From: John Stultz <john.stultz@linaro.org> To: LKML <linux-kernel@vger.kernel.org> Cc: Minchan Kim <minchan@kernel.org>, Andrew Morton <akpm@linux-foundation.org>, Android Kernel Team <kernel-team@android.com>, Robert Love <rlove@google.com>, Mel Gorman <mel@csn.ul.ie>, Hugh Dickins <hughd@google.com>, Dave Hansen <dave@linux.vnet.ibm.com>, Rik van Riel <riel@redhat.com>, Dmitry Adamushko <dmitry.adamushko@gmail.com>, Dave Chinner <david@fromorbit.com>, Neil Brown <neilb@suse.de>, Andrea Righi <andrea@betterlinux.com>, Andrea Arcangeli <aarcange@redhat.com>, "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>, Mike Hommey <mh@glandium.org>, Taras Glek <tglek@mozilla.com>, Dhaval Giani <dgiani@mozilla.com>, Jan Kara <jack@suse.cz>, KOSAKI Motohiro <kosaki.motohiro@gmail.com>, Michel Lespinasse <walken@google.com>, "linux-mm@kvack.org" <linux-mm@kvack.org>, John Stultz <john.stultz@linaro.org> Subject: [PATCH 8/8] vrange: Send SIGBUS when user try to access purged page Date: Tue, 11 Jun 2013 21:22:51 -0700 [thread overview] Message-ID: <1371010971-15647-9-git-send-email-john.stultz@linaro.org> (raw) In-Reply-To: <1371010971-15647-1-git-send-email-john.stultz@linaro.org> From: Minchan Kim <minchan@kernel.org> By vrange(2) semantic, user should see SIGBUG if he try to access purged page without vrange(...VRANGE_NOVOLATILE). This patch implements it. XXX: I reused PSE bit for quick prototype without enough considering so need time to see what's empty bit and I am surely missing many places to handle vrange pte bit. I should investigate all of pte handling places, especially pte_none case. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Android Kernel Team <kernel-team@android.com> Cc: Robert Love <rlove@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Neil Brown <neilb@suse.de> Cc: Andrea Righi <andrea@betterlinux.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Mike Hommey <mh@glandium.org> Cc: Taras Glek <tglek@mozilla.com> Cc: Dhaval Giani <dgiani@mozilla.com> Cc: Jan Kara <jack@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: linux-mm@kvack.org <linux-mm@kvack.org> Signed-off-by: Minchan Kim <minchan@kernel.org> [jstultz: Extended to work with file pages] Signed-off-by: John Stultz <john.stultz@linaro.org> --- arch/x86/include/asm/pgtable_types.h | 2 ++ include/asm-generic/pgtable.h | 11 +++++++++++ include/linux/vrange.h | 2 ++ mm/memory.c | 23 +++++++++++++++++++++-- mm/vrange.c | 35 ++++++++++++++++++++++++++++++++++- 5 files changed, 70 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index e642300..d7ea6a0 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -64,6 +64,8 @@ #define _PAGE_FILE (_AT(pteval_t, 1) << _PAGE_BIT_FILE) #define _PAGE_PROTNONE (_AT(pteval_t, 1) << _PAGE_BIT_PROTNONE) +#define _PAGE_VRANGE _PAGE_BIT_PSE + /* * _PAGE_NUMA indicates that this page will trigger a numa hinting * minor page fault to gather numa placement statistics (see diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index a59ff51..91e8f6f 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -479,6 +479,17 @@ static inline unsigned long my_zero_pfn(unsigned long addr) #ifdef CONFIG_MMU +static inline pte_t pte_mkvrange(pte_t pte) +{ + pte = pte_set_flags(pte, _PAGE_VRANGE); + return pte_clear_flags(pte, _PAGE_PRESENT); +} + +static inline int pte_vrange(pte_t pte) +{ + return ((pte_flags(pte) | _PAGE_PRESENT) == _PAGE_VRANGE); +} + #ifndef CONFIG_TRANSPARENT_HUGEPAGE static inline int pmd_trans_huge(pmd_t pmd) { diff --git a/include/linux/vrange.h b/include/linux/vrange.h index cbb609a..75754d1 100644 --- a/include/linux/vrange.h +++ b/include/linux/vrange.h @@ -41,6 +41,8 @@ int discard_vpage(struct page *page); bool vrange_address(struct mm_struct *mm, unsigned long start, unsigned long end); +extern bool is_purged_vrange(struct mm_struct *mm, unsigned long address); + #else static inline void vrange_init(void) {}; diff --git a/mm/memory.c b/mm/memory.c index 61a262b..cc5c70b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -59,6 +59,7 @@ #include <linux/gfp.h> #include <linux/migrate.h> #include <linux/string.h> +#include <linux/vrange.h> #include <asm/io.h> #include <asm/pgalloc.h> @@ -832,7 +833,7 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, /* pte contains position in swap or file, so copy. */ if (unlikely(!pte_present(pte))) { - if (!pte_file(pte)) { + if (!pte_file(pte) && !pte_vrange(pte)) { swp_entry_t entry = pte_to_swp_entry(pte); if (swap_duplicate(entry) < 0) @@ -1172,7 +1173,7 @@ again: if (pte_file(ptent)) { if (unlikely(!(vma->vm_flags & VM_NONLINEAR))) print_bad_pte(vma, addr, ptent, NULL); - } else { + } else if (!pte_vrange(ptent)) { swp_entry_t entry = pte_to_swp_entry(ptent); if (!non_swap_entry(entry)) @@ -3707,9 +3708,27 @@ int handle_pte_fault(struct mm_struct *mm, return do_linear_fault(mm, vma, address, pte, pmd, flags, entry); } +anon: return do_anonymous_page(mm, vma, address, pte, pmd, flags); } + + if (unlikely(pte_vrange(entry))) { + if (!is_purged_vrange(mm, address)) { + /* zap pte */ + ptl = pte_lockptr(mm, pmd); + spin_lock(ptl); + if (unlikely(!pte_same(*pte, entry))) + goto unlock; + flush_cache_page(vma, address, pte_pfn(*pte)); + ptep_clear_flush(vma, address, pte); + pte_unmap_unlock(pte, ptl); + goto anon; + } + + return VM_FAULT_SIGBUS; + } + if (pte_file(entry)) return do_nonlinear_fault(mm, vma, address, pte, pmd, flags, entry); diff --git a/mm/vrange.c b/mm/vrange.c index 1c8c447..fa965fb 100644 --- a/mm/vrange.c +++ b/mm/vrange.c @@ -504,7 +504,9 @@ int try_to_discard_one(struct vrange_root *vroot, struct page *page, present = pte_present(*pte); flush_cache_page(vma, address, page_to_pfn(page)); - pteval = ptep_clear_flush(vma, address, pte); + + ptep_clear_flush(vma, address, pte); + pteval = pte_mkvrange(*pte); update_hiwater_rss(mm); if (PageAnon(page)) @@ -521,6 +523,7 @@ int try_to_discard_one(struct vrange_root *vroot, struct page *page, BUG_ON(1); } + set_pte_at(mm, address, pte, pteval); pte_unmap_unlock(pte, ptl); mmu_notifier_invalidate_page(mm, address); ret = 1; @@ -696,3 +699,33 @@ int discard_vpage(struct page *page) return 0; } +bool is_purged_vrange(struct mm_struct *mm, unsigned long address) +{ + struct vrange_root *vroot; + struct interval_tree_node *node; + struct vrange *range; + unsigned long vstart_idx; + struct vm_area_struct *vma; + bool ret = false; + + vma = find_vma(mm, address); + if (vma->vm_file && (vma->vm_flags & VM_SHARED)) { + vroot = &vma->vm_file->f_mapping->vroot; + vstart_idx = vma->vm_pgoff + address - vma->vm_start; + } else { + vroot = &mm->vroot; + vstart_idx = address; + } + + vrange_lock(vroot); + node = interval_tree_iter_first(&vroot->v_rb, vstart_idx, + vstart_idx + PAGE_SIZE - 1); + if (node) { + range = container_of(node, struct vrange, node); + if (range->purged) + ret = true; + } + vrange_unlock(vroot); + return ret; +} + -- 1.8.1.2
