diff options
| -rw-r--r-- | fs/proc/task_mmu.c | 19 | ||||
| -rw-r--r-- | include/asm-generic/pgtable.h | 14 | ||||
| -rw-r--r-- | include/linux/mm.h | 5 | ||||
| -rw-r--r-- | mm/memory.c | 3 | ||||
| -rw-r--r-- | mm/mmap.c | 45 | ||||
| -rw-r--r-- | mm/mprotect.c | 20 |
6 files changed, 68 insertions, 38 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index b7a7dc9..4e0388c 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -827,8 +827,21 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, .private = &cp, }; down_read(&mm->mmap_sem); - if (type == CLEAR_REFS_SOFT_DIRTY) + if (type == CLEAR_REFS_SOFT_DIRTY) { + for (vma = mm->mmap; vma; vma = vma->vm_next) { + if (!(vma->vm_flags & VM_SOFTDIRTY)) + continue; + up_read(&mm->mmap_sem); + down_write(&mm->mmap_sem); + for (vma = mm->mmap; vma; vma = vma->vm_next) { + vma->vm_flags &= ~VM_SOFTDIRTY; + vma_set_page_prot(vma); + } + downgrade_write(&mm->mmap_sem); + break; + } mmu_notifier_invalidate_range_start(mm, 0, -1); + } for (vma = mm->mmap; vma; vma = vma->vm_next) { cp.vma = vma; if (is_vm_hugetlb_page(vma)) @@ -848,10 +861,6 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, continue; if (type == CLEAR_REFS_MAPPED && !vma->vm_file) continue; - if (type == CLEAR_REFS_SOFT_DIRTY) { - if (vma->vm_flags & VM_SOFTDIRTY) - vma->vm_flags &= ~VM_SOFTDIRTY; - } walk_page_range(vma->vm_start, vma->vm_end, &clear_refs_walk); } diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 081ff88..752e30d 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -253,6 +253,20 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b) #define pgprot_device pgprot_noncached #endif +#ifndef pgprot_modify +#define pgprot_modify pgprot_modify +static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) +{ + if (pgprot_val(oldprot) == pgprot_val(pgprot_noncached(oldprot))) + newprot = pgprot_noncached(newprot); + if (pgprot_val(oldprot) == pgprot_val(pgprot_writecombine(oldprot))) + newprot = pgprot_writecombine(newprot); + if (pgprot_val(oldprot) == pgprot_val(pgprot_device(oldprot))) + newprot = pgprot_device(newprot); + return newprot; +} +#endif + /* * When walking page tables, get the address of the next boundary, * or the end address of the range if that comes earlier. Although no diff --git a/include/linux/mm.h b/include/linux/mm.h index 4cd45cb9..02d11ee 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1974,11 +1974,16 @@ static inline struct vm_area_struct *find_exact_vma(struct mm_struct *mm, #ifdef CONFIG_MMU pgprot_t vm_get_page_prot(unsigned long vm_flags); +void vma_set_page_prot(struct vm_area_struct *vma); #else static inline pgprot_t vm_get_page_prot(unsigned long vm_flags) { return __pgprot(0); } +static inline void vma_set_page_prot(struct vm_area_struct *vma) +{ + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); +} #endif #ifdef CONFIG_NUMA_BALANCING diff --git a/mm/memory.c b/mm/memory.c index e229970..1cc6bfb 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2053,7 +2053,8 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, old_page = vm_normal_page(vma, address, orig_pte); if (!old_page) { /* - * VM_MIXEDMAP !pfn_valid() case + * VM_MIXEDMAP !pfn_valid() case, or VM_SOFTDIRTY clear on a + * VM_PFNMAP VMA. * * We should not cow pages in a shared writeable mapping. * Just mark the pages writable as we can't do any dirty @@ -89,6 +89,25 @@ pgprot_t vm_get_page_prot(unsigned long