* [PATCH 4.17] x86/mm: Don't free P4D table when it is folded at runtime
[not found] <20180701143858.GA22410@kroah.com>
@ 2018-07-02 8:45 ` Andrey Ryabinin
2018-07-02 8:47 ` Greg KH
2018-07-02 8:48 ` [PATCH 4.17 v2] " Andrey Ryabinin
1 sibling, 1 reply; 7+ messages in thread
From: Andrey Ryabinin @ 2018-07-02 8:45 UTC (permalink / raw)
To: Greg KH
Cc: stable-commits, Andrey Ryabinin, Linus Torvalds, Peter Zijlstra,
Thomas Gleixner, stable, Ingo Molnar
From: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
commit 0e311d237d7f3022b7dafb639b42541bfb42fe94 upstream.
When the P4D page table layer is folded at runtime, the p4d_free()
should do nothing, the same as in <asm-generic/pgtable-nop4d.h>.
It seems this bug should cause double-free in efi_call_phys_epilog(),
but I don't know how to trigger that code path, so I can't confirm that
by testing.
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org # 4.17
Fixes: 98219dda2ab5 ("x86/mm: Fold p4d page table layer at runtime")
Link: http://lkml.kernel.org/r/20180625102427.15015-1-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
---
arch/x86/include/asm/pgalloc.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
index 263c142a6a6c..f65e9e1cea4c 100644
--- a/arch/x86/include/asm/pgalloc.h
+++ b/arch/x86/include/asm/pgalloc.h
@@ -184,6 +184,9 @@ static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
{
+ if (!pgtable_l5_enabled)
+ return;
+
BUG_ON((unsigned long)p4d & (PAGE_SIZE-1));
free_page((unsigned long)p4d);
}
--
2.16.4
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH 4.17] x86/mm: Don't free P4D table when it is folded at runtime
2018-07-02 8:45 ` [PATCH 4.17] x86/mm: Don't free P4D table when it is folded at runtime Andrey Ryabinin
@ 2018-07-02 8:47 ` Greg KH
2018-07-02 9:01 ` Andrey Ryabinin
0 siblings, 1 reply; 7+ messages in thread
From: Greg KH @ 2018-07-02 8:47 UTC (permalink / raw)
To: Andrey Ryabinin
Cc: stable-commits, Linus Torvalds, Peter Zijlstra, Thomas Gleixner,
stable, Ingo Molnar
On Mon, Jul 02, 2018 at 11:45:36AM +0300, Andrey Ryabinin wrote:
> From: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Huh? I didn't write this patch.
>
> commit 0e311d237d7f3022b7dafb639b42541bfb42fe94 upstream.
>
> When the P4D page table layer is folded at runtime, the p4d_free()
> should do nothing, the same as in <asm-generic/pgtable-nop4d.h>.
>
> It seems this bug should cause double-free in efi_call_phys_epilog(),
> but I don't know how to trigger that code path, so I can't confirm that
> by testing.
>
> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: stable@vger.kernel.org # 4.17
> Fixes: 98219dda2ab5 ("x86/mm: Fold p4d page table layer at runtime")
> Link: http://lkml.kernel.org/r/20180625102427.15015-1-aryabinin@virtuozzo.com
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
> ---
> arch/x86/include/asm/pgalloc.h | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
> index 263c142a6a6c..f65e9e1cea4c 100644
> --- a/arch/x86/include/asm/pgalloc.h
> +++ b/arch/x86/include/asm/pgalloc.h
> @@ -184,6 +184,9 @@ static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
>
> static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
> {
> + if (!pgtable_l5_enabled)
> + return;
> +
Did you test build this patch?
