From: Steven Luong <sluong@cisco.com>
Date: Wed, 10 Nov 2021 16:54:38 +0000 (-0800)
Subject: ip: crash in ip_csum_fold due to illegal instruction shrx
X-Git-Tag: v22.06-rc0~268
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=4d769c71a10bb99a1afc369e85d7d444e7b439f3;p=vpp.git

ip: crash in ip_csum_fold due to illegal instruction shrx

Encounter a crash for the line
	shrx   edi,eax,edi
in ip_csum_fold. The target cpu is ivy bridge which does not support
shrx instruction.

Type: fix
Fixes: e6709ff37dc0f3a58ed5ad98aace73fe801f1e9d

Signed-off-by: Steven Luong <sluong@cisco.com>
Change-Id: Icc922d3b2ebfcfa721f63946a213b6c492874a9a
---

diff --git a/src/vnet/ip/ip_packet.h b/src/vnet/ip/ip_packet.h
old mode 100644
new mode 100755
index d862caa3a52..837b3df8563
--- a/src/vnet/ip/ip_packet.h
+++ b/src/vnet/ip/ip_packet.h
@@ -301,7 +301,7 @@ always_inline u16
 ip_csum_fold (ip_csum_t c)
 {
   /* Reduce to 16 bits. */
-#ifdef __x86_64__
+#if defined(__x86_64__) && defined(__BMI2__)
   u64 tmp;
   asm volatile(
     /* using ADC is much faster than mov, shift, add sequence