diff options
Diffstat (limited to 'fs/proc/task_mmu.c')
| -rw-r--r-- | fs/proc/task_mmu.c | 126 |
1 files changed, 92 insertions, 34 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 5066b0251ed8..217aa2705d5d 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -520,16 +520,10 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr, page = device_private_entry_to_page(swpent); } else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap && pte_none(*pte))) { - page = find_get_entry(vma->vm_file->f_mapping, + page = xa_load(&vma->vm_file->f_mapping->i_pages, linear_page_index(vma, addr)); - if (!page) - return; - if (xa_is_value(page)) mss->swap += PAGE_SIZE; - else - put_page(page); - return; } @@ -653,6 +647,10 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) [ilog2(VM_MERGEABLE)] = "mg", [ilog2(VM_UFFD_MISSING)]= "um", [ilog2(VM_UFFD_WP)] = "uw", +#ifdef CONFIG_ARM64_MTE + [ilog2(VM_MTE)] = "mt", + [ilog2(VM_MTE_ALLOWED)] = "", +#endif #ifdef CONFIG_ARCH_HAS_PKEYS /* These come out via ProtectionKey: */ [ilog2(VM_PKEY_BIT0)] = "", @@ -723,9 +721,21 @@ static const struct mm_walk_ops smaps_shmem_walk_ops = { .pte_hole = smaps_pte_hole, }; +/* + * Gather mem stats from @vma with the indicated beginning + * address @start, and keep them in @mss. + * + * Use vm_start of @vma as the beginning address if @start is 0. + */ static void smap_gather_stats(struct vm_area_struct *vma, - struct mem_size_stats *mss) + struct mem_size_stats *mss, unsigned long start) { + const struct mm_walk_ops *ops = &smaps_walk_ops; + + /* Invalid start */ + if (start >= vma->vm_end) + return; + #ifdef CONFIG_SHMEM /* In case of smaps_rollup, reset the value from previous vma */ mss->check_shmem_swap = false; @@ -742,18 +752,20 @@ static void smap_gather_stats(struct vm_area_struct *vma, */ unsigned long shmem_swapped = shmem_swap_usage(vma); - if (!shmem_swapped || (vma->vm_flags & VM_SHARED) || - !(vma->vm_flags & VM_WRITE)) { + if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) || + !(vma->vm_flags & VM_WRITE))) { mss->swap += shmem_swapped; } else { mss->check_shmem_swap = true; - walk_page_vma(vma, &smaps_shmem_walk_ops, mss); - return; + ops = &smaps_shmem_walk_ops; } } #endif /* mmap_lock is held in m_start */ - walk_page_vma(vma, &smaps_walk_ops, mss); + if (!start) + walk_page_vma(vma, ops, mss); + else + walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss); } #define SEQ_PUT_DEC(str, val) \ @@ -805,7 +817,7 @@ static int show_smap(struct seq_file *m, void *v) memset(&mss, 0, sizeof(mss)); - smap_gather_stats(vma, &mss); + smap_gather_stats(vma, &mss, 0); show_map_vma(m, vma); @@ -853,9 +865,73 @@ static int show_smaps_rollup(struct seq_file *m, void *v) hold_task_mempolicy(priv); - for (vma = priv->mm->mmap; vma; vma = vma->vm_next) { - smap_gather_stats(vma, &mss); + for (vma = priv->mm->mmap; vma;) { + smap_gather_stats(vma, &mss, 0); last_vma_end = vma->vm_end; + + /* + * Release mmap_lock temporarily if someone wants to + * access it for write request. + */ + if (mmap_lock_is_contended(mm)) { + mmap_read_unlock(mm); + ret = mmap_read_lock_killable(mm); + if (ret) { + release_task_mempolicy(priv); + goto out_put_mm; + } + + /* + * After dropping the lock, there are four cases to + * consider. See the following example for explanation. + * + * +------+------+-----------+ + * | VMA1 | VMA2 | VMA3 | + * +------+------+-----------+ + * | | | | + * 4k 8k 16k 400k + * + * Suppose we drop the lock after reading VMA2 due to + * contention, then we get: + * + * last_vma_end = 16k + * + * 1) VMA2 is freed, but VMA3 exists: + * + * find_vma(mm, 16k - 1) will return VMA3. + * In this case, just continue from VMA3. + * + * 2) VMA2 still exists: + * + * find_vma(mm, 16k - 1) will return VMA2. + * Iterate the loop like the original one. + * + * 3) No more VMAs can be found: + * + * find_vma(mm, 16k - 1) will return NULL. + * No more things to do, just break. + * + * 4) (last_vma_end - 1) is the middle of a vma (VMA'): + * + * find_vma(mm, 16k - 1) will return VMA' whose range + * contains last_vma_end. + * Iterate VMA' from last_vma_end. + */ + vma = find_vma(mm, last_vma_end - 1); + /* Case 3 above */ + if (!vma) + break; + + /* Case 1 above */ + if (vma->vm_start >= last_vma_end) + continue; + + /* Case 4 above */ + if (vma->vm_end > last_vma_end) + smap_gather_stats(vma, &mss, last_vma_end); + } + /* Case 2 above */ + vma = vma->vm_next; } show_vma_header_prefix(m, priv->mm->mmap->vm_start, @@ -1168,24 +1244,6 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, count = -EINTR; goto out_mm; } - /* - * Avoid to modify vma->vm_flags - * without locked ops while the - * coredump reads the vm_flags. - */ - if (!mmget_still_valid(mm)) { - /* - * Silently return "count" - * like if get_task_mm() - * failed. FIXME: should this - * function have returned - * -ESRCH if get_task_mm() - * failed like if - * get_proc_task() fails? - */ - mmap_write_unlock(mm); - goto out_mm; - } for (vma = mm->mmap; vma; vma = vma->vm_next) { vma->vm_flags &= ~VM_SOFTDIRTY; vma_set_page_prot(vma); |