diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 4 | ||||
| -rw-r--r-- | mm/vmalloc.c | 76 |
2 files changed, 50 insertions, 30 deletions
diff --git a/mm/memory.c b/mm/memory.c index 904f70b99498..d2155ced45f8 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5973,6 +5973,10 @@ int follow_phys(struct vm_area_struct *vma, goto out; pte = ptep_get(ptep); + /* Never return PFNs of anon folios in COW mappings. */ + if (vm_normal_folio(vma, address, pte)) + goto unlock; + if ((flags & FOLL_WRITE) && !pte_write(pte)) goto unlock; diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 22aa63f4ef63..68fa001648cc 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -989,6 +989,27 @@ unsigned long vmalloc_nr_pages(void) return atomic_long_read(&nr_vmalloc_pages); } +static struct vmap_area *__find_vmap_area(unsigned long addr, struct rb_root *root) +{ + struct rb_node *n = root->rb_node; + + addr = (unsigned long)kasan_reset_tag((void *)addr); + + while (n) { + struct vmap_area *va; + + va = rb_entry(n, struct vmap_area, rb_node); + if (addr < va->va_start) + n = n->rb_left; + else if (addr >= va->va_end) + n = n->rb_right; + else + return va; + } + + return NULL; +} + /* Look up the first VA which satisfies addr < va_end, NULL if none. */ static struct vmap_area * __find_vmap_area_exceed_addr(unsigned long addr, struct rb_root *root) @@ -1025,47 +1046,39 @@ __find_vmap_area_exceed_addr(unsigned long addr, struct rb_root *root) static struct vmap_node * find_vmap_area_exceed_addr_lock(unsigned long addr, struct vmap_area **va) { - struct vmap_node *vn, *va_node = NULL; - struct vmap_area *va_lowest; + unsigned long va_start_lowest; + struct vmap_node *vn; int i; - for (i = 0; i < nr_vmap_nodes; i++) { +repeat: + for (i = 0, va_start_lowest = 0; i < nr_vmap_nodes; i++) { vn = &vmap_nodes[i]; spin_lock(&vn->busy.lock); - va_lowest = __find_vmap_area_exceed_addr(addr, &vn->busy.root); - if (va_lowest) { - if (!va_node || va_lowest->va_start < (*va)->va_start) { - if (va_node) - spin_unlock(&va_node->busy.lock); - - *va = va_lowest; - va_node = vn; - continue; - } - } + *va = __find_vmap_area_exceed_addr(addr, &vn->busy.root); + + if (*va) + if (!va_start_lowest || (*va)->va_start < va_start_lowest) + va_start_lowest = (*va)->va_start; spin_unlock(&vn->busy.lock); } - return va_node; -} - -static struct vmap_area *__find_vmap_area(unsigned long addr, struct rb_root *root) -{ - struct rb_node *n = root->rb_node; + /* + * Check if found VA exists, it might have gone away. In this case we + * repeat the search because a VA has been removed concurrently and we + * need to proceed to the next one, which is a rare case. + */ + if (va_start_lowest) { + vn = addr_to_node(va_start_lowest); - addr = (unsigned long)kasan_reset_tag((void *)addr); + spin_lock(&vn->busy.lock); + *va = __find_vmap_area(va_start_lowest, &vn->busy.root); - while (n) { - struct vmap_area *va; + if (*va) + return vn; - va = rb_entry(n, struct vmap_area, rb_node); - if (addr < va->va_start) - n = n->rb_left; - else if (addr >= va->va_end) - n = n->rb_right; - else - return va; + spin_unlock(&vn->busy.lock); + goto repeat; } return NULL; @@ -2343,6 +2356,9 @@ struct vmap_area *find_vmap_area(unsigned long addr) struct vmap_area *va; int i, j; + if (unlikely(!vmap_initialized)) + return NULL; + /* * An addr_to_node_id(addr) converts an address to a node index * where a VA is located. If VA spans several zones and passed |