fs/proc/task_mmu: stop using linked list and highest_vm_end

Remove references to mm_struct linked list and highest_vm_end for when
they are removed

Link: https://lkml.kernel.org/r/20220906194824.2110408-44-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 06a80f78433d8b40f48aa9419f3b51c9e8f77f65..f03000764ce52a17539ae4b5192bee34a0defcc6 100644 (file)
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -285,7 +285,7 @@ struct proc_maps_private {
        struct task_struct *task;
        struct mm_struct *mm;
 #ifdef CONFIG_MMU
-       struct vm_area_struct *tail_vma;
+       struct vma_iterator iter;
 #endif
 #ifdef CONFIG_NUMA
        struct mempolicy *task_mempolicy;

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 9f70bc1c276611323722d11ba370fa926a41f8c0..8b4f3073f8f55e0bfc920f8c962d0d7dd3932c5c 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -123,12 +123,26 @@ 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;
-       struct vm_area_struct *vma;
 
        /* See m_next(). Zero at the start or after lseek. */
        if (last_addr == -1UL)
@@ -152,31 +166,21 @@ static void *m_start(struct seq_file *m, loff_t *ppos)
                return ERR_PTR(-EINTR);
        }
 
+       vma_iter_init(&priv->iter, mm, last_addr);
        hold_task_mempolicy(priv);
-       priv->tail_vma = get_gate_vma(mm);
-
-       vma = find_vma(mm, last_addr);
-       if (vma)
-               return vma;
+       if (last_addr == -2UL)
+               return get_gate_vma(mm);
 
-       return priv->tail_vma;
+       return proc_get_vma(priv, ppos);
 }
 
 static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
 {
-       struct proc_maps_private *priv = m->private;
-       struct vm_area_struct *next, *vma = v;
-
-       if (vma == priv->tail_vma)
-               next = NULL;
-       else if (vma->vm_next)
-               next = vma->vm_next;
-       else
-               next = priv->tail_vma;
-
-       *ppos = next ? next->vm_start : -1UL;
-
-       return next;
+       if (*ppos == -2UL) {
+               *ppos = -1UL;
+               return NULL;
+       }
+       return proc_get_vma(m->private, ppos);
 }
 
 static void m_stop(struct seq_file *m, void *v)
@@ -876,16 +880,16 @@ 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;
+       struct mm_struct *mm = priv->mm;
        struct vm_area_struct *vma;
-       unsigned long last_vma_end = 0;
+       unsigned long vma_start = 0, last_vma_end = 0;
        int ret = 0;
+       MA_STATE(mas, &mm->mm_mt, 0, 0);
 
        priv->task = get_proc_task(priv->inode);
        if (!priv->task)
                return -ESRCH;
 
-       mm = priv->mm;
        if (!mm || !mmget_not_zero(mm)) {
                ret = -ESRCH;
                goto out_put_task;
@@ -898,8 +902,13 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
                goto out_put_mm;
 
        hold_task_mempolicy(priv);
+       vma = mas_find(&mas, 0);
+
+       if (unlikely(!vma))
+               goto empty_set;
 
-       for (vma = priv->mm->mmap; vma;) {
+       vma_start = vma->vm_start;
+       do {
                smap_gather_stats(vma, &mss, 0);
                last_vma_end = vma->vm_end;
 
@@ -908,6 +917,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
                 * access it for write request.
                 */
                if (mmap_lock_is_contended(mm)) {
+                       mas_pause(&mas);
                        mmap_read_unlock(mm);
                        ret = mmap_read_lock_killable(mm);
                        if (ret) {
@@ -951,7 +961,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
                         *    contains last_vma_end.
                         *    Iterate VMA' from last_vma_end.
                         */
-                       vma = find_vma(mm, last_vma_end - 1);
+                       vma = mas_find(&mas, ULONG_MAX);
                        /* Case 3 above */
                        if (!vma)
                                break;
@@ -965,11 +975,10 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
                                smap_gather_stats(vma, &mss, last_vma_end);
                }
                /* Case 2 above */
-               vma = vma->vm_next;
-       }
+       } while ((vma = mas_find(&mas, ULONG_MAX)) != NULL);
 
-       show_vma_header_prefix(m, priv->mm->mmap->vm_start,
-                              last_vma_end, 0, 0, 0, 0);
+empty_set:
+       show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0);
        seq_pad(m, ' ');
        seq_puts(m, "[rollup]\n");
 
@@ -1262,6 +1271,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
                return -ESRCH;
        mm = get_task_mm(task);
        if (mm) {
+               MA_STATE(mas, &mm->mm_mt, 0, 0);
                struct mmu_notifier_range range;
                struct clear_refs_private cp = {
                        .type = type,
@@ -1281,7 +1291,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
                }
 
                if (type == CLEAR_REFS_SOFT_DIRTY) {
-                       for (vma = mm->mmap; vma; vma = vma->vm_next) {
+                       mas_for_each(&mas, vma, ULONG_MAX) {
                                if (!(vma->vm_flags & VM_SOFTDIRTY))
                                        continue;
                                vma->vm_flags &= ~VM_SOFTDIRTY;
@@ -1293,8 +1303,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
                                                0, NULL, mm, 0, -1UL);
                        mmu_notifier_invalidate_range_start(&range);
                }
-               walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops,
-                               &cp);
+               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);