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* [PATCH v2] drivers/virt/fsl_hypervisor: Correcting error handling path
@ 2020-06-17  3:00 Souptick Joarder
  2020-06-22 16:35 ` Souptick Joarder
  0 siblings, 1 reply; 6+ messages in thread
From: Souptick Joarder @ 2020-06-17  3:00 UTC (permalink / raw)
  To: jgg, dan.j.williams, gregkh, arnd, mchehab+samsung, akpm
  Cc: dan.carpenter, linux-kernel, Souptick Joarder, John Hubbard

First, when memory allocation for sg_list_unaligned failed, there
is no point of calling put_pages() as we haven't pinned any pages.

Second, if get_user_pages_fast() failed we should unpinned num_pinned
pages, no point of checking till num_pages.

This will address both.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: John Hubbard <jhubbard@nvidia.com>
---
v2:
	Added review tag.

 drivers/virt/fsl_hypervisor.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/virt/fsl_hypervisor.c b/drivers/virt/fsl_hypervisor.c
index 1b0b11b..ea344d7 100644
--- a/drivers/virt/fsl_hypervisor.c
+++ b/drivers/virt/fsl_hypervisor.c
@@ -157,7 +157,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
 
 	unsigned int i;
 	long ret = 0;
-	int num_pinned; /* return value from get_user_pages() */
+	int num_pinned = 0; /* return value from get_user_pages() */
 	phys_addr_t remote_paddr; /* The next address in the remote buffer */
 	uint32_t count; /* The number of bytes left to copy */
 
@@ -293,7 +293,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
 
 exit:
 	if (pages) {
-		for (i = 0; i < num_pages; i++)
+		for (i = 0; i < num_pinned; i++)
 			if (pages[i])
 				put_page(pages[i]);
 	}
-- 
1.9.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] drivers/virt/fsl_hypervisor: Correcting error handling path
  2020-06-17  3:00 [PATCH v2] drivers/virt/fsl_hypervisor: Correcting error handling path Souptick Joarder
@ 2020-06-22 16:35 ` Souptick Joarder
  2020-06-30  7:29   ` Souptick Joarder
  0 siblings, 1 reply; 6+ messages in thread
From: Souptick Joarder @ 2020-06-22 16:35 UTC (permalink / raw)
  To: Jason Gunthorpe, Dan Williams, Greg KH, Arnd Bergmann,
	mchehab+samsung, Andrew Morton
  Cc: Dan Carpenter, linux-kernel, John Hubbard

On Wed, Jun 17, 2020 at 8:22 AM Souptick Joarder <jrdr.linux@gmail.com> wrote:
>
> First, when memory allocation for sg_list_unaligned failed, there
> is no point of calling put_pages() as we haven't pinned any pages.
>
> Second, if get_user_pages_fast() failed we should unpinned num_pinned
> pages, no point of checking till num_pages.
>
> This will address both.
>
> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
> Cc: John Hubbard <jhubbard@nvidia.com>

Any suggestion, what is the right tree to take this patch forward ?

> ---
> v2:
>         Added review tag.
>
>  drivers/virt/fsl_hypervisor.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/virt/fsl_hypervisor.c b/drivers/virt/fsl_hypervisor.c
> index 1b0b11b..ea344d7 100644
> --- a/drivers/virt/fsl_hypervisor.c
> +++ b/drivers/virt/fsl_hypervisor.c
> @@ -157,7 +157,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
>
>         unsigned int i;
>         long ret = 0;
> -       int num_pinned; /* return value from get_user_pages() */
> +       int num_pinned = 0; /* return value from get_user_pages() */
>         phys_addr_t remote_paddr; /* The next address in the remote buffer */
>         uint32_t count; /* The number of bytes left to copy */
>
> @@ -293,7 +293,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
>
>  exit:
>         if (pages) {
> -               for (i = 0; i < num_pages; i++)
> +               for (i = 0; i < num_pinned; i++)
>                         if (pages[i])
>                                 put_page(pages[i]);
>         }
> --
> 1.9.1
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] drivers/virt/fsl_hypervisor: Correcting error handling path
  2020-06-22 16:35 ` Souptick Joarder
@ 2020-06-30  7:29   ` Souptick Joarder
  0 siblings, 0 replies; 6+ messages in thread
From: Souptick Joarder @ 2020-06-30  7:29 UTC (permalink / raw)
  To: Jason Gunthorpe, Dan Williams, Greg KH, Arnd Bergmann,
	mchehab+samsung, Andrew Morton
  Cc: Dan Carpenter, linux-kernel, John Hubbard

On Mon, Jun 22, 2020 at 10:05 PM Souptick Joarder <jrdr.linux@gmail.com> wrote:
>
> On Wed, Jun 17, 2020 at 8:22 AM Souptick Joarder <jrdr.linux@gmail.com> wrote:
> >
> > First, when memory allocation for sg_list_unaligned failed, there
> > is no point of calling put_pages() as we haven't pinned any pages.
> >
> > Second, if get_user_pages_fast() failed we should unpinned num_pinned
> > pages, no point of checking till num_pages.
> >
> > This will address both.
> >
> > Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> > Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
> > Cc: John Hubbard <jhubbard@nvidia.com>
>
> Any suggestion, what is the right tree to take this patch forward ?

