From: Richard Henderson <richard.henderson@linaro.org>
Date: Wed, 23 Mar 2022 00:58:37 +0000 (-0700)
Subject: linux-user/arm: Implement __kernel_memory_barrier
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6e05e7047c7271aa27e0cdd243a20dfd6c8cada2;p=qemu.git

linux-user/arm: Implement __kernel_memory_barrier

This fallback syscall was stubbed out.
It would only matter for emulating pre-armv6.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323005839.94327-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---

diff --git a/linux-user/arm/cpu_loop.c b/linux-user/arm/cpu_loop.c
index 032e1ffddf..a0e43b261c 100644
--- a/linux-user/arm/cpu_loop.c
+++ b/linux-user/arm/cpu_loop.c
@@ -158,7 +158,7 @@ do_kernel_trap(CPUARMState *env)
 
     switch (env->regs[15]) {
     case 0xffff0fa0: /* __kernel_memory_barrier */
-        /* ??? No-op. Will need to do better for SMP.  */
+        smp_mb();
         break;
     case 0xffff0fc0: /* __kernel_cmpxchg */
          /* XXX: This only works between threads, not between processes.