[Crash-utility] [PATCH] arm64: incorrect translation, physical address include flags

[Erlandsson, Johan]

> -----Original Message-----
> ----- Original Message -----
> > Hi
> >
> > We have seen a problem when translating virtual to physical addresses.
> > It appears that upper flags are not cleared.
> >
> > Example below, observe that physical address is incorrect for 'PAGE:',
> > it include flags in upper bits. This value is also returned from
> > arm64_vtop_3level_4k().
> >
> > crash> vtop ffffffc081000000
> > VIRTUAL           PHYSICAL
> > ffffffc081000000  81000000
> >
> > PAGE DIRECTORY: ffffffc00007d000
> >    PGD: ffffffc00007d810 => 61fe003
> >    PMD: ffffffc0061fe040 => 20000081000711
> >   PAGE: 20000081000000  (2MB)
> >
> >      PTE        PHYSICAL  FLAGS
> > 20000081000711  81000000  (VALID|SHARED|AF|PXN)
> >
> > vtop: WARNING: sparsemem: invalid section number: 8388610
> > ---
> >  arm64.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arm64.c b/arm64.c
> > index d1d75c4..2320df9 100644
> > --- a/arm64.c
> > +++ b/arm64.c
> > @@ -802,6 +802,7 @@ arm64_vtop_3level_4k(ulong pgd, ulong vaddr,
> > physaddr_t *paddr, int verbose)
> >
> >  	if ((pmd_val & PMD_TYPE_MASK) == PMD_TYPE_SECT) {
> >  		ulong sectionbase = pmd_val &
> SECTION_PAGE_MASK_2MB;
> > +		sectionbase &= PHYS_MASK;
> >  		if (verbose) {
> >  			fprintf(fp, "  PAGE: %lx  (2MB)\n\n",
> sectionbase);
> >  			arm64_translate_pte(pmd_val, 0, 0);
> > --
> > 1.9.1
> >
> > --
> > Crash-utility mailing list
> > Crash-utility at redhat.com
> > https://www.redhat.com/mailman/listinfo/crash-utility
> 
> Hi Johan,
> 
> I also see it with 64k pages when the referenced memory is in the high
> ranges.
> But there are actually two issues here, because the
> SECTION_PAGE_MASK_2MB and SECTION_PAGE_MASK_512MB macros are
> incorrectly being defined as 32-bit values.
> 
> How does this patch work for you?:
> 
> 
> --- a/arm64.c
> +++ b/arm64.c
> @@ -702,8 +702,8 @@ arm64_uvtop(struct task_context *tc, ulong uvaddr,
> physaddr_t *paddr, int verbos
>  #define PMD_TYPE_MASK   3
>  #define PMD_TYPE_SECT   1
>  #define PMD_TYPE_TABLE  2
> -#define SECTION_PAGE_MASK_2MB    (~((MEGABYTES(2))-1))
> -#define SECTION_PAGE_MASK_512MB  (~((MEGABYTES(512))-1))
> +#define SECTION_PAGE_MASK_2MB    ((long)(~((MEGABYTES(2))-1)))
> +#define SECTION_PAGE_MASK_512MB  ((long)(~((MEGABYTES(512))-1)))
> 
>  static int
>  arm64_vtop_2level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int
> verbose) @@ -729,7 +729,7 @@ arm64_vtop_2level_64k(ulong pgd, ulong
> vaddr, physaddr_t *paddr, int verbose)
>          */
> 
>         if ((pgd_val & PMD_TYPE_MASK) == PMD_TYPE_SECT) {
> -               ulong sectionbase = pgd_val & SECTION_PAGE_MASK_512MB;
> +               ulong sectionbase = (pgd_val & SECTION_PAGE_MASK_512MB)
> + & PHYS_MASK;
>                 if (verbose) {
>                         fprintf(fp, "  PAGE: %lx  (512MB)\n\n",
> sectionbase);
>                         arm64_translate_pte(pgd_val, 0, 0); @@ -801,7
> +801,7 @@ arm64_vtop_3level_4k(ulong pgd, ulong vaddr, physaddr_t
> *paddr, int verbose)
>                 goto no_page;
> 
>         if ((pmd_val & PMD_TYPE_MASK) == PMD_TYPE_SECT) {
> -               ulong sectionbase = pmd_val & SECTION_PAGE_MASK_2MB;
> +               ulong sectionbase = (pmd_val & SECTION_PAGE_MASK_2MB) &
> + PHYS_MASK;
>                 if (verbose) {
>                         fprintf(fp, "  PAGE: %lx  (2MB)\n\n",
> sectionbase);
>                         arm64_translate_pte(pmd_val, 0, 0);
> 
> 

Hi Dave

This patch seems to be working fine.

Thanks
Johan