* [PATCH v1] arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging
@ 2022-11-07 2:10 Naoya Horiguchi
2022-11-07 12:42 ` Ville Syrjälä
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Naoya Horiguchi @ 2022-11-07 2:10 UTC (permalink / raw)
To: linux-mm
Cc: Ville Syrjälä,
Andrew Morton, David Hildenbrand, Mike Kravetz, Miaohe Lin,
Liu Shixin, Yang Shi, Oscar Salvador, Muchun Song,
Naoya Horiguchi, linux-kernel
From: Naoya Horiguchi <naoya.horiguchi@nec.com>
The following bug is reported to be triggered when starting X on x86-32
system with i915:
[ 225.777375] kernel BUG at mm/memory.c:2664!
[ 225.777391] invalid opcode: 0000 [#1] PREEMPT SMP
[ 225.777405] CPU: 0 PID: 2402 Comm: Xorg Not tainted 6.1.0-rc3-bdg+ #86
[ 225.777415] Hardware name: /8I865G775-G, BIOS F1 08/29/2006
[ 225.777421] EIP: __apply_to_page_range+0x24d/0x31c
[ 225.777437] Code: ff ff 8b 55 e8 8b 45 cc e8 0a 11 ec ff 89 d8 83 c4 28 5b 5e 5f 5d c3 81 7d e0 a0 ef 96 c1 74 ad 8b 45 d0 e8 2d 83 49 00 eb a3 <0f> 0b 25 00 f0 ff ff 81 eb 00 00 00 40 01 c3 8b 45 ec 8b 00 e8 76
[ 225.777446] EAX: 00000001 EBX: c53a3b58 ECX: b5c00000 EDX: c258aa00
[ 225.777454] ESI: b5c00000 EDI: b5900000 EBP: c4b0fdb4 ESP: c4b0fd80
[ 225.777462] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010202
[ 225.777470] CR0: 80050033 CR2: b5900000 CR3: 053a3000 CR4: 000006d0
[ 225.777479] Call Trace:
[ 225.777486] ? i915_memcpy_init_early+0x63/0x63 [i915]
[ 225.777684] apply_to_page_range+0x21/0x27
[ 225.777694] ? i915_memcpy_init_early+0x63/0x63 [i915]
[ 225.777870] remap_io_mapping+0x49/0x75 [i915]
[ 225.778046] ? i915_memcpy_init_early+0x63/0x63 [i915]
[ 225.778220] ? mutex_unlock+0xb/0xd
[ 225.778231] ? i915_vma_pin_fence+0x6d/0xf7 [i915]
[ 225.778420] vm_fault_gtt+0x2a9/0x8f1 [i915]
[ 225.778644] ? lock_is_held_type+0x56/0xe7
[ 225.778655] ? lock_is_held_type+0x7a/0xe7
[ 225.778663] ? 0xc1000000
[ 225.778670] __do_fault+0x21/0x6a
[ 225.778679] handle_mm_fault+0x708/0xb21
[ 225.778686] ? mt_find+0x21e/0x5ae
[ 225.778696] exc_page_fault+0x185/0x705
[ 225.778704] ? doublefault_shim+0x127/0x127
[ 225.778715] handle_exception+0x130/0x130
[ 225.778723] EIP: 0xb700468a
Recently pud_huge() got aware of non-present entry by commit 3a194f3f8ad0
("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present
pud entry") to handle some special states of gigantic page. However, it's
overlooked that pud_none() always returns false when running with 2-level
paging, and as a result pmd_huge() can return true pointlessly.
Introduce "#if CONFIG_PGTABLE_LEVELS > 2" to pud_huge() to deal with this.
