| Message ID | 20221206105737.69478-1-david@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] mm/swap: fix SWP_PFN_BITS with CONFIG_PHYS_ADDR_T_64BIT on 32bit | expand |
On Tue, Dec 06, 2022 at 11:57:37AM +0100, David Hildenbrand wrote: > We use "unsigned long" to store a PFN in the kernel and phys_addr_t to > store a physical address. > > On a 64bit system, both are 64bit wide. However, on a 32bit system, the > latter might be 64bit wide. This is, for example, the case on x86 with > PAE: phys_addr_t and PTEs are 64bit wide, while "unsigned long" only > spans 32bit. > > The current definition of SWP_PFN_BITS without MAX_PHYSMEM_BITS misses > that case, and assumes that the maximum PFN is limited by an 32bit > phys_addr_t. This implies, that SWP_PFN_BITS will currently only be able to > cover 4 GiB - 1 on any 32bit system with 4k page size, which is wrong. > > Let's rely on the number of bits in phys_addr_t instead, but make sure to > not exceed the maximum swap offset, to not make the BUILD_BUG_ON() in > is_pfn_swap_entry() unhappy. Note that swp_entry_t is effectively an > unsigned long and the maximum swap offset shares that value with the > swap type. > > For example, on an 8 GiB x86 PAE system with a kernel config based on > Debian 11.5 (-> CONFIG_FLATMEM=y, CONFIG_X86_PAE=y), we will currently fail > removing migration entries (remove_migration_ptes()), because > mm/page_vma_mapped.c:check_pte() will fail to identify a PFN match as > swp_offset_pfn() wrongly masks off PFN bits. For example, > split_huge_page_to_list()->...->remap_page() will leave migration > entries in place and continue to unlock the page. > > Later, when we stumble over these migration entries (e.g., via > /proc/self/pagemap), pfn_swap_entry_to_page() will BUG_ON() because > these migration entries shouldn't exist anymore and the page was > unlocked. > > [ 33.067591] kernel BUG at include/linux/swapops.h:497! > [ 33.067597] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI > [ 33.067602] CPU: 3 PID: 742 Comm: cow Tainted: G E 6.1.0-rc8+ #16 > [ 33.067605] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 > [ 33.067606] EIP: pagemap_pmd_range+0x644/0x650 > [ 33.067612] Code: 00 00 00 00 66 90 89 ce b9 00 f0 ff ff e9 ff fb ff ff 89 d8 31 db e8 48 c6 52 00 e9 23 fb ff ff e8 61 83 56 00 e9 b6 fe ff ff <0f> 0b bf 00 f0 ff ff e9 38 fa ff ff 3e 8d 74 26 00 55 89 e5 57 31 > [ 33.067615] EAX: ee394000 EBX: 00000002 ECX: ee394000 EDX: 00000000 > [ 33.067617] ESI: c1b0ded4 EDI: 00024a00 EBP: c1b0ddb4 ESP: c1b0dd68 > [ 33.067619] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010246 > [ 33.067624] CR0: 80050033 CR2: b7a00000 CR3: 01bbbd20 CR4: 00350ef0 > [ 33.067625] Call Trace: > [ 33.067628] ? madvise_free_pte_range+0x720/0x720 > [ 33.067632] ? smaps_pte_range+0x4b0/0x4b0 > [ 33.067634] walk_pgd_range+0x325/0x720 > [ 33.067637] ? mt_find+0x1d6/0x3a0 > [ 33.067641] ? mt_find+0x1d6/0x3a0 > [ 33.067643] __walk_page_range+0x164/0x170 > [ 33.067646] walk_page_range+0xf9/0x170 > [ 33.067648] ? __kmem_cache_alloc_node+0x2a8/0x340 > [ 33.067653] pagemap_read+0x124/0x280 > [ 33.067658] ? default_llseek+0x101/0x160 > [ 33.067662] ? smaps_account+0x1d0/0x1d0 > [ 33.067664] vfs_read+0x90/0x290 > [ 33.067667] ? do_madvise.part.0+0x24b/0x390 > [ 33.067669] ? debug_smp_processor_id+0x12/0x20 > [ 33.067673] ksys_pread64+0x58/0x90 > [ 