2022-11-22 17:56:53

by Michael Kelley (LINUX)

[permalink] [raw]
Subject: [PATCH v4 1/1] x86/ioremap: Fix page aligned size calculation in __ioremap_caller()

Current code re-calculates the size after aligning the starting and
ending physical addresses on a page boundary. But the re-calculation
also embeds the masking of high order bits that exceed the size of
the physical address space (via PHYSICAL_PAGE_MASK). If the masking
removes any high order bits, the size calculation results in a huge
value that is likely to immediately fail.

Fix this by re-calculating the page-aligned size first. Then mask any
high order bits using PHYSICAL_PAGE_MASK.

Fixes: ffa71f33a820 ("x86, ioremap: Fix incorrect physical address handling in PAE mode")
Acked-by: Dave Hansen <[email protected]>
Signed-off-by: Michael Kelley <[email protected]>
---

This patch was previously Patch 1 of a larger series[1]. Breaking
it out separately per discussion with Dave Hansen and Boris Petkov.

[1] https://lore.kernel.org/linux-hyperv/[email protected]/

arch/x86/mm/ioremap.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 78c5bc6..6453fba 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -217,9 +217,15 @@ static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
* Mappings have to be page-aligned
*/
offset = phys_addr & ~PAGE_MASK;
- phys_addr &= PHYSICAL_PAGE_MASK;
+ phys_addr &= PAGE_MASK;
size = PAGE_ALIGN(last_addr+1) - phys_addr;

+ /*
+ * Mask out any bits not part of the actual physical
+ * address, like memory encryption bits.
+ */
+ phys_addr &= PHYSICAL_PAGE_MASK;
+
retval = memtype_reserve(phys_addr, (u64)phys_addr + size,
pcm, &new_pcm);
if (retval) {
--
1.8.3.1


2022-11-25 15:33:35

by Wei Liu

[permalink] [raw]
Subject: Re: [PATCH v4 1/1] x86/ioremap: Fix page aligned size calculation in __ioremap_caller()

On Tue, Nov 22, 2022 at 09:40:42AM -0800, Michael Kelley wrote:
> Current code re-calculates the size after aligning the starting and
> ending physical addresses on a page boundary. But the re-calculation
> also embeds the masking of high order bits that exceed the size of
> the physical address space (via PHYSICAL_PAGE_MASK). If the masking
> removes any high order bits, the size calculation results in a huge
> value that is likely to immediately fail.
>
> Fix this by re-calculating the page-aligned size first. Then mask any
> high order bits using PHYSICAL_PAGE_MASK.
>
> Fixes: ffa71f33a820 ("x86, ioremap: Fix incorrect physical address handling in PAE mode")
> Acked-by: Dave Hansen <[email protected]>
> Signed-off-by: Michael Kelley <[email protected]>

Reviewed-by: Wei Liu <[email protected]>

> ---
>
> This patch was previously Patch 1 of a larger series[1]. Breaking
> it out separately per discussion with Dave Hansen and Boris Petkov.
>
> [1] https://lore.kernel.org/linux-hyperv/[email protected]/
>
> arch/x86/mm/ioremap.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
> index 78c5bc6..6453fba 100644
> --- a/arch/x86/mm/ioremap.c
> +++ b/arch/x86/mm/ioremap.c
> @@ -217,9 +217,15 @@ static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
> * Mappings have to be page-aligned
> */
> offset = phys_addr & ~PAGE_MASK;
> - phys_addr &= PHYSICAL_PAGE_MASK;
> + phys_addr &= PAGE_MASK;
> size = PAGE_ALIGN(last_addr+1) - phys_addr;
>
> + /*
> + * Mask out any bits not part of the actual physical
> + * address, like memory encryption bits.
> + */
> + phys_addr &= PHYSICAL_PAGE_MASK;
> +
> retval = memtype_reserve(phys_addr, (u64)phys_addr + size,
> pcm, &new_pcm);
> if (retval) {
> --
> 1.8.3.1
>

