[PATCH 1/1] powerpc: Increase COMMAND_LINE_SIZE to 2048 from 512.

[PATCH 1/1] powerpc: Increase COMMAND_LINE_SIZE to 2048 from 512.

[Joseph Salisbury]

BugLink: http://bugs.launchpad.net/bugs/1306677

While booting the PPC64EL kernel, the command line gets truncated to 512 characters. This is due to a hard limit of 512 defined for COMMAND_LINE_SIZE.  It would be beneficial to have a command line longer than 512 characters, as iscsi targets and cloud-init parameters are passed through the kernel command line.

Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> (supporter:LINUX FOR POWERPC...)
Cc: Paul Mackerras <paulus@samba.org> (supporter:LINUX FOR POWERPC...)
Cc: linuxppc-dev@lists.ozlabs.org (open list:LINUX FOR POWERPC...)
Cc: linux-kernel@vger.kernel.org (open list)
Cc: stable@vger.kernel.org

---
 arch/powerpc/boot/ops.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/boot/ops.h b/arch/powerpc/boot/ops.h
index b3218ce..5a01fb1 100644
--- a/arch/powerpc/boot/ops.h
+++ b/arch/powerpc/boot/ops.h
@@ -15,7 +15,7 @@
 #include "types.h"
 #include "string.h"
 
-#define	COMMAND_LINE_SIZE	512
+#define	COMMAND_LINE_SIZE	2048	
 #define	MAX_PATH_LEN		256
 #define	MAX_PROP_LEN		256 /* What should this be? */
 
-- 
1.7.9.5

Re: [PATCH 1/1] powerpc: Increase COMMAND_LINE_SIZE to 2048 from 512.

[Joseph Salisbury]

On 04/14/2014 11:30 AM, Joseph Salisbury wrote:
> BugLink: http://bugs.launchpad.net/bugs/1306677
>
> While booting the PPC64EL kernel, the command line gets truncated to 512 characters. This is due to a hard limit of 512 defined for COMMAND_LINE_SIZE.  It would be beneficial to have a command line longer than 512 characters, as iscsi targets and cloud-init parameters are passed through the kernel command line.
>
> Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> (supporter:LINUX FOR POWERPC...)
> Cc: Paul Mackerras <paulus@samba.org> (supporter:LINUX FOR POWERPC...)
> Cc: linuxppc-dev@lists.ozlabs.org (open list:LINUX FOR POWERPC...)
> Cc: linux-kernel@vger.kernel.org (open list)
> Cc: stable@vger.kernel.org
>
> ---
>  arch/powerpc/boot/ops.h |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/boot/ops.h b/arch/powerpc/boot/ops.h
> index b3218ce..5a01fb1 100644
> --- a/arch/powerpc/boot/ops.h
> +++ b/arch/powerpc/boot/ops.h
> @@ -15,7 +15,7 @@
>  #include "types.h"
>  #include "string.h"
>  
> -#define	COMMAND_LINE_SIZE	512
> +#define	COMMAND_LINE_SIZE	2048	
>  #define	MAX_PATH_LEN		256
>  #define	MAX_PROP_LEN		256 /* What should this be? */
>  

After further review, it appears ppc does not actually use the define in
the ppc headers but uses the common generic
default(include/uapi/asm-generic/setup.h).  COMMAND_LINE_SIZE should
probably become a kernel config option.  Do folks agree that is the
correct thing to do?  If so, I can re-work the patch.

Thanks,

Joe

Re: [PATCH 1/1] powerpc: Increase COMMAND_LINE_SIZE to 2048 from 512.

[Benjamin Herrenschmidt]

On Mon, 2014-04-14 at 14:58 -0400, Joseph Salisbury wrote:
> 
> After further review, it appears ppc does not actually use the define
> in
> the ppc headers but uses the common generic
> default(include/uapi/asm-generic/setup.h).  COMMAND_LINE_SIZE should
> probably become a kernel config option.  Do folks agree that is the
> correct thing to do?  If so, I can re-work the patch.

No objection on my side.

Make sure you remove any unused arch define while at it.

Cheers,
Ben.

Re: [PATCH 1/1] powerpc: Increase COMMAND_LINE_SIZE to 2048 from 512.

[Joseph Salisbury]

On 04/15/2014 05:49 AM, Benjamin Herrenschmidt wrote:
> On Mon, 2014-04-14 at 14:58 -0400, Joseph Salisbury wrote:
>> After further review, it appears ppc does not actually use the define
>> in
>> the ppc headers but uses the common generic
>> default(include/uapi/asm-generic/setup.h).  COMMAND_LINE_SIZE should
>> probably become a kernel config option.  Do folks agree that is the
>> correct thing to do?  If so, I can re-work the patch.
> No objection on my side.
>
> Make sure you remove any unused arch define while at it.
>
> Cheers,
> Ben.
>
>
Hi Ben,

I can think of two ways to add the new config option.  One would be to
have a large entry in ~/arch/Kconfig, with a default COMMAND_LINE_SIZE
line for each architecture.  The other way would be to have the default
value for COMMAND_LINE_SIZE in the architecture sub-directory Kconfig
file: ~/arch/powerpc/Kconfig for example.

Do you have a preference for either way?

Thanks,

Joe