WARNING: multiple messages have this Message-ID (diff)
From: John Stultz <john.stultz@linaro.org> To: LKML <linux-kernel@vger.kernel.org> Cc: Minchan Kim <minchan@kernel.org>, Andrew Morton <akpm@linux-foundation.org>, Android Kernel Team <kernel-team@android.com>, Robert Love <rlove@google.com>, Mel Gorman <mel@csn.ul.ie>, Hugh Dickins <hughd@google.com>, Dave Hansen <dave@linux.vnet.ibm.com>, Rik van Riel <riel@redhat.com>, Dmitry Adamushko <dmitry.adamushko@gmail.com>, Dave Chinner <david@fromorbit.com>, Neil Brown <neilb@suse.de>, Andrea Righi <andrea@betterlinux.com>, Andrea Arcangeli <aarcange@redhat.com>, "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>, Mike Hommey <mh@glandium.org>, Taras Glek <tglek@mozilla.com>, Dhaval Giani <dgiani@mozilla.com>, Jan Kara <jack@suse.cz>, KOSAKI Motohiro <kosaki.motohiro@gmail.com>, Michel Lespinasse <walken@google.com>, "linux-mm@kvack.org" <linux-mm@kvack.org>, John Stultz <john.stultz@linaro.org> Subject: [PATCH 8/8] vrange: Send SIGBUS when user try to access purged page Date: Tue, 11 Jun 2013 21:22:51 -0700 [thread overview] Message-ID: <1371010971-15647-9-git-send-email-john.stultz@linaro.org> (raw) In-Reply-To: <1371010971-15647-1-git-send-email-john.stultz@linaro.org> From: Minchan Kim <minchan@kernel.org> By vrange(2) semantic, user should see SIGBUG if he try to access purged page without vrange(...VRANGE_NOVOLATILE). This patch implements it. XXX: I reused PSE bit for quick prototype without enough considering so need time to see what's empty bit and I am surely missing many places to handle vrange pte bit. I should investigate all of pte handling places, especially pte_none case. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Android Kernel Team <kernel-team@android.com> Cc: Robert Love <rlove@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Neil Brown <neilb@suse.de> Cc: Andrea Righi <andrea@betterlinux.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Mike Hommey <mh@glandium.org> Cc: Taras Glek <tglek@mozilla.com> Cc: Dhaval Giani <dgiani@mozilla.com> Cc: Jan Kara <jack@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: linux-mm@kvack.org <linux-mm@kvack.org> Signed-off-by: Minchan Kim <minchan@kernel.org> [jstultz: Extended to work with file pages] Signed-off-by: John Stultz <john.stultz@linaro.org> --- arch/x86/include/asm/pgtable_types.h | 2 ++ include/asm-generic/pgtable.h | 11 +++++++++++ include/linux/vrange.h | 2 ++ mm/memory.c | 23 +++++++++++++++++++++-- mm/vrange.c | 35 ++++++++++++++++++++++++++++++++++- 5 files changed, 70 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index e642300..d7ea6a0 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -64,6 +64,8 @@ #define _PAGE_FILE (_AT(pteval_t, 1) << _PAGE_BIT_FILE) #define _PAGE_PROTNONE (_AT(pteval_t, 1) << _PAGE_BIT_PROTNONE) +#define _PAGE_VRANGE _PAGE_BIT_PSE + /* * _PAGE_NUMA indicates that this page will trigger a numa hinting * minor page fault to gather numa placement statistics (see diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index a59ff51..91e8f6f 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -479,6 +479,17 @@ static inline