[PATCH] kexec: avoid freeing NULL pointer in function kimage_crash_alloc

Zhang Yanfei
2013-02-22T04:52:29Z

Though there is no error if we free a NULL pointer, I think we could
avoid this behaviour. Change the code a little in kimage_crash_alloc()
could avoid this kind of unnecessary free.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
---
kernel/kexec.c | 15 +++++++--------
1 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 5e4bd78..4e96fa7 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -310,7 +310,7 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
mend = mstart + image->segment[i].memsz - 1;
/* Ensure we are within the crash kernel limits */
if ((mstart < crashk_res.start) || (mend > crashk_res.end))
- goto out;
+ goto out_free;
}

/*
@@ -323,16 +323,15 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
get_order(KEXEC_CONTROL_PAGE_SIZE));
if (!image->control_code_page) {
printk(KERN_ERR "Could not allocate control_code_buffer\n");
- goto out;
+ goto out_free;
}

- result = 0;
-out:
- if (result == 0)
- *rimage = image;
- else
- kfree(image);
+ *rimage = image;
+ return 0;

+out_free:
+ kfree(image);
+out:
return result;
}

--
1.7.1

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