lkml.org 
[lkml]   [2022]   [Jul]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRE: [PATCH v3] x86/mce: retrieve poison range from hardware
Luck, Tony wrote:
> +m.misc = (MCI_MISC_ADDR_PHYS << 6) | __ffs64(mem_err->physical_addr_mask);
>
> Do we want to unconditionally trust the sanity of the BIOS provided physical_address_mask?
>
> There's a warning comment on the kernel __ffs64() function:
>
> * The result is not defined if no bits are set, so check that @word
> * is non-zero before calling this.
>
> Otherwise, this looks like a good idea.

It appears the kernel is trusting that ->physical_addr_mask is non-zero
in other paths. So this is at least equally broken in the presence of a
broken BIOS. The impact is potentially larger though with this change,
so it might be a good follow-on patch to make sure that
->physical_addr_mask gets fixed up to a minimum mask value.

\
 
 \ /
  Last update: 2022-07-18 21:16    [W:5.639 / U:0.292 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site