From af1694d94bf14371e4199d22464f214d4112b67a Mon Sep 17 00:00:00 2001 From: Tomasz Kulasek Date: Mon, 4 Apr 2016 16:45:23 +0200 Subject: [PATCH] examples/l3fwd: fix crash with gcc 5 It seems that with gcc >5.x and -O2/-O3 optimization breaks packet grouping algorithm. When last packet pointer "lp" and "pnum->u64" buffer points the same memory buffer, high optimization can cause unpredictable results. It seems that assignment of precalculated group sizes may interfere with initialization of new group size when lp points value inside current group and didn't should be changed. With gcc >5.x and optimization we cannot be sure which assignment will be done first, so the group size can be counted incorrectly. This patch eliminates intersection of assignment of initial group size (lp[0] = 1) and precalculated group sizes when gptbl[v].idx < 4. Fixes: 94c54b4158d5 ("examples/l3fwd: rework exact-match") Signed-off-by: Tomasz Kulasek Acked-by: Konstantin Ananyev --- examples/l3fwd/l3fwd_sse.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/examples/l3fwd/l3fwd_sse.h b/examples/l3fwd/l3fwd_sse.h index f9cf50a0ff..1afa1f006b 100644 --- a/examples/l3fwd/l3fwd_sse.h +++ b/examples/l3fwd/l3fwd_sse.h @@ -283,9 +283,9 @@ port_groupx4(uint16_t pn[FWDSTEP + 1], uint16_t *lp, __m128i dp1, __m128i dp2) /* if dest port value has changed. */ if (v != GRPMSK) { - lp = pnum->u16 + gptbl[v].idx; - lp[0] = 1; pnum->u64 = gptbl[v].pnum; + pnum->u16[FWDSTEP] = 1; + lp = pnum->u16 + gptbl[v].idx; } return lp; -- 2.20.1