3.7-stable review patch. If anyone has any objections, please let me know.
------------------ From: Nicolas Pitre <[email protected]> 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 <[email protected]> Tested-by: Sascha Hauer <[email protected]> Tested-by: Tomasz Figa <[email protected]> Signed-off-by: Russell King <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/arm/kernel/head.S | 3 +++ 1 file changed, 3 insertions(+) --- 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] #ifdef CONFIG_DEBUG_LL -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
