Re: [PATCH] ARM: add a private asm/unaligned.h

From: Ard Biesheuvel
Date: Mon Oct 30 2017 - 11:35:46 EST

On 30 October 2017 at 15:33, Gregory CLEMENT
<gregory.clement@xxxxxxxxxxxxxxxxxx> wrote:
> Hi Ard,
>
> On lun., oct. 30 2017, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote:
>
>> On 30 October 2017 at 15:09, Gregory CLEMENT
>> <gregory.clement@xxxxxxxxxxxxxxxxxx> wrote:
>>> Hi Ard,
>>>
>>> On lun., oct. 30 2017, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote:
>>>
>>>> On 30 October 2017 at 15:05, Gregory CLEMENT
>>>> <gregory.clement@xxxxxxxxxxxxxxxxxx> wrote:
>>>>> Hi Ard,
>>>>>
>>>>> On lun., oct. 30 2017, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote:
>>>>>
>>>> ...
>>>>>>
>>>>>> Could you please share the output of 'readelf -S' for those vmlinux
>>>>>> decompressor images?
>>>>>
>>>>> Here it is:
>>>>>
>>>>> In the meantime I also used an arm-linux-gnueabihf- in case it could be
>>>>> related to the toolchain, I had te same issue and here it is the readelf
>>>>> output:
>>>>> arm-linux-gnueabi-readelf -S ../build/vmlinux
>>>>
>>>> Actually, I meant the 'vmlinux' file in arch/arm/boot/compressed, not
>>>> the main one.
>>>
>>> Here it is then:
>>>
>>> arm-linux-gnueabi-readelf -S ../build/arch/arm/boot/compressed/vmlinux
>>> There are 22 section headers, starting at offset 0x4b3e14:
>>>
>>> Section Headers:
>>> [Nr] Name Type Addr Off Size ES Flg Lk Inf Al
>>> [ 0] NULL 00000000 000000 000000 00 0 0 0
>>> [ 1] .text PROGBITS 00000000 010000 005ef8 00 AX 0 0 32
>>> [ 2] .rodata PROGBITS 00005ef8 015ef8 000d4c 00 A 0 0 4
>>> [ 3] .piggydata PROGBITS 00006c44 016c44 48a33a 00 A 0 0 1
>>> [ 4] .got.plt PROGBITS 00490f80 4a0f80 00000c 04 WA 0 0 4
>>> [ 5] .got PROGBITS 00490f8c 4a0f8c 000028 00 WA 0 0 4
>>> [ 6] .pad PROGBITS 00490fb4 4a0fb4 000004 00 WA 0 0 1
>>> [ 7] .bss NOBITS 00490fb8 4a0fb8 00001c 00 WA 0 0 4
>>> [ 8] .stack NOBITS 00490fd8 4a0fb8 001000 00 WA 0 0 1
>>> [ 9] .comment PROGBITS 00000000 4a0fb8 00001c 01 MS 0 0 1
>>> [10] .ARM.attributes ARM_ATTRIBUTES 00000000 4a0fd4 00002d 00 0 0 1
>>> [11] .debug_line PROGBITS 00000000 4a1001 00281b 00 0 0 1
>>> [12] .debug_info PROGBITS 00000000 4a381c 0066cb 00 0 0 1
>>> [13] .debug_abbrev PROGBITS 00000000 4a9ee7 0013ea 00 0 0 1
>>> [14] .debug_aranges PROGBITS 00000000 4ab2d8 0001a8 00 0 0 8
>>> [15] .debug_str PROGBITS 00000000 4ab480 0019b4 01 MS 0 0 1
>>> [16] .debug_ranges PROGBITS 00000000 4ace38 000640 00 0 0 8
>>> [17] .debug_frame PROGBITS 00000000 4ad478 001010 00 0 0 4
>>> [18] .debug_loc PROGBITS 00000000 4ae488 003643 00 0 0 1
>>> [19] .symtab SYMTAB 00000000 4b1acc 0015b0 10 20 225 4
>>> [20] .strtab STRTAB 00000000 4b307c 000cc5 00 0 0 1
>>> [21] .shstrtab STRTAB 00000000 4b3d41 0000d2 00 0 0 1
>>> Key to Flags:
>>> W (write), A (alloc), X (execute), M (merge), S (strings), I (info),
>>> L (link order), O (extra OS processing required), G (group), T (TLS),
>>> C (compressed), x (unknown), o (OS specific), E (exclude),
>>> y (purecode), p (processor specific)
>>>
>>
>> And this is from the build the build that generated the linker assert?
>
> Humm no, actually it was with the wrong branch. If I have the patch
> "ARM: verify size of zImage" then arch/arm/boot/compressed/vmlinux is
> not generated.
>
> But if I remove this patch then I can generate this file and so:
> arm-linux-gnueabi-readelf -S ../build/arch/arm/boot/compressed/vmlinux
> There are 22 section headers, starting at offset 0x4b402c:
>
> Section Headers:
> [Nr] Name Type Addr Off Size ES Flg Lk Inf Al
> [ 0] NULL 00000000 000000 000000 00 0 0 0
> [ 1] .text PROGBITS 00000000 010000 005ef8 00 AX 0 0 32
> [ 2] .rodata PROGBITS 00005ef8 015ef8 000d4c 00 A 0 0 4
> [ 3] .piggydata PROGBITS 00006c44 016c44 48a552 00 A 0 0 1
> [ 4] .got.plt PROGBITS 00491198 4a1198 00000c 04 WA 0 0 4
> [ 5] .got PROGBITS 004911a4 4a11a4 000028 00 WA 0 0 4
> [ 6] .pad PROGBITS 004911cc 4a11cc 000004 00 WA 0 0 1
> [ 7] .bss NOBITS 004911d0 4a11d0 00001c 00 WA 0 0 4
> [ 8] .stack NOBITS 004911f0 4a11d0 001000 00 WA 0 0 1
> [ 9] .comment PROGBITS 00000000 4a11d0 00001c 01 MS 0 0 1
> [10] .ARM.attributes ARM_ATTRIBUTES 00000000 4a11ec 00002d 00 0 0 1
> [11] .debug_line PROGBITS 00000000 4a1219 00281b 00 0 0 1
> [12] .debug_info PROGBITS 00000000 4a3a34 0066cb 00 0 0 1
> [13] .debug_abbrev PROGBITS 00000000 4aa0ff 0013ea 00 0 0 1
> [14] .debug_aranges PROGBITS 00000000 4ab4f0 0001a8 00 0 0 8
> [15] .debug_str PROGBITS 00000000 4ab698 0019b4 01 MS 0 0 1
> [16] .debug_ranges PROGBITS 00000000 4ad050 000640 00 0 0 8
> [17] .debug_frame PROGBITS 00000000 4ad690 001010 00 0 0 4
> [18] .debug_loc PROGBITS 00000000 4ae6a0 003643 00 0 0 1
> [19] .symtab SYMTAB 00000000 4b1ce4 0015b0 10 20 225 4
> [20] .strtab STRTAB 00000000 4b3294 000cc5 00 0 0 1
> [21] .shstrtab STRTAB 00000000 4b3f59 0000d2 00 0 0 1
>
>>
>> Could you check the value of _edata in the output of 'nm vmlinux'
>> please?
> With this kernel:
>
> arm-linux-gnueabi-nm ../build/arch/arm/boot/compressed/vmlinux | grep _edata
> 004911d0 D _edata
>

Well, that is disappointing. This means the ASSERT() does not work
reliably, and we're back to using a bunch of shell scripts to check
whether _edata appears at the end of the image.

Which version of binutils are you using?