Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1433106

Re: [RESEND PATCH] x86/mm: only allow memmap=XX!YY over existing RAM

Show all headers | View raw

On Tue, Jun 28, 2016 at 1:31 AM, Yigal Korman <yigal@plexistor.com> wrote:
> Before this patch, passing a range that is beyond the physical memory
> range will succeed, the user will see a /dev/pmem0 and will be able to
> access it. Reads will always return 0 and writes will be silently
> ignored.
>
> I've gotten more than one bug report about mkfs.{xfs,ext4} or nvml
> failing that were eventually tracked down to be wrong values passed to
> memmap.
>
> This patch prevents the above issue by instead of adding a new memory
> range, only update a RAM memory range with the PRAM type. This way,
> passing the wrong memmap will either not give you a pmem at all or give
> you a smaller one that actually has RAM behind it.
>
> And if someone still needs to fake a pmem that doesn't have RAM behind
> it, they can simply do memmap=XX@YY,XX!YY.
>
> Signed-off-by: Yigal Korman <yigal@plexistor.com>
> Acked-by: Dan Williams <dan.j.williams@intel.com>
> Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
> Tested-by: Boaz Harrosh <boaz@plexistor.com>
> ---

I have some other libnvdimm fixes heading upstream shortly if x86
folks just want to ack this one...

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[RESEND PATCH] x86/mm: only allow memmap=XX!YY over existing RAM Yigal Korman <yigal@plexistor.com> - 2016-06-28 10:40 +0200
  Re: [RESEND PATCH] x86/mm: only allow memmap=XX!YY over existing RAM Dan Williams <dan.j.williams@intel.com> - 2016-06-28 18:40 +0200
    Re: [RESEND PATCH] x86/mm: only allow memmap=XX!YY over existing RAM "H. Peter Anvin" <hpa@zytor.com> - 2016-06-28 20:00 +0200
      Re: [RESEND PATCH] x86/mm: only allow memmap=XX!YY over existing RAM Dan Williams <dan.j.williams@intel.com> - 2016-06-29 03:10 +0200
        Re: [RESEND PATCH] x86/mm: only allow memmap=XX!YY over existing RAM Yigal Korman <yigal@plexistor.com> - 2016-06-29 07:20 +0200
          Re: [RESEND PATCH] x86/mm: only allow memmap=XX!YY over existing RAM Dan Williams <dan.j.williams@intel.com> - 2016-06-29 16:50 +0200

csiph-web