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authorNicolas Pitre <nicolas.pitre@linaro.org>2013-01-15 18:51:32 +0100
committerBen Hutchings <ben@decadent.org.uk>2013-02-06 04:33:35 +0000
commit3bba3a68cc9e846c33f7102d79bcf0ba10bad5f9 (patch)
tree461920dcdfa2a9f0811e1c979e6313a6ed1e1d4e /arch
parent04bab8d5caa173ea1faea7103bed30e12d73d3fe (diff)
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 <nico@linaro.org> Tested-by: Sascha Hauer <s.hauer@pengutronix.de> Tested-by: Tomasz Figa <t.figa@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> [bwh: Backported to 3.2: - Adjust context - The mapping is not conditional; drop the 'ne' suffixes] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/kernel/head.S3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 08c82fd844a8..3606e85cf8cc 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -221,6 +221,7 @@ __create_page_tables:
/*
* Then map boot params address in r2 or
* the first 1MB 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
@@ -229,6 +230,8 @@ __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