[PATCH v2 0/3] pstore: resend three patches

[PATCH v2 0/3] pstore: resend three patches

[Geliang Tang]

I sent these patches a few weeks ago. Due to the recent changes in pstore,
these patched might not apply anymore. So I refresh and resend them.

---
Changes in v2:
 - refresh the patches.
---

Geliang Tang (3):
  pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister
  efi-pstore: implement efivars_pstore_exit()
  pstore: drop file opened reference count

 drivers/firmware/efi/efi-pstore.c | 7 +++++++
 fs/pstore/inode.c                 | 1 -
 fs/pstore/platform.c              | 9 ++++++---
 3 files changed, 13 insertions(+), 4 deletions(-)

-- 
2.5.0

[PATCH v2 0/3] pstore: resend three patches

[Geliang Tang]

I sent these patches a few weeks ago. Due to the recent changes in pstore,
these patched might not apply anymore. So I refresh and resend them.

---
Changes in v2:
 - refresh the patches.
---

Geliang Tang (3):
  pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister
  efi-pstore: implement efivars_pstore_exit()
  pstore: drop file opened reference count

 drivers/firmware/efi/efi-pstore.c | 7 +++++++
 fs/pstore/inode.c                 | 1 -
 fs/pstore/platform.c              | 9 ++++++---
 3 files changed, 13 insertions(+), 4 deletions(-)

-- 
2.5.0

[PATCH v2 1/3] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister

[Geliang Tang]

When PSTORE_FLAGS_FRAGILE flag is set, only kmsg is registered in
pstore_register. So, under these circumstances, only kmsg needs to
be unregistered in pstore_unregister.

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
 fs/pstore/platform.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 588461b..5b8f1eb 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -497,9 +497,12 @@ EXPORT_SYMBOL_GPL(pstore_register);
 
 void pstore_unregister(struct pstore_info *psi)
 {
-	pstore_unregister_pmsg();
-	pstore_unregister_ftrace();
-	pstore_unregister_console();
+	if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {
+		pstore_unregister_pmsg();
+		pstore_unregister_ftrace();
+		pstore_unregister_console();
+	}
+
 	pstore_unregister_kmsg();
 
 	free_buf_for_compression();
-- 
2.5.0

[PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Geliang Tang]

The original efivars_pstore_exit() is empty. I
 1) add a bufsize check statement.
 2) call pstore_unregister as it is defined now.
 3) free the memory and set bufsize to 0.

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
 drivers/firmware/efi/efi-pstore.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index eac76a7..62d57d8 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -393,6 +393,13 @@ static __init int efivars_pstore_init(void)
 
 static __exit void efivars_pstore_exit(void)
 {
+	if (!efi_pstore_info.bufsize)
+		return;
+
+	pstore_unregister(&efi_pstore_info);
+	kfree(efi_pstore_info.buf);
+	efi_pstore_info.buf = NULL;
+	efi_pstore_info.bufsize = 0;
 }
 
 module_init(efivars_pstore_init);
-- 
2.5.0

[PATCH v2 3/3] pstore: drop file opened reference count

[Geliang Tang]

In my recent commit, I added '.owner = THIS_MODULE' in both
pstore_fs_type and pstore_file_operations to increase a reference count
when pstore filesystem is mounted and pstore file is opened.[1]

But, it's repetitive. There is no need to increase the opened reference
count. We only need to increase the mounted reference count. When a file
is opened, the filesystem can't be unmounted. Hence the pstore module
can't be unloaded either.

So I drop the opened reference count in this patch.

[1] https://lkml.org/lkml/2015/10/20/84

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
Here is the reference count test:

$ sudo /sbin/insmod lib/zlib_deflate/zlib_deflate.ko
$ sudo /sbin/insmod fs/pstore/pstore.ko
$ lsmod
Module                  Size  Used by
pstore                 13301  0
zlib_deflate           20156  1 pstore

$ sudo mount -t pstore pstore /sys/fs/pstore
$ lsmod
Module                  Size  Used by
pstore                 13301  1
zlib_deflate           20156  1 pstore