Fixes: 3a194f3f8ad0 ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry")
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
---
arch/x86/mm/hugetlbpage.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index 6b3033845c6d..5804bbae4f01 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -37,8 +37,12 @@ int pmd_huge(pmd_t pmd)
*/
int pud_huge(pud_t pud)
{
+#if CONFIG_PGTABLE_LEVELS > 2
return !pud_none(pud) &&
(pud_val(pud) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
+#else
+ return 0;
+#endif
}
#ifdef CONFIG_HUGETLB_PAGE
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v1] arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging
2022-11-07 2:10 [PATCH v1] arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging Naoya Horiguchi
@ 2022-11-07 12:42 ` Ville Syrjälä
2022-11-08 0:00 ` HORIGUCHI NAOYA(堀口 直也)
2022-11-08 1:36 ` Miaohe Lin
2022-11-09 3:14 ` Muchun Song
2 siblings, 1 reply; 6+ messages in thread
From: Ville Syrjälä @ 2022-11-07 12:42 UTC (permalink / raw)
To: Naoya Horiguchi
Cc: linux-mm, Andrew Morton, David Hildenbrand, Mike Kravetz,
Miaohe Lin, Liu Shixin, Yang Shi, Oscar Salvador, Muchun Song,
Naoya Horiguchi, linux-kernel
On Mon, Nov 07, 2022 at 11:10:10AM +0900, Naoya Horiguchi wrote:
> From: Naoya Horiguchi <naoya.horiguchi@nec.com>
>
> The following bug is reported to be triggered when starting X on x86-32
> system with i915:
>
> [ 225.777375] kernel BUG at mm/memory.c:2664!
> [ 225.777391] invalid opcode: 0000 [#1] PREEMPT SMP
> [ 225.777405] CPU: 0 PID: 2402 Comm: Xorg Not tainted 6.1.0-rc3-bdg+ #86
> [ 225.777415] Hardware name: /8I865G775-G, BIOS F1 08/29/2006
> [ 225.777421] EIP: __apply_to_page_range+0x24d/0x31c
> [ 225.777437] Code: ff ff 8b 55 e8 8b 45 cc e8 0a 11 ec ff 89 d8 83 c4 28 5b 5e 5f 5d c3 81 7d e0 a0 ef 96 c1 74 ad 8b 45 d0 e8 2d 83 49 00 eb a3 <0f> 0b 25 00 f0 ff ff 81 eb 00 00 00 40 01 c3 8b 45 ec 8b 00 e8 76
> [ 225.777446] EAX: 00000001 EBX: c53a3b58 ECX: b5c00000 EDX: c258aa00
> [ 225.777454] ESI: b5c00000 EDI: b5900000 EBP: c4b0fdb4 ESP: c4b0fd80
> [ 225.777462] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010202
> [ 225.777470] CR0: 80050033 CR2: b5900000 CR3: 053a3000 CR4: 000006d0
> [ 225.777479] Call Trace:
> [ 225.777486] ? i915_memcpy_init_early+0x63/0x63 [i915]
> [ 225.777684] apply_to_page_range+0x21/0x27
> [ 225.777694] ? i915_memcpy_init_early+0x63/0x63 [i915]
> [ 225.777870] remap_io_mapping+0x49/0x75 [i915]
> [ 225.778046] ? i915_memcpy_init_early+0x63/0x63 [i915]
> [ 225.778220] ? mutex_unlock+0xb/0xd
> [ 225.778231] ? i915_vma_pin_fence+0x6d/0xf7 [i915]
> [ 225.778420] vm_fault_gtt+0x2a9/0x8f1 [i915]
> [ 225.778644] ? lock_is_held_type+0x56/0xe7
> [ 225.778655] ? lock_is_held_type+0x7a/0xe7
> [ 225.778663] ? 0xc1000000
> [ 225.778670] __do_fault+0x21/0x6a
> [ 225.778679] handle_mm_fault+0x708/0xb21
> [ 225.778686] ? mt_find+0x21e/0x5ae
> [ 225.778696] exc_page_fault+0x185/0x705
> [ 225.778704] ? doublefault_shim+0x127/0x127
> [ 225.778715] handle_exception+0x130/0x130
> [ 225.778723] EIP: 0xb700468a
>
> Recently pud_huge() got aware of non-present entry by commit 3a194f3f8ad0
> ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present
> pud entry") to handle some special states of gigantic page. However, it's
> overlooked that pud_none() always returns false when running with 2-level
> paging, and as a result pmd_huge() can return true pointlessly.
