[PATCH] pstore: fix crypto dependencies without compression

[PATCH] pstore: fix crypto dependencies without compression

[Tobias Regnery]

Commit 58eb5b670747 ("pstore: fix crypto dependencies") fixed up the crypto
dependencies but missed the case when no compression is selected.

With CONFIG_PSTORE=y, CONFIG_PSTORE_COMPRESS=n  and CONFIG_CRYPTO=m we see
the following link error:

fs/pstore/platform.o: In function `pstore_register':
(.text+0x1b1): undefined reference to `crypto_has_alg'
(.text+0x205): undefined reference to `crypto_alloc_base'
fs/pstore/platform.o: In function `pstore_unregister':
(.text+0x3b0): undefined reference to `crypto_destroy_tfm'

Fix this by selecting CONFIG_CRYPTO unconditionally.

Fixes: 58eb5b670747 ("pstore: fix crypto dependencies")
Signed-off-by: Tobias Regnery <tobias.regnery@gmail.com>
---
 fs/pstore/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index 09c19ef91526..f42ea286ccd7 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -1,6 +1,6 @@
 config PSTORE
 	tristate "Persistent store support"
-	select CRYPTO if PSTORE_COMPRESS
+	select CRYPTO
 	default n
 	help
 	   This option enables generic access to platform level
-- 
2.16.3

Re: [PATCH] pstore: fix crypto dependencies without compression

[Arnd Bergmann]

On Fri, Apr 6, 2018 at 8:38 AM, Tobias Regnery <tobias.regnery@gmail.com> wrote:
> Commit 58eb5b670747 ("pstore: fix crypto dependencies") fixed up the crypto
> dependencies but missed the case when no compression is selected.
>
> With CONFIG_PSTORE=y, CONFIG_PSTORE_COMPRESS=n  and CONFIG_CRYPTO=m we see
> the following link error:
>
> fs/pstore/platform.o: In function `pstore_register':
> (.text+0x1b1): undefined reference to `crypto_has_alg'
> (.text+0x205): undefined reference to `crypto_alloc_base'
> fs/pstore/platform.o: In function `pstore_unregister':
> (.text+0x3b0): undefined reference to `crypto_destroy_tfm'
>
> Fix this by selecting CONFIG_CRYPTO unconditionally.
>
> Fixes: 58eb5b670747 ("pstore: fix crypto dependencies")
> Signed-off-by: Tobias Regnery <tobias.regnery@gmail.com>

Thanks, I wonder how I missed this one. Thanks for fixing it up.
It's a bit unfortunate that it now disallows the otherwise valid
CONFIG_PSTORE=y, CONFIG_PSTORE_COMPRESS=n
and CONFIG_CRYPTO=n configuration, though.

Could we do this by making the calls compile-time configured
in the pstore code instead? Please try the untested version
below.

        Arnd

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 1143ef351c58..dc720573fd53 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -258,7 +258,7 @@ static int pstore_decompress(void *in, void *out,

 static void allocate_buf_for_compression(void)
 {
-       if (!zbackend)
+       if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend)
                return;

        if (!crypto_has_comp(zbackend->name, 0, 0)) {
@@ -287,7 +287,7 @@ static void allocate_buf_for_compression(void)

 static void free_buf_for_compression(void)
 {
-       if (!IS_ERR_OR_NULL(tfm))
+       if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && !IS_ERR_OR_NULL(tfm))
                crypto_free_comp(tfm);
        kfree(big_oops_buf);
        big_oops_buf = NULL;

Re: [PATCH] pstore: fix crypto dependencies without compression

[Tobias Regnery]

On 06.04.18, Arnd Bergmann wrote:
> On Fri, Apr 6, 2018 at 8:38 AM, Tobias Regnery <tobias.regnery@gmail.com> wrote:
> > Commit 58eb5b670747 ("pstore: fix crypto dependencies") fixed up the crypto
> > dependencies but missed the case when no compression is selected.
> >
> > With CONFIG_PSTORE=y, CONFIG_PSTORE_COMPRESS=n  and CONFIG_CRYPTO=m we see
> > the following link error:
> >
> > fs/pstore/platform.o: In function `pstore_register':
> > (.text+0x1b1): undefined reference to `crypto_has_alg'
> > (.text+0x205): undefined reference to `crypto_alloc_base'
> > fs/pstore/platform.o: In function `pstore_unregister':
> > (.text+0x3b0): undefined reference to `crypto_destroy_tfm'
> >
> > Fix this by selecting CONFIG_CRYPTO unconditionally.
> >
> > Fixes: 58eb5b670747 ("pstore: fix crypto dependencies")
> > Signed-off-by: Tobias Regnery <tobias.regnery@gmail.com>
> 
> Thanks, I wonder how I missed this one. Thanks for fixing it up.
> It's a bit unfortunate that it now disallows the otherwise valid
> CONFIG_PSTORE=y, CONFIG_PSTORE_COMPRESS=n
> and CONFIG_CRYPTO=n configuration, though.
> 
> Could we do this by making the calls compile-time configured
> in the pstore code instead? Please try the untested version
> below.
> 
>         Arnd
> 
> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
> index 1143ef351c58..dc720573fd53 100644
> --- a/fs/pstore/platform.c
> +++ b/fs/pstore/platform.c
> @@ -258,7 +258,7 @@ static int pstore_decompress(void *in, void *out,
> 
>  static void allocate_buf_for_compression(void)
>  {
> -       if (!zbackend)
> +       if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend)
>                 return;
> 
>         if (!crypto_has_comp(zbackend->name, 0, 0)) {
> @@ -287,7 +287,7 @@ static void allocate_buf_for_compression(void)
> 
>  static void free_buf_for_compression(void)
>  {
> -       if (!IS_ERR_OR_NULL(tfm))
> +       if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && !IS_ERR_OR_NULL(tfm))
>                 crypto_free_comp(tfm);
>         kfree(big_oops_buf);
>         big_oops_buf = NULL;

Hi Arnd,

this seems to be the better fix, the link error goes away with this change.
Thanks for the suggestion, I will send an updated patch.

--
Tobias