// SPDX-License-Identifier: GPL-2.0 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "internal.h" #define SEQ_PUT_DEC(str, val) \ seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8) void task_mem(struct seq_file *m, struct mm_struct *mm) { unsigned long text, lib, swap, anon, file, shmem; unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss; anon = get_mm_counter(mm, MM_ANONPAGES); file = get_mm_counter(mm, MM_FILEPAGES); shmem = get_mm_counter(mm, MM_SHMEMPAGES); /* * Note: to minimize their overhead, mm maintains hiwater_vm and * hiwater_rss only when about to *lower* total_vm or rss. Any * collector of these hiwater stats must therefore get total_vm * and rss too, which will usually be the higher. Barriers? not * worth the effort, such snapshots can always be inconsistent. */ hiwater_vm = total_vm = mm->total_vm; if (hiwater_vm < mm->hiwater_vm) hiwater_vm = mm->hiwater_vm; hiwater_rss = total_rss = anon + file + shmem; if (hiwater_rss < mm->hiwater_rss) hiwater_rss = mm->hiwater_rss; /* split executable areas between text and lib */ text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK); text = min(text, mm->exec_vm << PAGE_SHIFT); lib = (mm->exec_vm << PAGE_SHIFT) - text; swap = get_mm_counter(mm, MM_SWAPENTS); SEQ_PUT_DEC("VmPeak:\t", hiwater_vm); SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm); SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm); SEQ_PUT_DEC(" kB\nVmPin:\t", atomic64_read(&mm->pinned_vm)); SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss); SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss); SEQ_PUT_DEC(" kB\nRssAnon:\t", anon); SEQ_PUT_DEC(" kB\nRssFile:\t", file); SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem); SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm); SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm); seq_put_decimal_ull_width(m, " kB\nVmExe:\t", text >> 10, 8); seq_put_decimal_ull_width(m, " kB\nVmLib:\t", lib >> 10, 8); seq_put_decimal_ull_width(m, " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8); SEQ_PUT_DEC(" kB\nVmSwap:\t", swap); seq_puts(m, " kB\n"); hugetlb_report_usage(m, mm); } #undef SEQ_PUT_DEC unsigned long task_vsize(struct mm_struct *mm) { return PAGE_SIZE * mm->total_vm; } unsigned long task_statm(struct mm_struct *mm, unsigned long *shared, unsigned long *text, unsigned long *data, unsigned long *resident) { *shared = get_mm_counter(mm, MM_FILEPAGES) + get_mm_counter(mm, MM_SHMEMPAGES); *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> PAGE_SHIFT; *data = mm->data_vm + mm->stack_vm; *resident = *shared + get_mm_counter(mm, MM_ANONPAGES); return mm->total_vm; } #ifdef CONFIG_NUMA /* * Save get_task_policy() for show_numa_map(). */ static void hold_task_mempolicy(struct proc_maps_private *priv) { struct task_struct *task = priv->task; task_lock(task); priv->task_mempolicy = get_task_policy(task); mpol_get(priv->task_mempolicy); task_unlock(task); } static void release_task_mempolicy(struct proc_maps_private *priv) { mpol_put(priv->task_mempolicy); } #else static void hold_task_mempolicy(struct proc_maps_private *priv) { } static void release_task_mempolicy(struct proc_maps_private *priv) { } #endif static struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv, loff_t *ppos) { struct vm_area_struct *vma = vma_next(&priv->iter); if (vma) { *ppos = vma->vm_start; } else { *ppos = -2UL; vma = get_gate_vma(priv->mm); } return vma; } static void *m_start(struct seq_file *m, loff_t *ppos) { struct proc_maps_private *priv = m->private; unsigned long last_addr = *ppos; struct mm_struct *mm; /* See m_next(). Zero at the start or after lseek. */ if (last_addr == -1UL) return NULL; priv->task = get_proc_task(priv->inode); if (!priv->task) return ERR_PTR(-ESRCH); mm = priv->mm; if (!mm || !mmget_not_zero(mm)) { put_task_struct(priv->task); priv->task = NULL; return NULL; } if (mmap_read_lock_killable(mm)) { mmput(mm); put_task_struct(priv->task); priv->task = NULL; return ERR_PTR(-EINTR); } vma_iter_init(&priv->iter, mm, last_addr); hold_task_mempolicy(priv); if (last_addr == -2UL) return get_gate_vma(mm); return proc_get_vma(priv, ppos); } static void *m_next(struct seq_file *m, void *v, loff_t *ppos) { if (*ppos == -2UL) { *ppos = -1UL; return NULL; } return proc_get_vma(m->private, ppos); } static void m_stop(struct seq_file *m, void *v) { struct proc_maps_private *priv = m->private; struct mm_struct *mm = priv->mm; if (!priv->task) return; release_task_mempolicy(priv); mmap_read_unlock(mm); mmput(mm); put_task_struct(priv->task); priv->task = NULL; } static int proc_maps_open(struct inode *inode, struct file *file, const struct seq_operations *ops, int psize) { struct proc_maps_private *priv = __seq_open_private(file, ops, psize); if (!priv) return -ENOMEM; priv->inode = inode; priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); if (IS_ERR(priv->mm)) { int err = PTR_ERR(priv->mm); seq_release_private(inode, file); return err; } return 0; } static int proc_map_release(struct inode *inode, struct file *file) { struct seq_file *seq = file->private_data; struct proc_maps_private *priv = seq->private; if (priv->mm) mmdrop(priv->mm); return seq_release_private(inode, file); } static int do_maps_open(struct inode *inode, struct file *file, const struct seq_operations *ops) { return proc_maps_open(inode, file, ops, sizeof(struct proc_maps_private)); } static void get_vma_name(struct vm_area_struct *vma, const struct path **path, const char **name, const char **name_fmt) { struct anon_vma_name *anon_name = vma->vm_mm ? anon_vma_name(vma) : NULL; *name = NULL; *path = NULL; *name_fmt = NULL; /* * Print the dentry name for named mappings, and a * special [heap] marker for the heap: */ if (vma->vm_file) { /* * If user named this anon shared memory via * prctl(PR_SET_VMA ..., use the provided name. */ if (anon_name) { *name_fmt = "[anon_shmem:%s]"; *name = anon_name->name; } else { *path = file_user_path(vma->vm_file); } return; } if (vma->vm_ops && vma->vm_ops->name) { *name = vma->vm_ops->name(vma); if (*name) return; } *name = arch_vma_name(vma); if (*name) return; if (!vma->vm_mm) { *name = "[vdso]"; return; } if (vma_is_initial_heap(vma)) { *name = "[heap]"; return; } if (vma_is_initial_stack(vma)) { *name = "[stack]"; return; } if (anon_name) { *name_fmt = "[anon:%s]"; *name = anon_name->name; return; } } static void show_vma_header_prefix(struct seq_file *m, unsigned long start, unsigned long end, vm_flags_t flags, unsigned long long pgoff, dev_t dev, unsigned long ino) { seq_setwidth(m, 25 + sizeof(void *) * 6 - 1); seq_put_hex_ll(m, NULL, start, 8); seq_put_hex_ll(m, "-", end, 8); seq_putc(m, ' '); seq_putc(m, flags & VM_READ ? 'r' : '-'); seq_putc(m, flags & VM_WRITE ? 'w' : '-'); seq_putc(m, flags & VM_EXEC ? 'x' : '-'); seq_putc(m, flags & VM_MAYSHARE ? 's' : 'p'); seq_put_hex_ll(m, " ", pgoff, 8); seq_put_hex_ll(m, " ", MAJOR(dev), 2); seq_put_hex_ll(m, ":", MINOR(dev), 2); seq_put_decimal_ull(m, " ", ino); seq_putc(m, ' '); } static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma) { const struct path *path; const char *name_fmt, *name; vm_flags_t flags = vma->vm_flags; unsigned long ino = 0; unsigned long long pgoff = 0; unsigned long start, end; dev_t dev = 0; if (vma->vm_file) { const struct inode *inode = file_user_inode(vma->vm_file); dev = inode->i_sb->s_dev; ino = inode->i_ino; pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT; } start = vma->vm_start; end = vma->vm_end; show_vma_header_prefix(m, start, end, flags, pgoff, dev, ino); get_vma_name(vma, &path, &name, &name_fmt); if (path) { seq_pad(m, ' '); seq_path(m, path, "\n"); } else if (name_fmt) { seq_pad(m, ' '); seq_printf(m, name_fmt, name); } else if (name) { seq_pad(m, ' '); seq_puts(m, name); } seq_putc(m, '\n'); } static int show_map(struct seq_file *m, void *v) { show_map_vma(m, v); return 0; } static const struct seq_operations proc_pid_maps_op = { .start = m_start, .next = m_next, .stop = m_stop, .show = show_map }; static int pid_maps_open(struct inode *inode, struct file *file) { return do_maps_open(inode, file, &proc_pid_maps_op); } #define PROCMAP_QUERY_VMA_FLAGS ( \ PROCMAP_QUERY_VMA_READABLE | \ PROCMAP_QUERY_VMA_WRITABLE | \ PROCMAP_QUERY_VMA_EXECUTABLE | \ PROCMAP_QUERY_VMA_SHARED \ ) #define PROCMAP_QUERY_VALID_FLAGS_MASK ( \ PROCMAP_QUERY_COVERING_OR_NEXT_VMA | \ PROCMAP_QUERY_FILE_BACKED_VMA | \ PROCMAP_QUERY_VMA_FLAGS \ ) static int query_vma_setup(struct mm_struct *mm) { return mmap_read_lock_killable(mm); } static void query_vma_teardown(struct mm_struct *mm, struct vm_area_struct *vma) { mmap_read_unlock(mm); } static struct vm_area_struct *query_vma_find_by_addr(struct mm_struct *mm, unsigned long addr) { return