>
> Introduce "#if CONFIG_PGTABLE_LEVELS > 2" to pud_huge() to deal with this.
>
> Fixes: 3a194f3f8ad0 ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry")
> Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
> Cc: <stable@vger.kernel.org>
Works for me.
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
> arch/x86/mm/hugetlbpage.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
> index 6b3033845c6d..5804bbae4f01 100644
> --- a/arch/x86/mm/hugetlbpage.c
> +++ b/arch/x86/mm/hugetlbpage.c
> @@ -37,8 +37,12 @@ int pmd_huge(pmd_t pmd)
> */
> int pud_huge(pud_t pud)
> {
> +#if CONFIG_PGTABLE_LEVELS > 2
> return !pud_none(pud) &&
> (pud_val(pud) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
> +#else
> + return 0;
> +#endif
> }
>
> #ifdef CONFIG_HUGETLB_PAGE
> --
> 2.25.1
--
Ville Syrjälä
Intel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v1] arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging
2022-11-07 12:42 ` Ville Syrjälä
@ 2022-11-08 0:00 ` HORIGUCHI NAOYA(堀口 直也)
2022-11-08 0:10 ` Andrew Morton
0 siblings, 1 reply; 6+ messages in thread
From: HORIGUCHI NAOYA(堀口 直也) @ 2022-11-08 0:00 UTC (permalink / raw)
To: Ville Syrjälä, Andrew Morton
Cc: Naoya Horiguchi, linux-mm, David Hildenbrand, Mike Kravetz,
Miaohe Lin, Liu Shixin, Yang Shi, Oscar Salvador, Muchun Song,
linux-kernel
On Mon, Nov 07, 2022 at 02:42:18PM +0200, Ville Syrjälä wrote:
> On Mon, Nov 07, 2022 at 11:10:10AM +0900, Naoya Horiguchi wrote:
> > From: Naoya Horiguchi <naoya.horiguchi@nec.com>
> >
> > The following bug is reported to be triggered when starting X on x86-32
> > system with i915:
> >
> > [ 225.777375] kernel BUG at mm/memory.c:2664!
> > [ 225.777391] invalid opcode: 0000 [#1] PREEMPT SMP
> > [ 225.777405] CPU: 0 PID: 2402 Comm: Xorg Not tainted 6.1.0-rc3-bdg+ #86
> > [ 225.777415] Hardware name: /8I865G775-G, BIOS F1 08/29/2006
> > [ 225.777421] EIP: __apply_to_page_range+0x24d/0x31c
> > [ 225.777437] Code: ff ff 8b 55 e8 8b 45 cc e8 0a 11 ec ff 89 d8 83 c4 28 5b 5e 5f 5d c3 81 7d e0 a0 ef 96 c1 74 ad 8b 45 d0 e8 2d 83 49 00 eb a3 <0f> 0b 25 00 f0 ff ff 81 eb 00 00 00 40 01 c3 8b 45 ec 8b 00 e8 76
> > [ 225.777446] EAX: 00000001 EBX: c53a3b58 ECX: b5c00000 EDX: c258aa00
> > [ 225.777454] ESI: b5c00000 EDI: b5900000 EBP: c4b0fdb4 ESP: c4b0fd80
> > [ 225.777462] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010202
> > [ 225.777470] CR0: 80050033 CR2: b5900000 CR3: 053a3000 CR4: 000006d0
> > [ 225.777479] Call Trace:
> > [ 225.777486] ? i915_memcpy_init_early+0x63/0x63 [i915]
> > [ 225.777684] apply_to_page_range+0x21/0x27
> > [ 225.777694] ? i915_memcpy_init_early+0x63/0x63 [i915]
> > [ 225.777870] remap_io_mapping+0x49/0x75 [i915]
> > [ 225.778046] ? i915_memcpy_init_early+0x63/0x63 [i915]
> > [ 225.778220] ? mutex_unlock+0xb/0xd
> > [ 225.778231] ? i915_vma_pin_fence+0x6d/0xf7 [i915]
> > [ 225.778420] vm_fault_gtt+0x2a9/0x8f1 [i915]
> > [ 225.778644] ? lock_is_held_type+0x56/0xe7
> > [ 225.778655] ? lock_is_held_type+0x7a/0xe7
> > [ 225.778663] ? 0xc1000000
> > [ 225.778670] __do_fault+0x21/0x6a
