Re: [PATCH] mm: pagewalk: call pte_hole() for VM_PFNMAP during walk_page_range
On Wed, 21 Jan 2015 11:43:13 +0530 Shiraz Hashim wrote: > walk_page_range silently skips vma having VM_PFNMAP set, > which leads to undesirable behaviour at client end (who > called walk_page_range). For example for pagemap_read, > when no callbacks are called against VM_PFNMAP vma, > pagemap_read may prepare pagemap data for next virtual > address range at wrong index. This changelog doesn't have enough information for me to be able to work out whether a -stable backport is needed. Please always describe the user-visible effects of a bug. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] mm: pagewalk: call pte_hole() for VM_PFNMAP during walk_page_range
On Wed, 21 Jan 2015 11:43:13 +0530 Shiraz Hashim shas...@codeaurora.org wrote: walk_page_range silently skips vma having VM_PFNMAP set, which leads to undesirable behaviour at client end (who called walk_page_range). For example for pagemap_read, when no callbacks are called against VM_PFNMAP vma, pagemap_read may prepare pagemap data for next virtual address range at wrong index. This changelog doesn't have enough information for me to be able to work out whether a -stable backport is needed. Please always describe the user-visible effects of a bug. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] mm: pagewalk: call pte_hole() for VM_PFNMAP during walk_page_range
On Wed, Jan 21, 2015 at 11:43:13AM +0530, Shiraz Hashim wrote:
> walk_page_range silently skips vma having VM_PFNMAP set,
> which leads to undesirable behaviour at client end (who
> called walk_page_range). For example for pagemap_read,
> when no callbacks are called against VM_PFNMAP vma,
> pagemap_read may prepare pagemap data for next virtual
> address range at wrong index.
>
> Signed-off-by: Shiraz Hashim
Thank you!
Acked-by: Naoya Horiguchi
> ---
> The fix is revised, based upon the suggestion here at
> http://www.spinics.net/lists/linux-mm/msg83058.html
>
> mm/pagewalk.c | 5 -
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/mm/pagewalk.c b/mm/pagewalk.c
> index ad83195..b264bda 100644
> --- a/mm/pagewalk.c
> +++ b/mm/pagewalk.c
> @@ -199,7 +199,10 @@ int walk_page_range(unsigned long addr, unsigned long
> end,
>*/
> if ((vma->vm_start <= addr) &&
> (vma->vm_flags & VM_PFNMAP)) {
> - next = vma->vm_end;
> + if (walk->pte_hole)
> + err = walk->pte_hole(addr, next, walk);
> + if (err)
> + break;
> pgd = pgd_offset(walk->mm, next);
> continue;
> }
> --
> Shiraz Hashim
>
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
> member of the Code Aurora Forum, hosted by The Linux Foundation
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majord...@kvack.org. For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: mailto:"d...@kvack.org;> em...@kvack.org --
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[PATCH] mm: pagewalk: call pte_hole() for VM_PFNMAP during walk_page_range
walk_page_range silently skips vma having VM_PFNMAP set,
which leads to undesirable behaviour at client end (who
called walk_page_range). For example for pagemap_read,
when no callbacks are called against VM_PFNMAP vma,
pagemap_read may prepare pagemap data for next virtual
address range at wrong index.
Signed-off-by: Shiraz Hashim
---
The fix is revised, based upon the suggestion here at
http://www.spinics.net/lists/linux-mm/msg83058.html
mm/pagewalk.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index ad83195..b264bda 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -199,7 +199,10 @@ int walk_page_range(unsigned long addr, unsigned long end,
*/
if ((vma->vm_start <= addr) &&
(vma->vm_flags & VM_PFNMAP)) {
- next = vma->vm_end;
+ if (walk->pte_hole)
+ err = walk->pte_hole(addr, next, walk);
+ if (err)
+ break;
pgd = pgd_offset(walk->mm, next);
continue;
}
--
Shiraz Hashim
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member of the Code Aurora Forum, hosted by The Linux Foundation
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] mm: pagewalk: call pte_hole() for VM_PFNMAP during walk_page_range
On Wed, Jan 21, 2015 at 11:43:13AM +0530, Shiraz Hashim wrote:
walk_page_range silently skips vma having VM_PFNMAP set,
which leads to undesirable behaviour at client end (who
called walk_page_range). For example for pagemap_read,
when no callbacks are called against VM_PFNMAP vma,
pagemap_read may prepare pagemap data for next virtual
address range at wrong index.
Signed-off-by: Shiraz Hashim shas...@codeaurora.org
Thank you!
Acked-by: Naoya Horiguchi n-horigu...@ah.jp.nec.com
---
The fix is revised, based upon the suggestion here at
http://www.spinics.net/lists/linux-mm/msg83058.html
mm/pagewalk.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index ad83195..b264bda 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -199,7 +199,10 @@ int walk_page_range(unsigned long addr, unsigned long
end,
*/
if ((vma-vm_start = addr)
(vma-vm_flags VM_PFNMAP)) {
- next = vma-vm_end;
+ if (walk-pte_hole)
+ err = walk-pte_hole(addr, next, walk);
+ if (err)
+ break;
pgd = pgd_offset(walk-mm, next);
continue;
}
--
Shiraz Hashim
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member of the Code Aurora Forum, hosted by The Linux Foundation
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majord...@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: a href=mailto:d...@kvack.org; em...@kvack.org /a--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH] mm: pagewalk: call pte_hole() for VM_PFNMAP during walk_page_range
walk_page_range silently skips vma having VM_PFNMAP set,
which leads to undesirable behaviour at client end (who
called walk_page_range). For example for pagemap_read,
when no callbacks are called against VM_PFNMAP vma,
pagemap_read may prepare pagemap data for next virtual
address range at wrong index.
Signed-off-by: Shiraz Hashim shas...@codeaurora.org
---
The fix is revised, based upon the suggestion here at
http://www.spinics.net/lists/linux-mm/msg83058.html
mm/pagewalk.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index ad83195..b264bda 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -199,7 +199,10 @@ int walk_page_range(unsigned long addr, unsigned long end,
*/
if ((vma-vm_start = addr)
(vma-vm_flags VM_PFNMAP)) {
- next = vma-vm_end;
+ if (walk-pte_hole)
+ err = walk-pte_hole(addr, next, walk);
+ if (err)
+ break;
pgd = pgd_offset(walk-mm, next);
continue;
}
--
Shiraz Hashim
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member of the Code Aurora Forum, hosted by The Linux Foundation
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