33.067675] __ia32_sys_ia32_pread64+0x1b/0x20 > [ 33.067680] __do_fast_syscall_32+0x4c/0xc0 > [ 33.067683] do_fast_syscall_32+0x29/0x60 > [ 33.067686] do_SYSENTER_32+0x15/0x20 > [ 33.067689] entry_SYSENTER_32+0x98/0xf1 > > Decrease the indentation level of SWP_PFN_BITS and SWP_PFN_MASK to keep > it readable and consistent. > > Fixes: 0d206b5d2e0d ("mm/swap: add swp_offset_pfn() to fetch PFN from swap entry") > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Peter Xu <peterx@redhat.com> > Cc: Yang Shi <shy828301@gmail.com> > Cc: Hugh Dickins <hughd@google.com> > Cc: Andrea Arcangeli <aarcange@redhat.com> > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > > v1 -> v2: > * Rely on sizeof(phys_addr_t) and min_t() instead. > * Survives my various cross compilations and testing on x86 PAE. Good to know it works, thanks a lot. Acked-by: Peter Xu <peterx@redhat.com>
On 06.12.22 23:12, Peter Xu wrote: > On Tue, Dec 06, 2022 at 11:57:37AM +0100, David Hildenbrand wrote: >> We use "unsigned long" to store a PFN in the kernel and phys_addr_t to >> store a physical address. >> >> On a 64bit system, both are 64bit wide. However, on a 32bit system, the >> latter might be 64bit wide. This is, for example, the case on x86 with >> PAE: phys_addr_t and PTEs are 64bit wide, while "unsigned long" only >> spans 32bit. >> >> The current definition of SWP_PFN_BITS without MAX_PHYSMEM_BITS misses >> that case, and assumes that the maximum PFN is limited by an 32bit >> phys_addr_t. This implies, that SWP_PFN_BITS will currently only be able to >> cover 4 GiB - 1 on any 32bit system with 4k page size, which is wrong. >> >> Let's rely on the number of bits in phys_addr_t instead, but make sure to >> not exceed the maximum swap offset, to not make the BUILD_BUG_ON() in >> is_pfn_swap_entry() unhappy. Note that swp_entry_t is effectively an >> unsigned long and the maximum swap offset shares that value with the >> swap type. >> >> For example, on an 8 GiB x86 PAE system with a kernel config based on >> Debian 11.5 (-> CONFIG_FLATMEM=y, CONFIG_X86_PAE=y), we will currently fail >> removing migration entries (remove_migration_ptes()), because >> mm/page_vma_mapped.c:check_pte() will fail to identify a PFN match as >> swp_offset_pfn() wrongly masks off PFN bits. For example, >> split_huge_page_to_list()->...->remap_page() will leave migration >> entries in place and continue to unlock the page. >> >> Later, when we stumble over these migration entries (e.g., via >> /proc/self/pagemap), pfn_swap_entry_to_page() will BUG_ON() because >> these migration entries shouldn't exist anymore and the page was >> unlocked. >> >> [ 33.067591] kernel BUG at include/linux/swapops.h:497! >> [ 33.067597] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI >> [ 33.067602] CPU: 3 PID: 742 Comm: cow Tainted: G E 6.1.0-rc8+ #16 >> [ 33.067605] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 >> [ 33.067606] EIP: pagemap_pmd_range+0x644/0x650 >> [ 33.067612] Code: 00 00 00 00 66 90 89 ce b9 00 f0 ff ff e9 ff fb ff ff 89 d8 31 db e8 48 c6 52 00 e9 23 fb ff ff e8 61 83 56 00 e9 b6 fe ff ff <0f> 0b bf 00 f0 ff ff e9 38 fa ff ff 3e 8d 74 26 00 55 89 e5 57 31 >> [ 33.067615] EAX: ee394000 EBX: 00000002 ECX: ee394000 EDX: 00000000 >> [ 33.067617] ESI: c1b0ded4 EDI: 00024a00 EBP: c1b0ddb4 ESP: c1b0dd68 >> [ 33.067619] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010246 >> [ 33.067624] CR0: 80050033 CR2: b7a00000 CR3: 01bbbd20 CR4: 00350ef0 >> [ 33.067625] Call Trace: >> [ 33.067628] ? madvise_free_pte_range+0x720/0x720 >> [ 33.067632] ? smaps_pte_range+0x4b0/0x4b0 >> [ 33.067634] walk_pgd_range+0x325/0x720 >> [ 33.067637] ? mt_find+0x1d6/0x3a0 >> [ 33.067641] ? mt_find+0x1d6/0x3a0 >> [ 33.067643] __walk_page_range+0x164/0x170 >> [ 33.067646] walk_page_range+0xf9/0x170 >> [ 33.067648] ? __kmem_cache_alloc_node+0x2a8/0x340 >> [ 33.067653] pagemap_read+0x124/0x280 >> [ 33.067658] ? default_llseek+0x101/0x160 >> [ 33.067662] ? smaps_account+0x1d0/0x1d0 >> [ 33.067664] vfs_read+0x90/0x290 >> [ 33.067667] ? do_madvise.part.0+0x24b/0x390 >> [ 33.067669] ? debug_smp_processor_id+0x12/0x20 >> [ 33.067673] ksys_pread64+0x58/0x90 >> [ 33.067675] __ia32_sys_ia32_pread64+0x1b/0x20 >> [ 33.067680] __do_fast_syscall_32+0x4c/0xc0 >> [ 33.067683] do_fast_syscall_32+0x29/0x60 >> [ 33.067686] do_SYSENTER_32+0x15/0x20 >> [ 33.067689] entry_SYSENTER_32+0x98/0xf1 >> >> Decrease the indentation level of SWP_PFN_BITS and SWP_PFN_MASK to keep >> it readable and consistent. >> >> Fixes: 0d206b5d2e0d ("mm/swap: add swp_offset_pfn() to fetch PFN from swap entry") >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: Peter Xu <peterx@redhat.com> >> Cc: Yang Shi <shy828301@gmail.com> >> Cc: Hugh Dickins <hughd@google.com> >> Cc: Andrea Arcangeli <aarcange@redhat.com> >> Signed-off-by: David Hildenbrand <david@redhat.com> >> --- >> >> v1 -> v2: >> * Rely on sizeof(phys_addr_t) and min_t() instead. >> * Survives my various cross compilations and testing on x86 PAE. > > Good to know it works, thanks a lot. > > Acked-by: Peter Xu <peterx@redhat.com> > Thanks. I realized that we can simply use min_t(int, instead of min_t(phys_addr_t, because we're only comparing numbers < 64 ... Might look cleaner and less complicated. From e6f0c1099de69a11e643e4d4ee6f470147aa174e Mon Sep 17 00:00:00 2001 From: David Hildenbrand <david@redhat.com> Date: Wed, 7 Dec 2022 21:15:36 +0100 Subject: [PATCH] Fixup: "mm/swap: fix SWP_PFN_BITS with CONFIG_PHYS_ADDR_T_64BIT on 32bit" Let's use "int" for comparison, as we're only comparing numbers < 64. Signed-off-by: David Hildenbrand <david@redhat.com> --- include/linux/swapops.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/swapops.h b/include/linux/swapops.h index a70b5c3a68d7..b982dd614572 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -35,7 +35,7 @@ #ifdef MAX_PHYSMEM_BITS #define SWP_PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) #else /* MAX_PHYSMEM_BITS */ -#define SWP_PFN_BITS min_t(phys_addr_t, \ +#define SWP_PFN_BITS min_t(int, \ sizeof(phys_addr_t) * 8 - PAGE_SHIFT, \ SWP_TYPE_SHIFT) #endif /* MAX_PHYSMEM_BITS */
On Tue, Dec 6, 2022 at 2:57 AM David Hildenbrand <david@redhat.com> wrote: > > We use "unsigned long" to store a PFN in the kernel and phys_addr_t to > store a physical address. > > On a 64bit system, both are 64bit wide. However, on a 32bit system, the > latter might be 64bit wide. This is, for example, the case on x86 with > PAE: phys_addr_t and PTEs are 64bit wide, while "unsigned long" only > spans 32bit. > > The current definition of SWP_PFN_BITS without MAX_PHYSMEM_BITS misses > that case, and assumes that the maximum PFN is limited by an 32bit > phys_addr_t. This implies, that SWP_PFN_BITS will currently only be able to > cover 4 GiB - 1 on