[PATCH] mm/memory_hotplug: Do not unlock when fails to take the device_hotplug_lock

[PATCH] mm/memory_hotplug: Do not unlock when fails to take the device_hotplug_lock

[zhong jiang]

When adding the memory by probing memory block in sysfs interface, there is an
obvious issue that we will unlock the device_hotplug_lock when fails to takes it.

That issue was introduced in Commit 8df1d0e4a265
("mm/memory_hotplug: make add_memory() take the device_hotplug_lock")

We should drop out in time when fails to take the device_hotplug_lock.

Fixes: 8df1d0e4a265 ("mm/memory_hotplug: make add_memory() take the device_hotplug_lock")
Reported-by: Yang yingliang <yangyingliang@huawei.com>
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 drivers/base/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index d9ebb89..8b0cec7 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -507,7 +507,7 @@ static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
 
 	ret = lock_device_hotplug_sysfs();
 	if (ret)
-		goto out;
+		goto ret;
 
 	nid = memory_add_physaddr_to_nid(phys_addr);
 	ret = __add_memory(nid, phys_addr,
-- 
1.7.12.4

Re: [PATCH] mm/memory_hotplug: Do not unlock when fails to take the device_hotplug_lock

[zhong jiang]

I am sorry,  It is incorrect.  please ignore the patch.  I will resent it.

Thanks,
zhong jiang
On 2019/4/8 12:00, zhong jiang wrote:
> When adding the memory by probing memory block in sysfs interface, there is an
> obvious issue that we will unlock the device_hotplug_lock when fails to takes it.
>
> That issue was introduced in Commit 8df1d0e4a265
> ("mm/memory_hotplug: make add_memory() take the device_hotplug_lock")
>
> We should drop out in time when fails to take the device_hotplug_lock.
>
> Fixes: 8df1d0e4a265 ("mm/memory_hotplug: make add_memory() take the device_hotplug_lock")
> Reported-by: Yang yingliang <yangyingliang@huawei.com>
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
> ---
>  drivers/base/memory.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index d9ebb89..8b0cec7 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -507,7 +507,7 @@ static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
>  
>  	ret = lock_device_hotplug_sysfs();
>  	if (ret)
> -		goto out;
> +		goto ret;
>  
>  	nid = memory_add_physaddr_to_nid(phys_addr);
>  	ret = __add_memory(nid, phys_addr,

Re: [PATCH] mm/memory_hotplug: Do not unlock when fails to take the device_hotplug_lock

[kbuild test robot]

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Hi zhong,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on driver-core/driver-core-testing]
[also build test ERROR on v5.1-rc4 next-20190405]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/zhong-jiang/mm-memory_hotplug-Do-not-unlock-when-fails-to-take-the-device_hotplug_lock/20190408-142325
config: x86_64-randconfig-x007-201914 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   drivers/base/memory.c: In function 'probe_store':
>> drivers/base/memory.c:509:3: error: label 'ret' used but not defined
      goto ret;
      ^~~~

vim +/ret +509 drivers/base/memory.c

   485	
   486	/*
   487	 * Some architectures will have custom drivers to do this, and
   488	 * will not need to do it from userspace.  The fake hot-add code
   489	 * as well as ppc64 will do all of their discovery in userspace
   490	 * and will require this interface.
   491	 */
   492	#ifdef CONFIG_ARCH_MEMORY_PROBE
   493	static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
   494				   const char *buf, size_t count)
   495	{
   496		u64 phys_addr;
   497		int nid, ret;
   498		unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block;
   499	
   500		ret = kstrtoull(buf, 0, &phys_addr);
   501		if (ret)
   502			return ret;
   503	
   504		if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1))
   505			return -EINVAL;
   506	
   507		ret = lock_device_hotplug_sysfs();
   508		if (ret)
 > 509			goto ret;
   510	
   511		nid = memory_add_physaddr_to_nid(phys_addr);
   512		ret = __add_memory(nid, phys_addr,
   513				   MIN_MEMORY_BLOCK_SIZE * sections_per_block);
   514	
   515		if (ret)
   516			goto out;
   517	
   518		ret = count;
   519	out:
   520		unlock_device_hotplug();
   521		return ret;
   522	}
   523	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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