find_vma(mm, addr); } static struct vm_area_struct *query_matching_vma(struct mm_struct *mm, unsigned long addr, u32 flags) { struct vm_area_struct *vma; next_vma: vma = query_vma_find_by_addr(mm, addr); if (!vma) goto no_vma; /* user requested only file-backed VMA, keep iterating */ if ((flags & PROCMAP_QUERY_FILE_BACKED_VMA) && !vma->vm_file) goto skip_vma; /* VMA permissions should satisfy query flags */ if (flags & PROCMAP_QUERY_VMA_FLAGS) { u32 perm = 0; if (flags & PROCMAP_QUERY_VMA_READABLE) perm |= VM_READ; if (flags & PROCMAP_QUERY_VMA_WRITABLE) perm |= VM_WRITE; if (flags & PROCMAP_QUERY_VMA_EXECUTABLE) perm |= VM_EXEC; if (flags & PROCMAP_QUERY_VMA_SHARED) perm |= VM_MAYSHARE; if ((vma->vm_flags & perm) != perm) goto skip_vma; } /* found covering VMA or user is OK with the matching next VMA */ if ((flags & PROCMAP_QUERY_COVERING_OR_NEXT_VMA) || vma->vm_start <= addr) return vma; skip_vma: /* * If the user needs closest matching VMA, keep iterating. */ addr = vma->vm_end; if (flags & PROCMAP_QUERY_COVERING_OR_NEXT_VMA) goto next_vma; no_vma: return ERR_PTR(-ENOENT); } static int do_procmap_query(struct proc_maps_private *priv, void __user *uarg) { struct procmap_query karg; struct vm_area_struct *vma; struct mm_struct *mm; const char *name = NULL; char build_id_buf[BUILD_ID_SIZE_MAX], *name_buf = NULL; __u64 usize; int err; if (copy_from_user(&usize, (void __user *)uarg, sizeof(usize))) return -EFAULT; /* argument struct can never be that large, reject abuse */ if (usize > PAGE_SIZE) return -E2BIG; /* argument struct should have at least query_flags and query_addr fields */ if (usize < offsetofend(struct procmap_query, query_addr)) return -EINVAL; err = copy_struct_from_user(&karg, sizeof(karg), uarg, usize); if (err) return err; /* reject unknown flags */ if (karg.query_flags & ~PROCMAP_QUERY_VALID_FLAGS_MASK) return -EINVAL; /* either both buffer address and size are set, or both should be zero */ if (!!karg.vma_name_size != !!karg.vma_name_addr) return -EINVAL; if (!!karg.build_id_size != !!karg.build_id_addr) return -EINVAL; mm = priv->mm; if (!mm || !mmget_not_zero(mm)) return -ESRCH; err = query_vma_setup(mm); if (err) { mmput(mm); return err; } vma = query_matching_vma(mm, karg.query_addr, karg.query_flags); if (IS_ERR(vma)) { err = PTR_ERR(vma); vma = NULL; goto out; } karg.vma_start = vma->vm_start; karg.vma_end = vma->vm_end; karg.vma_flags = 0; if (vma->vm_flags & VM_READ) karg.vma_flags |= PROCMAP_QUERY_VMA_READABLE; if (vma->vm_flags & VM_WRITE) karg.vma_flags |= PROCMAP_QUERY_VMA_WRITABLE; if (vma->vm_flags & VM_EXEC) karg.vma_flags |= PROCMAP_QUERY_VMA_EXECUTABLE; if (vma->vm_flags & VM_MAYSHARE) karg.vma_flags |= PROCMAP_QUERY_VMA_SHARED; karg.vma_page_size = vma_kernel_pagesize(vma); if (vma->vm_file) { const struct inode *inode = file_user_inode(vma->vm_file); karg.vma_offset = ((__u64)vma->vm_pgoff) << PAGE_SHIFT; karg.dev_major = MAJOR(inode->i_sb->s_dev); karg.dev_minor = MINOR(inode->i_sb->s_dev); karg.inode = inode->i_ino; } else { karg.vma_offset = 0; karg.dev_major = 0; karg.dev_minor = 0; karg.inode = 0; } if (karg.build_id_size) { __u32 build_id_sz; err = build_id_parse(vma, build_id_buf, &build_id_sz); if (err) { karg.build_id_size = 0; } else { if (karg.build_id_size < build_id_sz) { err = -ENAMETOOLONG; goto out; } karg.build_id_size = build_id_sz; } } if (karg.build_id_size) { __u32 build_id_sz; err = build_id_parse(vma, build_id_buf, &build_id_sz); if (err) { karg.build_id_size = 0; } else { if (karg.build_id_size < build_id_sz) { err = -ENAMETOOLONG; goto out; } karg.build_id_size = build_id_sz; } } if (karg.vma_name_size) { size_t name_buf_sz = min_t(size_t, PATH_MAX, karg.vma_name_size); const struct path *path; const char *name_fmt; size_t name_sz = 0; get_vma_name(vma, &path, &name, &name_fmt); if (path || name_fmt || name) { name_buf = kmalloc(name_buf_sz, GFP_KERNEL); if (!name_buf) { err = -ENOMEM; goto out; } } if (path) { name = d_path(path, name_buf, name_buf_sz); if (IS_ERR(name)) { err = PTR_ERR(name); goto out; } name_sz = name_buf + name_buf_sz - name; } else if (name || name_fmt) { name_sz = 1 + snprintf(name_buf, name_buf_sz, name_fmt ?: "%s", name); name = name_buf; } if (name_sz > name_buf_sz) { err = -ENAMETOOLONG; goto out; } karg.vma_name_size = name_sz; } /* unlock vma or mmap_lock, and put mm_struct before copying data to user */ query_vma_teardown(mm, vma); mmput(mm); if (karg.vma_name_size && copy_to_user(u64_to_user_ptr(karg.vma_name_addr), name, karg.vma_name_size)) { kfree(name_buf); return -EFAULT; } kfree(name_buf); if (karg.build_id_size && copy_to_user(u64_to_user_ptr(karg.build_id_addr), build_id_buf, karg.build_id_size)) return -EFAULT; if (copy_to_user(uarg, &karg, min_t(size_t, sizeof(karg), usize))) return -EFAULT; return 0; out: query_vma_teardown(mm, vma); mmput(mm); kfree(name_buf); return err; } static long procfs_procmap_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct seq_file *seq = file->private_data; struct proc_maps_private *priv = seq->private; switch (cmd) { case PROCMAP_QUERY: return do_procmap_query(priv, (void __user *)arg); default: return -ENOIOCTLCMD; } } const struct file_operations proc_pid_maps_operations = { .open = pid_maps_open, .read = seq_read, .llseek = seq_lseek, .release = proc_map_release, .unlocked_ioctl = procfs_procmap_ioctl, .compat_ioctl = compat_ptr_ioctl, }; /* * Proportional Set Size(PSS): my share of RSS. * * PSS of a process is the count of pages it has in memory, where each * page is divided by the number of processes sharing it. So if a * process has 1000 pages all to itself, and 1000 shared with one other * process, its PSS will be 1500. * * To keep (accumulated) division errors low, we adopt a 64bit * fixed-point pss counter to minimize division errors. So (pss >> * PSS_SHIFT) would be the real byte count. * * A shift of 12 before division means (assuming 4K page size): * - 1M 3-user-pages add up to 8KB errors; * - supports mapcount up to 2^24, or 16M; * - supports PSS up to 2^52 bytes, or 4PB. */ #define PSS_SHIFT 12 #ifdef CONFIG_PROC_PAGE_MONITOR struct mem_size_stats { unsigned long resident; unsigned long shared_clean; unsigned long shared_dirty; unsigned long private_clean; unsigned long private_dirty; unsigned long referenced; unsigned long anonymous; unsigned long lazyfree; unsigned long anonymous_thp; unsigned long shmem_thp; unsigned long file_thp; unsigned long swap; unsigned long shared_hugetlb; unsigned long private_hugetlb; unsigned long ksm; u64 pss; u64 pss_anon; u64 pss_file; u64 pss_shmem; u64 pss_dirty; u64 pss_locked; u64 swap_pss; }; static void smaps_page_accumulate(struct mem_size_stats *mss, struct folio *folio, unsigned long size, unsigned long pss, bool dirty, bool locked, bool private) { mss->pss += pss; if (folio_test_anon(folio)) mss->pss_anon += pss; else if (folio_test_swapbacked(folio)) mss->pss_shmem += pss; else mss->pss_file += pss; if (locked) mss->pss_locked += pss; if (dirty || folio_test_dirty(folio)) { mss->pss_dirty += pss; if (private) mss->private_dirty += size; else mss->shared_dirty += size; } else { if (private) mss->private_clean += size; else mss->shared_clean += size; } } static void smaps_account(struct mem_size_stats *mss, struct page *page, bool compound, bool young, bool dirty, bool locked, bool present) { struct folio *folio = page_folio(page); int i, nr = compound ? compound_nr(page) : 1; unsigned long size = nr * PAGE_SIZE; /* * First accumulate quantities that depend only on |size| and the type * of the compound page. */ if (folio_test_anon(folio)) { mss->anonymous += size; if (!folio_test_swapbacked(folio) && !dirty && !folio_test_dirty(folio)) mss->lazyfree += size; } if (folio_test_ksm(folio)) mss->ksm += size; mss->resident += size; /* Accumulate the size in pages that have been accessed. */ if (young || folio_test_young(folio) || folio_test_referenced(folio)) mss->referenced += size; /* * Then accumulate quantities that may depend on sharing, or that may * differ page-by-page. * * refcount == 1 for present entries guarantees that the folio is mapped * exactly once. For large folios this implies that exactly one * PTE/PMD/... maps (a part of) this folio. * * Treat all non-present entries (where relying on the mapcount and * refcount doesn't make sense) as "maybe shared, but not sure how * often". We treat device private entries as being fake-present. * * Note that it would not be safe to read the mapcount especially for * pages referenced by migration entries, even with the PTL held. */ if (folio_ref_count(folio) == 1 || !present) { smaps_page_accumulate(mss, folio, size, size << PSS_SHIFT, dirty, locked, present); return; } /* * We obtain a snapshot of the mapcount. Without holding the folio lock * this snapshot can be slightly wrong as we cannot always read the * mapcount atomically. */ for (i = 0; i < nr; i++, page++) { int mapcount = folio_precise_page_mapcount(folio, page); unsigned long pss = PAGE_SIZE << PSS_SHIFT; if (mapcount >= 2) pss /= mapcount; smaps_page_accumulate(mss, folio, PAGE_SIZE, pss, dirty, locked, mapcount < 2); } } #ifdef CONFIG_SHMEM static int smaps_pte_hole(unsigned long addr, unsigned long end, __always_unused int depth, struct mm_walk *walk) { struct mem_size_stats *mss = walk->private; struct vm_area_struct *vma = walk->vma; mss->swap += shmem_partial_swap_usage(walk->vma->vm_file->f_mapping, linear_page_index(vma, addr), linear_page_index(vma, end)); return 0; } #else #define smaps_pte_hole NULL #endif /* CONFIG_SHMEM */ static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk) { #ifdef CONFIG_SHMEM if (walk->ops->pte_hole) { /* depth is not used */ smaps_pte_hole(addr, addr + PAGE_SIZE, 0, walk); } #endif } static void smaps_pte_entry(pte_t *pte, unsigned long addr, struct mm_walk *walk) { struct mem_size_stats *mss = walk->private; struct vm_area_struct *vma = walk->vma; bool locked = !!