any 32bit system with 4k page size, which is wrong. Thanks for debugging this. IIUC this means even swap is actually broken on x86_32 + PAE? > > Let's rely on the number of bits in phys_addr_t instead, but make sure to > not exceed the maximum swap offset, to not make the BUILD_BUG_ON() in > is_pfn_swap_entry() unhappy. Note that swp_entry_t is effectively an > unsigned long and the maximum swap offset shares that value with the > swap type. > > For example, on an 8 GiB x86 PAE system with a kernel config based on > Debian 11.5 (-> CONFIG_FLATMEM=y, CONFIG_X86_PAE=y), we will currently fail > removing migration entries (remove_migration_ptes()), because > mm/page_vma_mapped.c:check_pte() will fail to identify a PFN match as > swp_offset_pfn() wrongly masks off PFN bits. For example, > split_huge_page_to_list()->...->remap_page() will leave migration > entries in place and continue to unlock the page. > > Later, when we stumble over these migration entries (e.g., via > /proc/self/pagemap), pfn_swap_entry_to_page() will BUG_ON() because > these migration entries shouldn't exist anymore and the page was > unlocked. > > [ 33.067591] kernel BUG at include/linux/swapops.h:497! > [ 33.067597] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI > [ 33.067602] CPU: 3 PID: 742 Comm: cow Tainted: G E 6.1.0-rc8+ #16 > [ 33.067605] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 > [ 33.067606] EIP: pagemap_pmd_range+0x644/0x650 > [ 33.067612] Code: 00 00 00 00 66 90 89 ce b9 00 f0 ff ff e9 ff fb ff ff 89 d8 31 db e8 48 c6 52 00 e9 23 fb ff ff e8 61 83 56 00 e9 b6 fe ff ff <0f> 0b bf 00 f0 ff ff e9 38 fa ff ff 3e 8d 74 26 00 55 89 e5 57 31 > [ 33.067615] EAX: ee394000 EBX: 00000002 ECX: ee394000 EDX: 00000000 > [ 33.067617] ESI: c1b0ded4 EDI: 00024a00 EBP: c1b0ddb4 ESP: c1b0dd68 > [ 33.067619] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010246 > [ 33.067624] CR0: 80050033 CR2: b7a00000 CR3: 01bbbd20 CR4: 00350ef0 > [ 33.067625] Call Trace: > [ 33.067628] ? madvise_free_pte_range+0x720/0x720 > [ 33.067632] ? smaps_pte_range+0x4b0/0x4b0 > [ 33.067634] walk_pgd_range+0x325/0x720 > [ 33.067637] ? mt_find+0x1d6/0x3a0 > [ 33.067641] ? mt_find+0x1d6/0x3a0 > [ 33.067643] __walk_page_range+0x164/0x170 > [ 33.067646] walk_page_range+0xf9/0x170 > [ 33.067648] ? __kmem_cache_alloc_node+0x2a8/0x340 > [ 33.067653] pagemap_read+0x124/0x280 > [ 33.067658] ? default_llseek+0x101/0x160 > [ 33.067662] ? smaps_account+0x1d0/0x1d0 > [ 33.067664] vfs_read+0x90/0x290 > [ 33.067667] ? do_madvise.part.0+0x24b/0x390 > [ 33.067669] ? debug_smp_processor_id+0x12/0x20 > [ 33.067673] ksys_pread64+0x58/0x90 > [ 33.067675] __ia32_sys_ia32_pread64+0x1b/0x20 > [ 33.067680] __do_fast_syscall_32+0x4c/0xc0 > [ 33.067683] do_fast_syscall_32+0x29/0x60 > [ 33.067686] do_SYSENTER_32+0x15/0x20 > [ 33.067689] entry_SYSENTER_32+0x98/0xf1 > > Decrease the indentation level of SWP_PFN_BITS and SWP_PFN_MASK to keep > it readable and consistent. > > Fixes: 0d206b5d2e0d ("mm/swap: add swp_offset_pfn() to fetch PFN from swap entry") > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Peter Xu <peterx@redhat.com> > Cc: Yang Shi <shy828301@gmail.com> > Cc: Hugh Dickins <hughd@google.com> > Cc: Andrea Arcangeli <aarcange@redhat.com> > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > > v1 -> v2: > * Rely on sizeof(phys_addr_t) and min_t() instead. > * Survives