From mboxrd@z Thu Jan 1 00:00:00 1970 From: ben.dooks@codethink.co.uk (Ben Dooks) Date: Fri, 8 Feb 2013 23:17:35 +0000 Subject: [PATCH 05/17] ARM: fixup_pv_table bug when CPU_ENDIAN_BE8 In-Reply-To: <1360365467-25056-1-git-send-email-ben.dooks@codethink.co.uk> References: <1360365467-25056-1-git-send-email-ben.dooks@codethink.co.uk> Message-ID: <1360365467-25056-6-git-send-email-ben.dooks@codethink.co.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The fixup_pv_table assumes that the instructions are in the same endian configuration as the data, but when the CPU is running in BE8 the instructions stay in little-endian format. Make sure if CONFIG_CPU_ENDIAN_BE8 is set that we do all the alterations to the instructions taking in to account the LDR/STR will be swapping the data endian-ness. Since the code is only modifying a byte, we avoid dual-swapping the data, and just change the bits we clear and ORR in. Note, not tested against an actual bug, it looked wrong. Signed-off-by: Ben Dooks --- arch/arm/kernel/head.S | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index f1ab279..aafb151 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -579,8 +579,14 @@ __fixup_a_pv_table: #else b 2f 1: ldr ip, [r7, r3] +#ifdef CONFIG_CPU_ENDIAN_BE8 + @ in BE8, we load data in BE, but instructions still in LE + bic ip, ip, #0xff000000 + orr ip, ip, r6, lsl#24 +#else bic ip, ip, #0x000000ff orr ip, ip, r6 @ mask in offset bits 31-24 +#endif str ip, [r7, r3] 2: cmp r4, r5 ldrcc r7, [r4], #4 @ use branch for delay slot -- 1.7.10.4