From: Nikhil Rao <nikhil.rao@intel.com>
Date: Thu, 29 Sep 2016 21:24:53 +0000 (+0530)
Subject: eal/x86: fix atomic cmpset
X-Git-Tag: spdx-start~1051
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=9d1c2a6a912bebde1139157b950e39ffa7192c9d;p=dpdk.git

eal/x86: fix atomic cmpset

The original code used movl instead of xchgl, this caused
rte_atomic64_cmpset to use ebx as the lower dword of the source
to cmpxchg8b instead of the lower dword of function argument "src".

Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org

Reported-by: Job Abraham <job.abraham@intel.com>
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Tested-by: Job Abraham <job.abraham@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
---

diff --git a/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h b/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h
index 2e04c7595f..fb3abf1879 100644
--- a/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h
@@ -81,7 +81,7 @@ rte_atomic64_cmpset(volatile uint64_t *dst, uint64_t exp, uint64_t src)
 			: "memory" );           /* no-clobber list */
 #else
 	asm volatile (
-            "mov %%ebx, %%edi\n"
+            "xchgl %%ebx, %%edi;\n"
 			MPLOCKED
 			"cmpxchg8b (%[dst]);"
 			"setz %[res];"