[PATCH] ARM: kdump: Avoid overflow when converting pfn to physaddr

[PATCH] ARM: kdump: Avoid overflow when converting pfn to physaddr

[Liu Hua]

When we configure CONFIG_LPAE=y, pfn << PAGE_SHIFT will
overflow if pfn >= 0x100000 in copy_oldmem_page.

So use __pfn_to_phys for converting.

Signed-off-by: Liu Hua <sdu.liu@huawei.com>
---
 arch/arm/kernel/crash_dump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/kernel/crash_dump.c b/arch/arm/kernel/crash_dump.c
index 90c50d4..5d1286d 100644
--- a/arch/arm/kernel/crash_dump.c
+++ b/arch/arm/kernel/crash_dump.c
@@ -39,7 +39,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	if (!csize)
 		return 0;
 
-	vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
+	vaddr = ioremap(__pfn_to_phys(pfn), PAGE_SIZE);
 	if (!vaddr)
 		return -ENOMEM;
 
-- 
1.8.5.5.dirty

[PATCH] ARM: kdump: Avoid overflow when converting pfn to physaddr

[Liu Hua]

When we configure CONFIG_LPAE=y, pfn << PAGE_SHIFT will
overflow if pfn >= 0x100000 in copy_oldmem_page.

So use __pfn_to_phys for converting.

Signed-off-by: Liu Hua <sdu.liu@huawei.com>
---
 arch/arm/kernel/crash_dump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/kernel/crash_dump.c b/arch/arm/kernel/crash_dump.c
index 90c50d4..5d1286d 100644
--- a/arch/arm/kernel/crash_dump.c
+++ b/arch/arm/kernel/crash_dump.c
@@ -39,7 +39,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	if (!csize)
 		return 0;
 
-	vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
+	vaddr = ioremap(__pfn_to_phys(pfn), PAGE_SIZE);
 	if (!vaddr)
 		return -ENOMEM;
 
-- 
1.8.5.5.dirty

[PATCH] ARM: kdump: Avoid overflow when converting pfn to physaddr

[Russell King - ARM Linux]

On Tue, Mar 18, 2014 at 06:20:42PM +0800, Liu Hua wrote:
> When we configure CONFIG_LPAE=y, pfn << PAGE_SHIFT will
> overflow if pfn >= 0x100000 in copy_oldmem_page.
> 
> So use __pfn_to_phys for converting.

Yes.  The sad thing is that if you grep the kernel for similar things,
it's littered with this problem.  I'm not sure whether anyone
particularly "owns" the crash_dump.c file - Mika Westerberg and
Olaf Hering were the last two to touch it... I guess put this in my
patch system please.

Thanks.

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

Re: [PATCH] ARM: kdump: Avoid overflow when converting pfn to physaddr

[Russell King - ARM Linux]

On Tue, Mar 18, 2014 at 06:20:42PM +0800, Liu Hua wrote:
> When we configure CONFIG_LPAE=y, pfn << PAGE_SHIFT will
> overflow if pfn >= 0x100000 in copy_oldmem_page.
> 
> So use __pfn_to_phys for converting.

Yes.  The sad thing is that if you grep the kernel for similar things,
it's littered with this problem.  I'm not sure whether anyone
particularly "owns" the crash_dump.c file - Mika Westerberg and
Olaf Hering were the last two to touch it... I guess put this in my
patch system please.

Thanks.

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

[PATCH] ARM: kdump: Avoid overflow when converting pfn to physaddr

[Liu hua]

On 2014/3/18 18:48, Russell King - ARM Linux wrote:
> On Tue, Mar 18, 2014 at 06:20:42PM +0800, Liu Hua wrote:
>> When we configure CONFIG_LPAE=y, pfn << PAGE_SHIFT will
>> overflow if pfn >= 0x100000 in copy_oldmem_page.
>>
>> So use __pfn_to_phys for converting.
> 
> Yes.  The sad thing is that if you grep the kernel for similar things,
> it's littered with this problem.  I'm not sure whether anyone
> particularly "owns" the crash_dump.c file - Mika Westerberg and
> Olaf Hering were the last two to touch it... I guess put this in my
> patch system please.
> 
> Thanks.
> 

Yes, I found this problem in serval places after a quick review. I will
do a check on this.

Re: [PATCH] ARM: kdump: Avoid overflow when converting pfn to physaddr

[Liu hua]

On 2014/3/18 18:48, Russell King - ARM Linux wrote:
> On Tue, Mar 18, 2014 at 06:20:42PM +0800, Liu Hua wrote:
>> When we configure CONFIG_LPAE=y, pfn << PAGE_SHIFT will
>> overflow if pfn >= 0x100000 in copy_oldmem_page.
>>
>> So use __pfn_to_phys for converting.
> 
> Yes.  The sad thing is that if you grep the kernel for similar things,
> it's littered with this problem.  I'm not sure whether anyone
> particularly "owns" the crash_dump.c file - Mika Westerberg and
> Olaf Hering were the last two to touch it... I guess put this in my
> patch system please.
> 
> Thanks.
> 

Yes, I found this problem in serval places after a quick review. I will
do a check on this.