2016-12-22 06:47:57

by Kenneth Lee

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

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 <[email protected]>
---
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


2016-12-22 10:33:37

by Mark Bloch

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

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 <[email protected]>
> ---
> 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.

2016-12-22 19:39:45

by Haggai Eran

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

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 <[email protected]>
> ---
> 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 <[email protected]>

2016-12-29 02:05:16

by Kenneth Lee

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

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 <[email protected]>
> To: Kenneth Lee <[email protected]>, [email protected],
> [email protected], [email protected]
> CC: [email protected], [email protected], [email protected],
> [email protected], [email protected], [email protected],
> [email protected], [email protected], [email protected],
> [email protected]
> 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: <[email protected]>
>
> 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 <[email protected]>
> > ---
> > 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)