unsigned long my_zero_pfn(unsigned long addr) #ifdef CONFIG_MMU +static inline pte_t pte_mkvrange(pte_t pte) +{ + pte = pte_set_flags(pte, _PAGE_VRANGE); + return pte_clear_flags(pte, _PAGE_PRESENT); +} + +static inline int pte_vrange(pte_t pte) +{ + return ((pte_flags(pte) | _PAGE_PRESENT) == _PAGE_VRANGE); +} + #ifndef CONFIG_TRANSPARENT_HUGEPAGE static inline int pmd_trans_huge(pmd_t pmd) { diff --git a/include/linux/vrange.h b/include/linux/vrange.h index cbb609a..75754d1 100644 --- a/include/linux/vrange.h +++ b/include/linux/vrange.h @@ -41,6 +41,8 @@ int discard_vpage(struct page *page); bool vrange_address(struct mm_struct *mm, unsigned long start, unsigned long end); +extern bool is_purged_vrange(struct mm_struct *mm, unsigned long address); + #else static inline void vrange_init(void) {}; diff --git a/mm/memory.c b/mm/memory.c index 61a262b..cc5c70b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -59,6 +59,7 @@ #include <linux/gfp.h> #include <linux/migrate.h> #include <linux/string.h> +#include <linux/vrange.h> #include <asm/io.h> #include <asm/pgalloc.h> @@ -832,7 +833,7 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, /* pte contains position in swap or file, so copy. */ if (unlikely(!pte_present(pte))) { - if (!pte_file(pte)) { + if (!pte_file(pte) && !pte_vrange(pte)) { swp_entry_t entry = pte_to_swp_entry(pte); if (swap_duplicate(entry) < 0) @@ -1172,7 +1173,7 @@ again: if (pte_file(ptent)) { if (unlikely(!(vma->vm_flags & VM_NONLINEAR))) print_bad_pte(vma, addr, ptent, NULL); - } else { + } else if (!pte_vrange(ptent)) { swp_entry_t entry = pte_to_swp_entry(ptent); if (!non_swap_entry(entry)) @@ -3707,9 +3708,27 @@ int handle_pte_fault(struct mm_struct *mm, return do_linear_fault(mm, vma, address, pte, pmd, flags, entry); } +anon: return do_anonymous_page(mm, vma, address, pte, pmd, flags); } + + if (unlikely(pte_vrange(entry))) { + if (!is_purged_vrange(mm, address)) { + /* zap pte */ + ptl = pte_lockptr(mm, pmd); + spin_lock(ptl); + if (unlikely(!pte_same(*pte, entry))) + goto unlock; + flush_cache_page(vma, address, pte_pfn(*pte)); + ptep_clear_flush(vma, address, pte); + pte_unmap_unlock(pte, ptl); + goto anon; + } + + return VM_FAULT_SIGBUS; + } + if (pte_file(entry)) return do_nonlinear_fault(mm, vma, address, pte, pmd, flags, entry); diff --git a/mm/vrange.c b/mm/vrange.c index 1c8c447..fa965fb 100644 --- a/mm/vrange.c +++ b/mm/vrange.c @@ -504,7 +504,9 @@ int try_to_discard_one(struct vrange_root *vroot, struct page *page, present = pte_present(*pte); flush_cache_page(vma, address, page_to_pfn(page)); - pteval = ptep_clear_flush(vma, address, pte); + + ptep_clear_flush(vma, address, pte); + pteval = pte_mkvrange(*pte); update_hiwater_rss(mm); if (PageAnon(page)) @@ -521,6 +523,7 @@ int try_to_discard_one(struct vrange_root *vroot, struct page *page, BUG_ON(1); } + set_pte_at(mm, address, pte, pteval); pte_unmap_unlock(pte, ptl); mmu_notifier_invalidate_page(mm, address); ret = 1; @@ -696,3 +699,33 @@ int discard_vpage(struct page *page) return 0; } +bool is_purged_vrange(struct mm_struct *mm, unsigned long address) +{ + struct vrange_root *vroot; + struct interval_tree_node *node; + struct vrange *range; + unsigned long vstart_idx; + struct vm_area_struct *vma; + bool ret = false; + + vma = find_vma(mm, address); + if (vma->vm_file && (vma->vm_flags & VM_SHARED)) { + vroot = &vma->vm_file->f_mapping->vroot; + vstart_idx = vma->vm_pgoff + address - vma->vm_start; + } else { + vroot = &mm->vroot; + vstart_idx = address; + } + + vrange_lock(vroot); + node = interval_tree_iter_first(&vroot->v_rb, vstart_idx, + vstart_idx + PAGE_SIZE - 1); + if (node) { + range = container_of(node, struct vrange, node); + if (range->purged) + ret = true; + } + vrange_unlock(vroot); + return ret; +} + -- 1.8.1.