From: zijun_hu <zijun_hu@zoho.com>
To: Andrew Morton <akpm@linux-foundation.org>,
tj@kernel.org, hannes@cmpxchg.org
Cc: mhocko@kernel.org, minchan@kernel.org, zijun_hu@htc.com,
rientjes@google.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org
Subject: [PATCH] mm/vmalloc: fix align value calculation error
Date: Thu, 4 Aug 2016 16:02:43 +0800 [thread overview]
Message-ID: <57A2F6A3.9080908@zoho.com> (raw)
WARNING: multiple messages have this Message-ID (diff)
From: zijun_hu <zijun_hu@zoho.com>
To: Andrew Morton <akpm@linux-foundation.org>,
tj@kernel.org, hannes@cmpxchg.org
Cc: mhocko@kernel.org, minchan@kernel.org, zijun_hu@htc.com,
rientjes@google.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org
Subject: [PATCH] mm/vmalloc: fix align value calculation error
Date: Thu, 4 Aug 2016 16:02:43 +0800 [thread overview]
Message-ID: <57A2F6A3.9080908@zoho.com> (raw)
>From e40d1066f61394992e0167f259001ae9d2581dc1 Mon Sep 17 00:00:00 2001
From: zijun_hu <zijun_hu@htc.com>
Date: Thu, 4 Aug 2016 14:22:52 +0800
Subject: [PATCH] mm/vmalloc: fix align value calculation error
it causes double align requirement for __get_vm_area_node() if parameter
size is power of 2 and VM_IOREMAP is set in parameter flags
it is fixed by using order_base_2 instead of fls_long() due to lack of
get_count_order() for long parameter
Signed-off-by: zijun_hu <zijun_hu@htc.com>
---
mm/vmalloc.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 91f44e7..8b17c51 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1357,11 +1357,19 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
{
struct vmap_area *va;
struct vm_struct *area;
+ int ioremap_size_order;
BUG_ON(in_interrupt());
- if (flags & VM_IOREMAP)
- align = 1ul << clamp_t(int, fls_long(size),
- PAGE_SHIFT, IOREMAP_MAX_ORDER);
+ if (flags & VM_IOREMAP) {
+ if (unlikely(size < 2))
+ ioremap_size_order = size;
+ else if (unlikely((signed long)size < 0))
+ ioremap_size_order = sizeof(size) * 8;
+ else
+ ioremap_size_order = order_base_2(size);
+ align = 1ul << clamp_t(int, ioremap_size_order, PAGE_SHIFT,
+ IOREMAP_MAX_ORDER);
+ }
size = PAGE_ALIGN(size);
if (unlikely(!size))
--
1.9.1
next reply other threads:[~2016-08-04 8:02 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-04 8:02 zijun_hu [this message]
2016-08-04 8:02 ` [PATCH] mm/vmalloc: fix align value calculation error zijun_hu
2016-08-04 8:36 ` zijun_hu
2016-08-04 8:36 ` zijun_hu
2016-08-04 21:24 ` Andrew Morton
2016-08-04 21:24 ` Andrew Morton
2016-08-05 2:27 ` zijun_hu
2016-08-05 2:27 ` zijun_hu
2016-08-05 15:48 ` zijun_hu
2016-08-05 15:48 ` zijun_hu
2016-08-09 21:28 ` Andrew Morton
2016-08-09 21:28 ` Andrew Morton
2016-08-10 5:32 ` zijun_hu
2016-08-10 5:32 ` zijun_hu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=57A2F6A3.9080908@zoho.com \
--to=zijun_hu@zoho.com \
--cc=akpm@linux-foundation.org \
--cc=hannes@cmpxchg.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=minchan@kernel.org \
--cc=rientjes@google.com \
--cc=tj@kernel.org \
--cc=zijun_hu@htc.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.