vm_flags) } EXPORT_SYMBOL(vm_get_page_prot); +static pgprot_t vm_pgprot_modify(pgprot_t oldprot, unsigned long vm_flags) +{ + return pgprot_modify(oldprot, vm_get_page_prot(vm_flags)); +} + +/* Update vma->vm_page_prot to reflect vma->vm_flags. */ +void vma_set_page_prot(struct vm_area_struct *vma) +{ + unsigned long vm_flags = vma->vm_flags; + + vma->vm_page_prot = vm_pgprot_modify(vma->vm_page_prot, vm_flags); + if (vma_wants_writenotify(vma)) { + vm_flags &= ~VM_SHARED; + vma->vm_page_prot = vm_pgprot_modify(vma->vm_page_prot, + vm_flags); + } +} + + int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS; /* heuristic overcommit */ int sysctl_overcommit_ratio __read_mostly = 50; /* default is 50% */ unsigned long sysctl_overcommit_kbytes __read_mostly; @@ -1475,11 +1494,16 @@ int vma_wants_writenotify(struct vm_area_struct *vma) if (vma->vm_ops && vma->vm_ops->page_mkwrite) return 1; - /* The open routine did something to the protections already? */ + /* The open routine did something to the protections that pgprot_modify + * won't preserve? */ if (pgprot_val(vma->vm_page_prot) != - pgprot_val(vm_get_page_prot(vm_flags))) + pgprot_val(vm_pgprot_modify(vma->vm_page_prot, vm_flags))) return 0; + /* Do we need to track softdirty? */ + if (IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) && !(vm_flags & VM_SOFTDIRTY)) + return 1; + /* Specialty mapping? */ if (vm_flags & VM_PFNMAP) return 0; @@ -1615,21 +1639,6 @@ munmap_back: goto free_vma; } - if (vma_wants_writenotify(vma)) { - pgprot_t pprot = vma->vm_page_prot; - - /* Can vma->vm_page_prot have changed?? - * - * Answer: Yes, drivers may have changed it in their - * f_op->mmap method. - * - * Ensures that vmas marked as uncached stay that way. - */ - vma->vm_page_prot = vm_get_page_prot(vm_flags & ~VM_SHARED); - if (pgprot_val(pprot) == pgprot_val(pgprot_noncached(pprot))) - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - } - vma_link(mm, vma, prev, rb_link, rb_parent); /* Once vma denies write, undo our temporary denial count */ if (file) { @@ -1663,6 +1672,8 @@ out: */ vma->vm_flags |= VM_SOFTDIRTY; + vma_set_page_prot(vma); + return addr; unmap_and_free_vma: diff --git a/mm/mprotect.c b/mm/mprotect.c index c43d557..ace9345 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -29,13 +29,6 @@ #include <asm/cacheflush.h> #include <asm/tlbflush.h> -#ifndef pgprot_modify -static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) -{ - return newprot; -} -#endif - /* * For a prot_numa update we only hold mmap_sem for read so there is a * potential race with faulting where a pmd was temporarily none. This @@ -93,7 +86,9 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, * Avoid taking write faults for pages we * know to be dirty. */ - if (dirty_accountable && pte_dirty(ptent)) + if (dirty_accountable && pte_dirty(ptent) && + (pte_soft_dirty(ptent) || + !(vma->vm_flags & VM_SOFTDIRTY))) ptent = pte_mkwrite(ptent); ptep_modify_prot_commit(mm, addr, pte, ptent); updated = true; @@ -320,13 +315,8 @@ success: * held in write mode. */ vma->vm_flags = newflags; - vma->vm_page_prot = pgprot_modify(vma->vm_page_prot, - vm_get_page_prot(newflags)); - - if (vma_wants_writenotify(vma)) { - vma->vm_page_prot = vm_get_page_prot(newflags & ~VM_SHARED); - dirty_accountable = 1; - } + dirty_accountable = vma_wants_writenotify(vma); + vma_set_page_prot(vma); change_protection(vma, start, end, vma->vm_page_prot, dirty_accountable, 0); |
