[PATCH v2 3/3] mm/vmalloc: move VM_UNINITIALIZED just before show_numa_info

From: Wanpeng Li
Date: Mon Sep 02 2013 - 23:00:46 EST


The VM_UNINITIALIZED/VM_UNLIST flag introduced by commit f5252e00(mm: avoid
null pointer access in vm_struct via /proc/vmallocinfo) is used to avoid
accessing the pages field with unallocated page when show_numa_info() is
called. This patch move the check just before show_numa_info in order that
some messages still can be dumped via /proc/vmallocinfo.

Signed-off-by: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index e3ec8b4..c4720cd 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2590,11 +2590,6 @@ static int s_show(struct seq_file *m, void *p)

v = va->vm;

- /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
- smp_rmb();
- if (v->flags & VM_UNINITIALIZED)
- return 0;
-
seq_printf(m, "0x%pK-0x%pK %7ld",
v->addr, v->addr + v->size, v->size);

@@ -2622,6 +2617,11 @@ static int s_show(struct seq_file *m, void *p)
if (v->flags & VM_VPAGES)
seq_printf(m, " vpages");

+ /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+ smp_rmb();
+ if (v->flags & VM_UNINITIALIZED)
+ return 0;
+
show_numa_info(m, v);
seq_putc(m, '\n');
return 0;
--
1.7.5.4

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