2022-11-28 14:48:59

by Michael Kelley (LINUX)

[permalink] [raw]
Subject: RE: [PATCH v4 1/1] x86/ioremap: Fix page aligned size calculation in __ioremap_caller()

From: Wei Liu <[email protected]> Sent: Friday, November 25, 2022 7:20 AM
>
> On Tue, Nov 22, 2022 at 09:40:42AM -0800, Michael Kelley wrote:
> > Current code re-calculates the size after aligning the starting and
> > ending physical addresses on a page boundary. But the re-calculation
> > also embeds the masking of high order bits that exceed the size of
> > the physical address space (via PHYSICAL_PAGE_MASK). If the masking
> > removes any high order bits, the size calculation results in a huge
> > value that is likely to immediately fail.
> >
> > Fix this by re-calculating the page-aligned size first. Then mask any
> > high order bits using PHYSICAL_PAGE_MASK.
> >
> > Fixes: ffa71f33a820 ("x86, ioremap: Fix incorrect physical address handling in PAE mode")
> > Acked-by: Dave Hansen <[email protected]>
> > Signed-off-by: Michael Kelley <[email protected]>
>
> Reviewed-by: Wei Liu <[email protected]>
>
> > ---
> >
> > This patch was previously Patch 1 of a larger series[1]. Breaking
> > it out separately per discussion with Dave Hansen and Boris Petkov.
> >
> > [1] https://lore.kernel.org/linux-hyperv/[email protected]/
> >

Boris -- you were going to pick up this patch separately
though urgent. Can you go ahead and do that?

https://lore.kernel.org/linux-hyperv/[email protected]/

Michael

> > arch/x86/mm/ioremap.c | 8 +++++++-
> > 1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
> > index 78c5bc6..6453fba 100644
> > --- a/arch/x86/mm/ioremap.c
> > +++ b/arch/x86/mm/ioremap.c
> > @@ -217,9 +217,15 @@ static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
> > * Mappings have to be page-aligned
> > */
> > offset = phys_addr & ~PAGE_MASK;
> > - phys_addr &= PHYSICAL_PAGE_MASK;
> > + phys_addr &= PAGE_MASK;
> > size = PAGE_ALIGN(last_addr+1) - phys_addr;
> >
> > + /*
> > + * Mask out any bits not part of the actual physical
> > + * address, like memory encryption bits.
> > + */
> > + phys_addr &= PHYSICAL_PAGE_MASK;
> > +
> > retval = memtype_reserve(phys_addr, (u64)phys_addr + size,
> > pcm, &new_pcm);
> > if (retval) {
> > --
> > 1.8.3.1
> >

2022-11-28 16:14:02

by Borislav Petkov

[permalink] [raw]
Subject: Re: [PATCH v4 1/1] x86/ioremap: Fix page aligned size calculation in __ioremap_caller()

On Mon, Nov 28, 2022 at 02:43:28PM +0000, Michael Kelley (LINUX) wrote:
> Boris -- you were going to pick up this patch separately
> though urgent. Can you go ahead and do that?

Did you not get the tip-bot notification?

https://lore.kernel.org/r/166911713030.4906.16935727667401525991.tip-bot2@tip-bot2

you're on Cc there too.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette

2022-11-28 16:42:05

by Michael Kelley (LINUX)

[permalink] [raw]
Subject: RE: [PATCH v4 1/1] x86/ioremap: Fix page aligned size calculation in __ioremap_caller()

From: Borislav Petkov <[email protected]> Sent: Monday, November 28, 2022 7:46 AM
>
> On Mon, Nov 28, 2022 at 02:43:28PM +0000, Michael Kelley (LINUX) wrote:
> > Boris -- you were going to pick up this patch separately
> > though urgent. Can you go ahead and do that?
>
> Did you not get the tip-bot notification?
>
> https://lore.kernel.org/all/166911713030.4906.16935727667401525991.tip-bot2@tip-bot2/
>
> you're on Cc there too.
>

Argh. My mistake. Thanks.

Michael