diff options
Diffstat (limited to 'mm/nommu.c')
| -rw-r--r-- | mm/nommu.c | 104 |
1 files changed, 72 insertions, 32 deletions
diff --git a/mm/nommu.c b/mm/nommu.c index 829fc904de11..4f87b2f43a2b 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -310,6 +310,48 @@ static void show_process_blocks(void) } #endif /* DEBUG */ +/* + * add a VMA into a process's mm_struct in the appropriate place in the list + * - should be called with mm->mmap_sem held writelocked + */ +static void add_vma_to_mm(struct mm_struct *mm, struct vm_list_struct *vml) +{ + struct vm_list_struct **ppv; + + for (ppv = ¤t->mm->context.vmlist; *ppv; ppv = &(*ppv)->next) + if ((*ppv)->vma->vm_start > vml->vma->vm_start) + break; + + vml->next = *ppv; + *ppv = vml; +} + +/* + * look up the first VMA in which addr resides, NULL if none + * - should be called with mm->mmap_sem at least held readlocked + */ +struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) +{ + struct vm_list_struct *loop, *vml; + + /* search the vm_start ordered list */ + vml = NULL; + for (loop = mm->context.vmlist; loop; loop = loop->next) { + if (loop->vma->vm_start > addr) + break; + vml = loop; + } + + if (vml && vml->vma->vm_end > addr) + return vml->vma; + + return NULL; +} +EXPORT_SYMBOL(find_vma); + +/* + * find a VMA in the global tree + */ static inline struct vm_area_struct *find_nommu_vma(unsigned long start) { struct vm_area_struct *vma; @@ -329,6 +371,9 @@ static inline struct vm_area_struct *find_nommu_vma(unsigned long start) return NULL; } +/* + * add a VMA in the global tree + */ static void add_nommu_vma(struct vm_area_struct *vma) { struct vm_area_struct *pvma; @@ -375,6 +420,9 @@ static void add_nommu_vma(struct vm_area_struct *vma) rb_insert_color(&vma->vm_rb, &nommu_vma_tree); } +/* + * delete a VMA from the global list + */ static void delete_nommu_vma(struct vm_area_struct *vma) { struct address_space *mapping; @@ -852,8 +900,7 @@ unsigned long do_mmap_pgoff(struct file *file, realalloc += kobjsize(vml); askedalloc += sizeof(*vml); - vml->next = current->mm->context.vmlist; - current->mm->context.vmlist = vml; + add_vma_to_mm(current->mm, vml); up_write(&nommu_vma_sem); @@ -932,6 +979,11 @@ static void put_vma(struct vm_area_struct *vma) } } +/* + * release a mapping + * - under NOMMU conditions the parameters must match exactly to the mapping to + * be removed + */ int do_munmap(struct mm_struct *mm, unsigned long addr, size_t len) { struct vm_list_struct *vml, **parent; @@ -941,10 +993,13 @@ int do_munmap(struct mm_struct *mm, unsigned long addr, size_t len) printk("do_munmap:\n"); #endif - for (parent = &mm->context.vmlist; *parent; parent = &(*parent)->next) + for (parent = &mm->context.vmlist; *parent; parent = &(*parent)->next) { + if ((*parent)->vma->vm_start > addr) + break; if ((*parent)->vma->vm_start == addr && ((len == 0) || ((*parent)->vma->vm_end == end))) goto found; + } printk("munmap of non-mmaped memory by process %d (%s): %p\n", current->pid, current->comm, (void *) addr); @@ -970,7 +1025,20 @@ int do_munmap(struct mm_struct *mm, unsigned long addr, size_t len) return 0; } -/* Release all mmaps. */ +asmlinkage long sys_munmap(unsigned long addr, size_t len) +{ + int ret; + struct mm_struct *mm = current->mm; + + down_write(&mm->mmap_sem); + ret = do_munmap(mm, addr, len); + up_write(&mm->mmap_sem); + return ret; +} + +/* + * Release all mappings + */ void exit_mmap(struct mm_struct * mm) { struct vm_list_struct *tmp; @@ -997,17 +1065,6 @@ void exit_mmap(struct mm_struct * mm) } } -asmlinkage long sys_munmap(unsigned long addr, size_t len) -{ - int ret; - struct mm_struct *mm = current->mm; - - down_write(&mm->mmap_sem); - ret = do_munmap(mm, addr, len); - up_write(&mm->mmap_sem); - return ret; -} - unsigned long do_brk(unsigned long addr, unsigned long len) { return -ENOMEM; @@ -1061,23 +1118,6 @@ unsigned long do_mremap(unsigned long addr, return vml->vma->vm_start; } -/* - * Look up the first VMA which satisfies addr < vm_end, NULL if none - * - should be called with mm->mmap_sem at least readlocked - */ -struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) -{ - struct vm_list_struct *vml; - - for (vml = mm->context.vmlist; vml; vml = vml->next) - if (addr >= vml->vma->vm_start && addr < vml->vma->vm_end) - return vml->vma; - - return NULL; -} - -EXPORT_SYMBOL(find_vma); - struct page *follow_page(struct vm_area_struct *vma, unsigned long address, unsigned int foll_flags) { |