my various cross compilations and testing on x86 PAE. Reviewed-by: Yang Shi <shy828301@gmail.com> > > --- > include/linux/swapops.h | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/include/linux/swapops.h b/include/linux/swapops.h > index 86b95ccb81bb..424d586ed1ca 100644 > --- a/include/linux/swapops.h > +++ b/include/linux/swapops.h > @@ -33,11 +33,13 @@ > * can use the extra bits to store other information besides PFN. > */ > #ifdef MAX_PHYSMEM_BITS > -#define SWP_PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) > +#define SWP_PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) > #else /* MAX_PHYSMEM_BITS */ > -#define SWP_PFN_BITS (BITS_PER_LONG - PAGE_SHIFT) > +#define SWP_PFN_BITS min_t(phys_addr_t, \ > + sizeof(phys_addr_t) * 8 - PAGE_SHIFT, \ > + SWP_TYPE_SHIFT) > #endif /* MAX_PHYSMEM_BITS */ > -#define SWP_PFN_MASK (BIT(SWP_PFN_BITS) - 1) > +#define SWP_PFN_MASK (BIT(SWP_PFN_BITS) - 1) > > /** > * Migration swap entry specific bitfield definitions. Layout: > > base-commit: 76dcd734eca23168cb008912c0f69ff408905235 > -- > 2.38.1 >
On 07.12.22 23:40, Yang Shi wrote: > On Tue, Dec 6, 2022 at 2:57 AM David Hildenbrand <david@redhat.com> wrote: >> >> We use "unsigned long" to store a PFN in the kernel and phys_addr_t to >> store a physical address. >> >> On a 64bit system, both are 64bit wide. However, on a 32bit system, the >> latter might be 64bit wide. This is, for example, the case on x86 with >> PAE: phys_addr_t and PTEs are 64bit wide, while "unsigned long" only >> spans 32bit. >> >> The current definition of SWP_PFN_BITS without MAX_PHYSMEM_BITS misses >> that case, and assumes that the maximum PFN is limited by an 32bit >> phys_addr_t. This implies, that SWP_PFN_BITS will currently only be able to >> cover 4 GiB - 1 on any 32bit system with 4k page size, which is wrong. > > Thanks for debugging this. IIUC this means even swap is actually > broken on x86_32 + PAE? I saw all different kinds of issues while testing debugging without this patch, but they might just be a fallout from previous page migration/THP splitting issues. I think swap should be fine, because SWP_PFN_BITS only affects swp_offset_pfn(): only used when is_pfn_swap_entry()==true. Thanks!
diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 86b95ccb81bb..424d586ed1ca 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -33,11 +33,13 @@ * can use the extra bits to store other information besides PFN. */ #ifdef MAX_PHYSMEM_BITS -#define SWP_PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) +#define SWP_PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) #else /* MAX_PHYSMEM_BITS */ -#define SWP_PFN_BITS (BITS_PER_LONG - PAGE_SHIFT) +#define SWP_PFN_BITS min_t(phys_addr_t, \ + sizeof(phys_addr_t) * 8 - PAGE_SHIFT, \ + SWP_TYPE_SHIFT) #endif /* MAX_PHYSMEM_BITS */ -#define SWP_PFN_MASK (BIT(SWP_PFN_BITS) - 1) +#define SWP_PFN_MASK (BIT(SWP_PFN_BITS) - 1) /** * Migration swap entry specific bitfield definitions. Layout:
