#include <linux/mm.h> #include <linux/vmacache.h> #include <linux/hugetlb.h> #include <linux/huge_mm.h> #include <linux/mount.h> #include <linux/seq_file.h> #include <linux/highmem.h> #include <linux/ptrace.h> #include <linux/slab.h> #include <linux/pagemap.h> #include <linux/mempolicy.h> #include <linux/rmap.h> #include <linux/swap.h> #include <linux/swapops.h> #include <linux/mmu_notifier.h> #include <asm/elf.h> #include <asm/uaccess.h> #include <asm/tlbflush.h> #include "internal.h" void task_mem(struct seq_file *m, struct mm_struct *mm) { unsigned long data, text, lib, swap; unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss; /* * 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 = get_mm_rss(mm); if (hiwater_rss < mm->hiwater_rss) hiwater_rss = mm->hiwater_rss; data = mm->total_vm - mm->shared_vm - mm->stack_vm; text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10; lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text; swap = get_mm_counter(mm, MM_SWAPENTS); seq_printf(m, "VmPeak:\t%8lu kB\n" "VmSize:\t%8lu kB\n" "VmLck:\t%8lu kB\n" "VmPin:\t%8lu kB\n" "VmHWM:\t%8lu kB\n" "VmRSS:\t%8lu kB\n" "VmData:\t%8lu kB\n" "VmStk:\t%8lu kB\n" "VmExe:\t%8lu kB\n" "VmLib:\t%8lu kB\n" "VmPTE:\t%8lu kB\n" "VmSwap:\t%8lu kB\n", hiwater_vm << (PAGE_SHIFT-10), total_vm << (PAGE_SHIFT-10), mm->locked_vm << (PAGE_SHIFT-10), mm->pinned_vm << (PAGE_SHIFT-10), hiwater_rss << (PAGE_SHIFT-10), total_rss << (PAGE_SHIFT-10), data << (PAGE_SHIFT-10), mm->stack_vm << (PAGE_SHIFT-10), text, lib, (PTRS_PER_PTE * sizeof(pte_t) * atomic_long_read(&mm->nr_ptes)) >> 10, swap << (PAGE_SHIFT-10)); } 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); *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> PAGE_SHIFT; *data = mm->total_vm - mm->shared_vm; *resident = *shared + get_mm_counter(mm, MM_ANONPAGES); return mm->total_vm; } #ifdef CONFIG_NUMA /* * These functions are for numa_maps but called in generic **maps seq_file * ->start(), ->stop() ops. * * numa_maps scans all vmas under mmap_sem and checks their mempolicy. * Each mempolicy object is controlled by reference counting. The problem here * is how to avoid accessing dead mempolicy object. * * Because we're holding mmap_sem while reading seq_file, it's safe to access * each vma's mempolicy, no vma objects will never drop refs to mempolicy. * * A task's mempolicy (task->mempolicy) has different behavior. task->mempolicy * is set and replaced under mmap_sem but unrefed and cleared under task_lock(). * So, without task_lock(), we cannot trust get_vma_policy() because we cannot * gurantee the task never exits under us. But taking task_lock() around * get_vma_plicy() causes lock order problem. * * To access task->mempolicy without lock, we hold a reference count of an * object pointed by task->mempolicy and remember it. This will guarantee * that task->mempolicy points to an alive object or NULL in numa_maps accesses. */ static void hold_task_mempolicy(struct proc_maps_private *priv) { struct task_struct *task = priv->task; task_lock(task); priv->task_mempolicy = task->mempolicy; 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 void vma_stop(struct proc_maps_private *priv, struct vm_area_struct *vma) { if (vma && vma != priv->tail_vma) { struct mm_struct *mm = vma->vm_mm; release_task_mempolicy(priv); up_read(&mm->mmap_sem); mmput(mm); } } static void *m_start(struct seq_file *m, loff_t *pos) { struct proc_maps_private *priv = m->private; unsigned long last_addr = m->version; struct mm_struct *mm; struct vm_area_struct *vma, *tail_vma = NULL; loff_t l = *pos; /* Clear the per syscall fields in priv */ priv->task = NULL; priv->tail_vma = NULL; /* * We remember last_addr rather than next_addr to hit with * vmacache most of the time. We have zero