[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 at canonical.com>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org> (supporter:LINUX FOR POWERPC...)
Cc: Paul Mackerras <paulus at samba.org> (supporter:LINUX FOR POWERPC...)
Cc: linuxppc-dev at lists.ozlabs.org (open list:LINUX FOR POWERPC...)
Cc: linux-kernel at vger.kernel.org (open list)
Cc: stable at 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? */

[Joseph Salisbury]

Post by 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 at canonical.com>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org> (supporter:LINUX FOR POWERPC...)
Cc: Paul Mackerras <paulus at samba.org> (supporter:LINUX FOR POWERPC...)
Cc: linuxppc-dev at lists.ozlabs.org (open list:LINUX FOR POWERPC...)
Cc: linux-kernel at vger.kernel.org (open list)
Cc: stable at 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

[Benjamin Herrenschmidt]

Post by Joseph Salisbury
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.

[Joseph Salisbury]

Post by Benjamin Herrenschmidt

Post by Joseph Salisbury
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