* [PATCH 1/2] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister
@ 2015-10-23 14:56 Geliang Tang
2015-10-23 14:56 ` [PATCH 2/2] efi-pstore: implement efivars_pstore_exit() Geliang Tang
2015-10-23 16:54 ` [PATCH 1/2] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister Kees Cook
0 siblings, 2 replies; 4+ messages in thread
From: Geliang Tang @ 2015-10-23 14:56 UTC (permalink / raw)
To: Anton Vorontsov, Colin Cross, Kees Cook, Tony Luck
Cc: Geliang Tang, linux-kernel
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 0aab920..7ad2038 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -496,9 +496,12 @@ 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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] efi-pstore: implement efivars_pstore_exit()
2015-10-23 14:56 [PATCH 1/2] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister Geliang Tang
@ 2015-10-23 14:56 ` Geliang Tang
2015-10-23 16:54 ` [PATCH 1/2] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister Kees Cook
1 sibling, 0 replies; 4+ messages in thread
From: Geliang Tang @ 2015-10-23 14:56 UTC (permalink / raw)
To: Matt Fleming, Anton Vorontsov, Colin Cross, Kees Cook, Tony Luck
Cc: Geliang Tang, linux-efi, linux-kernel
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 c8d794c..453ac19 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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister
2015-10-23 14:56 [PATCH 1/2] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister Geliang Tang
2015-10-23 14:56 ` [PATCH 2/2] efi-pstore: implement efivars_pstore_exit() Geliang Tang
@ 2015-10-23 16:54 ` Kees Cook
2015-10-25 2:22 ` Geliang Tang
1 sibling, 1 reply; 4+ messages in thread
From: Kees Cook @ 2015-10-23 16:54 UTC (permalink / raw)
To: Geliang Tang; +Cc: Anton Vorontsov, Colin Cross, Tony Luck, LKML
On Fri, Oct 23, 2015 at 7:56 AM, 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>
Would it make more sense to have the pstore_unregister_* calls be
defensive, like kfree() is? In other words, it would be safe to call
them, even if they hadn't been registered?
Either way, I'm fine with this. Good catch!
-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 0aab920..7ad2038 100644
> --- a/fs/pstore/platform.c
> +++ b/fs/pstore/platform.c
> @@ -496,9 +496,12 @@ 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 Security
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister
2015-10-23 16:54 ` [PATCH 1/2] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister Kees Cook
@ 2015-10-25 2:22 ` Geliang Tang
0 siblings, 0 replies; 4+ messages in thread
From: Geliang Tang @ 2015-10-25 2:22 UTC (permalink / raw)
To: Kees Cook
Cc: Anton Vorontsov, Colin Cross, Tony Luck, linux-kernel, Geliang Tang
On Fri, Oct 23, 2015 at 09:54:31AM -0700, Kees Cook wrote:
> On Fri, Oct 23, 2015 at 7:56 AM, 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>
>
> Would it make more sense to have the pstore_unregister_* calls be
> defensive, like kfree() is? In other words, it would be safe to call
> them, even if they hadn't been registered?
>
> Either way, I'm fine with this. Good catch!
>
> -Kees
>
Thanks for your reply.
pstore_unregister_* is defensive as you expected. I have tested it. it
is safe to call them if they haven't been registered. This won't cause
any trouble.
But logically, we should check this flag in pstore_unregister.
-Geliang Tang
> > ---
> > 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 0aab920..7ad2038 100644
> > --- a/fs/pstore/platform.c
> > +++ b/fs/pstore/platform.c
> > @@ -496,9 +496,12 @@ 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 Security
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-10-25 2:24 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2015-10-23 14:56 [PATCH 1/2] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister Geliang Tang
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2015-10-23 16:54 ` [PATCH 1/2] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister Kees Cook
2015-10-25 2:22 ` Geliang Tang
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