If no further comment, can we get this patch in queue for 5.9 ?

>
> > ---
> > v2:
> >         Added review tag.
> >
> >  drivers/virt/fsl_hypervisor.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/virt/fsl_hypervisor.c b/drivers/virt/fsl_hypervisor.c
> > index 1b0b11b..ea344d7 100644
> > --- a/drivers/virt/fsl_hypervisor.c
> > +++ b/drivers/virt/fsl_hypervisor.c
> > @@ -157,7 +157,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
> >
> >         unsigned int i;
> >         long ret = 0;
> > -       int num_pinned; /* return value from get_user_pages() */
> > +       int num_pinned = 0; /* return value from get_user_pages() */
> >         phys_addr_t remote_paddr; /* The next address in the remote buffer */
> >         uint32_t count; /* The number of bytes left to copy */
> >
> > @@ -293,7 +293,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
> >
> >  exit:
> >         if (pages) {
> > -               for (i = 0; i < num_pages; i++)
> > +               for (i = 0; i < num_pinned; i++)
> >                         if (pages[i])
> >                                 put_page(pages[i]);
> >         }
> > --
> > 1.9.1
> >

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] drivers/virt/fsl_hypervisor: Correcting error handling path
  2020-07-30  1:00 ` John Hubbard
@ 2020-08-25 20:20   ` Souptick Joarder
  0 siblings, 0 replies; 6+ messages in thread
From: Souptick Joarder @ 2020-08-25 20:20 UTC (permalink / raw)
  To: John Hubbard
  Cc: Andrew Morton, Jason Gunthorpe, Dan Williams, Greg KH,
	mchehab+samsung, linux-kernel, Dan Carpenter

On Thu, Jul 30, 2020 at 6:30 AM John Hubbard <jhubbard@nvidia.com> wrote:
>
> On 7/29/20 12:01 PM, Souptick Joarder wrote:
> > First, when memory allocation for sg_list_unaligned failed, there
> > is no point of calling put_pages() as we haven't pinned any pages.
> >
> > Second, if get_user_pages_fast() failed we should unpinned num_pinned
> > pages, no point of checking till num_pages.
>
> Hi Souptick,
>
> For both of the above, the wording "no point" is so overly gentle as
> to be misleading. That's because calling put_page() on any pages beyond
> num_pinned is a *bug*.
>
> So let's reword that. And let's change the patch subject from "Correcting" to
> "fix".
>
> And probably good to add a Fixes: tag, too.

Is there any scripts/ settings to fetch Fixes: tag other than using git blame ?

>
> More:
>
> >
> > This will address both.
> >
> > Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> > Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
> > Cc: John Hubbard <jhubbard@nvidia.com>
> > ---
> > v2:
> >       Added review tag.
> >
> >   drivers/virt/fsl_hypervisor.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/virt/fsl_hypervisor.c b/drivers/virt/fsl_hypervisor.c
> > index 1b0b11b..ea344d7 100644
> > --- a/drivers/virt/fsl_hypervisor.c
> > +++ b/drivers/virt/fsl_hypervisor.c
> > @@ -157,7 +157,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
> >
> >       unsigned int i;
> >       long ret = 0;
> > -     int num_pinned; /* return value from get_user_pages() */
> > +     int num_pinned = 0; /* return value from get_user_pages() */
> >       phys_addr_t remote_paddr; /* The next address in the remote buffer */
> >       uint32_t count; /* The number of bytes left to copy */
> >
> > @@ -293,7 +293,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
> >
> >   exit:
> >       if (pages) {
> > -             for (i = 0; i < num_pages; i++)
> > +             for (i = 0; i < num_pinned; i++)
> >                       if (pages[i])
>
> I suspect that this "if" is unnecessary now.
>
> Either way, the diff itself looks good to me, so with the wording changes to
> the commit description, you can add:
>
>      Reviewed-by: John Hubbard <jhubbard@nvidia.com>
>
> thanks,
> --
> John Hubbard
> NVIDIA
>
> >                               put_page(pages[i]);
> >       }
> >
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] drivers/virt/fsl_hypervisor: Correcting error handling path
  2020-07-29 19:01 Souptick Joarder
@ 2020-07-30  1:00 ` John Hubbard
  2020-08-25 20:20   ` Souptick Joarder
  0 siblings, 1 reply; 6+ messages in thread
From: John Hubbard @ 2020-07-30  1:00 UTC (permalink / raw)
  To: Souptick Joarder, akpm
  Cc: jgg, dan.j.williams, gregkh, mchehab+samsung, linux-kernel,
	dan.carpenter

