[PATCH] FRV: Fix mmap2 error handling

From: David Howells
Date: Thu Nov 27 2008 - 10:12:56 EST


Fix the error handling in sys_mmap2(). Currently, if the pgoff check fails,
fput() might have to be called (which it isn't), so do the pgoff check first,
before fget() is called.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

arch/frv/kernel/sys_frv.c | 17 ++++++++---------
1 files changed, 8 insertions(+), 9 deletions(-)


diff --git a/arch/frv/kernel/sys_frv.c b/arch/frv/kernel/sys_frv.c
index 49b2cf2..baadc97 100644
--- a/arch/frv/kernel/sys_frv.c
+++ b/arch/frv/kernel/sys_frv.c
@@ -35,22 +35,21 @@ asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
int error = -EBADF;
struct file * file = NULL;

- flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
- if (!(flags & MAP_ANONYMOUS)) {
- file = fget(fd);
- if (!file)
- goto out;
- }
-
/* As with sparc32, make sure the shift for mmap2 is constant
(12), no matter what PAGE_SIZE we have.... */

/* But unlike sparc32, don't just silently break if we're
trying to map something we can't */
- if (pgoff & ((1<<(PAGE_SHIFT-12))-1))
+ if (pgoff & ((1 << (PAGE_SHIFT - 12)) - 1))
return -EINVAL;
+ pgoff >>= PAGE_SHIFT - 12;

- pgoff >>= (PAGE_SHIFT - 12);
+ flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
+ if (!(flags & MAP_ANONYMOUS)) {
+ file = fget(fd);
+ if (!file)
+ goto out;
+ }

down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);

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