last_addr at * the beginning and also after lseek. We will have -1 last_addr * after the end of the vmas. */ if (last_addr == -1UL) return NULL; priv->task = get_pid_task(priv->pid, PIDTYPE_PID); if (!priv->task) return ERR_PTR(-ESRCH); mm = priv->mm; if (!mm || !atomic_inc_not_zero(&mm->mm_users)) return NULL; down_read(&mm->mmap_sem); tail_vma = get_gate_vma(mm); priv->tail_vma = tail_vma; hold_task_mempolicy(priv); /* Start with last addr hint */ vma = find_vma(mm, last_addr); if (last_addr && vma) { vma = vma->vm_next; goto out; } /* * Check the vma index is within the range and do * sequential scan until m_index. */ vma = NULL; if ((unsigned long)l < mm->map_count) { vma = mm->mmap; while (l-- && vma) vma = vma->vm_next; goto out; } if (l != mm->map_count) tail_vma = NULL; /* After gate vma */ out: if (vma) return vma; release_task_mempolicy(priv); /* End of vmas has been reached */ m->version = (tail_vma != NULL)? 0: -1UL; up_read(&mm->mmap_sem); mmput(mm); return tail_vma; } static void *m_next(struct seq_file *m, void *v, loff_t *pos) { struct proc_maps_private *priv = m->private; struct vm_area_struct *vma = v; struct vm_area_struct *tail_vma = priv->tail_vma; (*pos)++; if (vma && (vma != tail_vma) && vma->vm_next) return vma->vm_next; vma_stop(priv, vma); return (vma != tail_vma)? tail_vma: NULL; } static void m_stop(struct seq_file *m, void *v) { struct proc_maps_private *priv = m->private; struct vm_area_struct *vma = v; if (!IS_ERR(vma)) vma_stop(priv, vma); if (priv->task) put_task_struct(priv->task); } 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->pid = proc_pid(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 show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid) { struct mm_struct *mm = vma->vm_mm; struct file *file = vma->vm_file; struct proc_maps_private *priv = m->private; struct task_struct *task = priv->task; vm_flags_t flags = vma->vm_flags; unsigned long ino = 0; unsigned long long pgoff = 0; unsigned long start, end; dev_t dev = 0; const char *name = NULL; if (file) { struct inode *inode = file_inode(vma->vm_file); dev = inode->i_sb->s_dev; ino = inode->i_ino; pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT; } /* We don't show the stack guard page in /proc/maps */ start = vma->vm_start; if (stack_guard_page_start(vma, start)) start += PAGE_SIZE; end = vma->vm_end; if (stack_guard_page_end(vma, end)) end -= PAGE_SIZE; seq_setwidth(m, 25 + sizeof(void *) * 6 - 1); seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ", start, end, flags & VM_READ ? 'r' : '-', flags & VM_WRITE ? 'w' : '-', flags & VM_EXEC ? 'x' : '-', flags & VM_MAYSHARE ? 's' : 'p', pgoff, MAJOR(dev), MINOR(dev), ino); /* * Print the dentry name for named mappings, and a * special [heap] marker for the heap: */ if (file) { seq_pad(m, ' '); seq_path(m, &file->f_path, "\n"); goto done; } if (vma->vm_ops && vma->vm_ops->name) { name = vma->vm_ops->name(vma); if (name) goto done; } name = arch_vma_name(vma); if (!name) { pid_t tid; if (!mm) { name = "[vdso]"; goto done; } if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) { name = "[heap]"; goto done; } tid = vm_is_stack(task, vma, is_pid); if (tid != 0) { /* * Thread stack in /proc/PID/task/TID/maps or * the main process stack. */ if (!is_pid || (vma->vm_start <= mm->start_stack && vma->vm_end >= mm->start_stack)) { name = "[stack]"; } else { /* Thread stack in /proc/PID/maps */ seq_pad(m, ' '); seq_printf(m, "[stack:%d]", tid); } } } done: if (name) { seq_pad(m, ' '); seq_puts(m, name); } seq_putc(m, '\n'); } static int show_map(struct seq_file *m, void *v, int is_pid) { struct vm_area_struct *vma = v; struct proc_maps_private *priv = m->private; show_map_vma(m, vma, is_pid); if (m->count < m->size) /* vma is copied successfully */ m->version = (vma != priv->tail_vma) ? vma->vm_start : 0; return 0; } static int show_pid_map(struct seq_file *m, void *v) { return show_map(m, v, 1); } static int show_tid_map(struct seq_file *m, void *v) { return show_map(m, v, 0); } static const struct seq_operations proc_pid_maps_op = { .start = m_start, .next = m_next, .stop = m_stop, .show = show_pid_map }; static const struct seq_operations proc_tid_maps_op = { .start = m_start, .next = m_next, .stop = m_stop, .show = show_tid_map }; static int pid_maps_open(struct inode *inode, struct file *file) { return do_maps_open(inode, file, &proc_pid_maps_op); } static int tid_maps_open(struct inode *inode, struct file *file) { return do_maps_open(inode, file, &proc_tid_maps_op); } const struct file_operations proc_pid_maps_operations = { .open = pid_maps_open, .read = seq_read, .llseek = seq_lseek, .release = proc_map_release, }; const struct file_operations proc_tid_maps_operations = { .open = tid_maps_open, .read = seq_read, .llseek = seq_lseek, .release = proc_map_release, }; /* * 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 { struct vm_area_struct *vma; 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 anonymous_thp; unsigned long swap; unsigned long nonlinear; u64 pss; }; static void smaps_pte_entry(pte_t ptent, unsigned long addr, unsigned long ptent_size, struct mm_walk *walk) { struct mem_size_stats *mss = walk->private; struct vm_area_struct *vma = mss->vma; pgoff_t pgoff = linear_page_index(vma, addr); struct page *page = NULL; int mapcount; if (pte_present(ptent)) { page = vm_normal_page(vma, addr, ptent); } else if (is_swap_pte(ptent)) { swp_entry_t swpent = pte_to_swp_entry(ptent); if (!non_swap_entry(swpent)) mss->swap += ptent_size; else if (is_migration_entry(swpent)) page = migration_entry_to_page(swpent); } else if (pte_file(ptent)) { if (pte_to_pgoff(ptent) != pgoff) mss->nonlinear += ptent_size; } if (!page) return; if (PageAnon(page)) mss->anonymous += ptent_size; if (page->index != pgoff) mss->nonlinear += ptent_size; mss->resident += ptent_size; /* Accumulate the size in pages that have been accessed. */ if (pte_young(ptent) || PageReferenced(page)) mss->referenced += ptent_size; mapcount = page_mapcount(page); if (mapcount >= 2) { if (pte_dirty(ptent) || PageDirty(page)) mss->shared_dirty += ptent_size; else mss->shared_clean += ptent_size; mss->pss += (ptent_size << PSS_SHIFT) / mapcount; } else { if (pte_dirty(ptent) || PageDirty(page)) mss->private_dirty += ptent_size; else mss->private_clean += ptent_size; mss->pss += (ptent_size << PSS_SHIFT); } } static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct mem_size_stats *mss = walk->private; struct vm_area_struct *vma = mss->vma; pte_t *pte; spinlock_t *ptl; if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { smaps_pte_entry(*(pte_t *)pmd, addr, HPAGE_PMD_SIZE, walk); spin_unlock(ptl); mss->anonymous_thp += HPAGE_PMD_SIZE; return 0; } if (pmd_trans_unstable(pmd)) return 0; /* * The mmap_sem held all the way back in m_start() is what * keeps khugepaged out of here and from collapsing things * in here. */ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); for (; addr != end; pte++, addr += PAGE_SIZE) smaps_pte_entry(*pte, addr, PAGE_SIZE, walk); pte_unmap_unlock(pte - 1, ptl); 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_DENYWRITE)] = "dw", [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_ACCOUNT)] = "ac", [ilog2(VM_NORESERVE)] = "nr", [ilog2(VM_HUGETLB)] = "ht", [ilog2(VM_NONLINEAR)] = "nl", [ilog2(VM_ARCH_1)] = "ar", [ilog2(VM_DONTDUMP)] = "dd", #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", }; size_t i; seq_puts(m, "VmFlags: "); for (i = 0; i < BITS_PER_LONG; i++) { if (vma->vm_flags & (1UL << i)) { seq_printf(m, "%c%c ", mnemonics[i][0], mnemonics[i][1]); } } seq_putc(m, '\n'); } static int show_smap(struct seq_file *m, void *v, int is_pid) { struct proc_maps_private *priv = m->private; struct vm_area_struct *vma = v; struct mem_size_stats mss; struct mm_walk smaps_walk = { .pmd_entry = smaps_pte_range, .mm = vma->vm_mm, .private = &mss, }; memset(&mss, 0, sizeof mss); mss.vma = vma; /* mmap_sem is held in m_start */ if (vma->vm_mm && !is_vm_hugetlb_page(vma)) walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk); show_map_vma(m, vma, is_pid); seq_printf(m, "Size: %8lu kB\n" "Rss: %8lu kB\n" "Pss: %8lu kB\n" "Shared_Clean: %8lu kB\n" "Shared_Dirty: %8lu kB\n" "Private_Clean: %8lu kB\n" "Private_Dirty: %8lu kB\n" "Referenced: %8lu kB\n" "Anonymous: %8lu kB\n" "AnonHugePages: %8lu kB\n" "Swap: %8lu kB\n" "KernelPageSize: %8lu kB\n" "MMUPageSize: %8lu kB\n" "Locked: %8lu kB\n", (vma->vm_end - vma->vm_start) >> 10, mss.resident >> 10, (unsigned long)(mss.pss >> (10 + PSS_SHIFT)), mss.shared_clean >> 10, mss.shared_dirty >> 10, mss.private_clean >> 10, mss.private_dirty >> 10, mss.referenced >> 10, mss.anonymous >> 10, mss.anonymous_thp >> 10, mss.swap >> 10, vma_kernel_pagesize(vma) >> 10, vma_mmu_pagesize(vma) >> 10, (vma->vm_flags & VM_LOCKED) ? (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0); if (vma->vm_flags & VM_NONLINEAR) seq_printf(m, "Nonlinear: %8lu kB\n", mss.nonlinear >> 10); show_smap_vma_flags(m, vma); if (m->count < m->size) /* vma is copied successfully */ m->version = (vma != priv->tail_vma) ? vma->vm_start : 0; return 0; } static int show_pid_smap(struct seq_file *m, void *v) { return show_smap(m, v, 1); } static int show_tid_smap(struct seq_file *m, void *v) { return show_smap(m, v, 0); } static const struct seq_operations proc_pid_smaps_op = { .start = m_start, .next = m_next, .stop = m_stop, .show = show_pid_smap }; static const struct seq_operations proc_tid_smaps_op = { .start = m_start, .next = m_next, .stop = m_stop, .show = show_tid_smap }; static int pid_smaps_open(struct inode *inode, struct file *file) { return do_maps_open(inode, file, &proc_pid_smaps_op); } static int tid_smaps_open(struct inode *inode, struct file *file) { return do_maps_open(inode, file, &proc_tid_smaps_op); } 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_tid_smaps_operations = { .open = tid_smaps_open, .read = seq_read, .llseek = seq_lseek, .release = proc_map_release, }; /* * We do not want to have constant page-shift bits sitting in * pagemap entries and are about to reuse them some time soon. * * Here's the "migration strategy": * 1. when the system boots these bits remain what they are, * but a warning about future change is printed in log; * 2. once anyone clears soft-dirty bits via clear_refs file, * these flag is set to denote, that user is aware of the * new API and those page-shift bits change their meaning. * The respective warning is printed in dmesg; * 3. In a couple of releases we will remove all the mentions * of page-shift in pagemap entries. */ static bool soft_dirty_cleared __read_mostly; enum clear_refs_types { CLEAR_REFS_ALL = 1, CLEAR_REFS_ANON, CLEAR_REFS_MAPPED, CLEAR_REFS_SOFT_DIRTY, CLEAR_REFS_LAST, }; struct clear_refs_private { struct vm_area_struct *vma; enum clear_refs_types type; }; static inline void clear_soft_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *pte) { #ifdef CONFIG_MEM_SOFT_DIRTY /* * The soft-dirty tracker uses #PF-s to catch writes * to pages, so write-protect the pte as well. See the * Documentation/vm/soft-dirty.txt for full description * of how soft-dirty works. */ pte_t ptent = *pte; if (pte_present(ptent)) { ptent = pte_wrprotect(ptent); ptent = pte_clear_flags(ptent, _PAGE_SOFT_DIRTY); } else if (is_swap_pte(ptent)) { ptent = pte_swp_clear_soft_dirty(ptent); } else if (pte_file(ptent)) { ptent = pte_file_clear_soft_dirty(ptent); } set_pte_at(vma->vm_mm, addr, pte, ptent); #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 = cp->vma; pte_t *pte, ptent; spinlock_t *ptl; struct page *page; split_huge_page_pmd(vma, addr, pmd); if (pmd_trans_unstable(pmd)) return 0; pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); for (; addr != end; pte++, addr += PAGE_SIZE) { ptent = *pte; if (cp->type == CLEAR_REFS_SOFT_DIRTY) { clear_soft_dirty(vma, addr, pte); continue; } if (!pte_present(ptent)) continue; page = vm_normal_page(vma, addr, ptent); if (!page) continue; /* Clear accessed and referenced bits. */ ptep_test_and_clear_young(vma, addr, pte); ClearPageReferenced(page); } pte_unmap_unlock(pte - 1, ptl); cond_resched(); return 0; } 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; memset(buffer, 0, sizeof(buffer)); 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; if (type == CLEAR_REFS_SOFT_DIRTY) { soft_dirty_cleared = true; pr_warn_once("The pagemap bits 55-60 has changed their meaning!" " See the linux/Documentation/vm/pagemap.txt for " "details.\n"); } task = get_proc_task(file_inode(file)); if (!task) return -ESRCH; mm = get_task_mm(task); if (mm) { struct clear_refs_private cp = { .type = type, }; struct mm_walk clear_refs_walk = { .pmd_entry = clear_refs_pte_range, .mm = mm, .private = &cp, }; down_read(&mm->mmap_sem); if (type == CLEAR_REFS_SOFT_DIRTY) mmu_notifier_invalidate_range_start(mm, 0, -1); for (vma = mm->mmap; vma; vma = vma->vm_next) { cp.vma = vma; 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. * * Writing 4 to /proc/pid/clear_refs affects all pages. */ if (type == CLEAR_REFS_ANON && vma->vm_file) continue; if (type == CLEAR_REFS_MAPPED && !vma->vm_file) continue; if (type == CLEAR_REFS_SOFT_DIRTY) { if (vma->vm_flags & VM_SOFTDIRTY) vma->vm_flags &= ~VM_SOFTDIRTY; } walk_page_range(vma->vm_start, vma->vm_end, &clear_refs_walk); } if (type == CLEAR_REFS_SOFT_DIRTY) mmu_notifier_invalidate_range_end(mm, 0, -1); flush_tlb_mm(mm); up_read(&mm->mmap_sem); 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 v2; }; #define PAGEMAP_WALK_SIZE (PMD_SIZE) #define PAGEMAP_WALK_MASK (PMD_MASK) #define PM_ENTRY_BYTES sizeof(pagemap_entry_t) #define PM_STATUS_BITS 3 #define PM_STATUS_OFFSET (64 - PM_STATUS_BITS) #define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET) #define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK) #define PM_PSHIFT_BITS 6 #define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS) #define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET) #define __PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK) #define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1) #define PM_PFRAME(x) ((x) & PM_PFRAME_MASK) /* in "new" pagemap pshift bits are occupied with more status bits */ #define PM_STATUS2(v2, x) (__PM_PSHIFT(v2 ? x : PAGE_SHIFT)) #define __PM_SOFT_DIRTY (1LL) #define PM_PRESENT PM_STATUS(4LL) #define PM_SWAP PM_STATUS(2LL) #define PM_FILE PM_STATUS(1LL) #define PM_NOT_PRESENT(v2) PM_STATUS2(v2, 0) #define PM_END_OF_BUFFER 1 static inline pagemap_entry_t make_pme(u64 val) { return (pagemap_entry_t) { .pme = val }; } static int add_to_pagemap(unsigned long addr, 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, 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(PM_NOT_PRESENT(pm->v2)); /* 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(addr, &pme, pm); if (err) goto out; } if (!vma) break; /* Addresses in the VMA. */ if (vma->vm_flags & VM_SOFTDIRTY) pme.pme |= PM_STATUS2(pm->v2, __PM_SOFT_DIRTY); for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) { err = add_to_pagemap(addr, &pme, pm); if (err) goto out; } } out: return