diff options
| -rw-r--r-- | include/linux/mm_inline.h | 2 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 11 | ||||
| -rw-r--r-- | mm/memory.c | 82 | ||||
| -rw-r--r-- | mm/mmap.c | 5 | ||||
| -rw-r--r-- | mm/mremap.c | 4 | ||||
| -rw-r--r-- | mm/vma_init.c | 50 |
6 files changed, 129 insertions, 25 deletions
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h index f9157a0c42a5..89b518ff097e 100644 --- a/include/linux/mm_inline.h +++ b/include/linux/mm_inline.h @@ -447,6 +447,8 @@ static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1, #endif /* CONFIG_ANON_VMA_NAME */ +void pfnmap_track_ctx_release(struct kref *ref); + static inline void init_tlb_flush_pending(struct mm_struct *mm) { atomic_set(&mm->tlb_flush_pending, 0); diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 15808cad2bc1..3e934dc6057c 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -763,6 +763,14 @@ struct vma_numab_state { int prev_scan_seq; }; +#ifdef __HAVE_PFNMAP_TRACKING +struct pfnmap_track_ctx { + struct kref kref; + unsigned long pfn; + unsigned long size; /* in bytes */ +}; +#endif + /* * Describes a VMA that is about to be mmap()'ed. Drivers may choose to * manipulate mutable fields which will cause those fields to be updated in the @@ -900,6 +908,9 @@ struct vm_area_struct { struct anon_vma_name *anon_name; #endif struct vm_userfaultfd_ctx vm_userfaultfd_ctx; +#ifdef __HAVE_PFNMAP_TRACKING + struct pfnmap_track_ctx *pfnmap_track_ctx; +#endif } __randomize_layout; #ifdef CONFIG_NUMA diff --git a/mm/memory.c b/mm/memory.c index 064fc55d8eab..4cf4adb0de26 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1371,7 +1371,7 @@ copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma) struct mm_struct *dst_mm = dst_vma->vm_mm; struct mm_struct *src_mm = src_vma->vm_mm; struct mmu_notifier_range range; - unsigned long next, pfn = 0; + unsigned long next; bool is_cow; int ret; @@ -1381,12 +1381,6 @@ copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma) if (is_vm_hugetlb_page(src_vma)) return copy_hugetlb_page_range(dst_mm, src_mm, dst_vma, src_vma); - if (unlikely(src_vma->vm_flags & VM_PFNMAP)) { - ret = track_pfn_copy(dst_vma, src_vma, &pfn); - if (ret) - return ret; - } - /* * We need to invalidate the secondary MMU mappings only when * there could be a permission downgrade on the ptes of the @@ -1428,8 +1422,6 @@ copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma) raw_write_seqcount_end(&src_mm->write_protect_seq); mmu_notifier_invalidate_range_end(&range); } - if (ret && unlikely(src_vma->vm_flags & VM_PFNMAP)) - untrack_pfn_copy(dst_vma, pfn); return ret; } @@ -1924,9 +1916,6 @@ static void unmap_single_vma(struct mmu_gather *tlb, if (vma->vm_file) uprobe_munmap(vma, start, end); - if (unlikely(vma->vm_flags & VM_PFNMAP)) - untrack_pfn(vma, 0, 0, mm_wr_locked); - if (start != end) { if (unlikely(is_vm_hugetlb_page(vma))) { /* @@ -2872,6 +2861,36 @@ int remap_pfn_range_notrack(struct vm_area_struct *vma, unsigned long addr, return error; } +#ifdef __HAVE_PFNMAP_TRACKING +static inline struct pfnmap_track_ctx *pfnmap_track_ctx_alloc(unsigned long pfn, + unsigned long size, pgprot_t *prot) +{ + struct pfnmap_track_ctx *ctx; + + if (pfnmap_track(pfn, size, prot)) + return ERR_PTR(-EINVAL); + + ctx = kmalloc(sizeof(*ctx), GFP_KERNEL); + if (unlikely(!ctx)) { + pfnmap_untrack(pfn, size); + return ERR_PTR(-ENOMEM); + } + + ctx->pfn = pfn; + ctx->size = size; + kref_init(&ctx->kref); + return ctx; +} + +void pfnmap_track_ctx_release(struct kref *ref) +{ + struct pfnmap_track_ctx *ctx = container_of(ref, struct pfnmap_track_ctx, kref); + + pfnmap_untrack(ctx->pfn, ctx->size); + kfree(ctx); +} +#endif /* __HAVE_PFNMAP_TRACKING */ + /** * remap_pfn_range - remap kernel memory to userspace * @vma: user vma to map to @@ -2884,20 +2903,51 @@ int remap_pfn_range_notrack(struct vm_area_struct *vma, unsigned long addr, * * Return: %0 on success, negative error code otherwise. */ +#ifdef __HAVE_PFNMAP_TRACKING int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn, unsigned long size, pgprot_t prot) { + struct pfnmap_track_ctx *ctx = NULL; int