Please do so, and be careful about author attribution, again, I did not
write this patch.
greg k-h
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 4.17 v2] x86/mm: Don't free P4D table when it is folded at runtime
[not found] <20180701143858.GA22410@kroah.com>
2018-07-02 8:45 ` [PATCH 4.17] x86/mm: Don't free P4D table when it is folded at runtime Andrey Ryabinin
@ 2018-07-02 8:48 ` Andrey Ryabinin
2018-07-02 9:15 ` Greg KH
1 sibling, 1 reply; 7+ messages in thread
From: Andrey Ryabinin @ 2018-07-02 8:48 UTC (permalink / raw)
To: Greg KH
Cc: stable-commits, Andrey Ryabinin, Linus Torvalds, Peter Zijlstra,
Thomas Gleixner, stable, Ingo Molnar
commit 0e311d237d7f3022b7dafb639b42541bfb42fe94 upstream.
When the P4D page table layer is folded at runtime, the p4d_free()
should do nothing, the same as in <asm-generic/pgtable-nop4d.h>.
It seems this bug should cause double-free in efi_call_phys_epilog(),
but I don't know how to trigger that code path, so I can't confirm that
by testing.
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org # 4.17
Fixes: 98219dda2ab5 ("x86/mm: Fold p4d page table layer at runtime")
Link: http://lkml.kernel.org/r/20180625102427.15015-1-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
---
Changes since v1:
- Fix wrong "From:" field
arch/x86/include/asm/pgalloc.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
index 263c142a6a6c..f65e9e1cea4c 100644
--- a/arch/x86/include/asm/pgalloc.h
+++ b/arch/x86/include/asm/pgalloc.h
@@ -184,6 +184,9 @@ static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
{
+ if (!pgtable_l5_enabled)
+ return;
+
BUG_ON((unsigned long)p4d & (PAGE_SIZE-1));
free_page((unsigned long)p4d);
}
--
2.16.4
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH 4.17] x86/mm: Don't free P4D table when it is folded at runtime
2018-07-02 8:47 ` Greg KH
@ 2018-07-02 9:01 ` Andrey Ryabinin
0 siblings, 0 replies; 7+ messages in thread
From: Andrey Ryabinin @ 2018-07-02 9:01 UTC (permalink / raw)
To: Greg KH
Cc: stable-commits, Linus Torvalds, Peter Zijlstra, Thomas Gleixner,
stable, Ingo Molnar
On 07/02/2018 11:47 AM, Greg KH wrote:
> On Mon, Jul 02, 2018 at 11:45:36AM +0300, Andrey Ryabinin wrote:
>> From: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
>
> Huh? I didn't write this patch.
Right, I've noticed this and sent v2 with this fixed.
It's because I did 'git am' on your email with backported patch, but missed
that git changed the autorship.
>
>>
>> commit 0e311d237d7f3022b7dafb639b42541bfb42fe94 upstream.
>>
>> When the P4D page table layer is folded at runtime, the p4d_free()
>> should do nothing, the same as in <asm-generic/pgtable-nop4d.h>.
>>
>> It seems this bug should cause double-free in efi_call_phys_epilog(),
>> but I don't know how to trigger that code path, so I can't confirm that
>> by testing.
>>
>> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
>> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
>> Cc: Linus Torvalds <torvalds@linux-foundation.org>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: stable@vger.kernel.org # 4.17
>> Fixes: 98219dda2ab5 ("x86/mm: Fold p4d page table layer at runtime")
>> Link: http://lkml.kernel.org/r/20180625102427.15015-1-aryabinin@virtuozzo.com
>> Signed-off-by: Ingo Molnar <mingo@kernel.org>
>> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
>> ---
>> arch/x86/include/asm/pgalloc.h | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
>> index 263c142a6a6c..f65e9e1cea4c 100644
>> --- a/arch/x86/include/asm/pgalloc.h
>> +++ b/arch/x86/include/asm/pgalloc.h
>> @@ -184,6 +184,9 @@ static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
>>
>> static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
>> {
>> + if (!pgtable_l5_enabled)
>> + return;
>> +
>
> Did you test build this patch?
