From: zijun_hu <zijun_hu@zoho.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
zijun_hu@htc.com, tj@kernel.org, mingo@kernel.org,
rientjes@google.com, iamjoonsoo.kim@lge.com,
mgorman@techsingularity.net
Subject: Re: [PATCH v2 1/1] lib/ioremap.c: avoid endless loop under ioremapping page unaligned ranges
Date: Fri, 23 Sep 2016 13:53:03 +0800 [thread overview]
Message-ID: <57E4C33F.4080401@zoho.com> (raw)
In-Reply-To: <57E20A69.5010206@zoho.com>
On 09/21/2016 12:19 PM, zijun_hu wrote:
> From: zijun_hu <zijun_hu@htc.com>
>
> endless loop maybe happen if either of parameter addr and end is not
> page aligned for kernel API function ioremap_page_range()
>
> in order to fix this issue and alert improper range parameters to user
> WARN_ON() checkup and rounding down range lower boundary are performed
> firstly, loop end condition within ioremap_pte_range() is optimized due
> to lack of relevant macro pte_addr_end()
>
> Signed-off-by: zijun_hu <zijun_hu@htc.com>
> ---
> lib/ioremap.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/lib/ioremap.c b/lib/ioremap.c
> index 86c8911..911bdca 100644
> --- a/lib/ioremap.c
> +++ b/lib/ioremap.c
> @@ -64,7 +64,7 @@ static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
> BUG_ON(!pte_none(*pte));
> set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
> pfn++;
> - } while (pte++, addr += PAGE_SIZE, addr != end);
> + } while (pte++, addr += PAGE_SIZE, addr < end && addr >= PAGE_SIZE);
> return 0;
> }
>
> @@ -129,7 +129,9 @@ int ioremap_page_range(unsigned long addr,
> int err;
>
> BUG_ON(addr >= end);
> + WARN_ON(!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(end));
>
> + addr = round_down(addr, PAGE_SIZE);
> start = addr;
> phys_addr -= addr;
> pgd = pgd_offset_k(addr);
>
From: zijun_hu <zijun_hu@htc.com>
s/WARN_ON()/WARN_ON_ONCE()/ to reduce warning messages
Signed-off-by: zijun_hu <zijun_hu@htc.com>
---
lib/ioremap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/ioremap.c b/lib/ioremap.c
index 911bdca..974e88b 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -129,7 +129,7 @@ int ioremap_page_range(unsigned long addr,
int err;
BUG_ON(addr >= end);
- WARN_ON(!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(end));
+ WARN_ON_ONCE(!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(end));
addr = round_down(addr, PAGE_SIZE);
start = addr;
--
1.9.1
--
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WARNING: multiple messages have this Message-ID (diff)
From: zijun_hu <zijun_hu@zoho.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
zijun_hu@htc.com, tj@kernel.org, mingo@kernel.org,
rientjes@google.com, iamjoonsoo.kim@lge.com,
mgorman@techsingularity.net
Subject: Re: [PATCH v2 1/1] lib/ioremap.c: avoid endless loop under ioremapping page unaligned ranges
Date: Fri, 23 Sep 2016 13:53:03 +0800 [thread overview]
Message-ID: <57E4C33F.4080401@zoho.com> (raw)
In-Reply-To: <57E20A69.5010206@zoho.com>
On 09/21/2016 12:19 PM, zijun_hu wrote:
> From: zijun_hu <zijun_hu@htc.com>
>
> endless loop maybe happen if either of parameter addr and end is not
> page aligned for kernel API function ioremap_page_range()
>
> in order to fix this issue and alert improper range parameters to user
> WARN_ON() checkup and rounding down range lower boundary are performed
> firstly, loop end condition within ioremap_pte_range() is optimized due
> to lack of relevant macro pte_addr_end()
>
> Signed-off-by: zijun_hu <zijun_hu@htc.com>
> ---
> lib/ioremap.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/lib/ioremap.c b/lib/ioremap.c
> index 86c8911..911bdca 100644
> --- a/lib/ioremap.c
> +++ b/lib/ioremap.c
> @@ -64,7 +64,7 @@ static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
> BUG_ON(!pte_none(*pte));
> set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
> pfn++;
> - } while (pte++, addr += PAGE_SIZE, addr != end);
> + } while (pte++, addr += PAGE_SIZE, addr < end && addr >= PAGE_SIZE);
> return 0;
> }
>
> @@ -129,7 +129,9 @@ int ioremap_page_range(unsigned long addr,
> int err;
>
> BUG_ON(addr >= end);
> + WARN_ON(!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(end));
>
> + addr = round_down(addr, PAGE_SIZE);
> start = addr;
> phys_addr -= addr;
> pgd = pgd_offset_k(addr);
>
From: zijun_hu <zijun_hu@htc.com>
s/WARN_ON()/WARN_ON_ONCE()/ to reduce warning messages
Signed-off-by: zijun_hu <zijun_hu@htc.com>
---
lib/ioremap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/ioremap.c b/lib/ioremap.c
index 911bdca..974e88b 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -129,7 +129,7 @@ int ioremap_page_range(unsigned long addr,
int err;
BUG_ON(addr >= end);
- WARN_ON(!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(end));
+ WARN_ON_ONCE(!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(end));
addr = round_down(addr, PAGE_SIZE);
start = addr;
--
1.9.1
next prev parent reply other threads:[~2016-09-23 5:53 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-21 4:19 [PATCH 1/1] lib/ioremap.c: avoid endless loop under ioremapping page unaligned ranges zijun_hu
2016-09-21 4:19 ` zijun_hu
2016-09-22 12:47 ` Michal Hocko
2016-09-22 12:47 ` Michal Hocko
2016-09-22 15:13 ` zijun_hu
2016-09-22 15:13 ` zijun_hu
2016-09-23 8:45 ` Michal Hocko
2016-09-23 8:45 ` Michal Hocko
2016-09-23 12:29 ` zijun_hu
2016-09-23 12:29 ` zijun_hu
2016-09-23 12:42 ` Michal Hocko
2016-09-23 12:42 ` Michal Hocko
2016-09-23 13:00 ` zijun_hu
2016-09-23 13:00 ` zijun_hu
2016-09-23 13:33 ` Michal Hocko
2016-09-23 13:33 ` Michal Hocko
2016-09-23 14:14 ` zijun_hu
2016-09-23 14:14 ` zijun_hu
2016-09-23 14:27 ` Michal Hocko
2016-09-23 14:27 ` Michal Hocko
2016-09-23 14:58 ` zijun_hu
2016-09-23 14:58 ` zijun_hu
2016-09-23 5:53 ` zijun_hu [this message]
2016-09-23 5:53 ` [PATCH v2 " zijun_hu
2016-09-23 14:42 ` [PATCH " Tejun Heo
2016-09-23 14:42 ` Tejun Heo
2016-09-23 15:41 ` zijun_hu
2016-09-23 15:41 ` zijun_hu
2016-09-23 16:23 ` Tejun Heo
2016-09-23 16:23 ` Tejun Heo
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