On Wed, Jun 02, 2021 at 11:33:10AM +0300, Mike Rapoport wrote:

On Tue, Jun 01, 2021 at 02:54:15PM +0100, Russell King (Oracle) wrote:

quoted

On Mon, May 31, 2021 at 03:29:56PM +0300, Mike Rapoport wrote:

quoted

+	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.

Right, this needs to be fixed. Is there any reason the exception and unwind
tables cannot be placed between _sdata and _edata? 

It seems to me that they were left outside for purely historical reasons.
Commit ee951c630c5c ("ARM: 7568/1: Sort exception table at compile time")
moved the exception tables out of .data section before _sdata existed.
Commit 14c4a533e099 ("ARM: 8583/1: mm: fix location of _etext") moved
_etext before the unwind tables and didn't bother to put them into data or
rodata areas.

You can not assume that all sections will be between these symbols. This
isn't specific to 32-bit ARM. If you look at x86's vmlinux.lds.in, you
will see that BUG_TABLE and ORC_UNWIND_TABLE are after _edata, along
with many other undiscarded sections before __bss_start. So it seems
your assumptions in trying to clean this up are somewhat false.

-- 
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