diff options
Diffstat (limited to 'mm/nommu.c')
-rw-r--r-- | mm/nommu.c | 260 |
1 files changed, 141 insertions, 119 deletions
diff --git a/mm/nommu.c b/mm/nommu.c index e819cbc21b39..214c70e1d059 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -19,7 +19,6 @@ #include <linux/export.h> #include <linux/mm.h> #include <linux/sched/mm.h> -#include <linux/vmacache.h> #include <linux/mman.h> #include <linux/swap.h> #include <linux/file.h> @@ -545,26 +544,27 @@ static void put_nommu_region(struct vm_region *region) __put_nommu_region(region); } -/* - * add a VMA into a process's mm_struct in the appropriate place in the list - * and tree and add to the address space's page tree also if not an anonymous - * page - * - should be called with mm->mmap_lock held writelocked - */ -static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) +void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas) { - struct vm_area_struct *pvma, *prev; - struct address_space *mapping; - struct rb_node **p, *parent, *rb_prev; + mas_set_range(mas, vma->vm_start, vma->vm_end - 1); + mas_store_prealloc(mas, vma); +} - BUG_ON(!vma->vm_region); +void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas) +{ + mas->index = vma->vm_start; + mas->last = vma->vm_end - 1; + mas_store_prealloc(mas, NULL); +} +static void setup_vma_to_mm(struct vm_area_struct *vma, struct mm_struct *mm) +{ mm->map_count++; vma->vm_mm = mm; /* add the VMA to the mapping */ if (vma->vm_file) { - mapping = vma->vm_file->f_mapping; + struct address_space *mapping = vma->vm_file->f_mapping; i_mmap_lock_write(mapping); flush_dcache_mmap_lock(mapping); @@ -572,67 +572,51 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) flush_dcache_mmap_unlock(mapping); i_mmap_unlock_write(mapping); } +} - /* add the VMA to the tree */ - parent = rb_prev = NULL; - p = &mm->mm_rb.rb_node; - while (*p) { - parent = *p; - pvma = rb_entry(parent, struct vm_area_struct, vm_rb); - - /* sort by: start addr, end addr, VMA struct addr in that order - * (the latter is necessary as we may get identical VMAs) */ - if (vma->vm_start < pvma->vm_start) - p = &(*p)->rb_left; - else if (vma->vm_start > pvma->vm_start) { - rb_prev = parent; - p = &(*p)->rb_right; - } else if (vma->vm_end < pvma->vm_end) - p = &(*p)->rb_left; - else if (vma->vm_end > pvma->vm_end) { - rb_prev = parent; - p = &(*p)->rb_right; - } else if (vma < pvma) - p = &(*p)->rb_left; - else if (vma > pvma) { - rb_prev = parent; - p = &(*p)->rb_right; - } else - BUG(); - } - - rb_link_node(&vma->vm_rb, parent, p); - rb_insert_color(&vma->vm_rb, &mm->mm_rb); +/* + * mas_add_vma_to_mm() - Maple state variant of add_mas_to_mm(). + * @mas: The maple state with preallocations. + * @mm: The mm_struct + * @vma: The vma to add + * + */ +static void mas_add_vma_to_mm(struct ma_state *mas, struct mm_struct *mm, + struct vm_area_struct *vma) +{ + BUG_ON(!vma->vm_region); - /* add VMA to the VMA list also */ - prev = NULL; - if (rb_prev) - prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb); + setup_vma_to_mm(vma, mm); - __vma_link_list(mm, vma, prev); + /* add the VMA to the tree */ + vma_mas_store(vma, mas); } /* - * delete a VMA from its owning mm_struct and address space + * add a VMA into a process's mm_struct in the appropriate place in the list + * and tree and add to the address space's page tree also if not an anonymous + * page + * - should be called with mm->mmap_lock held writelocked */ -static void delete_vma_from_mm(struct vm_area_struct *vma) -{ - int i; - struct address_space *mapping; - struct mm_struct *mm = vma->vm_mm; - struct task_struct *curr = current; - - mm->map_count--; - for (i = 0; i < VMACACHE_SIZE; i++) { - /* if the vma is cached, invalidate the entire cache */ - if (curr->vmacache.vmas[i] == vma) { - vmacache_invalidate(mm); - break; - } +static int add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) +{ + MA_STATE(mas, &mm->mm_mt, vma->vm_start, vma->vm_end); + + if (mas_preallocate(&mas, vma, GFP_KERNEL)) { + pr_warn("Allocation of vma tree for process %d failed\n", + current->pid); + return -ENOMEM; } + mas_add_vma_to_mm(&mas, mm, vma); + return 0; +} +static void cleanup_vma_from_mm(struct vm_area_struct *vma) +{ + vma->vm_mm->map_count--; /* remove the VMA from the mapping */ if (vma->vm_file) { + struct address_space *mapping; mapping = vma->vm_file->f_mapping; i_mmap_lock_write(mapping); @@ -641,11 +625,24 @@ static void delete_vma_from_mm(struct vm_area_struct *vma) flush_dcache_mmap_unlock(mapping); i_mmap_unlock_write(mapping); } +} +/* + * delete a VMA from its owning mm_struct and address space + */ +static int delete_vma_from_mm(struct vm_area_struct *vma) +{ + MA_STATE(mas, &vma->vm_mm->mm_mt, 0, 0); - /* remove from the MM's tree and list */ - rb_erase(&vma->vm_rb, &mm->mm_rb); + if (mas_preallocate(&mas, vma, GFP_KERNEL)) { + pr_warn("Allocation of vma tree for process %d failed\n", + current->pid); + return -ENOMEM; + } + cleanup_vma_from_mm(vma); - __vma_unlink_list(mm, vma); + /* remove from the MM's tree and list */ + vma_mas_remove(vma, &mas); + return 0; } /* @@ -661,31 +658,26 @@ static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) vm_area_free(vma); } +struct vm_area_struct *find_vma_intersection(struct mm_struct *mm, + unsigned long start_addr, + unsigned long end_addr) +{ + unsigned long index = start_addr; + + mmap_assert_locked(mm); + return mt_find(&mm->mm_mt, &index, end_addr - 1); +} +EXPORT_SYMBOL(find_vma_intersection); + /* * look up the first VMA in which addr resides, NULL if none * - should be called with mm->mmap_lock at least held readlocked */ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) { - struct vm_area_struct *vma; + MA_STATE(mas, &mm->mm_mt, addr, addr); - /* check the cache first */ - vma = vmacache_find(mm, addr); - if (likely(vma)) - return vma; - - /* trawl the list (there may be multiple mappings in which addr - * resides) */ - for (vma = mm->mmap; vma; vma = vma->vm_next) { - if (vma->vm_start > addr) - return NULL; - if (vma->vm_end > addr) { - vmacache_update(addr, vma); - return vma; - } - } - - return NULL; + return mas_walk(&mas); } EXPORT_SYMBOL(find_vma); @@ -717,26 +709,17 @@ static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, { struct vm_area_struct *vma; unsigned long end = addr + len; + MA_STATE(mas, &mm->mm_mt, addr, addr); - /* check the cache first */ - vma = vmacache_find_exact(mm, addr, end); - if (vma) - return vma; - - /* trawl the list (there may be multiple mappings in which addr - * resides) */ - for (vma = mm->mmap; vma; vma = vma->vm_next) { - if (vma->vm_start < addr) - continue; - if (vma->vm_start > addr) - return NULL; - if (vma->vm_end == end) { - vmacache_update(addr, vma); - return vma; - } - } + vma = mas_walk(&mas); + if (!vma) + return NULL; + if (vma->vm_start != addr) + return NULL; + if (vma->vm_end != end) + return NULL; - return NULL; + return vma; } /* @@ -1069,6 +1052,7 @@ unsigned long do_mmap(struct file *file, vm_flags_t vm_flags; unsigned long capabilities, result; int ret; + MA_STATE(mas, ¤t->mm->mm_mt, 0, 0); *populate = 0; @@ -1087,6 +1071,7 @@ unsigned long do_mmap(struct file *file, * now know into VMA flags */ vm_flags = determine_vm_flags(file, prot, flags, capabilities); + /* we're going to need to record the mapping */ region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); if (!region) @@ -1096,6 +1081,9 @@ unsigned long do_mmap(struct file *file, if (!vma) goto error_getting_vma; + if (mas_preallocate(&mas, vma, GFP_KERNEL)) + goto error_maple_preallocate; + region->vm_usage = 1; region->vm_flags = vm_flags; region->vm_pgoff = pgoff; @@ -1236,7 +1224,7 @@ unsigned long do_mmap(struct file *file, current->mm->total_vm += len >> PAGE_SHIFT; share: - add_vma_to_mm(current->mm, vma); + mas_add_vma_to_mm(&mas, current->mm, vma); /* we flush the region from the icache only when the first executable * mapping of it is made */ @@ -1262,6 +1250,7 @@ error: sharing_violation: up_write(&nommu_region_sem); + mas_destroy(&mas); pr_warn("Attempt to share mismatched mappings\n"); ret = -EINVAL; goto