path: root/arch/arm
diff options
authorNicolas Pitre <nicolas.pitre@linaro.org>2013-01-15 18:51:32 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-01-16 16:51:13 +0000
commit6f16f4998f98e42e3f2dedf663cfb691ff0324af (patch)
treec66bfdaf4723ea6495e1b12df8c41f676b2fc102 /arch/arm
parent568dca15aa2a0f4ddee255894ec393a159f13147 (diff)
ARM: 7628/1: head.S: map one extra section for the ATAG/DTB area
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> Cc: stable@vger.kernel.org Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 4eee351f466..61fcb18c7e5 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -246,6 +246,7 @@ __create_page_tables:
* Then map boot params address in r2 if 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
@@ -253,6 +254,8 @@ __create_page_tables:
addne r3, r3, #PAGE_OFFSET
addne r3, r4, r3, lsr #(SECTION_SHIFT - PMD_ORDER)
orrne r6, r7, r0
+ strne r6, [r3], #1 << PMD_ORDER
+ addne r6, r6, #1 << SECTION_SHIFT
strne r6, [r3]