> > [ 225.778679] handle_mm_fault+0x708/0xb21
> > [ 225.778686] ? mt_find+0x21e/0x5ae
> > [ 225.778696] exc_page_fault+0x185/0x705
> > [ 225.778704] ? doublefault_shim+0x127/0x127
> > [ 225.778715] handle_exception+0x130/0x130
> > [ 225.778723] EIP: 0xb700468a
> >
> > Recently pud_huge() got aware of non-present entry by commit 3a194f3f8ad0
> > ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present
> > pud entry") to handle some special states of gigantic page. However, it's
> > overlooked that pud_none() always returns false when running with 2-level
> > paging, and as a result pmd_huge() can return true pointlessly.
Sorry, I found a non-negligible typo here (s/pmd_huge/pud_huge/).
Andrew, could you fix this on mm-hotfixes-unstable?
> >
> > Introduce "#if CONFIG_PGTABLE_LEVELS > 2" to pud_huge() to deal with this.
> >
> > Fixes: 3a194f3f8ad0 ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry")
> > Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
> > Cc: <stable@vger.kernel.org>
>
> Works for me.
> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Thank you for confirmation.
- Naoya Horiguchi
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v1] arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging
2022-11-08 0:00 ` HORIGUCHI NAOYA(堀口 直也)
@ 2022-11-08 0:10 ` Andrew Morton
0 siblings, 0 replies; 6+ messages in thread
From: Andrew Morton @ 2022-11-08 0:10 UTC (permalink / raw)
To: HORIGUCHI NAOYA
Cc: Ville Syrjälä,
Naoya Horiguchi, linux-mm, David Hildenbrand, Mike Kravetz,
Miaohe Lin, Liu Shixin, Yang Shi, Oscar Salvador, Muchun Song,
linux-kernel
On Tue, 8 Nov 2022 00:00:15 +0000 HORIGUCHI NAOYA(堀口 直也) <naoya.horiguchi@nec.com> wrote:
> > > Recently pud_huge() got aware of non-present entry by commit 3a194f3f8ad0
> > > ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present
> > > pud entry") to handle some special states of gigantic page. However, it's
> > > overlooked that pud_none() always returns false when running with 2-level
> > > paging, and as a result pmd_huge() can return true pointlessly.
>
> Sorry, I found a non-negligible typo here (s/pmd_huge/pud_huge/).
> Andrew, could you fix this on mm-hotfixes-unstable?
Done, thanks.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v1] arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging
2022-11-07 2:10 [PATCH v1] arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging Naoya Horiguchi
2022-11-07 12:42 ` Ville Syrjälä
@ 2022-11-08 1:36 ` Miaohe Lin
2022-11-09 3:14 ` Muchun Song
2 siblings, 0 replies; 6+ messages in thread
From: Miaohe Lin @ 2022-11-08 1:36 UTC (permalink / raw)
To: Naoya Horiguchi, linux-mm
Cc: Ville Syrjälä,
Andrew Morton, David Hildenbrand, Mike Kravetz, Liu Shixin,
Yang Shi, Oscar Salvador, Muchun Song, Naoya Horiguchi,
linux-kernel
On 2022/11/7 10:10, Naoya Horiguchi wrote:
> From: Naoya Horiguchi <naoya.horiguchi@nec.com>
>
> The following bug is reported to be triggered when starting X on x86-32
> system with i915:
>
> [ 225.777375] kernel BUG at mm/memory.c:2664!
