From: Rich Felker <dalias@libc.org>
Date: Fri, 15 Jul 2016 03:46:52 +0000 (+0000)
Subject: sh: fix futex/robust_list on nommu models
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=72cc564f16ca9f61a1d13f35cb247631d888a78e;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

sh: fix futex/robust_list on nommu models

The futex cmpxchg runtime testing in kernel/futex.c depends on
accesses to address 0 producing EFAULT, which obviously does not work
on nommu. Since SH always has cmpxchg, disable the broken runtime
detection.

At some point this should be fixed at the kernel/futex.c level. UP
machines can always provide a working cmpxchg with interrupt masking,
and SMP cannot function without a working cmpxchg anyway.

Signed-off-by: Rich Felker <dalias@libc.org>
---

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index ceeda5c1a70a..e6d88f9e978a 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -45,6 +45,7 @@ config SUPERH
 	select OLD_SIGSUSPEND
 	select OLD_SIGACTION
 	select HAVE_ARCH_AUDITSYSCALL
+	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_NMI
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems