Re: [PATCH] ARM: Fix zImage file size not aligned with CONFIG_EFI_STUB enabled

From: jeffy
Date: Mon Oct 23 2017 - 06:24:28 EST


Hi Russell,

Thanks for your reply.

On 10/23/2017 04:50 PM, Russell King - ARM Linux wrote:
>
>hmm, right, didn't notice the data is already aligned...
>so it's indeed caused by the ksym:
>
> [ 9] .data PROGBITS 006ce000 6d6000 000200 00 WA 0
>0 4096
> [10] ___ksymtab+sort PROGBITS 006ce200 6d6200 000008 00 WA 0
>0 4
> [11] .bss NOBITS 006ce208 6d6208 00001c 00 WA 0
>0 4
It's earlier - look for __ksymtab_strings.

the problem i meet is the appended dtb code found dtb invalid. i thought that is because of unaligned zImage size, but i was wrong...


it looks like the size is still aligned, and after add more logs, it seems the problem is due to _edata not matched the real file size, which is because of the unexpected ___ksymtab+sort:

currently:
zImage size is 6d6208:
-rwxr-xr-x 1 root root 7135752 Oct 23 18:12 zImage

_edata is 006ce200:
006ce200 0 NOTYPE GLOBAL DEFAULT 9 _edata

vmlinux sections:
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 008000 00b7a0 00 AX 0 0 4096
[ 2] .table PROGBITS 0000b7a0 0137a0 000014 00 WA 0 0 4
[ 3] .rodata PROGBITS 0000b7b4 0137b4 0015ef 00 A 0 0 2
[ 4] __ksymtab_strings PROGBITS 0000cda3 014da3 000005 00 A 0 0 1
[ 5] .piggydata PROGBITS 0000cda8 014da8 6c026f 00 A 0 0 1
[ 6] .got.plt PROGBITS 006cd018 6d5018 00000c 04 WA 0 0 4
[ 7] .got PROGBITS 006cd024 6d5024 000028 00 WA 0 0 4
[ 8] .pad PROGBITS 006cd04c 6d504c 000004 00 WA 0 0 1
[ 9] .data PROGBITS 006ce000 6d6000 000200 00 WA 0 0 4096
[10] ___ksymtab+sort PROGBITS 006ce200 6d6200 000008 00 WA 0 0 4
[11] .bss NOBITS 006ce208 6d6208 00001c 00 WA 0 0 4





and it turns out moving around .pad section only hide the problem by placing the .pad after the ___ksymtab+sort:

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 008000 00b7a0 00 AX 0 0 4096
[ 2] .table PROGBITS 0000b7a0 0137a0 000014 00 WA 0 0 4
[ 3] .rodata PROGBITS 0000b7b4 0137b4 0015ef 00 A 0 0 2
[ 4] __ksymtab_strings PROGBITS 0000cda3 014da3 000005 00 A 0 0 1
[ 5] .piggydata PROGBITS 0000cda8 014da8 6c026f 00 A 0 0 1
[ 6] .got.plt PROGBITS 006cd018 6d5018 00000c 04 WA 0 0 4
[ 7] .got PROGBITS 006cd024 6d5024 000028 00 WA 0 0 4
[ 8] .data PROGBITS 006ce000 6d6000 000200 00 WA 0 0 4096
[ 9] ___ksymtab+sort PROGBITS 006ce200 6d6200 000008 00 WA 0 0 4
[10] .pad PROGBITS 006ce208 6d6208 000008 00 WA 0 0 1
[11] .bss NOBITS 006ce210 6d6210 00001c 00 WA 0 0 4

-rwxr-xr-x 1 root root 7135760 Oct 23 18:09 zImage

006ce210 0 NOTYPE GLOBAL DEFAULT 10 _edata




and i think Ard's new patch could be the right way to fix it :)