[v2] x86: fix brk area initialization

[PATCH v2 0/3] x86: fix brk area initialization

Posted by Juergen Gross 1 year, 10 months ago

The brk area needs to be zeroed initially, like the .bss section.
At the same time its memory should be covered by the ELF program
headers.

Juergen Gross (3):
  x86/xen: use clear_bss() for Xen PV guests
  x86: fix setup of brk area
  x86: fix .brk attribute in linker script

 arch/x86/include/asm/setup.h  |  3 +++
 arch/x86/kernel/head64.c      |  4 +++-
 arch/x86/kernel/vmlinux.lds.S |  2 +-
 arch/x86/xen/enlighten_pv.c   |  8 ++++++--
 arch/x86/xen/xen-head.S       | 10 +---------
 5 files changed, 14 insertions(+), 13 deletions(-)

-- 
2.35.3

Re: [PATCH v2 0/3] x86: fix brk area initialization

Posted by Juergen Gross 1 year, 10 months ago

On 23.06.22 11:46, Juergen Gross wrote:
> The brk area needs to be zeroed initially, like the .bss section.
> At the same time its memory should be covered by the ELF program
> headers.
> 
> Juergen Gross (3):
>    x86/xen: use clear_bss() for Xen PV guests
>    x86: fix setup of brk area
>    x86: fix .brk attribute in linker script
> 
>   arch/x86/include/asm/setup.h  |  3 +++
>   arch/x86/kernel/head64.c      |  4 +++-
>   arch/x86/kernel/vmlinux.lds.S |  2 +-
>   arch/x86/xen/enlighten_pv.c   |  8 ++++++--
>   arch/x86/xen/xen-head.S       | 10 +---------
>   5 files changed, 14 insertions(+), 13 deletions(-)
> 

Could I please have some feedback? This series is fixing a major
regression regarding running as Xen PV guest (depending on kernel
configuration system will crash very early).

#regzbot ^introduced e32683c6f7d2


Juergen

Re: [PATCH v2 0/3] x86: fix brk area initialization

Posted by Boris Ostrovsky 1 year, 10 months ago

On 6/29/22 10:10 AM, Juergen Gross wrote:
> On 23.06.22 11:46, Juergen Gross wrote:
>> The brk area needs to be zeroed initially, like the .bss section.
>> At the same time its memory should be covered by the ELF program
>> headers.
>>
>> Juergen Gross (3):
>>    x86/xen: use clear_bss() for Xen PV guests
>>    x86: fix setup of brk area
>>    x86: fix .brk attribute in linker script
>>
>>   arch/x86/include/asm/setup.h  |  3 +++
>>   arch/x86/kernel/head64.c      |  4 +++-
>>   arch/x86/kernel/vmlinux.lds.S |  2 +-
>>   arch/x86/xen/enlighten_pv.c   |  8 ++++++--
>>   arch/x86/xen/xen-head.S       | 10 +---------
>>   5 files changed, 14 insertions(+), 13 deletions(-)
>>
>
> Could I please have some feedback? This series is fixing a major
> regression regarding running as Xen PV guest (depending on kernel
> configuration system will crash very early).
>
> #regzbot ^introduced e32683c6f7d2
>


I don't think you need this for Xen bits as Jan had already reviewed it but in case you do


Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>