[Linux-ia64] PATCH: Fix for 4KB kernel corruption

[Linux-ia64] PATCH: Fix for 4KB kernel corruption

[Siddha, Suresh B]

Hi,

4KB page size kernel is broken on Lion with 8GB memory. ia64_boot_param
structure was getting corrupted. Appended patch fixes this problem.

PAGE_ALIGN is required because: rsvd_region[i].end need not be page aligned
and in the next iteration of the for loop this can potentially become
bootmap_start. This can lead to corruption of rsvd_region[i] as
init_bootmem() takes the pfn of bootmap_start and initialises the bootmem.

Thanks,
Suresh

diff -u linux-2.4.14/arch/ia64/kernel/setup.c~
linux-2.4.14/arch/ia64/kernel/setup.c
--- linux-2.4.14/arch/ia64/kernel/setup.c~      Thu Nov 15 16:27:23 2001
+++ linux-2.4.14/arch/ia64/kernel/setup.c       Thu Nov 15 16:28:01 2001
@@ -175,7 +175,7 @@
                /* nothing more available in this segment */
                if (range_end = end) return 0;
 
-               free_start = rsvd_region[i].end;
+               free_start = PAGE_ALIGN(rsvd_region[i].end);
        }
        return 0;
 }

[Linux-ia64] PATCH: Fix for 4KB kernel corruption

[Siddha, Suresh B]

Hi,

4KB page size kernel is broken on Lion with 8GB memory. ia64_boot_param
structure was getting corrupted. Appended patch fixes this problem.

PAGE_ALIGN is required because: rsvd_region[i].end need not be page aligned
and in the next iteration of the for loop this can potentially become
bootmap_start. This can lead to corruption of rsvd_region[i] as
init_bootmem() takes the pfn of bootmap_start and initialises the bootmem.

Thanks,
Suresh

diff -u linux-2.4.14/arch/ia64/kernel/setup.c~
linux-2.4.14/arch/ia64/kernel/setup.c
--- linux-2.4.14/arch/ia64/kernel/setup.c~      Thu Nov 15 16:27:23 2001
+++ linux-2.4.14/arch/ia64/kernel/setup.c       Thu Nov 15 16:28:01 2001
@@ -175,7 +175,7 @@
                /* nothing more available in this segment */
                if (range_end = end) return 0;
 
-               free_start = rsvd_region[i].end;
+               free_start = PAGE_ALIGN(rsvd_region[i].end);
        }
        return 0;
 }

Re: [Linux-ia64] PATCH: Fix for 4KB kernel corruption

[Philippe Gramoullé]

Hi Siddha,

Can this corruption happen with on lion with 4Go of memory also ?

Thanks,

Philippe.

"Siddha, Suresh B" wrote:
> 
> Hi,
> 
> 4KB page size kernel is broken on Lion with 8GB memory. ia64_boot_param
> structure was getting corrupted. Appended patch fixes this problem.
> 
> PAGE_ALIGN is required because: rsvd_region[i].end need not be page aligned
> and in the next iteration of the for loop this can potentially become
> bootmap_start. This can lead to corruption of rsvd_region[i] as
> init_bootmem() takes the pfn of bootmap_start and initialises the bootmem.
> 
> Thanks,
> Suresh
> 
> diff -u linux-2.4.14/arch/ia64/kernel/setup.c~
> linux-2.4.14/arch/ia64/kernel/setup.c
> --- linux-2.4.14/arch/ia64/kernel/setup.c~      Thu Nov 15 16:27:23 2001
> +++ linux-2.4.14/arch/ia64/kernel/setup.c       Thu Nov 15 16:28:01 2001
> @@ -175,7 +175,7 @@
>                 /* nothing more available in this segment */
>                 if (range_end = end) return 0;
> 
> -               free_start = rsvd_region[i].end;
> +               free_start = PAGE_ALIGN(rsvd_region[i].end);
>         }
>         return 0;
>  }
> 
> _______________________________________________
> Linux-IA64 mailing list
> Linux-IA64@linuxia64.org
> http://lists.linuxia64.org/lists/listinfo/linux-ia64

RE: [Linux-ia64] PATCH: Fix for 4KB kernel corruption

[Siddha, Suresh B]

Hi Philippe,

You may or mayn't see this problem. It depends up on the EFI memory map. In
our case, it is so happening that bootmap is allocated from the end of one
of the reserved regions and corrupting that reserved region.

Thanks,
Suresh

> -----Original Message-----
> From: Philippe Gramoullé [mailto:philippe.gramoulle@mmania.com]
> Sent: Friday, November 16, 2001 2:24 AM
> To: Siddha, Suresh B
> Cc: linux-ia64@linuxia64.org
> Subject: Re: [Linux-ia64] PATCH: Fix for 4KB kernel corruption
> 
> 
> 
> Hi Siddha,
> 
> Can this corruption happen with on lion with 4Go of memory also ?
> 
> Thanks,
> 
> Philippe.
> 
> "Siddha, Suresh B" wrote:
> > 
> > Hi,
> > 
> > 4KB page size kernel is broken on Lion with 8GB memory. 
> ia64_boot_param
> > structure was getting corrupted. Appended patch fixes this problem.
> > 
> > PAGE_ALIGN is required because: rsvd_region[i].end need not 
> be page aligned
> > and in the next iteration of the for loop this can 
> potentially become
> > bootmap_start. This can lead to corruption of rsvd_region[i] as
> > init_bootmem() takes the pfn of bootmap_start and 
> initialises the bootmem.
> > 
> > Thanks,
> > Suresh
> > 
> > diff -u linux-2.4.14/arch/ia64/kernel/setup.c~
> > linux-2.4.14/arch/ia64/kernel/setup.c
> > --- linux-2.4.14/arch/ia64/kernel/setup.c~      Thu Nov 15 
> 16:27:23 2001
> > +++ linux-2.4.14/arch/ia64/kernel/setup.c       Thu Nov 15 
> 16:28:01 2001
> > @@ -175,7 +175,7 @@
> >                 /* nothing more available in this segment */
> >                 if (range_end == end) return 0;
> > 
> > -               free_start = rsvd_region[i].end;
> > +               free_start = PAGE_ALIGN(rsvd_region[i].end);
> >         }
> >         return 0;
> >  }
> > 
> > _______________________________________________
> > Linux-IA64 mailing list
> > Linux-IA64@linuxia64.org
> > http://lists.linuxia64.org/lists/listinfo/linux-ia64
> 

Re: [Linux-ia64] PATCH: Fix for 4KB kernel corruption

[David Mosberger]

>>>>> On Thu, 15 Nov 2001 18:05:47 -0800, "Siddha, Suresh B" <suresh.b.siddha@intel.com> said:

  Suresh> Hi, 4KB page size kernel is broken on Lion with 8GB
  Suresh> memory. ia64_boot_param structure was getting
  Suresh> corrupted. Appended patch fixes this problem.

Thanks I applied the patch and also make sure the end address is page
aligned.  It's not strictly needed, but it's cleaner that way (since
the bootmap size is measured as a page count).

	--david