From 37ab77b891f7284dc2cf89c6ceab4be8fb751dbb Mon Sep 17 00:00:00 2001 From: Ian Jackson Date: Fri, 26 Jul 2013 16:33:21 +0100 Subject: [PATCH 1/1] task_mmu.c for helping understand /proc/self/maps, copied from Linux 3.9-rc6 31880c37c11e28cb81c70757e38392b42e695dc6 fs/proc/task_mmu.c --- task_mmu.c | 1412 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1412 insertions(+) create mode 100644 task_mmu.c diff --git a/task_mmu.c b/task_mmu.c new file mode 100644 index 0000000..3e636d8 --- /dev/null +++ b/task_mmu.c @@ -0,0 +1,1412 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#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)*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; +} + +static void pad_len_spaces(struct seq_file *m, int len) +{ + len = 25 + sizeof(void*) * 6 - len; + if (len < 1) + len = 1; + seq_printf(m, "%*c", len, ' '); +} + +#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 + * mmap_cache 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 = mm_access(priv->task, PTRACE_MODE_READ); + if (!mm || IS_ERR(mm)) + return mm; + down_read(&mm->mmap_sem); + + tail_vma = get_gate_vma(priv->task->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 do_maps_open(struct inode *inode, struct file *file, + const struct seq_operations *ops) +{ + struct proc_maps_private *priv; + int ret = -ENOMEM; + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (priv) { + priv->pid = proc_pid(inode); + ret = seq_open(file, ops); + if (!ret) { + struct seq_file *m = file->private_data; + m->private = priv; + } else { + kfree(priv); + } + } + return ret; +} + +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; + int len; + 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_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n", + 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, &len); + + /* + * Print the dentry name for named mappings, and a + * special [heap] marker for the heap: + */ + if (file) { + pad_len_spaces(m, len); + seq_path(m, &file->f_path, "\n"); + 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 */ + pad_len_spaces(m, len); + seq_printf(m, "[stack:%d]", tid); + } + } + } + +done: + if (name) { + pad_len_spaces(m, len); + 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; + struct task_struct *task = priv->task; + + show_map_vma(m, vma, is_pid); + + if (m->count < m->size) /* vma is copied successfully */ + m->version = (vma != get_gate_vma(task->mm)) + ? 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 = seq_release_private, +}; + +const struct file_operations proc_tid_maps_operations = { + .open = tid_maps_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, +}; + +/* + * 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) == 1) { + smaps_pte_entry(*(pte_t *)pmd, addr, HPAGE_PMD_SIZE, walk); + spin_unlock(&walk->mm->page_table_lock); + 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", + [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 task_struct *task = priv->task; + 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 != get_gate_vma(task->mm)) + ? 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 = seq_release_private, +}; + +const struct file_operations proc_tid_smaps_operations = { + .open = tid_smaps_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, +}; + +static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, + unsigned long end, struct mm_walk *walk) +{ + struct vm_area_struct *vma = walk->private; + 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 (!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; +} + +#define CLEAR_REFS_ALL 1 +#define CLEAR_REFS_ANON 2 +#define CLEAR_REFS_MAPPED 3 + +static ssize_t clear_refs_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_struct *task; + char buffer[PROC_NUMBUF]; + struct mm_struct *mm; + struct vm_area_struct *vma; + int type; + 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, &type); + if (rv < 0) + return rv; + if (type < CLEAR_REFS_ALL || type > CLEAR_REFS_MAPPED) + return -EINVAL; + task = get_proc_task(file_inode(file)); + if (!task) + return -ESRCH; + mm = get_task_mm(task); + if (mm) { + struct mm_walk clear_refs_walk = { + .pmd_entry = clear_refs_pte_range, + .mm = mm, + }; + down_read(&mm->mmap_sem); + for (vma = mm->mmap; vma; vma = vma->vm_next) { + clear_refs_walk.private = vma; + if (is_vm_hugetlb_page(vma)) + continue; + /* + * Writing 1 to /proc/pid/clear_refs affects all pages. + * + * Writing 2 to /proc/pid/clear_refs only affects + * Anonymous pages. + * + * Writing 3 to /proc/pid/clear_refs only affects file + * mapped pages. + */ + if (type == CLEAR_REFS_ANON && vma->vm_file) + continue; + if (type == CLEAR_REFS_MAPPED && !vma->vm_file) + continue; + walk_page_range(vma->vm_start, vma->vm_end, + &clear_refs_walk); + } + flush_tlb_mm(mm); + up_read(&mm->mmap_sem); + 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; + pagemap_entry_t *buffer; +}; + +#define PAGEMAP_WALK_SIZE (PMD_SIZE) +#define PAGEMAP_WALK_MASK (PMD_MASK) + +#define PM_ENTRY_BYTES sizeof(u64) +#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) + +#define PM_PRESENT PM_STATUS(4LL) +#define PM_SWAP PM_STATUS(2LL) +#define PM_FILE PM_STATUS(1LL) +#define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT) +#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; + int err = 0; + pagemap_entry_t pme = make_pme(PM_NOT_PRESENT); + + for (addr = start; addr < end; addr += PAGE_SIZE) { + err = add_to_pagemap(addr, &pme, pm); + if (err) + break; + } + return err; +} + +static void pte_to_pagemap_entry(pagemap_entry_t *pme, + struct vm_area_struct *vma, unsigned long addr, pte_t pte) +{ + u64 frame, flags; + struct page *page = NULL; + + if (pte_present(pte)) { + frame = pte_pfn(pte); + flags = PM_PRESENT; + page = vm_normal_page(vma, addr, pte); + } else if (is_swap_pte(pte)) { + swp_entry_t 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 { + *pme = make_pme(PM_NOT_PRESENT); + return; + } + + if (page && !PageAnon(page)) + flags |= PM_FILE; + + *pme = make_pme(PM_PFRAME(frame) | PM_PSHIFT(PAGE_SHIFT) | flags); +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, + pmd_t pmd, int offset) +{ + /* + * 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_PSHIFT(PAGE_SHIFT) | PM_PRESENT); + else + *pme = make_pme(PM_NOT_PRESENT); +} +#else +static inline void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, + pmd_t pmd, int offset) +{ +} +#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; + pte_t *pte; + int err = 0; + pagemap_entry_t pme = make_pme(PM_NOT_PRESENT); + + /* find the first VMA at or above 'addr' */ + vma = find_vma(walk->mm, addr); + if (vma && pmd_trans_huge_lock(pmd, vma) == 1) { + for (; addr != end; addr += PAGE_SIZE) { + unsigned long offset; + + offset = (addr & ~PAGEMAP_WALK_MASK) >> + PAGE_SHIFT; + thp_pmd_to_pagemap_entry(&pme, *pmd, offset); + err = add_to_pagemap(addr, &pme, pm); + if (err) + break; + } + spin_unlock(&walk->mm->page_table_lock); + return err; + } + + if (pmd_trans_unstable(pmd)) + return 0; + for (; addr != end; addr += PAGE_SIZE) { + + /* 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); + pme = make_pme(PM_NOT_PRESENT); + } + + /* 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, 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, + pte_t pte, int offset) +{ + if (pte_present(pte)) + *pme = make_pme(PM_PFRAME(pte_pfn(pte) + offset) + | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT); + else + *pme = make_pme(PM_NOT_PRESENT); +} + +/* 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; + int err = 0; + pagemap_entry_t pme; + + for (; addr != end; addr += PAGE_SIZE) { + int offset = (addr & ~hmask) >> PAGE_SHIFT; + huge_pte_to_pagemap_entry(&pme, *pte, offset); + 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); + pm.buffer = kmalloc(pm.len, 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; +} + +const struct file_operations proc_pagemap_operations = { + .llseek = mem_lseek, /* borrow this */ + .read = pagemap_read, +}; +#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) == 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(&walk->mm->page_table_lock); + 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_none(*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; + int n; + char buffer[50]; + + 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_printf(m, " file="); + seq_path(m, &file->f_path, "\n\t= "); + } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) { + seq_printf(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_printf(m, " stack"); + else + seq_printf(m, " stack:%d", tid); + } + } + + if (is_vm_hugetlb_page(vma)) + seq_printf(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(n, N_MEMORY) + if (md->node[n]) + seq_printf(m, " N%d=%lu", n, md->node[n]); +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) +{ + struct numa_maps_private *priv; + int ret = -ENOMEM; + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (priv) { + priv->proc_maps.pid = proc_pid(inode); + ret = seq_open(file, ops); + if (!ret) { + struct seq_file *m = file->private_data; + m->private = priv; + } else { + kfree(priv); + } + } + return ret; +} + +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 = seq_release_private, +}; + +const struct file_operations proc_tid_numa_maps_operations = { + .open = tid_numa_maps_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, +}; +#endif /* CONFIG_NUMA */ -- 2.30.2