Re: [PATCH v2 3/3] x86: fix .brk attribute in linker script

From: Josh Poimboeuf
Date: Wed Jun 29 2022 - 13:18:35 EST


On Thu, Jun 23, 2022 at 11:46:08AM +0200, Juergen Gross wrote:
> Commit e32683c6f7d2 ("x86/mm: Fix RESERVE_BRK() for older binutils")
> added the "NOLOAD" attribute to the .brk section as a "failsafe"
> measure.
>
> Unfortunately this leads to the linker no longer covering the .brk
> section in a program header, resulting in the kernel loader not knowing
> that the memory for the .brk section must be reserved.
>
> This has led to crashes when loading the kernel as PV dom0 under Xen,
> but other scenarios could be hit by the same problem (e.g. in case an
> uncompressed kernel is used and the initrd is placed directly behind
> it).
>
> So drop the "NOLOAD" attribute. This has been verified to correctly
> cover the .brk section by a program header of the resulting ELF file.
>
> Fixes: e32683c6f7d2 ("x86/mm: Fix RESERVE_BRK() for older binutils")
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

--
Josh