The patch titled
Fix VMA display mismatch between /proc/pid/{maps,smaps}
has been added to the -mm tree. Its filename is
fix-vma-display-mismatch-between-proc-pid-mapssmaps.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: Fix VMA display mismatch between /proc/pid/{maps,smaps}
From: Joe Korty <joe.korty@xxxxxxxx>
Fix vma display mismatch between /proc/pid/{maps,smaps}
The following commit
From 4752c369789250eafcd7813e11c8fb689235b0d2
From: Matt Mackall <mpm@xxxxxxxxxxx>
Date: Mon, 4 Feb 2008 22:29:02 -0800
Subject: [PATCH] maps4: simplify interdependence of maps and smaps
broke /proc/pid/smaps, causing it to display some vmas twice and other
vmas not at all. For example:
grep .- /proc/1/smaps >/tmp/smaps; diff /proc/1/maps /tmp/smaps
1 25d24
2 < 7fd7e23aa000-7fd7e23ac000 rw-p 7fd7e23aa000 00:00 0
3 28a28
4 > ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]
The bug has something to do with setting m->version before all the
seq_printf's have been performed. show_map was doing this correctly,
but show_smap was doing this in the middle of its seq_printf sequence.
This patch arranges things so that the setting of m->version in show_smap
is also done at the end of its seq_printf sequence.
Testing: in addition to the above grep test, for each process I summed
up the 'Rss' fields of /proc/pid/smaps and compared that to the 'VmRSS'
field of /proc/pid/status. All matched except for Xorg (which has a
/dev/mem mapping which Rss accounts for but VmRSS does not). This result
gives us some confidence that neither /proc/pid/maps nor /proc/pid/smaps
are any longer skipping or double-counting vmas.
Signed-off-by: Joe Korty <joe.korty@xxxxxxxx>
Cc: Matt Mackall <mpm@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/task_mmu.c | 37 ++++++++++++++++++++++++-------------
1 file changed, 24 insertions(+), 13 deletions(-)
diff -puN fs/proc/task_mmu.c~fix-vma-display-mismatch-between-proc-pid-mapssmaps fs/proc/task_mmu.c
--- a/fs/proc/task_mmu.c~fix-vma-display-mismatch-between-proc-pid-mapssmaps
+++ a/fs/proc/task_mmu.c
@@ -198,11 +198,8 @@ static int do_maps_open(struct inode *in
return ret;
}
-static int show_map(struct seq_file *m, void *v)
+static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
{
- struct proc_maps_private *priv = m->private;
- struct task_struct *task = priv->task;
- struct vm_area_struct *vma = v;
struct mm_struct *mm = vma->vm_mm;
struct file *file = vma->vm_file;
int flags = vma->vm_flags;
@@ -210,9 +207,6 @@ static int show_map(struct seq_file *m,
dev_t dev = 0;
int len;
- if (maps_protect && !ptrace_may_access(task, PTRACE_MODE_READ))
- return -EACCES;
-
if (file) {
struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
dev = inode->i_sb->s_dev;
@@ -257,9 +251,21 @@ static int show_map(struct seq_file *m,
}
}
seq_putc(m, '\n');
+}
+
+static int show_map(struct seq_file *m, void *v)
+{
+ struct vm_area_struct *vma = v;
+ struct proc_maps_private *priv = m->private;
+ struct task_struct *task = priv->task;
+
+ if (maps_protect && !ptrace_may_access(task, PTRACE_MODE_READ))
+ return -EACCES;
+
+ show_map_vma(m, vma);
if (m->count < m->size) /* vma is copied successfully */
- m->version = (vma != get_gate_vma(task))? vma->vm_start: 0;
+ m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0;
return 0;
}
@@ -367,9 +373,10 @@ static int smaps_pte_range(pmd_t *pmd, u
static int show_smap(struct seq_file *m, void *v)
{
+ struct proc_maps_private *priv = m->private;
+ struct task_struct *task = priv->task;
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,
@@ -381,9 +388,10 @@ static int show_smap(struct seq_file *m,
if (vma->vm_mm && !is_vm_hugetlb_page(vma))
walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk);
- ret = show_map(m, v);
- if (ret)
- return ret;
+ if (maps_protect && !ptrace_may_access(task, PTRACE_MODE_READ))
+ return -EACCES;
+
+ show_map_vma(m, vma);
seq_printf(m,
"Size: %8lu kB\n"
@@ -405,7 +413,10 @@ static int show_smap(struct seq_file *m,
mss.referenced >> 10,
mss.swap >> 10);
- return ret;
+ if (m->count < m->size) /* vma is copied successfully */
+ m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0;
+
+ return 0;
}
static const struct seq_operations proc_pid_smaps_op = {
_
Patches currently in -mm which might be from joe.korty@xxxxxxxx are
linux-next.patch
forcdeth-increase-max_interrupt_work.patch
fix-vma-display-mismatch-between-proc-pid-mapssmaps.patch
message-queues-increase-range-limits.patch
message-queues-increase-range-limits-checkpatch-fixes.patch
--
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