From 44554e1bc4cb55c139c17ba1602755ee0652afd8 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Tue, 15 Jan 2013 18:51:32 +0100 Subject: ARM: 7628/1: head.S: map one extra section for the ATAG/DTB area commit 6f16f4998f98e42e3f2dedf663cfb691ff0324af upstream. We currently use a temporary 1MB section aligned to a 1MB boundary for mapping the provided device tree until the final page table is created. However, if the device tree happens to cross that 1MB boundary, the end of it remains unmapped and the kernel crashes when it attempts to access it. Given no restriction on the location of that DTB, it could end up with only a few bytes mapped at the end of a section. Solve this issue by mapping two consecutive sections. Signed-off-by: Nicolas Pitre Tested-by: Sascha Hauer Tested-by: Tomasz Figa Signed-off-by: Russell King [bwh: Backported to 3.2: - Adjust context - The mapping is not conditional; drop the 'ne' suffixes] Signed-off-by: Ben Hutchings [ herton: same backport applies to 3.5, with context adjusted on comment ] Signed-off-by: Herton Ronaldo Krzesinski --- arch/arm/kernel/head.S | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 835898e7d704..458b8d3ca444 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -254,6 +254,7 @@ __create_page_tables: /* * Then map boot params address in r2 or the first 1MB (2MB with LPAE) * of ram if boot params address is not specified. + * We map 2 sections in case the ATAGs/DTB crosses a section boundary. */ mov r0, r2, lsr #SECTION_SHIFT movs r0, r0, lsl #SECTION_SHIFT @@ -262,6 +263,8 @@ __create_page_tables: add r3, r3, #PAGE_OFFSET add r3, r4, r3, lsr #(SECTION_SHIFT - PMD_ORDER) orr r6, r7, r0 + str r6, [r3], #1 << PMD_ORDER + add r6, r6, #1 << SECTION_SHIFT str r6, [r3] #ifdef CONFIG_DEBUG_LL -- cgit v1.2.3