4 files changed, 93 insertions, 59 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 9e3b8c33c24b..797d775e0354 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -288,7 +288,7 @@ static void render_cap_t(struct seq_file *m, const char *header,
         seq_printf(m, "%s", header);
         CAP_FOR_EACH_U32(__capi) {
                 seq_printf(m, "%08x",
-                           a->cap[(_LINUX_CAPABILITY_U32S-1) - __capi]);
+                           a->cap[(_KERNEL_CAPABILITY_U32S-1) - __capi]);
         }
         seq_printf(m, "\n");
 }
diff --git a/fs/proc/base.c b/fs/proc/base.c
index c447e0743a3c..3b455371e7ff 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -127,6 +127,25 @@ struct pid_entry {
                 NULL, &proc_single_file_operations,     \
                 { .proc_show = &proc_##OTYPE } )
 
+/*
+ * Count the number of hardlinks for the pid_entry table, excluding the .
+ * and .. links.
+ */
+static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
+        unsigned int n)
+{
+        unsigned int i;
+        unsigned int count;
+
+        count = 0;
+        for (i = 0; i < n; ++i) {
+                if (S_ISDIR(entries[i].mode))
+                        ++count;
+        }
+
+        return count;
+}
+
 int maps_protect;
 EXPORT_SYMBOL(maps_protect);
 
@@ -2585,10 +2604,9 @@ static struct dentry *proc_pid_instantiate(struct inode *dir,
         inode->i_op = &proc_tgid_base_inode_operations;
         inode->i_fop = &proc_tgid_base_operations;
         inode->i_flags|=S_IMMUTABLE;
-        inode->i_nlink = 5;
-#ifdef CONFIG_SECURITY
-        inode->i_nlink += 1;
-#endif
+
+        inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
+                ARRAY_SIZE(tgid_base_stuff));
 
         dentry->d_op = &pid_dentry_operations;
 
@@ -2816,10 +2834,9 @@ static struct dentry *proc_task_instantiate(struct inode *dir,
         inode->i_op = &proc_tid_base_inode_operations;
         inode->i_fop = &proc_tid_base_operations;
         inode->i_flags|=S_IMMUTABLE;
-        inode->i_nlink = 4;
-#ifdef CONFIG_SECURITY
-        inode->i_nlink += 1;
-#endif
+
+        inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
+                ARRAY_SIZE(tid_base_stuff));
 
         dentry->d_op = &pid_dentry_operations;
 
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index 32dc14cd8900..7e277f2ad466 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -716,7 +716,7 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf,
         pfn = src / KPMSIZE;
         count = min_t(size_t, count, (max_pfn * KPMSIZE) - src);
         if (src & KPMMASK || count & KPMMASK)
-                return -EIO;
+                return -EINVAL;
 
         while (count > 0) {
                 ppage = NULL;
@@ -726,7 +726,7 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf,
                 if (!ppage)
                         pcount = 0;
                 else
-                        pcount = atomic_read(&ppage->_count);
+                        pcount = page_mapcount(ppage);
 
                 if (put_user(pcount, out++)) {
                         ret = -EFAULT;
@@ -782,7 +782,7 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
         pfn = src / KPMSIZE;
         count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
         if (src & KPMMASK || count & KPMMASK)
-                return -EIO;
+                return -EINVAL;
 
         while (count > 0) {
                 ppage = NULL;
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 88717c0f941b..ab8ccc9d14ff 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -315,9 +315,9 @@ struct mem_size_stats {
 };
 
 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
-                           void *private)
+                           struct mm_walk *walk)
 {
-        struct mem_size_stats *mss = private;
+        struct mem_size_stats *mss = walk->private;
         struct vm_area_struct *vma = mss->vma;
         pte_t *pte, ptent;
         spinlock_t *ptl;
@@ -365,19 +365,21 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
         return 0;
 }
 
-static struct mm_walk smaps_walk = { .pmd_entry = smaps_pte_range };
-
 static int show_smap(struct seq_file *m, void *v)
 {
         struct vm_area_struct *vma = v;
         struct mem_size_stats mss;
         int ret;
+        struct mm_walk smaps_walk = {
+                .pmd_entry = smaps_pte_range,
+                .mm = vma->vm_mm,
+                .private = &mss,
+        };
 
         memset(&mss, 0, sizeof mss);
         mss.vma = vma;
         if (vma->vm_mm && !is_vm_hugetlb_page(vma))
-                walk_page_range(vma->vm_mm, vma->vm_start, vma->vm_end,
-                                &smaps_walk, &mss);
+                walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk);
 
         ret = show_map(m, v);
         if (ret)
@@ -426,9 +428,9 @@ const struct file_operations proc_smaps_operations = {
 };
 
 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
-                                unsigned long end, void *private)
+                                unsigned long end, struct mm_walk *walk)
 {
-        struct vm_area_struct *vma = private;
+        struct vm_area_struct *vma = walk->private;
         pte_t *pte, ptent;
         spinlock_t *ptl;
         struct page *page;
@@ -452,8 +454,6 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
         return 0;
 }
 
