diff options
| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2015-01-27 16:10:42 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-01-29 15:23:01 +0000 |
| commit | c2607f74aad96d18316a6e709b40e0ffe9def148 (patch) | |
| tree | 7ca8b21b5631d9fe31faa075544cfe1c26db5f3f | |
| parent | c2273a185354fe9420fb342b1ca09a6fed857fb3 (diff) | |
ARM: 8294/1: ATAG_DTB_COMPAT: remove the DT workspace's hardcoded 64KB size
There is currently a hardcoded limit of 64KB for the DTB to live in and
be extended with ATAG info. Some DTBs have outgrown that limit:
$ du -b arch/arm/boot/dts/omap3-n900.dtb
70212 arch/arm/boot/dts/omap3-n900.dtb
Furthermore, the actual size passed to atags_to_fdt() included the stack
size which is obviously wrong.
The initial DTB size is known, so use it to size the allocated workspace
with a 50% growth assumption and relocate the temporary stack above that.
This is also clamped to 32KB min / 1MB max for robustness against bad
DTB data.
Reported-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/boot/compressed/head.S | 39 |
1 files changed, 30 insertions, 9 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 68be9017593d..132c70e2d2f1 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -263,16 +263,37 @@ restart: adr r0, LC0 * OK... Let's do some funky business here. * If we do have a DTB appended to zImage, and we do have * an ATAG list around, we want the later to be translated - * and folded into the former here. To be on the safe side, - * let's temporarily move the stack away into the malloc - * area. No GOT fixup has occurred yet, but none of the - * code we're about to call uses any global variable. + * and folded into the former here. No GOT fixup has occurred + * yet, but none of the code we're about to call uses any + * global variable. */ - add sp, sp, #0x10000 + + /* Get the initial DTB size */ + ldr r5, [r6, #4] +#ifndef __ARMEB__ + /* convert to little endian */ + eor r1, r5, r5, ror #16 + bic r1, r1, #0x00ff0000 + mov r5, r5, ror #8 + eor r5, r5, r1, lsr #8 +#endif + /* 50% DTB growth should be good enough */ + add r5, r5, r5, lsr #1 + /* preserve 64-bit alignment */ + add r5, r5, #7 + bic r5, r5, #7 + /* clamp to 32KB min and 1MB max */ + cmp r5, #(1 << 15) + movlo r5, #(1 << 15) + cmp r5, #(1 << 20) + movhi r5, #(1 << 20) + /* temporarily relocate the stack past the DTB work space */ + add sp, sp, r5 + stmfd sp!, {r0-r3, ip, lr} mov r0, r8 mov r1, r6 - sub r2, sp, r6 + mov r2, r5 bl atags_to_fdt /* @@ -285,11 +306,11 @@ restart: adr r0, LC0 bic r0, r0, #1 add r0, r0, #0x100 mov r1, r6 - sub r2, sp, r6 + mov r2, r5 bleq atags_to_fdt ldmfd sp!, {r0-r3, ip, lr} - sub sp, sp, #0x10000 + sub sp, sp, r5 #endif mov r8, r6 @ use the appended device tree @@ -306,7 +327,7 @@ restart: adr r0, LC0 subs r1, r5, r1 addhi r9, r9, r1 - /* Get the dtb's size */ + /* Get the current DTB size */ ldr r5, [r6, #4] #ifndef __ARMEB__ /* convert r5 (dtb size) to little endian */ |