err; - err = track_pfn_remap(vma, &prot, pfn, addr, PAGE_ALIGN(size)); - if (err) + size = PAGE_ALIGN(size); + + /* + * If we cover the full VMA, we'll perform actual tracking, and + * remember to untrack when the last reference to our tracking + * context from a VMA goes away. We'll keep tracking the whole pfn + * range even during VMA splits and partial unmapping. + * + * If we only cover parts of the VMA, we'll only setup the cachemode + * in the pgprot for the pfn range. + */ + if (addr == vma->vm_start && addr + size == vma->vm_end) { + if (vma->pfnmap_track_ctx) + return -EINVAL; + ctx = pfnmap_track_ctx_alloc(pfn, size, &prot); + if (IS_ERR(ctx)) + return PTR_ERR(ctx); + } else if (pfnmap_setup_cachemode(pfn, size, &prot)) { return -EINVAL; + } err = remap_pfn_range_notrack(vma, addr, pfn, size, prot); - if (err) - untrack_pfn(vma, pfn, PAGE_ALIGN(size), true); + if (ctx) { + if (err) + kref_put(&ctx->kref, pfnmap_track_ctx_release); + else + vma->pfnmap_track_ctx = ctx; + } return err; } + +#else +int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, + unsigned long pfn, unsigned long size, pgprot_t prot) +{ + return remap_pfn_range_notrack(vma, addr, pfn, size, prot); +} +#endif EXPORT_SYMBOL(remap_pfn_range); /** diff --git a/mm/mmap.c b/mm/mmap.c index 50f902c08341..09c563c95112 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1784,11 +1784,6 @@ __latent_entropy int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) tmp = vm_area_dup(mpnt); if (!tmp) goto fail_nomem; - - /* track_pfn_copy() will later take care of copying internal state. */ - if (unlikely(tmp->vm_flags & VM_PFNMAP)) - untrack_pfn_clear(tmp); - retval = vma_dup_policy(mpnt, tmp); if (retval) goto fail_nomem_policy; diff --git a/mm/mremap.c b/mm/mremap.c index 7db9da609c84..6e78e02f74bd 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -1191,10 +1191,6 @@ static int copy_vma_and_data(struct vma_remap_struct *vrm, if (is_vm_hugetlb_page(vma)) clear_vma_resv_huge_pages(vma); - /* Tell pfnmap has moved from this vma */ - if (unlikely(vma->vm_flags & VM_PFNMAP)) - untrack_pfn_clear(vma); - *new_vma_ptr = new_vma; return err; } diff --git a/mm/vma_init.c b/mm/vma_init.c index 967ca8517986..8e53c7943561 100644 --- a/mm/vma_init.c +++ b/mm/vma_init.c @@ -71,7 +71,51 @@ static void vm_area_init_from(const struct vm_area_struct *src, #ifdef CONFIG_NUMA dest->vm_policy = src->vm_policy; #endif +#ifdef __HAVE_PFNMAP_TRACKING + dest->pfnmap_track_ctx = NULL; +#endif +} + +#ifdef __HAVE_PFNMAP_TRACKING +static inline int vma_pfnmap_track_ctx_dup(struct vm_area_struct *orig, + struct vm_area_struct *new) +{ + struct pfnmap_track_ctx *ctx = orig->pfnmap_track_ctx; + + if (likely(!ctx)) + return 0; + + /* + * We don't expect to ever hit this. If ever required, we would have + * to duplicate the tracking. + */ + if (unlikely(kref_read(&ctx->kref) >= REFCOUNT_MAX)) + return -ENOMEM; + kref_get(&ctx->kref); + new->pfnmap_track_ctx = ctx; + return 0; +} + +static inline void vma_pfnmap_track_ctx_release(struct vm_area_struct *vma) +{ + struct pfnmap_track_ctx *ctx = vma->pfnmap_track_ctx; + + if (likely(!ctx)) + return; + + kref_put(&ctx->kref, pfnmap_track_ctx_release); + vma->pfnmap_track_ctx = NULL; +} +#else +static inline int vma_pfnmap_track_ctx_dup(struct vm_area_struct *orig, + struct vm_area_struct *new) +{ + return 0; } +static inline void vma_pfnmap_track_ctx_release(struct vm_area_struct *vma) +{ +} +#endif struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig) { @@ -83,6 +127,11 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig) ASSERT_EXCLUSIVE_WRITER(orig->vm_flags); ASSERT_EXCLUSIVE_WRITER(orig->vm_file); vm_area_init_from(orig, new); + + if (vma_pfnmap_track_ctx_dup(orig, new)) { + kmem_cache_free(vm_area_cachep, new); + return NULL; + } vma_lock_init(new, true); INIT_LIST_HEAD(&new->anon_vma_chain); vma_numab_state_init(new); @@ -97,5 +146,6 @@ void vm_area_free(struct vm_area_struct *vma) vma_assert_detached(vma); vma_numab_state_free(vma); free_anon_vma_name(vma); + vma_pfnmap_track_ctx_release(vma); kmem_cache_free(vm_area_cachep, vma); } |