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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, stable@vger.kernel.org,
        Hanjun Guo <guohanjun@huawei.com>,
        Xuefeng Wang <wxf.wang@hisilicon.com>,
        James Morse <james.morse@arm.com>, Will Deacon <will.deacon@arm.com>
Subject: [PATCH 4.4 015/137] arm64: opcodes.h: Add arm big-endian config options before including arm header
Date: Mon, 18 Apr 2016 11:27:57 +0900
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4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: James Morse <james.morse@arm.com>

commit a6002ec5a8c68e69706b2efd6db6d682d0ab672c upstream.

arm and arm64 use different config options to specify big endian. This
needs taking into account when including code/headers between the two
architectures.

A case in point is PAN, which uses the __instr_arm() macro to output
instructions. The macro comes from opcodes.h, which lives under arch/arm.
On a big-endian build the mismatched config options mean the instruction
isn't byte swapped correctly, resulting in undefined instruction exceptions
during boot:

| alternatives: patching kernel code
| kdevtmpfs[87]: undefined instruction: pc=ffffffc0004505b4
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c
| Internal error: Oops - undefined instruction: 0 [#1] SMP
| Modules linked in:
| CPU: 0 PID: 87 Comm: kdevtmpfs Not tainted 4.1.16+ #5
| Hardware name: Hisilicon PhosphorHi1382 EVB (DT)
| task: ffffffc336591700 ti: ffffffc3365a4000 task.ti: ffffffc3365a4000
| PC is at dump_instr+0x68/0x100
| LR is at do_undefinstr+0x1d4/0x2a4
| pc : [<ffffffc00076231c>] lr : [<ffffffc0000811d4>] pstate: 604001c5
| sp : ffffffc3365a6450

Reported-by: Hanjun Guo <guohanjun@huawei.com>
Tested-by: Xuefeng Wang <wxf.wang@hisilicon.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/arm64/include/asm/opcodes.h |    4 ++++
 1 file changed, 4 insertions(+)

--- a/arch/arm64/include/asm/opcodes.h
+++ b/arch/arm64/include/asm/opcodes.h
@@ -1 +1,5 @@
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define CONFIG_CPU_ENDIAN_BE8 CONFIG_CPU_BIG_ENDIAN
+#endif
+
 #include <../../arm/include/asm/opcodes.h>