>
Sure, successfully built on top of 4.17.3
> Please do so, and be careful about author attribution, again, I did not
> write this patch.
>
> greg k-h
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 4.17 v2] x86/mm: Don't free P4D table when it is folded at runtime
2018-07-02 8:48 ` [PATCH 4.17 v2] " Andrey Ryabinin
@ 2018-07-02 9:15 ` Greg KH
2018-07-02 9:20 ` Andrey Ryabinin
0 siblings, 1 reply; 7+ messages in thread
From: Greg KH @ 2018-07-02 9:15 UTC (permalink / raw)
To: Andrey Ryabinin
Cc: stable-commits, Linus Torvalds, Peter Zijlstra, Thomas Gleixner,
stable, Ingo Molnar
On Mon, Jul 02, 2018 at 11:48:28AM +0300, Andrey Ryabinin wrote:
> commit 0e311d237d7f3022b7dafb639b42541bfb42fe94 upstream.
>
> When the P4D page table layer is folded at runtime, the p4d_free()
> should do nothing, the same as in <asm-generic/pgtable-nop4d.h>.
>
> It seems this bug should cause double-free in efi_call_phys_epilog(),
> but I don't know how to trigger that code path, so I can't confirm that
> by testing.
>
> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: stable@vger.kernel.org # 4.17
> Fixes: 98219dda2ab5 ("x86/mm: Fold p4d page table layer at runtime")
> Link: http://lkml.kernel.org/r/20180625102427.15015-1-aryabinin@virtuozzo.com
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
> ---
>
> Changes since v1:
> - Fix wrong "From:" field
>
> arch/x86/include/asm/pgalloc.h | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
> index 263c142a6a6c..f65e9e1cea4c 100644
> --- a/arch/x86/include/asm/pgalloc.h
> +++ b/arch/x86/include/asm/pgalloc.h
> @@ -184,6 +184,9 @@ static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
>
> static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
> {
> + if (!pgtable_l5_enabled)
> + return;
> +
Again, did you actually test-build this? What changed from the original
patch which blew the build up into little tiny pieces?
greg k-h
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 4.17 v2] x86/mm: Don't free P4D table when it is folded at runtime
2018-07-02 9:15 ` Greg KH
@ 2018-07-02 9:20 ` Andrey Ryabinin
2018-07-02 9:37 ` Greg KH
0 siblings, 1 reply; 7+ messages in thread
From: Andrey Ryabinin @ 2018-07-02 9:20 UTC (permalink / raw)
To: Greg KH
Cc: stable-commits, Linus Torvalds, Peter Zijlstra, Thomas Gleixner,
stable, Ingo Molnar
On 07/02/2018 12:15 PM, Greg KH wrote:
> On Mon, Jul 02, 2018 at 11:48:28AM +0300, Andrey Ryabinin wrote:
>> commit 0e311d237d7f3022b7dafb639b42541bfb42fe94 upstream.
>>
>> When the P4D page table layer is folded at runtime, the p4d_free()
>> should do nothing, the same as in <asm-generic/pgtable-nop4d.h>.
>>
>> It seems this bug should cause double-free in efi_call_phys_epilog(),
>> but I don't know how to trigger that code path, so I can't confirm that
>> by testing.
>>
>> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
>> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
>> Cc: Linus Torvalds <torvalds@linux-foundation.org>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: stable@vger.kernel.org # 4.17
>> Fixes: 98219dda2ab5 ("x86/mm: Fold p4d page table layer at runtime")
>> Link: http://lkml.kernel.org/r/20180625102427.15015-1-aryabinin@virtuozzo.com
>> Signed-off-by: Ingo Molnar <mingo@kernel.org>
>> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
>> ---
>>
>> Changes since v1:
>> - Fix wrong "From:" field
>>
>> arch/x86/include/asm/pgalloc.h | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
>> index 263c142a6a6c..f65e9e1cea4c 100644
>> --- a/arch/x86/include/asm/pgalloc.h
>> +++ b/arch/x86/include/asm/pgalloc.h
>> @@ -184,6 +184,9 @@ static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
>>
>> static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
>> {
>> + if (!pgtable_l5_enabled)
>> + return;
>> +
>
> Again, did you actually test-build this?
