I did is to
> initiate a TCP client in my plugin, however, when I build the debug image
> and test, the vpp
> will crash and complaint about out of memory.
>
> After doing some research, it seems the following code may cause the crash:
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> *always_inline session_t *ho_session_alloc (void){ session_t *s; ASSERT
> (vlib_get_thread_index () == 0); s = session_alloc (0); s->session_state
> = SESSION_STATE_CONNECTING; s->flags |= SESSION_F_HALF_OPEN; /* Not
> ideal. Half-opens are only allocated from main with worker barrier * but
> can be cleaned up, i.e., session_half_open_free, from main without * a
> barrier. In debug images, the free_bitmap can grow while workers peek *
> the sessions pool, e.g., session_half_open_migrate_notify, and as a *
> result crash while validating the session. To avoid this, grow the bitmap
> * now. */ if (CLIB_DEBUG) { session_t *sp =
> session_main.wrk[0].sessions; clib_bitmap_validate (pool_header
> (sp)->free_bitmap, s->session_index); } return s;}*
>
> since the clib_bitmap_validate is defined as:
>
>
>
> */* Make sure that a bitmap is at least n_bits in size */#define
> clib_bitmap_validate(v,n_bits) \ clib_bitmap_vec_validate ((v), ((n_bits)
> - 1) / BITS (uword))*
>
>
> The first half open session have a session_index with zero, so 0-1 will
> make a overflow which cause it try to allocate (UINT64_MAX-1)/ 64 memory
> which make
> the vppinfra abort.
>
> I think we should modify the code above with s->session_index + 1, if
> that's correct, I will submit a patch later.
>
>
>
>
>
>
>
>
-=-=-=-=-=-=-=-=-=-=-=-
Links: You receive all messages sent to this group.
View/Reply Online (#22069): https://lists.fd.io/g/vpp-dev/message/22069
Mute This Topic: https://lists.fd.io/mt/94529335/21656
Group Owner: vpp-dev+ow...@lists.fd.io
Unsubscribe: https://lists.fd.io/g/vpp-dev/leave/1480452/21656/631435203/xyzzy
[arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
