Re: [RFC/RFT PATCH 2/5] memblock: introduce generic memblock_setup_resources()

From: Russell King (Oracle)
Date: Tue Jun 01 2021 - 09:54:21 EST


On Mon, May 31, 2021 at 03:29:56PM +0300, Mike Rapoport wrote:
> + code_resource.start = __pa_symbol(_text);
> + code_resource.end = __pa_symbol(_etext)-1;
> + rodata_resource.start = __pa_symbol(__start_rodata);
> + rodata_resource.end = __pa_symbol(__end_rodata)-1;
> + data_resource.start = __pa_symbol(_sdata);
> + data_resource.end = __pa_symbol(_edata)-1;
> + bss_resource.start = __pa_symbol(__bss_start);
> + bss_resource.end = __pa_symbol(__bss_stop)-1;

This falls short on 32-bit ARM. The old code was:

- kernel_code.start = virt_to_phys(_text);
- kernel_code.end = virt_to_phys(__init_begin - 1);
- kernel_data.start = virt_to_phys(_sdata);
- kernel_data.end = virt_to_phys(_end - 1);

If I look at one of my kernels:

c0008000 T _text
c0b5b000 R __end_rodata
... exception and unwind tables live here ...
c0c00000 T __init_begin
c0e00000 D _sdata
c0e68870 D _edata
c0e68870 B __bss_start
c0e995d4 B __bss_stop
c0e995d4 B _end

So the original covers _text..__init_begin-1 which includes the
exception and unwind tables. Your version above omits these, which
leaves them exposed.

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