From: Steven Price <steven.price@arm.com> To: Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org Cc: "Steven Price" <steven.price@arm.com>, "Andy Lutomirski" <luto@kernel.org>, "Ard Biesheuvel" <ard.biesheuvel@linaro.org>, "Arnd Bergmann" <arnd@arndb.de>, "Borislav Petkov" <bp@alien8.de>, "Catalin Marinas" <catalin.marinas@arm.com>, "Dave Hansen" <dave.hansen@linux.intel.com>, "Ingo Molnar" <mingo@redhat.com>, "James Morse" <james.morse@arm.com>, "Jérôme Glisse" <jglisse@redhat.com>, "Peter Zijlstra" <peterz@infradead.org>, "Thomas Gleixner" <tglx@linutronix.de>, "Will Deacon" <will@kernel.org>, x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, "Mark Rutland" <Mark.Rutland@arm.com>, "Liang, Kan" <kan.liang@linux.intel.com> Subject: [PATCH v15 12/23] mm: pagewalk: Allow walking without vma Date: Fri, 1 Nov 2019 14:09:31 +0000 [thread overview] Message-ID: <20191101140942.51554-13-steven.price@arm.com> (raw) In-Reply-To: <20191101140942.51554-1-steven.price@arm.com> Since 48684a65b4e3: "mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)", page_table_walk() will report any kernel area as a hole, because it lacks a vma. This means each arch has re-implemented page table walking when needed, for example in the per-arch ptdump walker. Remove the requirement to have a vma in the generic code and add a new function walk_page_range_novma() which ignores the VMAs and simply walks the page tables. Signed-off-by: Steven Price <steven.price@arm.com> --- include/linux/pagewalk.h | 5 +++++ mm/pagewalk.c | 44 ++++++++++++++++++++++++++++++++-------- 2 files changed, 41 insertions(+), 8 deletions(-) diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h index 12004b097eae..ed2bb399fac2 100644 --- a/include/linux/pagewalk.h +++ b/include/linux/pagewalk.h @@ -53,6 +53,7 @@ struct mm_walk_ops { * @ops: operation to call during the walk * @mm: mm_struct representing the target process of page table walk * @vma: vma currently walked (NULL if walking outside vmas) + * @no_vma: walk ignoring vmas (vma will always be NULL) * @private: private data for callbacks' usage * * (see the comment on walk_page_range() for more details) @@ -61,12 +62,16 @@ struct mm_walk { const struct mm_walk_ops *ops; struct mm_struct *mm; struct vm_area_struct *vma; + bool no_vma; void *private; }; int walk_page_range(struct mm_struct *mm, unsigned long start, unsigned long end, const struct mm_walk_ops *ops, void *private); +int walk_page_range_novma(struct mm_struct *mm, unsigned long start, + unsigned long end, const struct mm_walk_ops *ops, + void *private); int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, void *private); diff --git a/mm/pagewalk.c b/mm/pagewalk.c index fc4d98a3a5a0..626e7fdb0508 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -38,7 +38,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, do { again: next = pmd_addr_end(addr, end); - if (pmd_none(*pmd) || !walk->vma) { + if (pmd_none(*pmd) || (!walk->vma && !walk->no_vma)) { if (ops->pte_hole) err = ops->pte_hole(addr, next, walk); if (err) @@ -61,9 +61,14 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, if (!ops->pte_entry) continue; - split_huge_pmd(walk->vma, pmd, addr); - if (pmd_trans_unstable(pmd)) - goto again; + if (walk->vma) { + split_huge_pmd(walk->vma, pmd, addr); + if (pmd_trans_unstable(pmd)) + goto again; + } else if (pmd_leaf(*pmd)) { + continue; + } + err = walk_pte_range(pmd, addr, next, walk); if (err) break; @@ -84,7 +89,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, do { again: next = pud_addr_end(addr, end); - if (pud_none(*pud) || !walk->vma) { + if (pud_none(*pud) || (!walk->vma && !walk->no_vma)) { if (ops->pte_hole) err = ops->pte_hole(addr, next, walk); if (err) @@ -98,9 +103,13 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, break; } - split_huge_pud(walk->vma, pud, addr); - if (pud_none(*pud)) - goto again; + if (walk->vma) { + split_huge_pud(walk->vma, pud, addr); + if (pud_none(*pud)) + goto again; + } else if (pud_leaf(*pud)) { + continue; + } if (ops->pmd_entry || ops->pte_entry) err = walk_pmd_range(pud, addr, next, walk); @@ -358,6 +367,25 @@ int walk_page_range(struct mm_struct *mm, unsigned long start, return err; } +int walk_page_range_novma(struct mm_struct *mm, unsigned