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-06-12 4:24 UTC|newest] Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-06-12 4:22 [PATCH 0/8] Volatile Ranges (v8?) John Stultz 2013-06-12 4:22 ` John Stultz 2013-06-12 4:22 ` [PATCH 1/8] vrange: Add basic data structure and functions John Stultz 2013-06-12 4:22 ` John Stultz 2013-06-12 4:22 ` [PATCH 2/8] vrange: Add vrange support for file address_spaces John Stultz 2013-06-12 4:22 ` John Stultz 2013-06-12 4:22 ` [PATCH 3/8] vrange: Add vrange support to mm_structs John Stultz 2013-06-12 4:22 ` John Stultz 2013-06-12 4:22 ` [PATCH 4/8] vrange: Clear volatility on new mmaps John Stultz 2013-06-12 4:22 ` John Stultz 2013-06-13 6:28 ` Minchan Kim 2013-06-13 6:28 ` Minchan Kim 2013-06-13 23:43 ` John Stultz 2013-06-13 23:43 ` John Stultz 2013-06-14 0:21 ` Minchan Kim 2013-06-14 0:21 ` Minchan Kim 2013-06-12 4:22 ` [PATCH 5/8] vrange: Add new vrange(2) system call John Stultz 2013-06-12 4:22 ` John Stultz 2013-06-12 6:48 ` NeilBrown 2013-06-12 18:47 ` John Stultz 2013-06-12 18:47 ` John Stultz 2013-06-20 21:05 ` Dhaval Giani 2013-06-20 21:05 ` Dhaval Giani 2013-06-12 4:22 ` [PATCH 6/8] vrange: Add GFP_NO_VRANGE allocation flag John Stultz 2013-06-12 4:22 ` John Stultz 2013-06-12 4:22 ` [PATCH 7/8] vrange: Add method to purge volatile ranges John Stultz 2013-06-12 4:22 ` John Stultz 2013-06-17 7:13 ` Minchan Kim 2013-06-17 7:13 ` Minchan Kim 2013-06-17 7:24 ` Minchan Kim 2013-06-17 7:24 ` Minchan Kim 2013-06-19 4:34 ` Minchan Kim 2013-06-19 4:34 ` Minchan Kim 2013-10-01 14:00 ` Krzysztof Kozlowski 2013-10-02 1:32 ` Minchan Kim 2013-06-12 4:22 ` John Stultz [this message] 2013-06-12 4:22 ` [PATCH 8/8] vrange: Send SIGBUS when user try to access purged page John Stultz 2013-06-19 4:36 ` Minchan Kim 2013-06-19 4:36 ` Minchan Kim 2013-06-17 16:24 ` [PATCH 0/8] Volatile Ranges (v8?) Dhaval Giani 2013-06-18 4:11 ` Minchan Kim 2013-06-18 4:11 ` Minchan Kim 2013-06-18 16:59 ` Dhaval Giani 2013-06-18 16:59 ` Dhaval Giani 2013-06-19 4:41 ` Minchan Kim 2013-06-19 4:41 ` Minchan Kim 2013-06-19 18:36 ` Dhaval Giani 2013-06-19 18:36 ` Dhaval Giani
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1371010971-15647-9-git-send-email-john.stultz@linaro.org \ --to=john.stultz@linaro.org \ --cc=aarcange@redhat.com \ --cc=akpm@linux-foundation.org \ --cc=andrea@betterlinux.com \ --cc=aneesh.kumar@linux.vnet.ibm.com \ --cc=dave@linux.vnet.ibm.com \ --cc=david@fromorbit.com \ --cc=dgiani@mozilla.com \ --cc=dmitry.adamushko@gmail.com \ --cc=hughd@google.com \ --cc=jack@suse.cz \ --cc=kernel-team@android.com \ --cc=kosaki.motohiro@gmail.com \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=mel@csn.ul.ie \ --cc=mh@glandium.org \ --cc=minchan@kernel.org \ --cc=neilb@suse.de \ --cc=riel@redhat.com \ --cc=rlove@google.com \ --cc=tglek@mozilla.com \ --cc=walken@google.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.