(vma->vm_flags & VM_LOCKED); struct page *page = NULL; bool present = false, young = false, dirty = false; pte_t ptent = ptep_get(pte); if (pte_present(ptent)) { page = vm_normal_page(vma, addr, ptent); young = pte_young(ptent); dirty = pte_dirty(ptent); present = true; } else if (is_swap_pte(ptent)) { swp_entry_t swpent = pte_to_swp_entry(ptent); if (!non_swap_entry(swpent)) { int mapcount; mss->swap += PAGE_SIZE; mapcount = swp_swapcount(swpent); if (mapcount >= 2) { u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT; do_div(pss_delta, mapcount); mss->swap_pss += pss_delta; } else { mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT; } } else if (is_pfn_swap_entry(swpent)) { if (is_device_private_entry(swpent)) present = true; page = pfn_swap_entry_to_page(swpent); } } else { smaps_pte_hole_lookup(addr, walk); return; } if (!page) return; smaps_account(mss, page, false, young, dirty, locked, present); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, struct mm_walk *walk) { struct mem_size_stats *mss = walk->private; struct vm_area_struct *vma = walk->vma; bool locked = !!(vma->vm_flags & VM_LOCKED); struct page *page = NULL; bool present = false; struct folio *folio; if (pmd_present(*pmd)) { page = vm_normal_page_pmd(vma, addr, *pmd); present = true; } else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) { swp_entry_t entry = pmd_to_swp_entry(*pmd); if (is_pfn_swap_entry(entry)) page = pfn_swap_entry_to_page(entry); } if (IS_ERR_OR_NULL(page)) return; folio = page_folio(page); if (folio_test_anon(folio)) mss->anonymous_thp += HPAGE_PMD_SIZE; else if (folio_test_swapbacked(folio)) mss->shmem_thp += HPAGE_PMD_SIZE; else if (folio_is_zone_device(folio)) /* pass */; else mss->file_thp += HPAGE_PMD_SIZE; smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked, present); } #else static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, struct mm_walk *walk) { } #endif static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct vm_area_struct *vma = walk->vma; pte_t *pte; spinlock_t *ptl; ptl = pmd_trans_huge_lock(pmd, vma); if (ptl) { smaps_pmd_entry(pmd, addr, walk); spin_unlock(ptl); goto out; } pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); if (!pte) { walk->action = ACTION_AGAIN; return 0; } for (; addr != end; pte++, addr += PAGE_SIZE) smaps_pte_entry(pte, addr, walk); pte_unmap_unlock(pte - 1, ptl); out: cond_resched(); return 0; } static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) { /* * Don't forget to update Documentation/ on changes. */ static const char mnemonics[BITS_PER_LONG][2] = { /* * In case if we meet a flag we don't know about. */ [0 ... (BITS_PER_LONG-1)] = "??", [ilog2(VM_READ)] = "rd", [ilog2(VM_WRITE)] = "wr", [ilog2(VM_EXEC)] = "ex", [ilog2(VM_SHARED)] = "sh", [ilog2(VM_MAYREAD)] = "mr", [ilog2(VM_MAYWRITE)] = "mw", [ilog2(VM_MAYEXEC)] = "me", [ilog2(VM_MAYSHARE)] = "ms", [ilog2(VM_GROWSDOWN)] = "gd", [ilog2(VM_PFNMAP)] = "pf", [ilog2(VM_LOCKED)] = "lo", [ilog2(VM_IO)] = "io", [ilog2(VM_SEQ_READ)] = "sr", [ilog2(VM_RAND_READ)] = "rr", [ilog2(VM_DONTCOPY)] = "dc", [ilog2(VM_DONTEXPAND)] = "de", [ilog2(VM_LOCKONFAULT)] = "lf", [ilog2(VM_ACCOUNT)] = "ac", [ilog2(VM_NORESERVE)] = "nr", [ilog2(VM_HUGETLB)] = "ht", [ilog2(VM_SYNC)] = "sf", [ilog2(VM_ARCH_1)] = "ar", [ilog2(VM_WIPEONFORK)] = "wf", [ilog2(VM_DONTDUMP)] = "dd", #ifdef CONFIG_ARM64_BTI [ilog2(VM_ARM64_BTI)] = "bt", #endif #ifdef CONFIG_MEM_SOFT_DIRTY [ilog2(VM_SOFTDIRTY)] = "sd", #endif [ilog2(VM_MIXEDMAP)] = "mm", [ilog2(VM_HUGEPAGE)] = "hg", [ilog2(VM_NOHUGEPAGE)] = "nh", [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)] = "", [ilog2(VM_PKEY_BIT1)] = "", [ilog2(VM_PKEY_BIT2)] = "", #if VM_PKEY_BIT3 [ilog2(VM_PKEY_BIT3)] = "", #endif #if VM_PKEY_BIT4 [ilog2(VM_PKEY_BIT4)] = "", #endif #endif /* CONFIG_ARCH_HAS_PKEYS */ #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR [ilog2(VM_UFFD_MINOR)] = "ui", #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */ #ifdef CONFIG_X86_USER_SHADOW_STACK [ilog2(VM_SHADOW_STACK)] = "ss", #endif #ifdef CONFIG_64BIT [ilog2(VM_DROPPABLE)] = "dp", [ilog2(VM_SEALED)] = "sl", #endif }; size_t i; seq_puts(m, "VmFlags: "); for (i = 0; i < BITS_PER_LONG; i++) { if (!mnemonics[i][0]) continue; if (vma->vm_flags & (1UL << i)) { seq_putc(m, mnemonics[i][0]); seq_putc(m, mnemonics[i][1]); seq_putc(m, ' '); } } seq_putc(m, '\n'); } #ifdef CONFIG_HUGETLB_PAGE static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct mem_size_stats *mss = walk->private; struct vm_area_struct *vma = walk->vma; pte_t ptent = huge_ptep_get(walk->mm, addr, pte); struct folio *folio = NULL; bool present = false; if (pte_present(ptent)) { folio = page_folio(pte_page(ptent)); present = true; } else if (is_swap_pte(ptent)) { swp_entry_t swpent = pte_to_swp_entry(ptent); if (is_pfn_swap_entry(swpent)) folio = pfn_swap_entry_folio(swpent); } if (folio) { /* We treat non-present entries as "maybe shared". */ if (!present || folio_likely_mapped_shared(folio) || hugetlb_pmd_shared(pte)) mss->shared_hugetlb += huge_page_size(hstate_vma(vma)); else mss->private_hugetlb += huge_page_size(hstate_vma(vma)); } return 0; } #else #define smaps_hugetlb_range NULL #endif /* HUGETLB_PAGE */ static const struct mm_walk_ops smaps_walk_ops = { .pmd_entry = smaps_pte_range, .hugetlb_entry = smaps_hugetlb_range, .walk_lock = PGWALK_RDLOCK, }; static const struct mm_walk_ops smaps_shmem_walk_ops = { .pmd_entry = smaps_pte_range, .hugetlb_entry = smaps_hugetlb_range, .pte_hole = smaps_pte_hole, .walk_lock = PGWALK_RDLOCK, }; /* * 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, unsigned long start) { const struct mm_walk_ops *ops = &smaps_walk_ops; /* Invalid start */ if (start >= vma->vm_end) return; if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) { /* * For shared or readonly shmem mappings we know that all * swapped out pages belong to the shmem object, and we can * obtain the swap value much more efficiently. For private * writable mappings, we might have COW pages that are * not affected by the parent swapped out pages of the shmem * object, so we have to distinguish them during the page walk. * Unless we know that the shmem object (or the part mapped by * our VMA) has no swapped out pages at all. */ unsigned long shmem_swapped = shmem_swap_usage(vma); if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) || !