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

[Gregory CLEMENT]

Hi Ard,
 
 On lun., oct. 30 2017, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote:

> 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?

arm-linux-gnueabi-ld -v
GNU ld (GNU Binutils for Debian) 2.29.1

And for gcc:
arm-linux-gnueabi-gcc -v
Using built-in specs.
COLLECT_GCC=arm-linux-gnueabi-gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/arm-linux-gnueabi/7/lto-wrapper
Target: arm-linux-gnueabi
Configured with: ../src/configure -v --with-pkgversion='Debian 7.2.0-6' --with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-7 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libitm --disable-libquadmath --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib --enable-multiarch --disable-sjlj-exceptions --with-arch=armv4t --with-float=soft --disable-werror --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=arm-linux-gnueabi --program-prefix=arm-linux-gnueabi- --includedir=/usr/arm-linux-gnueabi/include
Thread model: posix
gcc version 7.2.0 (Debian 7.2.0-6)

Gregory

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com