long start, + unsigned long end, const struct mm_walk_ops *ops, + void *private) +{ + struct mm_walk walk = { + .ops = ops, + .mm = mm, + .private = private, + .no_vma = true + }; + + if (start >= end || !walk.mm) + return -EINVAL; + + lockdep_assert_held(&walk.mm->mmap_sem); + + return __walk_page_range(start, end, &walk); +} + int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, void *private) { -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Steven Price <steven.price@arm.com> To: Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org Cc: "Mark Rutland" <Mark.Rutland@arm.com>, x86@kernel.org, "Arnd Bergmann" <arnd@arndb.de>, "Ard Biesheuvel" <ard.biesheuvel@linaro.org>, "Peter Zijlstra" <peterz@infradead.org>, "Catalin Marinas" <catalin.marinas@arm.com>, "Dave Hansen" <dave.hansen@linux.intel.com>, linux-kernel@vger.kernel.org, "Steven Price" <steven.price@arm.com>, "Jérôme Glisse" <jglisse@redhat.com>, "Ingo Molnar" <mingo@redhat.com>, "Borislav Petkov" <bp@alien8.de>, "Andy Lutomirski" <luto@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>, "James Morse" <james.morse@arm.com>, "Thomas Gleixner" <tglx@linutronix.de>, "Will Deacon" <will@kernel.org>, linux-arm-kernel@lists.infradead.org, "Liang, Kan" <kan.liang@linux.intel.com> Subject: [PATCH v15 12/23] mm: pagewalk: Allow walking without vma Date: Fri, 1 Nov 2019 14:09:31 +0000 [thread overview] Message-ID: <20191101140942.51554-13-steven.price@arm.com> (raw) In-Reply-To: <20191101140942.51554-1-steven.price@arm.com> Since 48684a65b4e3: "mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)", page_table_walk() will report any kernel area as a hole, because it lacks a vma. This means each arch has re-implemented page table walking when needed, for example in the per-arch ptdump walker. Remove the requirement to have a vma in the generic code and add a new function walk_page_range_novma() which ignores the VMAs and simply walks the page tables. Signed-off-by: Steven Price <steven.price@arm.com> --- include/linux/pagewalk.h | 5 +++++ mm/pagewalk.c | 44 ++++++++++++++++++++++++++++++++-------- 2 files changed, 41 insertions(+), 8 deletions(-) diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h index 12004b097eae..ed2bb399fac2 100644 --- a/include/linux/pagewalk.h +++ b/include/linux/pagewalk.h @@ -53,6 +53,7 @@ struct mm_walk_ops { * @ops: operation to call during the walk * @mm: mm_struct representing the target process of page table walk * @vma: vma currently walked (NULL if walking outside vmas) + * @no_vma: walk ignoring vmas (vma will always be NULL) * @private: private data for callbacks' usage * * (see the comment on walk_page_range() for more details) @@ -61,12 +62,16 @@ struct mm_walk { const struct mm_walk_ops *ops; struct mm_struct *mm; struct vm_area_struct *vma; + bool no_vma; void *private; }; int walk_page_range(struct mm_struct *mm, unsigned long start, unsigned long end, const struct mm_walk_ops *ops, void *private); +int walk_page_range_novma(struct mm_struct *mm, unsigned long start, + unsigned long end, const struct mm_walk_ops *ops, + void *private); int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, void *private); diff --git a/mm/pagewalk.c b/mm/pagewalk.c index fc4d98a3a5a0..626e7fdb0508 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -38,7 +38,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, do { again: next = pmd_addr_end(addr, end); - if (pmd_none(*pmd) || !walk->vma) { + if (pmd_none(*pmd) || (!walk->vma && !walk->no_vma)) { if (ops->pte_hole) err = ops->pte_hole(addr, next, walk); if (err) @@ -61,9 +61,14 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, if (!ops->pte_entry) continue; - split_huge_pmd(walk->vma, pmd, addr); - if (pmd_trans_unstable(pmd)) - goto again; + if (walk->vma) { + split_huge_pmd(walk->vma, pmd, addr); + if (pmd_trans_unstable(pmd)) + goto again; + } else if (pmd_leaf(*pmd)) { + continue; + } + err = walk_pte_range(pmd, addr, next, walk); if (err) break; @@ -84,7 +89,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, do { again: next = pud_addr_end(addr, end); - if (pud_none(*pud) || !walk->vma) { + if (pud_none(*pud) || (!walk->vma && !walk->no_vma)) { if (ops->pte_hole) err = ops->pte_hole(addr, next, walk); if (err) @@ -98,9 +103,13 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, break; } - split_huge_pud(walk->vma, pud, addr); - if (pud_none(*pud)) - goto again; + if (walk->vma) { + split_huge_pud(walk->vma, pud, addr); + if (pud_none(*pud)) + goto again; + } else if (pud_leaf(*pud)) { + continue; + } if (ops->pmd_entry || ops->pte_entry) err = walk_pmd_range(pud, addr, next, walk); @@ -358,6 +367,25 @@ int walk_page_range(struct mm_struct *mm, unsigned long start, return err; } +int walk_page_range_novma(struct mm_struct *mm, unsigned long start, + unsigned long end, const struct mm_walk_ops *ops, + void *private) +{ + struct mm_walk walk = { + .ops = ops, + .mm = mm, + .private = private, + .no_vma = true + }; + + if (start >= end || !walk.mm) + return -EINVAL; + + lockdep_assert_held(&walk.mm->mmap_sem); + + return __walk_page_range(start, end, &walk); +} + int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, void *private) { -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-11-01 14:10 UTC|newest] Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-01 14:09 [PATCH v15 00/23] Generic page walk and ptdump Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 01/23] mm: Add generic p?d_leaf() macros Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 02/23] arc: mm: Add p?d_leaf() definitions Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 03/23] arm: " Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 04/23] arm64: " Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 05/23] mips: " Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 06/23] powerpc: " Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 07/23] riscv: " Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 08/23] s390: " Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 09/23] sparc: " Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 10/23] x86: " Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 11/23] mm: pagewalk: Add p4d_entry() and pgd_entry() Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` Steven Price [this message] 2019-11-01 14:09 ` [PATCH v15 12/23] mm: pagewalk: Allow walking without vma Steven Price 2019-11-01 14:09 ` [PATCH v15 13/23] mm: pagewalk: Add test_p?d callbacks Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 14/23] mm: pagewalk: Add 'depth' parameter to pte_hole Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 15/23] x86: mm: Point to struct seq_file from struct pg_state Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 16/23] x86: mm+efi: Convert ptdump_walk_pgd_level() to take a mm_struct Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 17/23] x86: mm: Convert ptdump_walk_pgd_level_debugfs() to take an mm_struct Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 18/23] x86: mm: Convert ptdump_walk_pgd_level_core() " Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 19/23] mm: Add generic ptdump Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 20/23] x86: mm: Convert dump_pagetables to use walk_page_range Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 21/23] arm64: mm: Convert mm/dump.c to use walk_page_range() Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 22/23] arm64: mm: Display non-present entries in ptdump Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-01 14:09 ` [PATCH v15 23/23] mm: ptdump: Reduce level numbers by 1 in note_page() Steven Price 2019-11-01 14:09 ` Steven Price 2019-11-04 19:35 ` [PATCH v15 00/23] Generic page walk and ptdump Qian Cai 2019-11-04 19:35 ` Qian Cai 2019-11-06 13:31 ` Qian Cai 2019-11-06 13:31 ` Qian Cai 2019-11-06 15:05 ` Steven Price 2019-11-06 15:05 ` Steven Price 2019-12-03 11:02 ` David Hildenbrand 2019-12-03 11:02 ` David Hildenbrand 2019-12-04 14:54 ` Qian Cai 2019-12-04 14:54 ` Qian Cai 2019-12-04 14:56 ` David Hildenbrand 2019-12-04 14:56 ` David Hildenbrand 2019-12-04 16:32 ` Steven Price 2019-12-04 16:32 ` Steven Price 2019-12-04 17:51 ` Thomas Hellstrom 2019-12-04 17:51 ` Thomas Hellstrom 2019-12-05 13:15 ` Qian Cai 2019-12-05 13:15 ` Qian Cai 2019-12-05 14:32 ` Thomas Hellstrom 2019-12-05 14:32 ` Thomas Hellstrom 2019-12-05 14:32 ` Thomas Hellstrom 2019-12-05 14:38 ` Qian Cai 2019-12-05 14:38 ` Qian Cai 2019-12-05 14:38 ` Qian Cai
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