From: Mischa Jonker <mjonker@synopsys.com>
Date: Thu, 26 Sep 2013 13:44:56 +0000 (+0200)
Subject: ARC: Handle zero-overhead-loop in unaligned access handler
X-Git-Tag: v3.11.6~37
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=49cac7d9e62954e2235ae342ee15e0e0a7995a16;p=thirdparty%2Fkernel%2Fstable.git

ARC: Handle zero-overhead-loop in unaligned access handler

commit c11eb222fd7d4db91196121dbf854178505d2751 upstream.

If a load or store is the last instruction in a zero-overhead-loop, and
it's misaligned, the loop would execute only once.

This fixes that problem.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/arc/kernel/unaligned.c b/arch/arc/kernel/unaligned.c
index c0f832f595d31..00ad0703ac863 100644
--- a/arch/arc/kernel/unaligned.c
+++ b/arch/arc/kernel/unaligned.c
@@ -233,6 +233,12 @@ int misaligned_fixup(unsigned long address, struct pt_regs *regs,
 		regs->status32 &= ~STATUS_DE_MASK;
 	} else {
 		regs->ret += state.instr_len;
+
+		/* handle zero-overhead-loop */
+		if ((regs->ret == regs->lp_end) && (regs->lp_count)) {
+			regs->ret = regs->lp_start;
+			regs->lp_count--;
+		}
 	}
 
 	return 0;