(vma->vm_flags & VM_WRITE))) { mss->swap += shmem_swapped; } else { ops = &smaps_shmem_walk_ops; } } /* mmap_lock is held in m_start */ 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) \ seq_put_decimal_ull_width(m, str, (val) >> 10, 8) /* Show the contents common for smaps and smaps_rollup */ static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss, bool rollup_mode) { SEQ_PUT_DEC("Rss: ", mss->resident); SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT); SEQ_PUT_DEC(" kB\nPss_Dirty: ", mss->pss_dirty >> PSS_SHIFT); if (rollup_mode) { /* * These are meaningful only for smaps_rollup, otherwise two of * them are zero, and the other one is the same as Pss. */ SEQ_PUT_DEC(" kB\nPss_Anon: ", mss->pss_anon >> PSS_SHIFT); SEQ_PUT_DEC(" kB\nPss_File: ", mss->pss_file >> PSS_SHIFT); SEQ_PUT_DEC(" kB\nPss_Shmem: ", mss->pss_shmem >> PSS_SHIFT); } SEQ_PUT_DEC(" kB\nShared_Clean: ", mss->shared_clean); SEQ_PUT_DEC(" kB\nShared_Dirty: ", mss->shared_dirty); SEQ_PUT_DEC(" kB\nPrivate_Clean: ", mss->private_clean); SEQ_PUT_DEC(" kB\nPrivate_Dirty: ", mss->private_dirty); SEQ_PUT_DEC(" kB\nReferenced: ", mss->referenced); SEQ_PUT_DEC(" kB\nAnonymous: ", mss->anonymous); SEQ_PUT_DEC(" kB\nKSM: ", mss->ksm); SEQ_PUT_DEC(" kB\nLazyFree: ", mss->lazyfree); SEQ_PUT_DEC(" kB\nAnonHugePages: ", mss->anonymous_thp); SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp); SEQ_PUT_DEC(" kB\nFilePmdMapped: ", mss->file_thp); SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb); seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ", mss->private_hugetlb >> 10, 7); SEQ_PUT_DEC(" kB\nSwap: ", mss->swap); SEQ_PUT_DEC(" kB\nSwapPss: ", mss->swap_pss >> PSS_SHIFT); SEQ_PUT_DEC(" kB\nLocked: ", mss->pss_locked >> PSS_SHIFT); seq_puts(m, " kB\n"); } static int show_smap(struct seq_file *m, void *v) { struct vm_area_struct *vma = v; struct mem_size_stats mss = {}; smap_gather_stats(vma, &mss, 0); show_map_vma(m, vma); SEQ_PUT_DEC("Size: ", vma->vm_end - vma->vm_start); SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma)); SEQ_PUT_DEC(" kB\nMMUPageSize: ", vma_mmu_pagesize(vma)); seq_puts(m, " kB\n"); __show_smap(m, &mss, false); seq_printf(m, "THPeligible: %8u\n", !!thp_vma_allowable_orders(vma, vma->vm_flags, TVA_SMAPS | TVA_ENFORCE_SYSFS, THP_ORDERS_ALL)); if (arch_pkeys_enabled()) seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); show_smap_vma_flags(m, vma); return 0; } static int show_smaps_rollup(struct seq_file *m, void *v) { struct proc_maps_private *priv = m->private; struct mem_size_stats mss = {}; struct mm_struct *mm = priv->mm; struct vm_area_struct *vma; unsigned long vma_start = 0, last_vma_end = 0; int ret = 0; VMA_ITERATOR(vmi, mm, 0); priv->task = get_proc_task(priv->inode); if (!priv->task) return -ESRCH; if (!mm || !mmget_not_zero(mm)) { ret = -ESRCH; goto out_put_task; } ret = mmap_read_lock_killable(mm); if (ret) goto out_put_mm; hold_task_mempolicy(priv); vma = vma_next(&vmi); if (unlikely(!vma)) goto empty_set; vma_start = vma->vm_start; do { 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)) { vma_iter_invalidate(&vmi); 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: * * vma_next(vmi) will return VMA3. * In this case, just continue from VMA3. * * 2) VMA2 still exists: * * vma_next(vmi) will return VMA3. * In this case, just continue from VMA3. * * 3) No more VMAs can be found: * * vma_next(vmi) will return NULL. * No more things to do, just break. * * 4) (last_vma_end - 1) is the middle of a vma (VMA'): * * vma_next(vmi) will return VMA' whose range * contains last_vma_end. * Iterate VMA' from last_vma_end. */ vma = vma_next(&vmi); /* Case 3 above */ if (!vma) break; /* Case 1 and 2 above */ if (vma->vm_start >= last_vma_end) { smap_gather_stats(vma, &mss, 0); last_vma_end = vma->vm_end; continue; } /* Case 4 above */ if (vma->vm_end > last_vma_end) { smap_gather_stats(vma, &mss, last_vma_end); last_vma_end = vma->vm_end; } } } for_each_vma(vmi, vma); empty_set: show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0); seq_pad(m, ' '); seq_puts(m, "[rollup]\n"); __show_smap(m, &mss, true); release_task_mempolicy(priv); mmap_read_unlock(mm); out_put_mm: mmput(mm); out_put_task: put_task_struct(priv->task); priv->task = NULL; return ret; } #undef SEQ_PUT_DEC static const struct seq_operations proc_pid_smaps_op = { .start = m_start, .next = m_next, .stop = m_stop, .show = show_smap }; static int pid_smaps_open(struct inode *inode, struct file *file) { return do_maps_open(inode, file, &proc_pid_smaps_op); } static int smaps_rollup_open(struct inode *inode, struct file *file) { int ret; struct proc_maps_private *priv; priv = kzalloc(sizeof(*priv), GFP_KERNEL_ACCOUNT); if (!priv) return -ENOMEM; ret = single_open(file, show_smaps_rollup, priv); if (ret) goto out_free; priv->inode = inode; priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); if (IS_ERR(priv->mm)) { ret = PTR_ERR(priv->mm); single_release(inode, file); goto out_free; } return 0; out_free: kfree(priv); return ret; } static int smaps_rollup_release(struct inode *inode, struct file *file) { struct seq_file *seq = file->private_data; struct proc_maps_private *priv = seq->private; if (priv->mm) mmdrop(priv->mm); kfree(priv); return single_release(inode, file); } const struct file_operations proc_pid_smaps_operations = { .open = pid_smaps_open, .read = seq_read, .llseek = seq_lseek, .release = proc_map_release, }; const struct file_operations proc_pid_smaps_rollup_operations = { .open = smaps_rollup_open, .read = seq_read, .llseek = seq_lseek, .release = smaps_rollup_release, }; enum clear_refs_types { CLEAR_REFS_ALL = 1, CLEAR_REFS_ANON, CLEAR_REFS_MAPPED, CLEAR_REFS_SOFT_DIRTY, CLEAR_REFS_MM_HIWATER_RSS, CLEAR_REFS_LAST, }; struct clear_refs_private { enum clear_refs_types type; }; #ifdef CONFIG_MEM_SOFT_DIRTY static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte) { struct folio *folio; if (!pte_write(pte)) return false; if (!is_cow_mapping(vma->vm_flags)) return false; if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags))) return false; folio = vm_normal_folio(vma, addr, pte); if (!folio) return false; return folio_maybe_dma_pinned(folio); } static inline void clear_soft_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *pte) { /* * The soft-dirty tracker uses #PF-s to catch writes * to pages, so write-protect the pte as well. See the * Documentation/admin-guide/mm/soft-dirty.rst for full description * of how soft-dirty works. */ pte_t ptent = ptep_get(pte); if (pte_present(ptent)) { pte_t old_pte; if (pte_is_pinned(vma, addr, ptent)) return; old_pte = ptep_modify_prot_start(vma, addr, pte); ptent = pte_wrprotect(old_pte); ptent = pte_clear_soft_dirty(ptent); ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); } else if (is_swap_pte(ptent)) { ptent = pte_swp_clear_soft_dirty(ptent); set_pte_at(vma->vm_mm, addr, pte, ptent); } } #else static inline void clear_soft_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *pte) { } #endif #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE) static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmdp) { pmd_t old, pmd = *pmdp; if (pmd_present(pmd)) { /* See comment in change_huge_pmd() */ old = pmdp_invalidate(vma, addr, pmdp); if (pmd_dirty(old)) pmd = pmd_mkdirty(pmd); if (pmd_young(old)) pmd = pmd_mkyoung(pmd); pmd = pmd_wrprotect(pmd); pmd = pmd_clear_soft_dirty(pmd); set_pmd_at(vma->vm_mm, addr, pmdp, pmd); } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { pmd = pmd_swp_clear_soft_dirty(pmd); set_pmd_at(vma->vm_mm, addr, pmdp, pmd); } } #else static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmdp) { } #endif static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct clear_refs_private *cp = walk->private; struct vm_area_struct *vma = walk->vma; pte_t *pte, ptent; spinlock_t *ptl; struct folio *folio; ptl = pmd_trans_huge_lock(pmd, vma); if (ptl) { if (cp->type == CLEAR_REFS_SOFT_DIRTY) { clear_soft_dirty_pmd(vma, addr, pmd); goto out; } if (!pmd_present(*pmd)) goto out; folio = pmd_folio(*pmd); /* Clear accessed and referenced bits. */ pmdp_test_and_clear_young(vma, addr, pmd); folio_test_clear_young(folio); folio_clear_referenced(folio); out: spin_unlock(ptl); return 0; } pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); if (!pte) { walk->action = ACTION_AGAIN; return 0; } for (; addr != end; pte++, addr += PAGE_SIZE) { ptent = ptep_get(pte); if (cp->type == CLEAR_REFS_SOFT_DIRTY) { clear_soft_dirty(vma, addr, pte); continue; } if (!pte_present(ptent)) continue; folio = vm_normal_folio(vma, addr, ptent); if (!folio) continue; /* Clear accessed and referenced bits. */ ptep_test_and_clear_young(vma, addr, pte); folio_test_clear_young(folio); folio_clear_referenced(folio); } pte_unmap_unlock(pte - 1, ptl); cond_resched(); return 0; } static int clear_refs_test_walk(unsigned long start, unsigned long end, struct mm_walk *walk) { struct clear_refs_private *cp = walk->private; struct vm_area_struct *vma = walk->vma; if (vma->vm_flags & VM_PFNMAP) return 1; /* * 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. * Writing 4 to /proc/pid/clear_refs affects all pages. */ if (cp->type == CLEAR_REFS_ANON && vma->vm_file) return 1; if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file) return 1; return 0; } static const struct mm_walk_ops clear_refs_walk_ops = { .pmd_entry = clear_refs_pte_range, .test_walk = clear_refs_test_walk, .walk_lock = PGWALK_WRLOCK, }; static ssize_t clear_refs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct task_struct *task; char buffer[PROC_NUMBUF] = {}; struct mm_struct *mm; struct vm_area_struct *vma; enum clear_refs_types type; int itype; int rv; if (count > sizeof(buffer) - 1) count = sizeof(buffer) - 1; if (copy_from_user(buffer, buf, count)) return -EFAULT; rv = kstrtoint(strstrip(buffer), 10, &itype); if (rv < 0) return rv; type = (enum clear_refs_types)itype; if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST) return -EINVAL; task = get_proc_task(file_inode(file)); if (!task) return -ESRCH; mm = get_task_mm(task); if (mm) { VMA_ITERATOR(vmi, mm, 0); struct mmu_notifier_range range; struct clear_refs_private cp = { .type = type, }; if (mmap_write_lock_killable(mm)) { count = -EINTR; goto out_mm; } if (type == CLEAR_REFS_MM_HIWATER_RSS) { /* * Writing 5 to /proc/pid/clear_refs resets the peak * resident set size to this mm's current rss value. */ reset_mm_hiwater_rss(mm); goto out_unlock; } if (type == CLEAR_REFS_SOFT_DIRTY) { for_each_vma(vmi, vma) { if (!