Again, yes, I did test-build this.
> What changed from the original
> patch which blew the build up into little tiny pieces?
>
Removed '()'. In 4.17 pgtable_l5_enabled is variable, in 4.18 it's function.
> greg k-h
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 4.17 v2] x86/mm: Don't free P4D table when it is folded at runtime
2018-07-02 9:20 ` Andrey Ryabinin
@ 2018-07-02 9:37 ` Greg KH
0 siblings, 0 replies; 7+ messages in thread
From: Greg KH @ 2018-07-02 9:37 UTC (permalink / raw)
To: Andrey Ryabinin
Cc: stable-commits, Linus Torvalds, Peter Zijlstra, Thomas Gleixner,
stable, Ingo Molnar
On Mon, Jul 02, 2018 at 12:20:06PM +0300, Andrey Ryabinin wrote:
>
>
> On 07/02/2018 12:15 PM, Greg KH wrote:
> > On Mon, Jul 02, 2018 at 11:48:28AM +0300, Andrey Ryabinin wrote:
> >> commit 0e311d237d7f3022b7dafb639b42541bfb42fe94 upstream.
> >>
> >> When the P4D page table layer is folded at runtime, the p4d_free()
> >> should do nothing, the same as in <asm-generic/pgtable-nop4d.h>.
> >>
> >> It seems this bug should cause double-free in efi_call_phys_epilog(),
> >> but I don't know how to trigger that code path, so I can't confirm that
> >> by testing.
> >>
> >> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
> >> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> >> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> >> Cc: Peter Zijlstra <peterz@infradead.org>
> >> Cc: Thomas Gleixner <tglx@linutronix.de>
> >> Cc: stable@vger.kernel.org # 4.17
> >> Fixes: 98219dda2ab5 ("x86/mm: Fold p4d page table layer at runtime")
> >> Link: http://lkml.kernel.org/r/20180625102427.15015-1-aryabinin@virtuozzo.com
> >> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> >> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
> >> ---
> >>
> >> Changes since v1:
> >> - Fix wrong "From:" field
> >>
> >> arch/x86/include/asm/pgalloc.h | 3 +++
> >> 1 file changed, 3 insertions(+)
> >>
> >> diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
> >> index 263c142a6a6c..f65e9e1cea4c 100644
> >> --- a/arch/x86/include/asm/pgalloc.h
> >> +++ b/arch/x86/include/asm/pgalloc.h
> >> @@ -184,6 +184,9 @@ static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
> >>
> >> static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
> >> {
> >> + if (!pgtable_l5_enabled)
> >> + return;
> >> +
> >
> > Again, did you actually test-build this?
>
> Again, yes, I did test-build this.
>
> > What changed from the original
> > patch which blew the build up into little tiny pieces?
> >
>
> Removed '()'. In 4.17 pgtable_l5_enabled is variable, in 4.18 it's function.
Ah, good, it wasn't obvious that you changed anything. I'll queue this
up after these latest kernels are released in a few days.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2018-07-02 9:37 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
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[not found] <20180701143858.GA22410@kroah.com>
2018-07-02 8:45 ` [PATCH 4.17] x86/mm: Don't free P4D table when it is folded at runtime Andrey Ryabinin
2018-07-02 8:47 ` Greg KH
2018-07-02 9:01 ` Andrey Ryabinin
2018-07-02 8:48 ` [PATCH 4.17 v2] " Andrey Ryabinin
2018-07-02 9:15 ` Greg KH
2018-07-02 9:20 ` Andrey Ryabinin
2018-07-02 9:37 ` Greg KH
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