err; } static void pte_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm, struct vm_area_struct *vma, unsigned long addr, pte_t pte) { u64 frame, flags; struct page *page = NULL; int flags2 = 0; if (pte_present(pte)) { frame = pte_pfn(pte); flags = PM_PRESENT; page = vm_normal_page(vma, addr, pte); if (pte_soft_dirty(pte)) flags2 |= __PM_SOFT_DIRTY; } else if (is_swap_pte(pte)) { swp_entry_t entry; if (pte_swp_soft_dirty(pte)) flags2 |= __PM_SOFT_DIRTY; entry = pte_to_swp_entry(pte); frame = swp_type(entry) | (swp_offset(entry) << MAX_SWAPFILES_SHIFT); flags = PM_SWAP; if (is_migration_entry(entry)) page = migration_entry_to_page(entry); } else { if (vma->vm_flags & VM_SOFTDIRTY) flags2 |= __PM_SOFT_DIRTY; *pme = make_pme(PM_NOT_PRESENT(pm->v2) | PM_STATUS2(pm->v2, flags2)); return; } if (page && !PageAnon(page)) flags |= PM_FILE; if ((vma->vm_flags & VM_SOFTDIRTY)) flags2 |= __PM_SOFT_DIRTY; *pme = make_pme(PM_PFRAME(frame) | PM_STATUS2(pm->v2, flags2) | flags); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE static void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm, pmd_t pmd, int offset, int pmd_flags2) { /* * Currently pmd for thp is always present because thp can not be * swapped-out, migrated, or HWPOISONed (split in such cases instead.) * This if-check is just to prepare for future implementation. */ if (pmd_present(pmd)) *pme = make_pme(PM_PFRAME(pmd_pfn(pmd) + offset) | PM_STATUS2(pm->v2, pmd_flags2) | PM_PRESENT); else *pme = make_pme(PM_NOT_PRESENT(pm->v2) | PM_STATUS2(pm->v2, pmd_flags2)); } #else static inline void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm, pmd_t pmd, int offset, int pmd_flags2) { } #endif static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct vm_area_struct *vma; struct pagemapread *pm = walk->private; spinlock_t *ptl; pte_t *pte; int err = 0; pagemap_entry_t pme = make_pme(PM_NOT_PRESENT(pm->v2)); /* find the first VMA at or above 'addr' */ vma = find_vma(walk->mm, addr); if (vma && pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { int pmd_flags2; if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(*pmd)) pmd_flags2 = __PM_SOFT_DIRTY; else pmd_flags2 = 0; for (; addr != end; addr += PAGE_SIZE) { unsigned long offset; offset = (addr & ~PAGEMAP_WALK_MASK) >> PAGE_SHIFT; thp_pmd_to_pagemap_entry(&pme, pm, *pmd, offset, pmd_flags2); err = add_to_pagemap(addr, &pme, pm); if (err) break; } spin_unlock(ptl); return err; } if (pmd_trans_unstable(pmd)) return 0; for (; addr != end; addr += PAGE_SIZE) { int flags2; /* check to see if we've left 'vma' behind * and need a new, higher one */ if (vma && (addr >= vma->vm_end)) { vma = find_vma(walk->mm, addr); if (vma && (vma->vm_flags & VM_SOFTDIRTY)) flags2 = __PM_SOFT_DIRTY; else flags2 = 0; pme = make_pme(PM_NOT_PRESENT(pm->v2) | PM_STATUS2(pm->v2, flags2)); } /* check that 'vma' actually covers this address, * and that it isn't a huge page vma */ if (vma && (vma->vm_start <= addr) && !is_vm_hugetlb_page(vma)) { pte = pte_offset_map(pmd, addr); pte_to_pagemap_entry(&pme, pm, vma, addr, *pte); /* unmap before userspace copy */ pte_unmap(pte); } err = add_to_pagemap(addr, &pme, pm); if (err) return err; } cond_resched(); return err; } #ifdef CONFIG_HUGETLB_PAGE static void huge_pte_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm, pte_t pte, int offset, int flags2) { if (pte_present(pte)) *pme = make_pme(PM_PFRAME(pte_pfn(pte) + offset) | PM_STATUS2(pm->v2, flags2) | PM_PRESENT); else *pme = make_pme(PM_NOT_PRESENT(pm->v2) | PM_STATUS2(pm->v2, flags2)); } /* This function walks within one hugetlb entry in the single call */ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct pagemapread *pm = walk->private; struct vm_area_struct *vma; int err = 0; int flags2; pagemap_entry_t