error; @@ -1278,6 +1267,14 @@ error_getting_region: len, current->pid); show_free_areas(0, NULL); return -ENOMEM; + +error_maple_preallocate: + kmem_cache_free(vm_region_jar, region); + vm_area_free(vma); + pr_warn("Allocation of vma tree for process %d failed\n", current->pid); + show_free_areas(0, NULL); + return -ENOMEM; + } unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, @@ -1343,6 +1340,7 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *new; struct vm_region *region; unsigned long npages; + MA_STATE(mas, &mm->mm_mt, vma->vm_start, vma->vm_end); /* we're only permitted to split anonymous regions (these should have * only a single usage on the region) */ @@ -1357,9 +1355,13 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, return -ENOMEM; new = vm_area_dup(vma); - if (!new) { - kmem_cache_free(vm_region_jar, region); - return -ENOMEM; + if (!new) + goto err_vma_dup; + + if (mas_preallocate(&mas, vma, GFP_KERNEL)) { + pr_warn("Allocation of vma tree for process %d failed\n", + current->pid); + goto err_mas_preallocate; } /* most fields are the same, copy all, and then fixup */ @@ -1378,7 +1380,6 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, if (new->vm_ops && new->vm_ops->open) new->vm_ops->open(new); - delete_vma_from_mm(vma); down_write(&nommu_region_sem); delete_nommu_region(vma->vm_region); if (new_below) { @@ -1391,9 +1392,19 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, add_nommu_region(vma->vm_region); add_nommu_region(new->vm_region); up_write(&nommu_region_sem); - add_vma_to_mm(mm, vma); - add_vma_to_mm(mm, new); + + setup_vma_to_mm(vma, mm); + setup_vma_to_mm(new, mm); + mas_set_range(&mas, vma->vm_start, vma->vm_end - 1); + mas_store(&mas, vma); + vma_mas_store(new, &mas); return 0; + +err_mas_preallocate: + vm_area_free(new); +err_vma_dup: + kmem_cache_free(vm_region_jar, region); + return -ENOMEM; } /* @@ -1408,12 +1419,14 @@ static int shrink_vma(struct mm_struct *mm, /* adjust the VMA's pointers, which may reposition it in the MM's tree * and list */ - delete_vma_from_mm(vma); + if (delete_vma_from_mm(vma)) + return -ENOMEM; if (from > vma->vm_start) vma->vm_end = from; else vma->vm_start = to; - add_vma_to_mm(mm, vma); + if (add_vma_to_mm(mm, vma)) + return -ENOMEM; /* cut the backing region down to size */ region = vma->vm_region; @@ -1441,9 +1454,10 @@ static int shrink_vma(struct mm_struct *mm, */ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf) { + MA_STATE(mas, &mm->mm_mt, start, start); struct vm_area_struct *vma; unsigned long end; - int ret; + int ret = 0; len = PAGE_ALIGN(len); if (len == 0) @@ -1452,7 +1466,7 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list end = start + len; /* find the first potentially overlapping VMA */ - vma = find_vma(mm, start); + vma = mas_find(&mas, end - 1); if (!vma) { static int limit; if (limit < 5) { @@ -1471,7 +1485,7 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list return -EINVAL; if (end == vma->vm_end) goto erase_whole_vma; - vma = vma->vm_next; + vma = mas_next(&mas, end - 1); } while (vma); return -EINVAL; } else { @@ -1493,9 +1507,10 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list } erase_whole_vma: - delete_vma_from_mm(vma); + if (delete_vma_from_mm(vma)) + ret = -ENOMEM; delete_vma(mm, vma); - return 0; + return ret; } int vm_munmap(unsigned long addr, size_t len) @@ -1520,6 +1535,7 @@ SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) */ void exit_mmap(struct mm_struct *mm) { + VMA_ITERATOR(vmi, mm, 0); struct vm_area_struct *vma; if (!mm) @@ -1527,12 +1543,18 @@ void exit_mmap(struct mm_struct *mm) mm->total_vm = 0; - while ((vma = mm->mmap)) { - mm->mmap = vma->vm_next; - delete_vma_from_mm(vma); + /* + * Lock the mm to avoid assert complaining even though this is the only + * user of the mm + */ + mmap_write_lock(mm); + for_each_vma(vmi, vma) { + cleanup_vma_from_mm(vma); delete_vma(mm, vma); cond_resched(); } + __mt_destroy(&mm->mm_mt); + mmap_write_unlock(mm); } int vm_brk(unsigned long addr, unsigned long len) |