(vma->vm_flags & VM_SOFTDIRTY)) continue; vm_flags_clear(vma, VM_SOFTDIRTY); vma_set_page_prot(vma); } inc_tlb_flush_pending(mm); mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY, 0, mm, 0, -1UL); mmu_notifier_invalidate_range_start(&range); } walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp); if (type == CLEAR_REFS_SOFT_DIRTY) { mmu_notifier_invalidate_range_end(&range); flush_tlb_mm(mm); dec_tlb_flush_pending(mm); } out_unlock: mmap_write_unlock(mm); out_mm: mmput(mm); } put_task_struct(task); return count; } const struct file_operations proc_clear_refs_operations = { .write = clear_refs_write, .llseek = noop_llseek, }; typedef struct { u64 pme; } pagemap_entry_t; struct pagemapread { int pos, len; /* units: PM_ENTRY_BYTES, not bytes */ pagemap_entry_t *buffer; bool show_pfn; }; #define PAGEMAP_WALK_SIZE (PMD_SIZE) #define PAGEMAP_WALK_MASK (PMD_MASK) #define PM_ENTRY_BYTES sizeof(pagemap_entry_t) #define PM_PFRAME_BITS 55 #define PM_PFRAME_MASK GENMASK_ULL(PM_PFRAME_BITS - 1, 0) #define PM_SOFT_DIRTY BIT_ULL(55) #define PM_MMAP_EXCLUSIVE BIT_ULL(56) #define PM_UFFD_WP BIT_ULL(57) #define PM_FILE BIT_ULL(61) #define PM_SWAP BIT_ULL(62) #define PM_PRESENT BIT_ULL(63) #define PM_END_OF_BUFFER 1 static inline pagemap_entry_t make_pme(u64 frame, u64 flags) { return (pagemap_entry_t) { .pme = (frame & PM_PFRAME_MASK) | flags }; } static int add_to_pagemap(pagemap_entry_t *pme, struct pagemapread *pm) { pm->buffer[pm->pos++] = *pme; if (pm->pos >= pm->len) return PM_END_OF_BUFFER; return 0; } static int pagemap_pte_hole(unsigned long start, unsigned long end, __always_unused int depth, struct mm_walk *walk) { struct pagemapread *pm = walk->private; unsigned long addr = start; int err = 0; while (addr < end) { struct vm_area_struct *vma = find_vma(walk->mm, addr); pagemap_entry_t pme = make_pme(0, 0); /* End of address space hole, which we mark as non-present. */ unsigned long hole_end; if (vma) hole_end = min(end, vma->vm_start); else hole_end = end; for (; addr < hole_end; addr += PAGE_SIZE) { err = add_to_pagemap(&pme, pm); if (err) goto out; } if (!vma) break; /* Addresses in the VMA. */ if (vma->vm_flags & VM_SOFTDIRTY) pme = make_pme(0, PM_SOFT_DIRTY); for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) { err = add_to_pagemap(&pme, pm); if (err) goto out; } } out: return err; } static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm, struct vm_area_struct *vma, unsigned long addr, pte_t pte) { u64 frame = 0, flags = 0; struct page *page = NULL; struct folio *folio; if (pte_present(pte)) { if (pm->show_pfn) frame = pte_pfn(pte); flags |= PM_PRESENT; page = vm_normal_page(vma, addr, pte); if (pte_soft_dirty(pte)) flags |= PM_SOFT_DIRTY; if (pte_uffd_wp(pte)) flags |= PM_UFFD_WP; } else if (is_swap_pte(pte)) { swp_entry_t entry; if (pte_swp_soft_dirty(pte)) flags |= PM_SOFT_DIRTY; if (pte_swp_uffd_wp(pte)) flags |= PM_UFFD_WP; entry = pte_to_swp_entry(pte); if (pm->show_pfn) { pgoff_t offset; /* * For PFN swap offsets, keeping the offset field * to be PFN only to be compatible with old smaps. */ if (is_pfn_swap_entry(entry)) offset = swp_offset_pfn(entry); else offset = swp_offset(entry); frame = swp_type(entry) | (offset << MAX_SWAPFILES_SHIFT); } flags |= PM_SWAP; if (is_pfn_swap_entry(entry)) page = pfn_swap_entry_to_page(entry); if (pte_marker_entry_uffd_wp(entry)) flags |= PM_UFFD_WP; } if (page) { folio = page_folio(page); if (!folio_test_anon(folio)) flags |= PM_FILE; if ((flags & PM_PRESENT) && folio_precise_page_mapcount(folio, page) == 1) flags |= PM_MMAP_EXCLUSIVE; } if (vma->vm_flags & VM_SOFTDIRTY) flags |= PM_SOFT_DIRTY; return make_pme(frame, flags); } static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct vm_area_struct *vma = walk->vma; struct pagemapread *pm = walk->private; spinlock_t *ptl; pte_t *pte, *orig_pte; int err = 0; #ifdef CONFIG_TRANSPARENT_HUGEPAGE ptl = pmd_trans_huge_lock(pmdp, vma); if (ptl) { unsigned int idx = (addr & ~PMD_MASK) >> PAGE_SHIFT; u64 flags = 0, frame = 0; pmd_t pmd = *pmdp; struct page *page = NULL; struct folio *folio = NULL; if (vma->vm_flags & VM_SOFTDIRTY) flags |= PM_SOFT_DIRTY; if (pmd_present(pmd)) { page = pmd_page(pmd); flags |= PM_PRESENT; if (pmd_soft_dirty(pmd)) flags |= PM_SOFT_DIRTY; if (pmd_uffd_wp(pmd)) flags |= PM_UFFD_WP; if (pm->show_pfn) frame = pmd_pfn(pmd) + idx; } #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION else if (is_swap_pmd(pmd)) { swp_entry_t entry = pmd_to_swp_entry(pmd); unsigned long offset; if (pm->show_pfn) { if (is_pfn_swap_entry(entry)) offset = swp_offset_pfn(entry) + idx; else offset = swp_offset(entry) + idx; frame = swp_type(entry) | (offset << MAX_SWAPFILES_SHIFT); } flags |= PM_SWAP; if (pmd_swp_soft_dirty(pmd)) flags |= PM_SOFT_DIRTY; if (pmd_swp_uffd_wp(pmd)) flags |= PM_UFFD_WP; VM_BUG_ON(!is_pmd_migration_entry(pmd)); page = pfn_swap_entry_to_page(entry); } #endif if (page) { folio = page_folio(page); if (!folio_test_anon(folio)) flags |= PM_FILE; } for (; addr != end; addr += PAGE_SIZE, idx++) { unsigned long cur_flags = flags; pagemap_entry_t pme; if (folio && (flags & PM_PRESENT) && folio_precise_page_mapcount(folio, page + idx) == 1) cur_flags |= PM_MMAP_EXCLUSIVE; pme = make_pme(frame, cur_flags); err = add_to_pagemap(&pme, pm); if (err) break; if (pm->show_pfn) { if (flags & PM_PRESENT) frame++; else if (flags & PM_SWAP) frame += (1 << MAX_SWAPFILES_SHIFT); } } spin_unlock(ptl); return err; } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ /* * We can assume that @vma always points to a valid one and @end never * goes beyond vma->vm_end. */ orig_pte = pte = pte_offset_map_lock(walk->mm, pmdp, addr, &ptl); if (!pte) { walk->action = ACTION_AGAIN; return err; } for (; addr < end; pte++, addr += PAGE_SIZE) { pagemap_entry_t pme; pme = pte_to_pagemap_entry(pm, vma, addr, ptep_get(pte)); err = add_to_pagemap(&pme, pm); if (err) break; } pte_unmap_unlock(orig_pte, ptl); cond_resched(); return err; } #ifdef CONFIG_HUGETLB_PAGE /* This function walks within one hugetlb entry in the single call */ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct pagemapread *pm = walk->private; struct vm_area_struct *vma = walk->vma; u64 flags = 0, frame = 0; int err = 0; pte_t pte; if (vma->vm_flags & VM_SOFTDIRTY) flags |= PM_SOFT_DIRTY; pte = huge_ptep_get(walk->mm, addr, ptep); if (pte_present(pte)) { struct folio *folio = page_folio(pte_page(pte)); if (!folio_test_anon(folio)) flags |= PM_FILE; if (!folio_likely_mapped_shared(folio) && !hugetlb_pmd_shared(ptep)) flags |= PM_MMAP_EXCLUSIVE; if (huge_pte_uffd_wp(pte)) flags |= PM_UFFD_WP; flags |= PM_PRESENT; if (pm->show_pfn) frame = pte_pfn(pte) + ((addr & ~hmask) >> PAGE_SHIFT); } else if (pte_swp_uffd_wp_any(pte)) { flags |= PM_UFFD_WP; } for (; addr != end; addr += PAGE_SIZE) { pagemap_entry_t pme = make_pme(frame, flags); err = add_to_pagemap(&pme, pm); if (err) return err; if (pm->show_pfn && (flags & PM_PRESENT)) frame++; } cond_resched(); return err; } #else #define pagemap_hugetlb_range NULL #endif /* HUGETLB_PAGE */ static const struct mm_walk_ops pagemap_ops = { .pmd_entry = pagemap_pmd_range, .pte_hole = pagemap_pte_hole, .hugetlb_entry = pagemap_hugetlb_range, .walk_lock = PGWALK_RDLOCK, }; /* * /proc/pid/pagemap - an array mapping virtual pages to pfns * * For each page in the address space, this file contains one 64-bit entry * consisting of the following: * * Bits 0-54 page frame number (PFN) if present * Bits 0-4 swap type if swapped * Bits 5-54 swap offset if swapped * Bit 55 pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst) * Bit 56 page exclusively mapped * Bit 57 pte is uffd-wp write-protected * Bits 58-60 zero * Bit 61 page is file-page or shared-anon * Bit 62 page swapped * Bit 63 page present * * If the page is not present but in swap, then the PFN contains an * encoding of the swap file number and the page's offset into the * swap. Unmapped pages return a null PFN. This allows determining * precisely which pages are mapped (or in swap) and comparing mapped * pages between processes. * * Efficient users of this interface will use /proc/pid/maps to * determine which areas of memory are actually mapped and llseek to * skip over unmapped regions. */ static ssize_t pagemap_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { struct mm_struct *mm = file->private_data; struct pagemapread pm; unsigned long src; unsigned long svpfn; unsigned long start_vaddr; unsigned long end_vaddr; int ret = 0, copied = 0; if (!mm || !mmget_not_zero(mm)) goto out; ret = -EINVAL; /* file position must be aligned */ if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES)) goto out_mm; ret = 0; if (!count) goto out_mm; /* do not disclose physical addresses: attack vector */ pm.show_pfn = file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN); pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT); pm.buffer = kmalloc_array(pm.len, PM_ENTRY_BYTES, GFP_KERNEL); ret = -ENOMEM; if (!pm.buffer) goto out_mm; src = *ppos; svpfn = src / PM_ENTRY_BYTES; end_vaddr = mm->task_size; /* watch out for wraparound */ start_vaddr = end_vaddr; if (svpfn <= (ULONG_MAX >> PAGE_SHIFT)) { unsigned long end; ret = mmap_read_lock_killable(mm); if (ret) goto out_free; start_vaddr = untagged_addr_remote(mm, svpfn << PAGE_SHIFT); mmap_read_unlock(mm); end = start_vaddr + ((count / PM_ENTRY_BYTES) << PAGE_SHIFT); if (end >= start_vaddr && end < mm->task_size) end_vaddr = end; } /* Ensure the address is inside the task */ if (start_vaddr > mm->task_size) start_vaddr = end_vaddr; ret = 0; while (count && (start_vaddr < end_vaddr)) { int len; unsigned long end; pm.pos = 0; end = (start_vaddr + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK; /* overflow ? */ if (end < start_vaddr || end > end_vaddr) end = end_vaddr; ret = mmap_read_lock_killable(mm); if (ret) goto out_free; ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm); mmap_read_unlock(mm); start_vaddr = end; len = min(count, PM_ENTRY_BYTES * pm.pos); if (copy_to_user(buf, pm.buffer, len)) { ret = -EFAULT; goto out_free; } copied += len; buf += len; count -= len; } *ppos += copied; if (!ret || ret == PM_END_OF_BUFFER) ret = copied; out_free: kfree(pm.buffer); out_mm: mmput(mm); out: return ret; } static int pagemap_open(struct inode *inode, struct file *file) { struct mm_struct *mm; mm = proc_mem_open(inode, PTRACE_MODE_READ); if (IS_ERR(mm)) return PTR_ERR(mm); file->private_data = mm; return 0; } static int pagemap_release(struct inode *inode, struct file *file) { struct mm_struct *mm = file->private_data; if (mm) mmdrop(mm); return 0; } #define PM_SCAN_CATEGORIES (PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | \ PAGE_IS_FILE | PAGE_IS_PRESENT | \ PAGE_IS_SWAPPED | PAGE_IS_PFNZERO | \ PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY) #define PM_SCAN_FLAGS (PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC) struct pagemap_scan_private { struct pm_scan_arg arg; unsigned long masks_of_interest, cur_vma_category; struct page_region *vec_buf; unsigned long vec_buf_len, vec_buf_index, found_pages; struct page_region __user *vec_out; }; static unsigned long pagemap_page_category(struct pagemap_scan_private *p, struct vm_area_struct *vma, unsigned long addr, pte_t pte) { unsigned long categories = 0; if (pte_present(pte)) { struct page *page; categories |= PAGE_IS_PRESENT; if (!pte_uffd_wp(pte)) categories |= PAGE_IS_WRITTEN; if (p->masks_of_interest & PAGE_IS_FILE) { page = vm_normal_page(vma, addr, pte); if (page && !PageAnon(page)) categories |= PAGE_IS_FILE; } if (is_zero_pfn(pte_pfn(pte))) categories |= PAGE_IS_PFNZERO; if (pte_soft_dirty(pte)) categories |= PAGE_IS_SOFT_DIRTY; } else if (is_swap_pte(pte)) { swp_entry_t swp; categories |= PAGE_IS_SWAPPED; if (!pte_swp_uffd_wp_any(pte)) categories |= PAGE_IS_WRITTEN; if (p->masks_of_interest & PAGE_IS_FILE) { swp = pte_to_swp_entry(pte); if (is_pfn_swap_entry(swp) && !folio_test_anon(pfn_swap_entry_folio(swp))) categories |= PAGE_IS_FILE; } if (pte_swp_soft_dirty(pte)) categories |= PAGE_IS_SOFT_DIRTY; } return categories; } static void make_uffd_wp_pte(struct vm_area_struct *vma, unsigned long addr, pte_t *pte, pte_t ptent) { if (pte_present(ptent)) { pte_t old_pte; old_pte = ptep_modify_prot_start(vma, addr, pte); ptent = pte_mkuffd_wp(old_pte); ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); } else if (is_swap_pte(ptent)) { ptent = pte_swp_mkuffd_wp(ptent); set_pte_at(vma->vm_mm, addr, pte, ptent); } else { set_pte_at(vma->vm_mm, addr, pte, make_pte_marker(PTE_MARKER_UFFD_WP)); } } #ifdef CONFIG_TRANSPARENT_HUGEPAGE static unsigned long pagemap_thp_category(struct pagemap_scan_private *p, struct vm_area_struct *vma, unsigned long addr, pmd_t pmd) { unsigned long categories = PAGE_IS_HUGE; if (pmd_present(pmd)) { struct page *page; categories |= PAGE_IS_PRESENT; if (!pmd_uffd_wp(pmd)) categories |= PAGE_IS_WRITTEN; if (p->masks_of_interest & PAGE_IS_FILE) { page = vm_normal_page_pmd(vma, addr, pmd); if (page && !PageAnon(page)) categories |= PAGE_IS_FILE; } if (is_zero_pfn(pmd_pfn(pmd))) categories |= PAGE_IS_PFNZERO; if (pmd_soft_dirty(pmd)) categories |= PAGE_IS_SOFT_DIRTY; } else if (is_swap_pmd(pmd)) { swp_entry_t swp; categories |= PAGE_IS_SWAPPED; if (!pmd_swp_uffd_wp(pmd)) categories |= PAGE_IS_WRITTEN; if (pmd_swp_soft_dirty(pmd)) categories |= PAGE_IS_SOFT_DIRTY; if (p->masks_of_interest & PAGE_IS_FILE) { swp = pmd_to_swp_entry(pmd); if (is_pfn_swap_entry(swp) && !folio_test_anon(pfn_swap_entry_folio(swp))) categories |= PAGE_IS_FILE; } } return categories; } static void make_uffd_wp_pmd(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmdp) { pmd_t old, pmd = *pmdp; if (pmd_present(pmd)) { old = pmdp_invalidate_ad(vma, addr, pmdp); pmd = pmd_mkuffd_wp(old); set_pmd_at(vma->vm_mm, addr, pmdp, pmd); } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { pmd = pmd_swp_mkuffd_wp(pmd); set_pmd_at(vma->vm_mm, addr, pmdp, pmd); } } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #ifdef CONFIG_HUGETLB_PAGE static unsigned long pagemap_hugetlb_category(pte_t pte) { unsigned long categories = PAGE_IS_HUGE; /* * According to pagemap_hugetlb_range(), file-backed HugeTLB * page cannot be swapped. So PAGE_IS_FILE is not checked for * swapped pages. */ if (pte_present(pte)) { categories |= PAGE_IS_PRESENT; if (!huge_pte_uffd_wp(pte)) categories |= PAGE_IS_WRITTEN; if (!PageAnon(pte_page(pte))) categories |= PAGE_IS_FILE; if (is_zero_pfn(pte_pfn(pte))) categories |= PAGE_IS_PFNZERO; if (pte_soft_dirty(pte)) categories |= PAGE_IS_SOFT_DIRTY; } else if (is_swap_pte(pte)) { categories |= PAGE_IS_SWAPPED; if (!pte_swp_uffd_wp_any(pte)) categories |= PAGE_IS_WRITTEN; if (pte_swp_soft_dirty(pte)) categories |= PAGE_IS_SOFT_DIRTY; } return categories; } static void make_uffd_wp_huge_pte(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, pte_t ptent) { unsigned long psize; if (is_hugetlb_entry_hwpoisoned(ptent) || is_pte_marker(ptent)) return; psize = huge_page_size(hstate_vma(vma)); if (is_hugetlb_entry_migration(ptent)) set_huge_pte_at(vma->vm_mm, addr, ptep, pte_swp_mkuffd_wp(ptent), psize); else if (!huge_pte_none(ptent)) huge_ptep_modify_prot_commit(vma, addr, ptep, ptent, huge_pte_mkuffd_wp(ptent)); else set_huge_pte_at(vma->vm_mm, addr, ptep, make_pte_marker(PTE_MARKER_UFFD_WP), psize); } #endif /* CONFIG_HUGETLB_PAGE */ #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE) static void pagemap_scan_backout_range(struct pagemap_scan_private *p, unsigned long addr, unsigned long end) { struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index]; if (cur_buf->start != addr) cur_buf->end = addr; else cur_buf->start = cur_buf->end = 0; p->found_pages -= (end - addr) / PAGE_SIZE; } #endif static bool pagemap_scan_is_interesting_page(unsigned long categories, const struct pagemap_scan_private *p) { categories ^= p->arg.category_inverted; if ((categories & p->arg.category_mask) != p->arg.category_mask) return false; if (p->arg.category_anyof_mask && !