[PATCH] ib umem: bug: put pid back before return from error path

[PATCH] ib umem: bug: put pid back before return from error path

[Kenneth Lee]

I catched this bug when reading the code. I'm sorry I have no hardware to test
it. But it is abviously a bug.

Signed-off-by: Kenneth Lee <liguozhu@hisilicon.com>
---
 drivers/infiniband/core/umem.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 1e62a5f..4609b92 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -134,6 +134,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
 		 IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND));
 
 	if (access & IB_ACCESS_ON_DEMAND) {
+		put_pid(umem->pid);
 		ret = ib_umem_odp_get(context, umem);
 		if (ret) {
 			kfree(umem);
@@ -149,6 +150,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
 
 	page_list = (struct page **) __get_free_page(GFP_KERNEL);
 	if (!page_list) {
+		put_pid(umem->pid);
 		kfree(umem);
 		return ERR_PTR(-ENOMEM);
 	}
-- 
1.9.1

Re: [PATCH] ib umem: bug: put pid back before return from error path

[Mark Bloch]

Hi,

You have two bugs here:
1) When using ODP, ib_umem_release() checks for umem->odp_data != NULL 
   calls ib_umem_odp_release() and returns immediately without calling put_pid().
   This one isn't in the error path so the title doesn't fit.

2) In case the allocation failed, we return in -ENOMEM without calling put_pid().

Can you please resend this with proper fixes line and a better description of what is going on.

On 22/12/2016 09:11, Kenneth Lee wrote:
> I catched this bug when reading the code. I'm sorry I have no hardware to test
> it. But it is abviously a bug.
> 
> Signed-off-by: Kenneth Lee <liguozhu@hisilicon.com>
> ---
>  drivers/infiniband/core/umem.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
> index 1e62a5f..4609b92 100644
> --- a/drivers/infiniband/core/umem.c
> +++ b/drivers/infiniband/core/umem.c
> @@ -134,6 +134,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
>  		 IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND));
>  
>  	if (access & IB_ACCESS_ON_DEMAND) {
> +		put_pid(umem->pid);
>  		ret = ib_umem_odp_get(context, umem);
>  		if (ret) {
>  			kfree(umem);
> @@ -149,6 +150,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
>  
>  	page_list = (struct page **) __get_free_page(GFP_KERNEL);
>  	if (!page_list) {
> +		put_pid(umem->pid);
>  		kfree(umem);
>  		return ERR_PTR(-ENOMEM);
>  	}
> 

Mark.

Re: [PATCH] ib umem: bug: put pid back before return from error path

[Kenneth Lee]

Hi, 

Sorry for the delay (I'd got some problem in my procmailrc file, and miss this 
mail).

The new patch, with title "[PATCH] ib umem: bugfix: mixed put_pid()s in
ib_umem_get()", has been sent.

On Thu, Dec 22, 2016 at 10:00:57AM +0200, Mark Bloch wrote:
> Date: Thu, 22 Dec 2016 10:00:57 +0200
> From: Mark Bloch <markb@mellanox.com>
> To: Kenneth Lee <liguozhu@hisilicon.com>, dledford@redhat.com,
>  sean.hefty@intel.com, hal.rosenstock@gmail.com
> CC: robin.murphy@arm.com, jroedel@suse.de, egtvedt@samfundet.no,
>  vgupta@synopsys.com, dave.hansen@linux.intel.com, lstoakes@gmail.com,
>  krzk@kernel.org, sebott@linux.vnet.ibm.com, linux-rdma@vger.kernel.org,
>  linux-kernel@vger.kernel.org
> Subject: Re: [PATCH] ib umem: bug: put pid back before return from error
>  path
> User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101
>  Thunderbird/45.5.1
> Message-ID: <e470fbab-a330-b9c4-f2b3-65fb45f24e0a@mellanox.com>
> 
> Hi,
> 
> You have two bugs here:
> 1) When using ODP, ib_umem_release() checks for umem->odp_data != NULL 
>    calls ib_umem_odp_release() and returns immediately without calling put_pid().
>    This one isn't in the error path so the title doesn't fit.
> 
> 2) In case the allocation failed, we return in -ENOMEM without calling put_pid().
> 
> Can you please resend this with proper fixes line and a better description of what is going on.
> 
> On 22/12/2016 09:11, Kenneth Lee wrote:
> > I catched this bug when reading the code. I'm sorry I have no hardware to test
> > it. But it is abviously a bug.
> > 
> > Signed-off-by: Kenneth Lee <liguozhu@hisilicon.com>
> > ---
> >  drivers/infiniband/core/umem.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
> > index 1e62a5f..4609b92 100644
> > --- a/drivers/infiniband/core/umem.c
> > +++ b/drivers/infiniband/core/umem.c
> > @@ -134,6 +134,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
> >  		 IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND));
> >  
> >  	if (access & IB_ACCESS_ON_DEMAND) {
> > +		put_pid(umem->pid);
> >  		ret = ib_umem_odp_get(context, umem);
> >  		if (ret) {
> >  			kfree(umem);
> > @@ -149,6 +150,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
> >  
> >  	page_list = (struct page **) __get_free_page(GFP_KERNEL);
> >  	if (!page_list) {
> > +		put_pid(umem->pid);
> >  		kfree(umem);
> >  		return ERR_PTR(-ENOMEM);
> >  	}
> > 
> 
> Mark.

-- 
			-Kenneth(Hisilicon)

Re: [PATCH] ib umem: bug: put pid back before return from error path

[Haggai Eran]

On 12/22/2016 9:11 AM, Kenneth Lee wrote:
> I catched this bug when reading the code. I'm sorry I have no hardware to test
> it. But it is abviously a bug.
> 
> Signed-off-by: Kenneth Lee <liguozhu-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org>
> ---
>  drivers/infiniband/core/umem.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
> index 1e62a5f..4609b92 100644
> --- a/drivers/infiniband/core/umem.c
> +++ b/drivers/infiniband/core/umem.c
> @@ -134,6 +134,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
>  		 IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND));
>  
>  	if (access & IB_ACCESS_ON_DEMAND) {
> +		put_pid(umem->pid);
>  		ret = ib_umem_odp_get(context, umem);
>  		if (ret) {
>  			kfree(umem);
> @@ -149,6 +150,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
>  
>  	page_list = (struct page **) __get_free_page(GFP_KERNEL);
>  	if (!page_list) {
> +		put_pid(umem->pid);
>  		kfree(umem);
>  		return ERR_PTR(-ENOMEM);
>  	}
> 

Looks good to me. Thanks!

Reviewed-by: Haggai Eran <haggaie-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
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