On Sun, 2013-02-03 at 15:47 +0100, Ben Hutchings wrote: > 3.2-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Nicolas Pitre <nicolas.pi...@linaro.org> > > 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 <n...@linaro.org> > Tested-by: Sascha Hauer <s.ha...@pengutronix.de> > Tested-by: Tomasz Figa <t.f...@samsung.com> > Signed-off-by: Russell King <rmk+ker...@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 <b...@decadent.org.uk>
I haven't been able to test this and would really appreciate an expert review. Ben. > --- > arch/arm/kernel/head.S | 3 +++ > 1 file changed, 3 insertions(+) > > --- 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 > > > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Ben Hutchings Everything should be made as simple as possible, but not simpler. - Albert Einstein
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