Commit c2e88d22 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Linus Torvalds
Browse files

proc: remove m_cache_vma 



Instead of setting m->version in the show method, set it in m_next(),
where it should be.  Also remove the fallback code for failing to find a
vma, or version being zero.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200317193201.9924-2-adobriyan@gmail.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d07ded61

fs/proc/task_mmu.c

+6 −32
Original line number Diff line number Diff line
@@ -131,21 +131,14 @@ m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma) 
	return vma->vm_next ?: priv->tail_vma;

}



static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma)

{

	if (m->count < m->size)	/* vma is copied successfully */

		m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL;

}



static void *m_start(struct seq_file *m, loff_t *ppos)

{

	struct proc_maps_private *priv = m->private;

	unsigned long last_addr = m->version;

	struct mm_struct *mm;

	struct vm_area_struct *vma;

	unsigned int pos = *ppos;



	/* See m_cache_vma(). Zero at the start or after lseek. */

	/* See m_next(). Zero at the start or after lseek. */

	if (last_addr == -1UL)

		return NULL;
@@ -170,28 +163,11 @@ static void *m_start(struct seq_file *m, loff_t *ppos) 
	hold_task_mempolicy(priv);

	priv->tail_vma = get_gate_vma(mm);



	if (last_addr) {

		vma = find_vma(mm, last_addr - 1);

		if (vma && vma->vm_start <= last_addr)

			vma = m_next_vma(priv, vma);

	vma = find_vma(mm, last_addr);

	if (vma)

		return vma;

	}



	m->version = 0;

	if (pos < mm->map_count) {

		for (vma = mm->mmap; pos; pos--) {

			m->version = vma->vm_start;

			vma = vma->vm_next;

		}

		return vma;

	}



	/* we do not bother to update m->version in this case */

	if (pos == mm->map_count && priv->tail_vma)

	return priv->tail_vma;



	return NULL;

}



static void *m_next(struct seq_file *m, void *v, loff_t *pos)
@@ -201,6 +177,8 @@ static void *m_next(struct seq_file *m, void *v, loff_t *pos) 


	(*pos)++;

	next = m_next_vma(priv, v);

	m->version = next ? next->vm_start : -1UL;



	return next;

}
@@ -359,7 +337,6 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma) 
static int show_map(struct seq_file *m, void *v)

{

	show_map_vma(m, v);

	m_cache_vma(m, v);

	return 0;

}
@@ -843,8 +820,6 @@ static int show_smap(struct seq_file *m, void *v) 
		seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));

	show_smap_vma_flags(m, vma);



	m_cache_vma(m, vma);



	return 0;

}
@@ -1883,7 +1858,6 @@ static int show_numa_map(struct seq_file *m, void *v) 
	seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10);

out:

	seq_putc(m, '\n');

	m_cache_vma(m, vma);

	return 0;

}