On 7/29/20 12:01 PM, Souptick Joarder wrote:
> First, when memory allocation for sg_list_unaligned failed, there
> is no point of calling put_pages() as we haven't pinned any pages.
> 
> Second, if get_user_pages_fast() failed we should unpinned num_pinned
> pages, no point of checking till num_pages.

Hi Souptick,

For both of the above, the wording "no point" is so overly gentle as
to be misleading. That's because calling put_page() on any pages beyond
num_pinned is a *bug*.

So let's reword that. And let's change the patch subject from "Correcting" to
"fix".

And probably good to add a Fixes: tag, too.

More:

> 
> This will address both.
> 
> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
> Cc: John Hubbard <jhubbard@nvidia.com>
> ---
> v2:
> 	Added review tag.
> 
>   drivers/virt/fsl_hypervisor.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/virt/fsl_hypervisor.c b/drivers/virt/fsl_hypervisor.c
> index 1b0b11b..ea344d7 100644
> --- a/drivers/virt/fsl_hypervisor.c
> +++ b/drivers/virt/fsl_hypervisor.c
> @@ -157,7 +157,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
>   
>   	unsigned int i;
>   	long ret = 0;
> -	int num_pinned; /* return value from get_user_pages() */
> +	int num_pinned = 0; /* return value from get_user_pages() */
>   	phys_addr_t remote_paddr; /* The next address in the remote buffer */
>   	uint32_t count; /* The number of bytes left to copy */
>   
> @@ -293,7 +293,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
>   
>   exit:
>   	if (pages) {
> -		for (i = 0; i < num_pages; i++)
> +		for (i = 0; i < num_pinned; i++)
>   			if (pages[i])

I suspect that this "if" is unnecessary now.

Either way, the diff itself looks good to me, so with the wording changes to
the commit description, you can add:

     Reviewed-by: John Hubbard <jhubbard@nvidia.com>

thanks,
-- 
John Hubbard
NVIDIA

>   				put_page(pages[i]);
>   	}
> 


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v2] drivers/virt/fsl_hypervisor: Correcting error handling path
@ 2020-07-29 19:01 Souptick Joarder
  2020-07-30  1:00 ` John Hubbard
  0 siblings, 1 reply; 6+ messages in thread
From: Souptick Joarder @ 2020-07-29 19:01 UTC (permalink / raw)
  To: akpm
  Cc: jgg, dan.j.williams, gregkh, mchehab+samsung, linux-kernel,
	dan.carpenter, Souptick Joarder, John Hubbard

First, when memory allocation for sg_list_unaligned failed, there
is no point of calling put_pages() as we haven't pinned any pages.

Second, if get_user_pages_fast() failed we should unpinned num_pinned
pages, no point of checking till num_pages.

This will address both.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: John Hubbard <jhubbard@nvidia.com>
---
v2:
	Added review tag.

 drivers/virt/fsl_hypervisor.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/virt/fsl_hypervisor.c b/drivers/virt/fsl_hypervisor.c
index 1b0b11b..ea344d7 100644
--- a/drivers/virt/fsl_hypervisor.c
+++ b/drivers/virt/fsl_hypervisor.c
@@ -157,7 +157,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
 
 	unsigned int i;
 	long ret = 0;
-	int num_pinned; /* return value from get_user_pages() */
+	int num_pinned = 0; /* return value from get_user_pages() */
 	phys_addr_t remote_paddr; /* The next address in the remote buffer */
 	uint32_t count; /* The number of bytes left to copy */
 
@@ -293,7 +293,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
 
 exit:
 	if (pages) {
-		for (i = 0; i < num_pages; i++)
+		for (i = 0; i < num_pinned; i++)
 			if (pages[i])
 				put_page(pages[i]);
 	}
-- 
1.9.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-08-25 20:20 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-06-17  3:00 [PATCH v2] drivers/virt/fsl_hypervisor: Correcting error handling path Souptick Joarder
2020-06-22 16:35 ` Souptick Joarder
2020-06-30  7:29   ` Souptick Joarder
2020-07-29 19:01 Souptick Joarder
2020-07-30  1:00 ` John Hubbard
2020-08-25 20:20   ` Souptick Joarder

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