$ sudo /sbin/insmod lib/reed_solomon/reed_solomon.ko
$ sudo /sbin/insmod fs/pstore/ramoops.ko mem_address=0x80000000 mem_size=0x40000 ecc=1
$ lsmod
Module                  Size  Used by
ramoops                11156  0
reed_solomon            5878  1 ramoops
pstore                 13301  2 ramoops
zlib_deflate           20156  1 pstore

$ sudo rmmod ramoops
$ lsmod
Module                  Size  Used by
reed_solomon            5878  0
pstore                 13301  1
zlib_deflate           20156  1 pstore

$ tail -f /sys/fs/pstore/console-ramoops-0 &
[1] 4479
$ lsmod
Module                  Size  Used by
reed_solomon            5878  0
pstore                 13301  1
zlib_deflate           20156  1 pstore

$ sudo umount /sys/fs/pstore
umount: /sys/fs/pstore: target is busy
        (In some cases useful info about processes that
         use the device is found by lsof(8) or fuser(1).)

$ kill -9 4479
[1]+  Killed                  tail -f /sys/fs/pstore/console-ramoops-0
$ lsmod
Module                  Size  Used by
reed_solomon            5878  0
pstore                 13301  1
zlib_deflate           20156  1 pstore

$ sudo umount /sys/fs/pstore
$ lsmod
Module                  Size  Used by
reed_solomon            5878  0
pstore                 13301  0
zlib_deflate           20156  1 pstore

$ sudo rmmod pstore
$ lsmod
Module                  Size  Used by
reed_solomon            5878  0
zlib_deflate           20156  0
---
 fs/pstore/inode.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index d8c439d..ac6c78fe 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -178,7 +178,6 @@ static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence)
 }
 
 static const struct file_operations pstore_file_operations = {
-	.owner		= THIS_MODULE,
 	.open		= pstore_file_open,
 	.read		= pstore_file_read,
 	.llseek		= pstore_file_llseek,
-- 
2.5.0

Re: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Matt Fleming]

On Sat, 07 Nov, at 12:43:48PM, Geliang Tang wrote:
> The original efivars_pstore_exit() is empty. I
>  1) add a bufsize check statement.
>  2) call pstore_unregister as it is defined now.
>  3) free the memory and set bufsize to 0.
> 
> Signed-off-by: Geliang Tang <geliangtang@163.com>
> ---
>  drivers/firmware/efi/efi-pstore.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
> index eac76a7..62d57d8 100644
> --- a/drivers/firmware/efi/efi-pstore.c
> +++ b/drivers/firmware/efi/efi-pstore.c
> @@ -393,6 +393,13 @@ static __init int efivars_pstore_init(void)
>  
>  static __exit void efivars_pstore_exit(void)
>  {
> +	if (!efi_pstore_info.bufsize)
> +		return;
> +
> +	pstore_unregister(&efi_pstore_info);
> +	kfree(efi_pstore_info.buf);
> +	efi_pstore_info.buf = NULL;
> +	efi_pstore_info.bufsize = 0;
>  }
>  
>  module_init(efivars_pstore_init);

Looks OK to me. Kees, are you picking this up?

Re: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Matt Fleming]

On Sat, 07 Nov, at 12:43:48PM, Geliang Tang wrote:
> The original efivars_pstore_exit() is empty. I
>  1) add a bufsize check statement.
>  2) call pstore_unregister as it is defined now.
>  3) free the memory and set bufsize to 0.
> 
> Signed-off-by: Geliang Tang <geliangtang-9Onoh4P/yGk@public.gmane.org>
> ---
>  drivers/firmware/efi/efi-pstore.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
> index eac76a7..62d57d8 100644
> --- a/drivers/firmware/efi/efi-pstore.c
> +++ b/drivers/firmware/efi/efi-pstore.c
> @@ -393,6 +393,13 @@ static __init int efivars_pstore_init(void)
>  
>  static __exit void efivars_pstore_exit(void)
>  {
> +	if (!efi_pstore_info.bufsize)
> +		return;
> +
> +	pstore_unregister(&efi_pstore_info);
> +	kfree(efi_pstore_info.buf);
> +	efi_pstore_info.buf = NULL;
> +	efi_pstore_info.bufsize = 0;
>  }
>  
>  module_init(efivars_pstore_init);

Looks OK to me. Kees, are you picking this up?

Re: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Kees Cook]

On Wed, Nov 11, 2015 at 8:59 AM, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> On Sat, 07 Nov, at 12:43:48PM, Geliang Tang wrote:
>> The original efivars_pstore_exit() is empty. I
>>  1) add a bufsize check statement.
>>  2) call pstore_unregister as it is defined now.
>>  3) free the memory and set bufsize to 0.
>>
>> Signed-off-by: Geliang Tang <geliangtang@163.com>
>> ---
>>  drivers/firmware/efi/efi-pstore.c | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
>> index eac76a7..62d57d8 100644
>> --- a/drivers/firmware/efi/efi-pstore.c
>> +++ b/drivers/firmware/efi/efi-pstore.c
>> @@ -393,6 +393,13 @@ static __init int efivars_pstore_init(void)
>>
>>  static __exit void efivars_pstore_exit(void)
>>  {
>> +     if (!efi_pstore_info.bufsize)
>> +             return;
>> +
>> +     pstore_unregister(&efi_pstore_info);
>> +     kfree(efi_pstore_info.buf);
>> +     efi_pstore_info.buf = NULL;
>> +     efi_pstore_info.bufsize = 0;
>>  }
>>
>>  module_init(efivars_pstore_init);
>
> Looks OK to me. Kees, are you picking this up?

I can, though usually it goes through Tony.

-Kees

-- 
Kees Cook
Chrome OS Security

RE: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Luck, Tony]

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[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 357 bytes --]

>>>  module_init(efivars_pstore_init);
>>
>> Looks OK to me. Kees, are you picking this up?
>
> I can, though usually it goes through Tony.

Can I count that as "Acked-by" from both of you?

-Tony
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RE: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Luck, Tony]

>>>  module_init(efivars_pstore_init);
>>
>> Looks OK to me. Kees, are you picking this up?
>
> I can, though usually it goes through Tony.

Can I count that as "Acked-by" from both of you?

-Tony

Re: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Kees Cook]

On Wed, Nov 11, 2015 at 3:23 PM, Luck, Tony <tony.luck@intel.com> wrote:
>>>>  module_init(efivars_pstore_init);
>>>
>>> Looks OK to me. Kees, are you picking this up?
>>
>> I can, though usually it goes through Tony.
>
> Can I count that as "Acked-by" from both of you?

Yup, sorry. I thought I'd acked them already. :) My bad!

Acked-by: Kees Cook <keescook@chromium.org>

-Kees

-- 
Kees Cook
Chrome OS Security

Re: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Kees Cook]

On Wed, Nov 11, 2015 at 3:23 PM, Luck, Tony <tony.luck-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:
>>>>  module_init(efivars_pstore_init);
>>>
>>> Looks OK to me. Kees, are you picking this up?
>>
>> I can, though usually it goes through Tony.
>
> Can I count that as "Acked-by" from both of you?

Yup, sorry. I thought I'd acked them already. :) My bad!

Acked-by: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>

-Kees

-- 
Kees Cook
Chrome OS Security

Re: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Geliang Tang, Kees Cook]

On Wed, Nov 11, 2015 at 03:24:33PM -0800, Kees Cook wrote:
> On Wed, Nov 11, 2015 at 3:23 PM, Luck, Tony <tony.luck@intel.com> wrote:
> >>>>  module_init(efivars_pstore_init);
> >>>
> >>> Looks OK to me. Kees, are you picking this up?
> >>
> >> I can, though usually it goes through Tony.
> >
> > Can I count that as "Acked-by" from both of you?
> 
> Yup, sorry. I thought I'd acked them already. :) My bad!
> 
> Acked-by: Kees Cook <keescook@chromium.org>
> 

Hi Kees,

Could you please apply these three pending patches for me?
I think they are still valid. Thank you very much.

-Geliang

> -Kees
> 
> -- 
> Kees Cook
> Chrome OS Security

Re: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Geliang Tang, Kees Cook]

On Wed, Nov 11, 2015 at 03:24:33PM -0800, Kees Cook wrote:
> On Wed, Nov 11, 2015 at 3:23 PM, Luck, Tony <tony.luck-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:
> >>>>  module_init(efivars_pstore_init);
> >>>
> >>> Looks OK to me. Kees, are you picking this up?
> >>
> >> I can, though usually it goes through Tony.
> >
> > Can I count that as "Acked-by" from both of you?
> 
> Yup, sorry. I thought I'd acked them already. :) My bad!
> 
> Acked-by: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
> 

Hi Kees,

Could you please apply these three pending patches for me?
I think they are still valid. Thank you very much.

-Geliang

> -Kees
> 
> -- 
> Kees Cook
> Chrome OS Security

Re: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Kees Cook]

On Thu, Jun 2, 2016 at 12:26 AM, Geliang Tang <geliangtang@163.com> wrote:
> On Wed, Nov 11, 2015 at 03:24:33PM -0800, Kees Cook wrote:
>> On Wed, Nov 11, 2015 at 3:23 PM, Luck, Tony <tony.luck@intel.com> wrote:
>> >>>>  module_init(efivars_pstore_init);
>> >>>
>> >>> Looks OK to me. Kees, are you picking this up?
>> >>
>> >> I can, though usually it goes through Tony.
>> >
>> > Can I count that as "Acked-by" from both of you?
>>
>> Yup, sorry. I thought I'd acked them already. :) My bad!
>>
>> Acked-by: Kees Cook <keescook@chromium.org>
>>
>
> Hi Kees,
>
> Could you please apply these three pending patches for me?
> I think they are still valid. Thank you very much.

Yes, added to my for-next tree now. Thanks!

-Kees

-- 
Kees Cook
Chrome OS & Brillo Security

Re: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Kees Cook]

On Thu, Jun 2, 2016 at 12:26 AM, Geliang Tang <geliangtang-9Onoh4P/yGk@public.gmane.org> wrote:
> On Wed, Nov 11, 2015 at 03:24:33PM -0800, Kees Cook wrote:
>> On Wed, Nov 11, 2015 at 3:23 PM, Luck, Tony <tony.luck-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:
>> >>>>  module_init(efivars_pstore_init);
>> >>>
>> >>> Looks OK to me. Kees, are you picking this up?
>> >>
>> >> I can, though usually it goes through Tony.
>> >
>> > Can I count that as "Acked-by" from both of you?
>>
>> Yup, sorry. I thought I'd acked them already. :) My bad!
>>
>> Acked-by: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
>>
>
> Hi Kees,
>
> Could you please apply these three pending patches for me?
> I think they are still valid. Thank you very much.

Yes, added to my for-next tree now. Thanks!

-Kees

-- 
Kees Cook
Chrome OS & Brillo Security

Re: [PATCH v2 2/3] efi-pstore: implement efivars_pstore_exit()

[Matt Fleming]

On Wed, 11 Nov, at 11:23:15PM, Luck, Tony wrote:
> >>>  module_init(efivars_pstore_init);
> >>
> >> Looks OK to me. Kees, are you picking this up?
> >
> > I can, though usually it goes through Tony.
> 
> Can I count that as "Acked-by" from both of you?

Yep, Acked-by: Matt Fleming <matt@codeblueprint.co.uk>

Re: [PATCH v2 1/3] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister

[Kees Cook]

On Fri, Nov 6, 2015 at 8:43 PM, Geliang Tang <geliangtang@163.com> wrote:
> When PSTORE_FLAGS_FRAGILE flag is set, only kmsg is registered in
> pstore_register. So, under these circumstances, only kmsg needs to
> be unregistered in pstore_unregister.
>
> Signed-off-by: Geliang Tang <geliangtang@163.com>

I actually did the exact same thing recently, sorry to missing this
earlier version.

-Kees

> ---
>  fs/pstore/platform.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
> index 588461b..5b8f1eb 100644
> --- a/fs/pstore/platform.c
> +++ b/fs/pstore/platform.c
> @@ -497,9 +497,12 @@ EXPORT_SYMBOL_GPL(pstore_register);
>
>  void pstore_unregister(struct pstore_info *psi)
>  {
> -       pstore_unregister_pmsg();
> -       pstore_unregister_ftrace();
> -       pstore_unregister_console();
> +       if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {
> +               pstore_unregister_pmsg();
> +               pstore_unregister_ftrace();
> +               pstore_unregister_console();
> +       }
> +
>         pstore_unregister_kmsg();
>
>         free_buf_for_compression();
> --
> 2.5.0
>
>



-- 
Kees Cook
Chrome OS & Brillo Security