> [ 225.777391] invalid opcode: 0000 [#1] PREEMPT SMP
> [ 225.777405] CPU: 0 PID: 2402 Comm: Xorg Not tainted 6.1.0-rc3-bdg+ #86
> [ 225.777415] Hardware name: /8I865G775-G, BIOS F1 08/29/2006
> [ 225.777421] EIP: __apply_to_page_range+0x24d/0x31c
> [ 225.777437] Code: ff ff 8b 55 e8 8b 45 cc e8 0a 11 ec ff 89 d8 83 c4 28 5b 5e 5f 5d c3 81 7d e0 a0 ef 96 c1 74 ad 8b 45 d0 e8 2d 83 49 00 eb a3 <0f> 0b 25 00 f0 ff ff 81 eb 00 00 00 40 01 c3 8b 45 ec 8b 00 e8 76
> [ 225.777446] EAX: 00000001 EBX: c53a3b58 ECX: b5c00000 EDX: c258aa00
> [ 225.777454] ESI: b5c00000 EDI: b5900000 EBP: c4b0fdb4 ESP: c4b0fd80
> [ 225.777462] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010202
> [ 225.777470] CR0: 80050033 CR2: b5900000 CR3: 053a3000 CR4: 000006d0
> [ 225.777479] Call Trace:
> [ 225.777486] ? i915_memcpy_init_early+0x63/0x63 [i915]
> [ 225.777684] apply_to_page_range+0x21/0x27
> [ 225.777694] ? i915_memcpy_init_early+0x63/0x63 [i915]
> [ 225.777870] remap_io_mapping+0x49/0x75 [i915]
> [ 225.778046] ? i915_memcpy_init_early+0x63/0x63 [i915]
> [ 225.778220] ? mutex_unlock+0xb/0xd
> [ 225.778231] ? i915_vma_pin_fence+0x6d/0xf7 [i915]
> [ 225.778420] vm_fault_gtt+0x2a9/0x8f1 [i915]
> [ 225.778644] ? lock_is_held_type+0x56/0xe7
> [ 225.778655] ? lock_is_held_type+0x7a/0xe7
> [ 225.778663] ? 0xc1000000
> [ 225.778670] __do_fault+0x21/0x6a
> [ 225.778679] handle_mm_fault+0x708/0xb21
> [ 225.778686] ? mt_find+0x21e/0x5ae
> [ 225.778696] exc_page_fault+0x185/0x705
> [ 225.778704] ? doublefault_shim+0x127/0x127
> [ 225.778715] handle_exception+0x130/0x130
> [ 225.778723] EIP: 0xb700468a
>
> Recently pud_huge() got aware of non-present entry by commit 3a194f3f8ad0
> ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present
> pud entry") to handle some special states of gigantic page. However, it's
> overlooked that pud_none() always returns false when running with 2-level
> paging, and as a result pmd_huge() can return true pointlessly.
LGTM. Thanks for your fixing.
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Thanks,
Miaohe Lin
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v1] arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging
2022-11-07 2:10 [PATCH v1] arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging Naoya Horiguchi
2022-11-07 12:42 ` Ville Syrjälä
2022-11-08 1:36 ` Miaohe Lin
@ 2022-11-09 3:14 ` Muchun Song
2 siblings, 0 replies; 6+ messages in thread
From: Muchun Song @ 2022-11-09 3:14 UTC (permalink / raw)
To: Naoya Horiguchi
Cc: Linux Memory Management List, Ville Syrjälä,
Andrew Morton, David Hildenbrand, Mike Kravetz, Miaohe Lin,
Liu Shixin, Yang Shi, Oscar Salvador, Muchun Song,
Naoya Horiguchi, linux-kernel
> On Nov 7, 2022, at 10:10, Naoya Horiguchi <naoya.horiguchi@linux.dev> wrote:
>
> From: Naoya Horiguchi <naoya.horiguchi@nec.com>
>
> The following bug is reported to be triggered when starting X on x86-32
> system with i915:
>
> [ 225.777375] kernel BUG at mm/memory.c:2664!