-static struct mm_walk clear_refs_walk = { .pmd_entry = clear_refs_pte_range };
-
 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
                                 size_t count, loff_t *ppos)
 {
@@ -476,11 +476,17 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
                 return -ESRCH;
         mm = get_task_mm(task);
         if (mm) {
+                static struct mm_walk clear_refs_walk;
+                memset(&clear_refs_walk, 0, sizeof(clear_refs_walk));
+                clear_refs_walk.pmd_entry = clear_refs_pte_range;
+                clear_refs_walk.mm = mm;
                 down_read(&mm->mmap_sem);
-                for (vma = mm->mmap; vma; vma = vma->vm_next)
+                for (vma = mm->mmap; vma; vma = vma->vm_next) {
+                        clear_refs_walk.private = vma;
                         if (!is_vm_hugetlb_page(vma))
-                                walk_page_range(mm, vma->vm_start, vma->vm_end,
-                                                &clear_refs_walk, vma);
+                                walk_page_range(vma->vm_start, vma->vm_end,
+                                                &clear_refs_walk);
+                }
                 flush_tlb_mm(mm);
                 up_read(&mm->mmap_sem);
                 mmput(mm);
@@ -496,7 +502,7 @@ const struct file_operations proc_clear_refs_operations = {
 };
 
 struct pagemapread {
-        char __user *out, *end;
+        u64 __user *out, *end;
 };
 
 #define PM_ENTRY_BYTES      sizeof(u64)
@@ -519,28 +525,18 @@ struct pagemapread {
 static int add_to_pagemap(unsigned long addr, u64 pfn,
                           struct pagemapread *pm)
 {
-        /*
-         * Make sure there's room in the buffer for an
-         * entire entry.  Otherwise, only copy part of
-         * the pfn.
-         */
-        if (pm->out + PM_ENTRY_BYTES >= pm->end) {
-                if (copy_to_user(pm->out, &pfn, pm->end - pm->out))
-                        return -EFAULT;
-                pm->out = pm->end;
-                return PM_END_OF_BUFFER;
-        }
-
         if (put_user(pfn, pm->out))
                 return -EFAULT;
-        pm->out += PM_ENTRY_BYTES;
+        pm->out++;
+        if (pm->out >= pm->end)
+                return PM_END_OF_BUFFER;
         return 0;
 }
 
 static int pagemap_pte_hole(unsigned long start, unsigned long end,
-                                void *private)
+                                struct mm_walk *walk)
 {
-        struct pagemapread *pm = private;
+        struct pagemapread *pm = walk->private;
         unsigned long addr;
         int err = 0;
         for (addr = start; addr < end; addr += PAGE_SIZE) {
@@ -557,24 +553,45 @@ static u64 swap_pte_to_pagemap_entry(pte_t pte)
         return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
 }
 
+static unsigned long pte_to_pagemap_entry(pte_t pte)
+{
+        unsigned long pme = 0;
+        if (is_swap_pte(pte))
+                pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte))
+                        | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
+        else if (pte_present(pte))
+                pme = PM_PFRAME(pte_pfn(pte))
+                        | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
+        return pme;
+}
+
 static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
-                             void *private)
+                             struct mm_walk *walk)
 {
-        struct pagemapread *pm = private;
+        struct vm_area_struct *vma;
+        struct pagemapread *pm = walk->private;
         pte_t *pte;
         int err = 0;
 
+        /* find the first VMA at or above 'addr' */
+        vma = find_vma(walk->mm, addr);
         for (; addr != end; addr += PAGE_SIZE) {
                 u64 pfn = PM_NOT_PRESENT;
-                pte = pte_offset_map(pmd, addr);
-                if (is_swap_pte(*pte))
-                        pfn = PM_PFRAME(swap_pte_to_pagemap_entry(*pte))
-                                | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
-                else if (pte_present(*pte))
-                        pfn = PM_PFRAME(pte_pfn(*pte))
-                                | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
-                /* unmap so we're not in atomic when we copy to userspace */
-                pte_unmap(pte);
+
+                /* 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);
+
+                /* 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);
+                        pfn = pte_to_pagemap_entry(*pte);
+                        /* unmap before userspace copy */
+                        pte_unmap(pte);
+                }
                 err = add_to_pagemap(addr, pfn, pm);
                 if (err)
                         return err;
@@ -634,7 +651,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
 
         ret = -EINVAL;
         /* file position must be aligned */
-        if (*ppos % PM_ENTRY_BYTES)
+        if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
                 goto out_task;
 
         ret = 0;
@@ -664,8 +681,8 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
                 goto out_pages;
         }
 
-        pm.out = buf;
-        pm.end = buf + count;
+        pm.out = (u64 *)buf;
+        pm.end = (u64 *)(buf + count);
 
         if (!ptrace_may_attach(task)) {
                 ret = -EIO;
@@ -685,14 +702,14 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
                  * user buffer is tracked in "pm", and the walk
                  * will stop when we hit the end of the buffer.
                  */
-                ret = walk_page_range(mm, start_vaddr, end_vaddr,
-                                        &pagemap_walk, &pm);
+                ret = walk_page_range(start_vaddr, end_vaddr,
+                                        &pagemap_walk);
                 if (ret == PM_END_OF_BUFFER)
                         ret = 0;
                 /* don't need mmap_sem for these, but this looks cleaner */
-                *ppos += pm.out - buf;
+                *ppos += (char *)pm.out - buf;
                 if (!ret)
-                        ret = pm.out - buf;
+                        ret = (char *)pm.out - buf;
         }
 
 out_pages: