From: David S. Miller <davem@davemloft.net>
Date: Tue, 1 Mar 2016 05:25:32 +0000 (-0500)
Subject: sparc64: Fix sparc64_set_context stack handling.
X-Git-Tag: firefly_0821_release~176^2~4^2~40^2~28
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b1206090828584bcb1caf4c850d175f297eb7bc8;p=firefly-linux-kernel-4.4.55.git

sparc64: Fix sparc64_set_context stack handling.

[ Upstream commit 397d1533b6cce0ccb5379542e2e6d079f6936c46 ]

Like a signal return, we should use synchronize_user_stack() rather
than flush_user_windows().

Reported-by: Ilya Malakhov <ilmalakhovthefirst@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c
index d88beff47bab..39aaec173f66 100644
--- a/arch/sparc/kernel/signal_64.c
+++ b/arch/sparc/kernel/signal_64.c
@@ -52,7 +52,7 @@ asmlinkage void sparc64_set_context(struct pt_regs *regs)
 	unsigned char fenab;
 	int err;
 
-	flush_user_windows();
+	synchronize_user_stack();
 	if (get_thread_wsaved()					||
 	    (((unsigned long)ucp) & (sizeof(unsigned long)-1))	||
 	    (!__access_ok(ucp, sizeof(*ucp))))