> [ 225.777391] invalid opcode: 0000 [#1] PREEMPT SMP
> [ 225.777405] CPU: 0 PID: 2402 Comm: Xorg Not tainted 6.1.0-rc3-bdg+ #86
> [ 225.777415] Hardware name: /8I865G775-G, BIOS F1 08/29/2006
> [ 225.777421] EIP: __apply_to_page_range+0x24d/0x31c
> [ 225.777437] Code: ff ff 8b 55 e8 8b 45 cc e8 0a 11 ec ff 89 d8 83 c4 28 5b 5e 5f 5d c3 81 7d e0 a0 ef 96 c1 74 ad 8b 45 d0 e8 2d 83 49 00 eb a3 <0f> 0b 25 00 f0 ff ff 81 eb 00 00 00 40 01 c3 8b 45 ec 8b 00 e8 76
> [ 225.777446] EAX: 00000001 EBX: c53a3b58 ECX: b5c00000 EDX: c258aa00
> [ 225.777454] ESI: b5c00000 EDI: b5900000 EBP: c4b0fdb4 ESP: c4b0fd80
> [ 225.777462] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010202
> [ 225.777470] CR0: 80050033 CR2: b5900000 CR3: 053a3000 CR4: 000006d0
> [ 225.777479] Call Trace:
> [ 225.777486] ? i915_memcpy_init_early+0x63/0x63 [i915]
> [ 225.777684] apply_to_page_range+0x21/0x27
> [ 225.777694] ? i915_memcpy_init_early+0x63/0x63 [i915]
> [ 225.777870] remap_io_mapping+0x49/0x75 [i915]
> [ 225.778046] ? i915_memcpy_init_early+0x63/0x63 [i915]
> [ 225.778220] ? mutex_unlock+0xb/0xd
> [ 225.778231] ? i915_vma_pin_fence+0x6d/0xf7 [i915]
> [ 225.778420] vm_fault_gtt+0x2a9/0x8f1 [i915]
> [ 225.778644] ? lock_is_held_type+0x56/0xe7
> [ 225.778655] ? lock_is_held_type+0x7a/0xe7
> [ 225.778663] ? 0xc1000000
> [ 225.778670] __do_fault+0x21/0x6a
> [ 225.778679] handle_mm_fault+0x708/0xb21
> [ 225.778686] ? mt_find+0x21e/0x5ae
> [ 225.778696] exc_page_fault+0x185/0x705
> [ 225.778704] ? doublefault_shim+0x127/0x127
> [ 225.778715] handle_exception+0x130/0x130
> [ 225.778723] EIP: 0xb700468a
>
> Recently pud_huge() got aware of non-present entry by commit 3a194f3f8ad0
> ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present
> pud entry") to handle some special states of gigantic page. However, it's
> overlooked that pud_none() always returns false when running with 2-level
> paging, and as a result pmd_huge() can return true pointlessly.
>
> Introduce "#if CONFIG_PGTABLE_LEVELS > 2" to pud_huge() to deal with this.
>
> Fixes: 3a194f3f8ad0 ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry")
> Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
> Cc: <stable@vger.kernel.org>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Thanks.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-11-09 3:14 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-11-07 2:10 [PATCH v1] arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level paging Naoya Horiguchi
2022-11-07 12:42 ` Ville Syrjälä
2022-11-08 0:00 ` HORIGUCHI NAOYA(堀口 直也)
2022-11-08 0:10 ` Andrew Morton
2022-11-08 1:36 ` Miaohe Lin
2022-11-09 3:14 ` Muchun Song
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