diff options
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/task_mmu.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 9bd8be1d235..59e98fea34a 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -465,6 +465,10 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, return 0; } +#define CLEAR_REFS_ALL 1 +#define CLEAR_REFS_ANON 2 +#define CLEAR_REFS_MAPPED 3 + static ssize_t clear_refs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { @@ -472,13 +476,15 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, char buffer[PROC_NUMBUF], *end; struct mm_struct *mm; struct vm_area_struct *vma; + int type; memset(buffer, 0, sizeof(buffer)); if (count > sizeof(buffer) - 1) count = sizeof(buffer) - 1; if (copy_from_user(buffer, buf, count)) return -EFAULT; - if (!simple_strtol(buffer, &end, 0)) + type = simple_strtol(buffer, &end, 0); + if (type < CLEAR_REFS_ALL || type > CLEAR_REFS_MAPPED) return -EINVAL; if (*end == '\n') end++; @@ -494,9 +500,23 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, down_read(&mm->mmap_sem); for (vma = mm->mmap; vma; vma = vma->vm_next) { clear_refs_walk.private = vma; - if (!is_vm_hugetlb_page(vma)) - walk_page_range(vma->vm_start, vma->vm_end, - &clear_refs_walk); + if (is_vm_hugetlb_page(vma)) + continue; + /* + * Writing 1 to /proc/pid/clear_refs affects all pages. + * + * Writing 2 to /proc/pid/clear_refs only affects + * Anonymous pages. + * + * Writing 3 to /proc/pid/clear_refs only affects file + * mapped pages. + */ + if (type == CLEAR_REFS_ANON && vma->vm_file) + continue; + if (type == CLEAR_REFS_MAPPED && !vma->vm_file) + continue; + walk_page_range(vma->vm_start, vma->vm_end, + &clear_refs_walk); } flush_tlb_mm(mm); up_read(&mm->mmap_sem); |