[U-Boot] [PATCH V4 1/3] arm: discard relocation entries for secure text

[Peng Fan]

Hi Stefano,

On Tue, Nov 10, 2015 at 02:14:10PM +0100, Albert ARIBAUD wrote:
>Hello Peng,
>
>On Fri, 23 Oct 2015 10:13:03 +0800, Peng Fan <Peng.Fan at freescale.com>
>wrote:
>> The code such as PSCI in section named secure is bundled with
>> u-boot image, and when bootm, the code will be copied to their
>> runtime address same to compliation/linking address -
>> CONFIG_ARMV7_SECURE_BASE.
>> 
>> When compile the PSCI code and link it into the u-boot image,
>> there will be relocation entries in .rel.dyn section for PSCI.
>> Actually, we do not needs these relocation entries.
>> 
>> If still keep the relocation entries in .rel.dyn section,
>> r0 at line 103 and 106 in arch/arm/lib/relocate.S may be an invalid
>> address which may not support read/write for one SoC.
>> 102         /* relative fix: increase location by offset */
>> 103         add     r0, r0, r4
>> 104         ldr     r1, [r0]
>> 105         add     r1, r1, r4
>> 106         str     r1, [r0]
>> 
>> So discard them to avoid touching the relocation entry in
>> arch/arm/lib/relocate.S.
>> 
>> Signed-off-by: Peng Fan <Peng.Fan at freescale.com>
>> Cc: Tom Warren <twarren at nvidia.com>
>> Cc: York Sun <yorksun at freescale.com>
>> Cc: Hans De Goede <hdegoede at redhat.com>
>> Cc: Ian Campbell <ijc at hellion.org.uk>
>> Cc: Albert Aribaud <albert.u.boot at aribaud.net>
>> Cc: Tom Rini <trini at konsulko.com>
>> Cc: Jan Kiszka <jan.kiszka at siemens.com>
>> Cc: Stefano Babic <sbabic at denx.de>
>> ---
>> 
>> Changes v4:
>>  none
>> 
>> V2 thread: http://lists.denx.de/pipermail/u-boot/2015-October/230755.html
>> Changes v3:
>>  Move the relocation entries to the very begining and discard them.
>> 
>> V1 thread: http://lists.denx.de/pipermail/u-boot/2015-October/229426.html
>> Changes V2:
>>  Refine commit msg.
>>  Discard the relocation entry section for secure text.
>> 
>>  arch/arm/cpu/u-boot.lds | 17 +++++++++++++++++
>>  1 file changed, 17 insertions(+)
>> 
>> diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds
>> index 03cd9f6..d48a905 100644
>> --- a/arch/arm/cpu/u-boot.lds
>> +++ b/arch/arm/cpu/u-boot.lds
>> @@ -14,6 +14,23 @@ OUTPUT_ARCH(arm)
>>  ENTRY(_start)
>>  SECTIONS
>>  {
>> +	/*
>> +	 * Discard the relocation entries for secure text.
>> +	 * The secure code is bundled with u-boot image, so there will
>> +	 * be relocations entries for the secure code, since we use
>> +	 * "-mword-relocations" to compile and "-pie" to link into the
>> +	 * final image. We do not need the relocation entries for secure
>> +	 * code, because secure code will not be relocated, it only needs
>> +	 * to be copied from loading address to CONFIG_ARMV7_SECURE_BASE,
>> +	 * which is the linking and running address for secure code.
>> +	 * If keep the relocation entries in .rel.dyn section,
>> +	 * "relocation offset + linking address" may locates into an
>> +	 * address that is reserved by SoC, then will trigger data abort.
>> +	 *
>> +	 * The reason that move .rel._secure at the beginning, is to
>> +	 * avoid hole in the final image.
>> +	 */
>> +	/DISCARD/ : { *(.rel._secure*) }
>>  	. = 0x00000000;
>>  
>>  	. = ALIGN(4);
>> -- 
>> 1.8.4
>> 
>> 
>
>Acked-by: Albert ARIBAUD <albert.u.boot at aribaud.net>
>

Can you please take a look at the patch set and merge?

Thanks,
Peng.

>Amicalement,
>-- 
>Albert.

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