(categories & p->arg.category_anyof_mask)) return false; return true; } static bool pagemap_scan_is_interesting_vma(unsigned long categories, const struct pagemap_scan_private *p) { unsigned long required = p->arg.category_mask & PAGE_IS_WPALLOWED; categories ^= p->arg.category_inverted; if ((categories & required) != required) return false; return true; } static int pagemap_scan_test_walk(unsigned long start, unsigned long end, struct mm_walk *walk) { struct pagemap_scan_private *p = walk->private; struct vm_area_struct *vma = walk->vma; unsigned long vma_category = 0; bool wp_allowed = userfaultfd_wp_async(vma) && userfaultfd_wp_use_markers(vma); if (!wp_allowed) { /* User requested explicit failure over wp-async capability */ if (p->arg.flags & PM_SCAN_CHECK_WPASYNC) return -EPERM; /* * User requires wr-protect, and allows silently skipping * unsupported vmas. */ if (p->arg.flags & PM_SCAN_WP_MATCHING) return 1; /* * Then the request doesn't involve wr-protects at all, * fall through to the rest checks, and allow vma walk. */ } if (vma->vm_flags & VM_PFNMAP) return 1; if (wp_allowed) vma_category |= PAGE_IS_WPALLOWED; if (vma->vm_flags & VM_SOFTDIRTY) vma_category |= PAGE_IS_SOFT_DIRTY; if (!pagemap_scan_is_interesting_vma(vma_category, p)) return 1; p->cur_vma_category = vma_category; return 0; } static bool pagemap_scan_push_range(unsigned long categories, struct pagemap_scan_private *p, unsigned long addr, unsigned long end) { struct page_region *cur_buf = &p->vec_buf[p->vec_buf_index]; /* * When there is no output buffer provided at all, the sentinel values * won't match here. There is no other way for `cur_buf->end` to be * non-zero other than it being non-empty. */ if (addr == cur_buf->end && categories == cur_buf->categories) { cur_buf->end = end; return true; } if (cur_buf->end) { if (p->vec_buf_index >= p->vec_buf_len - 1) return false; cur_buf = &p->vec_buf[++p->vec_buf_index]; } cur_buf->start = addr; cur_buf->end = end; cur_buf->categories = categories; return true; } static int pagemap_scan_output(unsigned long categories, struct pagemap_scan_private *p, unsigned long addr, unsigned long *end) { unsigned long n_pages, total_pages; int ret = 0; if (!p->vec_buf) return 0; categories &= p->arg.return_mask; n_pages = (*end - addr) / PAGE_SIZE; if (check_add_overflow(p->found_pages, n_pages, &total_pages) || total_pages > p->arg.max_pages) { size_t n_too_much = total_pages - p->arg.max_pages; *end -= n_too_much * PAGE_SIZE; n_pages -= n_too_much; ret = -ENOSPC; } if (!pagemap_scan_push_range(categories, p, addr, *end)) { *end = addr; n_pages = 0; ret = -ENOSPC; } p->found_pages += n_pages; if (ret) p->arg.walk_end = *end; return ret; } static int pagemap_scan_thp_entry(pmd_t *pmd, unsigned long start, unsigned long end, struct mm_walk *walk) { #ifdef CONFIG_TRANSPARENT_HUGEPAGE struct pagemap_scan_private *p = walk->private; struct vm_area_struct *vma = walk->vma; unsigned long categories; spinlock_t *ptl; int ret = 0; ptl = pmd_trans_huge_lock(pmd, vma); if (!ptl) return -ENOENT; categories = p->cur_vma_category | pagemap_thp_category(p, vma, start, *pmd); if (!pagemap_scan_is_interesting_page(categories, p)) goto out_unlock; ret = pagemap_scan_output(categories, p, start, &end); if (start == end) goto out_unlock; if (~p->arg.flags & PM_SCAN_WP_MATCHING) goto out_unlock; if (~categories & PAGE_IS_WRITTEN) goto out_unlock; /* * Break huge page into small pages if the WP operation * needs to be performed on a portion of the huge page. */ if (end != start + HPAGE_SIZE) { spin_unlock(ptl); split_huge_pmd(vma, pmd, start); pagemap_scan_backout_range(p, start, end); /* Report as if there was no THP */ return -ENOENT; } make_uffd_wp_pmd(vma, start, pmd); flush_tlb_range(vma, start, end); out_unlock: spin_unlock(ptl); return ret; #else /* !CONFIG_TRANSPARENT_HUGEPAGE */ return -ENOENT; #endif } static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start, unsigned long end, struct mm_walk *walk) { struct pagemap_scan_private *p = walk->private; struct vm_area_struct *vma = walk->vma; unsigned long addr, flush_end = 0; pte_t *pte, *start_pte; spinlock_t *ptl; int ret; arch_enter_lazy_mmu_mode(); ret = pagemap_scan_thp_entry(pmd, start, end, walk); if (ret != -ENOENT) { arch_leave_lazy_mmu_mode(); return ret; } ret = 0; start_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); if (!pte) { arch_leave_lazy_mmu_mode(); walk->action = ACTION_AGAIN; return 0; } if ((p->arg.flags & PM_SCAN_WP_MATCHING) && !p->vec_out) { /* Fast path for performing exclusive WP */ for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { pte_t ptent = ptep_get(pte); if ((pte_present(ptent) && pte_uffd_wp(ptent)) || pte_swp_uffd_wp_any(ptent)) continue; make_uffd_wp_pte(vma, addr, pte, ptent); if (!flush_end) start = addr; flush_end = addr + PAGE_SIZE; } goto flush_and_return; } if (!p->arg.category_anyof_mask && !p->arg.category_inverted && p->arg.category_mask == PAGE_IS_WRITTEN && p->arg.return_mask == PAGE_IS_WRITTEN) { for (addr = start; addr < end; pte++, addr += PAGE_SIZE) { unsigned long next = addr + PAGE_SIZE; pte_t ptent = ptep_get(pte); if ((pte_present(ptent) && pte_uffd_wp(ptent)) || pte_swp_uffd_wp_any(ptent)) continue; ret = pagemap_scan_output(p->cur_vma_category | PAGE_IS_WRITTEN, p, addr, &next); if (next == addr) break; if (~p->arg.flags & PM_SCAN_WP_MATCHING) continue; make_uffd_wp_pte(vma, addr, pte, ptent); if (!flush_end) start = addr; flush_end = next; } goto flush_and_return; } for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { pte_t ptent = ptep_get(pte); unsigned long categories = p->cur_vma_category | pagemap_page_category(p, vma, addr, ptent); unsigned long next = addr + PAGE_SIZE; if (!pagemap_scan_is_interesting_page(categories, p)) continue; ret = pagemap_scan_output(categories, p, addr, &next); if (next == addr) break; if (~p->arg.flags & PM_SCAN_WP_MATCHING) continue; if (~categories & PAGE_IS_WRITTEN) continue; make_uffd_wp_pte(vma, addr, pte, ptent); if (!flush_end) start = addr; flush_end = next; } flush_and_return: if (flush_end) flush_tlb_range(vma, start, addr); pte_unmap_unlock(start_pte, ptl); arch_leave_lazy_mmu_mode(); cond_resched(); return ret; } #ifdef CONFIG_HUGETLB_PAGE static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask, unsigned long start, unsigned long end, struct mm_walk *walk) { struct pagemap_scan_private *p = walk->private; struct vm_area_struct *vma = walk->vma; unsigned long categories; spinlock_t *ptl; int ret = 0; pte_t pte; if (~p->arg.flags & PM_SCAN_WP_MATCHING) { /* Go the short route when not write-protecting pages. */ pte = huge_ptep_get(walk->mm, start, ptep); categories = p->cur_vma_category | pagemap_hugetlb_category(pte); if (!pagemap_scan_is_interesting_page(categories, p)) return 0; return pagemap_scan_output(categories, p, start, &end); } i_mmap_lock_write(vma->vm_file->f_mapping); ptl = huge_pte_lock(hstate_vma(vma), vma->vm_mm, ptep); pte = huge_ptep_get(walk->mm, start, ptep); categories = p->cur_vma_category | pagemap_hugetlb_category(pte); if (!pagemap_scan_is_interesting_page(categories, p)) goto out_unlock; ret = pagemap_scan_output(categories, p, start, &end); if (start == end) goto out_unlock; if (~categories & PAGE_IS_WRITTEN) goto out_unlock; if (end != start + HPAGE_SIZE) { /* Partial HugeTLB page WP isn't possible. */ pagemap_scan_backout_range(p, start, end); p->arg.walk_end = start; ret = 0; goto out_unlock; } make_uffd_wp_huge_pte(vma, start, ptep, pte); flush_hugetlb_tlb_range(vma, start, end); out_unlock: spin_unlock(ptl); i_mmap_unlock_write(vma->vm_file->f_mapping); return ret; } #else #define pagemap_scan_hugetlb_entry NULL #endif static int pagemap_scan_pte_hole(unsigned long addr, unsigned long end, int depth, struct mm_walk *walk) { struct pagemap_scan_private *p = walk->private; struct vm_area_struct *vma = walk->vma; int ret, err; if (!vma || !pagemap_scan_is_interesting_page(p->cur_vma_category, p)) return 0; ret = pagemap_scan_output(p->cur_vma_category, p, addr, &end); if (addr == end) return ret; if (~p->arg.flags & PM_SCAN_WP_MATCHING) return ret; err = uffd_wp_range(vma, addr, end - addr, true); if (err < 0) ret = err; return ret; } static const struct mm_walk_ops pagemap_scan_ops = { .test_walk = pagemap_scan_test_walk, .pmd_entry = pagemap_scan_pmd_entry, .pte_hole = pagemap_scan_pte_hole, .hugetlb_entry = pagemap_scan_hugetlb_entry, }; static int pagemap_scan_get_args(struct pm_scan_arg *arg, unsigned long uarg) { if (copy_from_user(arg, (void __user *)uarg, sizeof(*arg))) return -EFAULT; if (arg->size != sizeof(struct pm_scan_arg)) return -EINVAL; /* Validate requested features */ if (arg->flags & ~PM_SCAN_FLAGS) return -EINVAL; if ((arg->category_inverted | arg->category_mask | arg->category_anyof_mask | arg->return_mask) & ~PM_SCAN_CATEGORIES) return -EINVAL; arg->start = untagged_addr((unsigned long)arg->start); arg->end = untagged_addr((unsigned long)arg->end); arg->vec = untagged_addr((unsigned long)arg->vec); /* Validate memory pointers */ if (!IS_ALIGNED(arg->start, PAGE_SIZE)) return -EINVAL; if (!access_ok((void __user *)(long)arg->start, arg->end - arg->start)) return -EFAULT; if (!arg->vec && arg->vec_len) return -EINVAL; if (arg->vec && !access_ok((void __user *)(long)arg->vec, arg->vec_len * sizeof(struct page_region))) return -EFAULT; /* Fixup default values */ arg->end = ALIGN(arg->end, PAGE_SIZE); arg->walk_end = 0; if (!arg->max_pages) arg->max_pages = ULONG_MAX; return 0; } static int pagemap_scan_writeback_args(struct pm_scan_arg *arg, unsigned