pme; vma = find_vma(walk->mm, addr); WARN_ON_ONCE(!vma); if (vma && (vma->vm_flags & VM_SOFTDIRTY)) flags2 = __PM_SOFT_DIRTY; else flags2 = 0; for (; addr != end; addr += PAGE_SIZE) { int offset = (addr & ~hmask) >> PAGE_SHIFT; huge_pte_to_pagemap_entry(&pme, pm, *pte, offset, flags2); err = add_to_pagemap(addr, &pme, pm); if (err) return err; } cond_resched(); return err; } #endif /* HUGETLB_PAGE */ /* * /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 * Bits 55-60 page shift (page size = 1<<page shift) * 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 task_struct *task = get_proc_task(file_inode(file)); struct mm_struct *mm; struct pagemapread pm; int ret = -ESRCH; struct mm_walk pagemap_walk = {}; unsigned long src; unsigned long svpfn; unsigned long start_vaddr; unsigned long end_vaddr; int copied = 0; if (!task) goto out; ret = -EINVAL; /* file position must be aligned */ if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES)) goto out_task; ret = 0; if (!count) goto out_task; pm.v2 = soft_dirty_cleared; pm.len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT); pm.buffer = kmalloc(pm.len * PM_ENTRY_BYTES, GFP_TEMPORARY); ret = -ENOMEM; if (!pm.buffer) goto out_task; mm = mm_access(task, PTRACE_MODE_READ); ret = PTR_ERR(mm); if (!mm || IS_ERR(mm)) goto out_free; pagemap_walk.pmd_entry = pagemap_pte_range; pagemap_walk.pte_hole = pagemap_pte_hole; #ifdef CONFIG_HUGETLB_PAGE pagemap_walk.hugetlb_entry = pagemap_hugetlb_range; #endif pagemap_walk.mm = mm; pagemap_walk.private = ± src = *ppos; svpfn = src / PM_ENTRY_BYTES; start_vaddr = svpfn << PAGE_SHIFT; end_vaddr = TASK_SIZE_OF(task); /* watch out for wraparound */ if (svpfn > TASK_SIZE_OF(task) >> PAGE_SHIFT) start_vaddr = end_vaddr; /* * The odds are that this will stop walking way * before end_vaddr, because the length of the * user buffer is tracked in "pm", and the walk * will stop when we hit the end of the buffer. */ 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; down_read(&mm->mmap_sem); ret = walk_page_range(start_vaddr, end, &pagemap_walk); up_read(&mm->mmap_sem); start_vaddr = end; len = min(count, PM_ENTRY_BYTES * pm.pos); if (copy_to_user(buf, pm.buffer, len)) { ret = -EFAULT; goto out_mm; } copied += len; buf += len; count -= len; } *ppos += copied; if (!ret || ret == PM_END_OF_BUFFER) ret = copied; out_mm: mmput(mm); out_free: kfree(pm.buffer); out_task: put_task_struct(task); out: return ret; } static int pagemap_open(struct inode *inode, struct file *file) { pr_warn_once("Bits 55-60 of /proc/PID/pagemap entries are about " "to stop being page-shift some time soon. See the " "linux/Documentation/vm/pagemap.txt for details.\n"); return 0; } const struct file_operations proc_pagemap_operations = { .llseek = mem_lseek, /* borrow this */ .read = pagemap_read, .open = pagemap_open, }; #endif /* CONFIG_PROC_PAGE_MONITOR */ #ifdef CONFIG_NUMA struct numa_maps { struct vm_area_struct *vma; 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) { int count = page_mapcount(page); md->pages += nr_pages; if (pte_dirty || PageDirty(page)) md->dirty += nr_pages; if (PageSwapCache(page)) md->swapcache += nr_pages; if (PageActive(page) || PageUnevictable(page)) md->active += nr_pages; if (PageWriteback(page)) md->writeback += nr_pages; if (PageAnon(page)) md->anon += nr_pages; if (count > md->mapcount_max) md->mapcount_max = count; md->node[page_to_nid(page)] += 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) return NULL; if (PageReserved(page)) return NULL; nid = page_to_nid(page); if (!node_isset(nid, node_states[N_MEMORY])) return NULL; return page; } static int gather_pte_stats(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct numa_maps *md; spinlock_t *ptl; pte_t *orig_pte; pte_t *pte; md = walk->private; if (pmd_trans_huge_lock(pmd, md->vma, &ptl) == 1) { pte_t huge_pte = *(pte_t *)pmd; struct page *page; page = can_gather_numa_stats(huge_pte, md->vma, addr); if (page) gather_stats(page, md, pte_dirty(huge_pte), HPAGE_PMD_SIZE/PAGE_SIZE); spin_unlock(ptl); return 0; } if (pmd_trans_unstable(pmd)) return 0; orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); do { struct page *page = can_gather_numa_stats(*pte, md->vma, addr); if (!page) continue; gather_stats(page, md, pte_dirty(*pte), 1); } while (pte++, addr += PAGE_SIZE, addr != end); pte_unmap_unlock(orig_pte, ptl); return 0; } #ifdef CONFIG_HUGETLB_PAGE static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct numa_maps *md; struct page *page; if (!pte_present(*pte)) return 0; page = pte_page(*pte); if (!page) return 0; md = walk->private; gather_stats(page, md, pte_dirty(*pte), 1); return 0; } #else static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask, unsigned long addr, unsigned long end, struct mm_walk *walk) { return 0; } #endif /* * Display pages allocated per node and memory policy via /proc. */ static int show_numa_map(struct seq_file *m, void *v, int is_pid) { 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 task_struct *task = proc_priv->task; struct mm_struct *mm = vma->vm_mm; struct mm_walk walk = {}; struct mempolicy *pol; char buffer[64]; int nid; if (!mm) return 0; /* Ensure we start with an empty set of numa_maps statistics. */ memset(md, 0, sizeof(*md)); md->vma = vma; walk.hugetlb_entry = gather_hugetbl_stats; walk.pmd_entry = gather_pte_stats; walk.private = md; walk.mm = mm; pol = get_vma_policy(task, vma, vma->vm_start); mpol_to_str(buffer, sizeof(buffer), pol); mpol_cond_put(pol); seq_printf(m, "%08lx %s", vma->vm_start, buffer); if (file) { seq_puts(m, " file="); seq_path(m, &file->f_path, "\n\t= "); } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) { seq_puts(m, " heap"); } else { pid_t tid = vm_is_stack(task, vma, is_pid); if (tid != 0) { /* * Thread stack in /proc/PID/task/TID/maps or * the main process stack. */ if (!is_pid || (vma->vm_start <= mm->start_stack && vma->vm_end >= mm->start_stack)) seq_puts(m, " stack"); else seq_printf(m, " stack:%d", tid); } } if (is_vm_hugetlb_page(vma)) seq_puts(m, " huge"); walk_page_range(vma->vm_start, vma->vm_end, &walk); 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]); out: seq_putc(m, '\n'); if (m->count < m->size) m->version = (vma != proc_priv->tail_vma) ? vma->vm_start : 0; return 0; } static int show_pid_numa_map(struct seq_file *m, void *v) { return show_numa_map(m, v, 1); } static int show_tid_numa_map(struct seq_file *m, void *v) { return show_numa_map(m, v, 0); } static const struct seq_operations proc_pid_numa_maps_op = { .start = m_start, .next = m_next, .stop = m_stop, .show = show_pid_numa_map, }; static const struct seq_operations proc_tid_numa_maps_op = { .start = m_start, .next = m_next, .stop = m_stop, .show = show_tid_numa_map, }; static int numa_maps_open(struct inode *inode, struct file *file, const struct seq_operations *ops) { return proc_maps_open(inode, file, ops, sizeof(struct numa_maps_private)); } static int pid_numa_maps_open(struct inode *inode, struct file *file) { return numa_maps_open(inode, file, &proc_pid_numa_maps_op); } static int tid_numa_maps_open(struct inode *inode, struct file *file) { return numa_maps_open(inode, file, &proc_tid_numa_maps_op); } const struct file_operations proc_pid_numa_maps_operations = { .open = pid_numa_maps_open, .read = seq_read, .llseek = seq_lseek, .release = proc_map_release, }; const struct file_operations proc_tid_numa_maps_operations = { .open = tid_numa_maps_open, .read = seq_read, .llseek = seq_lseek, .release = proc_map_release, }; #endif /* CONFIG_NUMA */