We use "unsigned long" to store a PFN in the kernel and phys_addr_t to store a physical address. On a 64bit system, both are 64bit wide. However, on a 32bit system, the latter might be 64bit wide. This is, for example, the case on x86 with PAE: phys_addr_t and PTEs are 64bit wide, while "unsigned long" only spans 32bit. The current definition of SWP_PFN_BITS without MAX_PHYSMEM_BITS misses that case, and assumes that the maximum PFN is limited by an 32bit phys_addr_t. This implies, that SWP_PFN_BITS will currently only be able to cover 4 GiB - 1 on any 32bit system with 4k page size, which is wrong. Let's rely on the number of bits in phys_addr_t instead, but make sure to not exceed the maximum swap offset, to not make the BUILD_BUG_ON() in is_pfn_swap_entry() unhappy. Note that swp_entry_t is effectively an unsigned long and the maximum swap offset shares that value with the swap type. For example, on an 8 GiB x86 PAE system with a kernel config based on Debian 11.5 (-> CONFIG_FLATMEM=y, CONFIG_X86_PAE=y), we will currently fail removing migration entries (remove_migration_ptes()), because mm/page_vma_mapped.c:check_pte() will fail to identify a PFN match as swp_offset_pfn() wrongly masks off PFN bits. For example, split_huge_page_to_list()->...->remap_page() will leave migration entries in place and continue to unlock the page. Later, when we stumble over these migration entries (e.g., via /proc/self/pagemap), pfn_swap_entry_to_page() will BUG_ON() because these migration entries shouldn't exist anymore and the page was unlocked. [ 33.067591] kernel BUG at include/linux/swapops.h:497! [ 33.067597] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 33.067602] CPU: 3 PID: 742 Comm: cow Tainted: G E 6.1.0-rc8+ #16 [ 33.067605] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 [ 33.067606] EIP: pagemap_pmd_range+0x644/0x650 [ 33.067612] Code: 00 00 00 00 66 90 89 ce b9 00 f0 ff ff e9 ff fb ff ff 89 d8 31 db e8 48 c6 52 00 e9 23 fb ff ff e8 61 83 56 00 e9 b6 fe ff ff <0f> 0b bf 00 f0 ff ff e9 38 fa ff ff 3e 8d 74 26 00 55 89 e5 57 31 [ 33.067615] EAX: ee394000 EBX: 00000002 ECX: ee394000 EDX: 00000000 [ 33.067617] ESI: c1b0ded4 EDI: 00024a00 EBP: c1b0ddb4 ESP: c1b0dd68 [ 33.067619] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010246 [ 33.067624] CR0: 80050033 CR2: b7a00000 CR3: 01bbbd20 CR4: 00350ef0 [ 33.067625] Call Trace: [ 33.067628] ? madvise_free_pte_range+0x720/0x720 [ 33.067632] ? smaps_pte_range+0x4b0/0x4b0 [ 33.067634] walk_pgd_range+0x325/0x720 [ 33.067637] ? mt_find+0x1d6/0x3a0 [ 33.067641] ? mt_find+0x1d6/0x3a0 [ 33.067643] __walk_page_range+0x164/0x170 [ 33.067646] walk_page_range+0xf9/0x170 [ 33.067648] ? __kmem_cache_alloc_node+0x2a8/0x340 [ 33.067653] pagemap_read+0x124/0x280 [ 33.067658] ? default_llseek+0x101/0x160 [ 33.067662] ? smaps_account+0x1d0/0x1d0 [ 33.067664] vfs_read+0x90/0x290 [ 33.067667] ? do_madvise.part.0+0x24b/0x390 [ 33.067669] ? debug_smp_processor_id+0x12/0x20 [ 33.067673] ksys_pread64+0x58/0x90 [ 33.067675] __ia32_sys_ia32_pread64+0x1b/0x20 [ 33.067680] __do_fast_syscall_32+0x4c/0xc0 [ 33.067683] do_fast_syscall_32+0x29/0x60 [ 33.067686] do_SYSENTER_32+0x15/0x20 [ 33.067689] entry_SYSENTER_32+0x98/0xf1 Decrease the indentation level of SWP_PFN_BITS and SWP_PFN_MASK to keep it readable and consistent. Fixes: 0d206b5d2e0d ("mm/swap: add swp_offset_pfn() to fetch PFN from swap entry") Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Xu <peterx@redhat.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> --- v1 -> v2: * Rely on sizeof(phys_addr_t) and min_t() instead. * Survives my various cross compilations and testing on x86 PAE. --- include/linux/swapops.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) base-commit: 76dcd734eca23168cb008912c0f69ff408905235