long uargl) { struct pm_scan_arg __user *uarg = (void __user *)uargl; if (copy_to_user(&uarg->walk_end, &arg->walk_end, sizeof(arg->walk_end))) return -EFAULT; return 0; } static int pagemap_scan_init_bounce_buffer(struct pagemap_scan_private *p) { if (!p->arg.vec_len) return 0; p->vec_buf_len = min_t(size_t, PAGEMAP_WALK_SIZE >> PAGE_SHIFT, p->arg.vec_len); p->vec_buf = kmalloc_array(p->vec_buf_len, sizeof(*p->vec_buf), GFP_KERNEL); if (!p->vec_buf) return -ENOMEM; p->vec_buf->start = p->vec_buf->end = 0; p->vec_out = (struct page_region __user *)(long)p->arg.vec; return 0; } static long pagemap_scan_flush_buffer(struct pagemap_scan_private *p) { const struct page_region *buf = p->vec_buf; long n = p->vec_buf_index; if (!p->vec_buf) return 0; if (buf[n].end != buf[n].start) n++; if (!n) return 0; if (copy_to_user(p->vec_out, buf, n * sizeof(*buf))) return -EFAULT; p->arg.vec_len -= n; p->vec_out += n; p->vec_buf_index = 0; p->vec_buf_len = min_t(size_t, p->vec_buf_len, p->arg.vec_len); p->vec_buf->start = p->vec_buf->end = 0; return n; } static long do_pagemap_scan(struct mm_struct *mm, unsigned long uarg) { struct pagemap_scan_private p = {0}; unsigned long walk_start; size_t n_ranges_out = 0; int ret; ret = pagemap_scan_get_args(&p.arg, uarg); if (ret) return ret; p.masks_of_interest = p.arg.category_mask | p.arg.category_anyof_mask | p.arg.return_mask; ret = pagemap_scan_init_bounce_buffer(&p); if (ret) return ret; for (walk_start = p.arg.start; walk_start < p.arg.end; walk_start = p.arg.walk_end) { struct mmu_notifier_range range; long n_out; if (fatal_signal_pending(current)) { ret = -EINTR; break; } ret = mmap_read_lock_killable(mm); if (ret) break; /* Protection change for the range is going to happen. */ if (p.arg.flags & PM_SCAN_WP_MATCHING) { mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 0, mm, walk_start, p.arg.end); mmu_notifier_invalidate_range_start(&range); } ret = walk_page_range(mm, walk_start, p.arg.end, &pagemap_scan_ops, &p); if (p.arg.flags & PM_SCAN_WP_MATCHING) mmu_notifier_invalidate_range_end(&range); mmap_read_unlock(mm); n_out = pagemap_scan_flush_buffer(&p); if (n_out < 0) ret = n_out; else n_ranges_out += n_out; if (ret != -ENOSPC) break; if (p.arg.vec_len == 0 || p.found_pages == p.arg.max_pages) break; } /* ENOSPC signifies early stop (buffer full) from the walk. */ if (!ret || ret == -ENOSPC) ret = n_ranges_out; /* The walk_end isn't set when ret is zero */ if (!p.arg.walk_end) p.arg.walk_end = p.arg.end; if (pagemap_scan_writeback_args(&p.arg, uarg)) ret = -EFAULT; kfree(p.vec_buf); return ret; } static long do_pagemap_cmd(struct file *file, unsigned int cmd, unsigned long arg) { struct mm_struct *mm = file->private_data; switch (cmd) { case PAGEMAP_SCAN: return do_pagemap_scan(mm, arg); default: return -EINVAL; } } const struct file_operations proc_pagemap_operations = { .llseek = mem_lseek, /* borrow this */ .read = pagemap_read, .open = pagemap_open, .release = pagemap_release, .unlocked_ioctl = do_pagemap_cmd, .compat_ioctl = do_pagemap_cmd, }; #endif /* CONFIG_PROC_PAGE_MONITOR */ #ifdef CONFIG_NUMA struct numa_maps { unsigned long pages; unsigned long anon; unsigned long active; unsigned long writeback; unsigned long mapcount_max; unsigned long dirty; unsigned long swapcache; unsigned long node[MAX_NUMNODES]; }; struct numa_maps_private { struct proc_maps_private proc_maps; struct numa_maps md; }; static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty, unsigned long nr_pages) { struct folio *folio = page_folio(page); int count = folio_precise_page_mapcount(folio, page); md->pages += nr_pages; if (pte_dirty || folio_test_dirty(folio)) md->dirty += nr_pages; if (folio_test_swapcache(folio)) md->swapcache += nr_pages; if (folio_test_active(folio) || folio_test_unevictable(folio)) md->active += nr_pages; if (folio_test_writeback(folio)) md->writeback += nr_pages; if (folio_test_anon(folio)) md->anon += nr_pages; if (count > md->mapcount_max) md->mapcount_max = count; md->node[folio_nid(folio)] += nr_pages; } static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma, unsigned long addr) { struct page *page; int nid; if (!pte_present(pte)) return NULL; page = vm_normal_page(vma, addr, pte); if (!page || is_zone_device_page(page)) return NULL; if (PageReserved(page)) return NULL; nid = page_to_nid(page); if (!node_isset(nid, node_states[N_MEMORY])) return NULL; return page; } #ifdef CONFIG_TRANSPARENT_HUGEPAGE static struct page *can_gather_numa_stats_pmd(pmd_t pmd, struct vm_area_struct *vma, unsigned long addr) { struct page *page; int nid; if (!pmd_present(pmd)) return NULL; page = vm_normal_page_pmd(vma, addr, pmd); if (!page) return NULL; if (PageReserved(page)) return NULL; nid = page_to_nid(page); if (!node_isset(nid, node_states[N_MEMORY])) return NULL; return page; } #endif static int gather_pte_stats(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct numa_maps *md = walk->private; struct vm_area_struct *vma = walk->vma; spinlock_t *ptl; pte_t *orig_pte; pte_t *pte; #ifdef CONFIG_TRANSPARENT_HUGEPAGE ptl = pmd_trans_huge_lock(pmd, vma); if (ptl) { struct page *page; page = can_gather_numa_stats_pmd(*pmd, vma, addr); if (page) gather_stats(page, md, pmd_dirty(*pmd), HPAGE_PMD_SIZE/PAGE_SIZE); spin_unlock(ptl); return 0; } #endif orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); if (!pte) { walk->action = ACTION_AGAIN; return 0; } do { pte_t ptent = ptep_get(pte); struct page *page = can_gather_numa_stats(ptent, vma, addr); if (!page) continue; gather_stats(page, md, pte_dirty(ptent), 1); } while (pte++, addr += PAGE_SIZE, addr != end); pte_unmap_unlock(orig_pte, ptl); cond_resched(); return 0; } #ifdef CONFIG_HUGETLB_PAGE static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, unsigned long addr, unsigned long end, struct mm_walk *walk) { pte_t huge_pte = huge_ptep_get(walk->mm, addr, pte); struct numa_maps *md; struct page *page; if (!pte_present(huge_pte)) return 0; page = pte_page(huge_pte); md = walk->private; gather_stats(page, md, pte_dirty(huge_pte), 1); return 0; } #else static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, unsigned long addr, unsigned long end, struct mm_walk *walk) { return 0; } #endif static const struct mm_walk_ops show_numa_ops = { .hugetlb_entry = gather_hugetlb_stats, .pmd_entry = gather_pte_stats, .walk_lock = PGWALK_RDLOCK, }; /* * Display pages allocated per node and memory policy via /proc. */ static int show_numa_map(struct seq_file *m, void *v) { struct numa_maps_private *numa_priv = m->private; struct proc_maps_private *proc_priv = &numa_priv->proc_maps; struct vm_area_struct *vma = v; struct numa_maps *md = &numa_priv->md; struct file *file = vma->vm_file; struct mm_struct *mm = vma->vm_mm; char buffer[64]; struct mempolicy *pol; pgoff_t ilx; int nid; if (!mm) return 0; /* Ensure we start with an empty set of numa_maps statistics. */ memset(md, 0, sizeof(*md)); pol = __get_vma_policy(vma, vma->vm_start, &ilx); if (pol) { mpol_to_str(buffer, sizeof(buffer), pol); mpol_cond_put(pol); } else { mpol_to_str(buffer, sizeof(buffer), proc_priv->task_mempolicy); } seq_printf(m, "%08lx %s", vma->vm_start, buffer); if (file) { seq_puts(m, " file="); seq_path(m, file_user_path(file), "\n\t= "); } else if (vma_is_initial_heap(vma)) { seq_puts(m, " heap"); } else if (vma_is_initial_stack(vma)) { seq_puts(m, " stack"); } if (is_vm_hugetlb_page(vma)) seq_puts(m, " huge"); /* mmap_lock is held by m_start */ walk_page_vma(vma, &show_numa_ops, md); if (!md->pages) goto out; if (md->anon) seq_printf(m, " anon=%lu", md->anon); if (md->dirty) seq_printf(m, " dirty=%lu", md->dirty); if (md->pages != md->anon && md->pages != md->dirty) seq_printf(m, " mapped=%lu", md->pages); if (md->mapcount_max > 1) seq_printf(m, " mapmax=%lu", md->mapcount_max); if (md->swapcache) seq_printf(m, " swapcache=%lu", md->swapcache); if (md->active < md->pages && !is_vm_hugetlb_page(vma)) seq_printf(m, " active=%lu", md->active); if (md->writeback) seq_printf(m, " writeback=%lu", md->writeback); for_each_node_state(nid, N_MEMORY) if (md->node[nid]) seq_printf(m, " N%d=%lu", nid, md->node[nid]); seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10); out: seq_putc(m, '\n'); return 0; } static const struct seq_operations proc_pid_numa_maps_op = { .start = m_start, .next = m_next, .stop = m_stop, .show = show_numa_map, }; static int pid_numa_maps_open(struct inode *inode, struct file *file) { return proc_maps_open(inode, file, &proc_pid_numa_maps_op, sizeof(struct numa_maps_private)); } const struct file_operations proc_pid_numa_maps_operations = { .open = pid_numa_maps_open, .read = seq_read, .llseek = seq_lseek, .release = proc_map_release, }; #endif /* CONFIG_NUMA */