Hello,
On Tue, Jul 26, 2016 at 03:03:58PM +0000, zijun_hu@xxxxxxx wrote:
> I am sorry, I don't take any test for the patch attached in previous
> mail, and it can't fix the bug completely, please ignore it I
> provide a new patch attached in this mail which pass test and can
> fix the issue described below
>
> __next_mem_range_rev() defined in mm/memblock.c doesn't Achieve
> desired purpose if parameter type_b ==NULL This new patch can fix
> the issue and get the last reversed region contained in type_a
> rightly
Can you please flow future mails to 80 column?
> The new patch is descripted as follows
>
> From 0e242eda7696f176a9a2e585a1db01f0575b39c9 Mon Sep 17 00:00:00 2001
> From: zijun_hu <zijun_hu@xxxxxxx>
> Date: Mon, 25 Jul 2016 15:06:57 +0800
> Subject: [PATCH] mm/memblock.c: fix index adjustment error in
> __next_mem_range_rev()
>
> fix region index adjustment error when parameter type_b of
> __next_mem_range_rev() == NULL
The patch is now fixing two bugs. It'd be nice to describe each in
the description and how the patch was tested.
> @@ -991,7 +991,11 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid, ulong flags,
>
> if (*idx == (u64)ULLONG_MAX) {
> idx_a = type_a->cnt - 1;
> - idx_b = type_b->cnt;
> + /* in order to get the last reversed region rightly */
Before, it would trigger null deref. I don't think the above comment
is necessary.
> + if (type_b != NULL)
> + idx_b = type_b->cnt;
> + else
> + idx_b = 0;
> }
>
> for (; idx_a >= 0; idx_a--) {
> @@ -1024,7 +1028,7 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid, ulong flags,
> *out_end = m_end;
> if (out_nid)
> *out_nid = m_nid;
> - idx_a++;
> + idx_a--;
> *idx = (u32)idx_a | (u64)idx_b << 32;
> return;
> }
Both changes look good to me. Provided the changes are tested,
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Thanks.
--
tejun
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