On Fri, 18 Nov 2011 17:13:50 +0530
Kautuk Consul <consul.kautuk@xxxxxxxxx> wrote:
> If either of the vas or vms arrays are not properly kzalloced,
> then the code jumps to the err_free label.
>
> The err_free label runs a loop to check and free each of the array
> members of the vas and vms arrays which is not required for this
> situation as none of the array members have been allocated till this
> point.
>
> Eliminate the extra loop we have to go through by introducing a new
> label err_free2 and then jumping to it.
>
> Signed-off-by: Kautuk Consul <consul.kautuk@xxxxxxxxx>
> ---
> mm/vmalloc.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index b669aa6..1a0d4e2 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -2352,7 +2352,7 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
> vms = kzalloc(sizeof(vms[0]) * nr_vms, GFP_KERNEL);
> vas = kzalloc(sizeof(vas[0]) * nr_vms, GFP_KERNEL);
> if (!vas || !vms)
> - goto err_free;
> + goto err_free2;
>
> for (area = 0; area < nr_vms; area++) {
> vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
> @@ -2455,6 +2455,7 @@ err_free:
> if (vms)
> kfree(vms[area]);
> }
> +err_free2:
> kfree(vas);
> kfree(vms);
> return NULL;
Which means we can also do the below, yes? (please check my homework!)
--- a/mm/vmalloc.c~mm-vmallocc-eliminate-extra-loop-in-pcpu_get_vm_areas-error-path-fix
+++ a/mm/vmalloc.c
@@ -2449,10 +2449,8 @@ found:
err_free:
for (area = 0; area < nr_vms; area++) {
- if (vas)
- kfree(vas[area]);
- if (vms)
- kfree(vms[area]);
+ kfree(vas[area]);
+ kfree(vms[area]);
}
err_free2:
kfree(vas);
_
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