[PATCH mm] limit the mm->map_count not greater thansysctl_max_map_count

From: Li Zhong
Date: Wed Apr 18 2012 - 05:27:26 EST


When reading the mmap codes, I found the checking of mm->map_count
against sysctl_max_map_count is not consistent. At some places, ">" is
used; at some other places, ">=" is used.

This patch changes ">" to ">=", so they are consistent, and makes sure
the value is not greater (one more) than sysctl_max_map_count.

Signed-off-by: Li Zhong <zhong@xxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index a7bf6a3..85f4816 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -987,7 +987,7 @@ unsigned long do_mmap_pgoff(struct file *file,
unsigned long addr,
return -EOVERFLOW;

/* Too many mappings? */
- if (mm->map_count > sysctl_max_map_count)
+ if (mm->map_count >= sysctl_max_map_count)
return -ENOMEM;

/* Obtain the address to map to. we verify (or select) it and ensure
@@ -2193,7 +2193,7 @@ unsigned long do_brk(unsigned long addr, unsigned
long len)
if (!may_expand_vm(mm, len >> PAGE_SHIFT))
return -ENOMEM;

- if (mm->map_count > sysctl_max_map_count)
+ if (mm->map_count >= sysctl_max_map_count)
return -ENOMEM;

if (security_vm_enough_memory_mm(mm, len >> PAGE_SHIFT))
--
1.7.6.5



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/