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fs/proc/task_mmu: stop using linked list and highest_vm_end
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Remove references to mm_struct linked list and highest_vm_end for when
they are removed

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Liam R. Howlett <[email protected]>
Tested-by: Yu Zhao <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: David Howells <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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@akpm00
Matthew Wilcox (Oracle) authored and akpm00 committed Sep 27, 2022
1 parent 5f14b92 commit c4c84f0
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Showing 2 changed files with 42 additions and 33 deletions.
2 changes: 1 addition & 1 deletion fs/proc/internal.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down
73 changes: 41 additions & 32 deletions fs/proc/task_mmu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand All @@ -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)
Expand Down Expand Up @@ -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;
Expand All @@ -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;

Expand All @@ -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) {
Expand Down Expand Up @@ -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;
Expand All @@ -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");

Expand Down Expand Up @@ -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,
Expand All @@ -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;
Expand All @@ -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);
Expand Down

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