[PATCH RFC v2 bootconfig 0/3] Distinguish bootloader and embedded kernel parameters

Paul E. McKenney
2023-07-31T23:30:17Z

On Thu, Jul 27, 2023 at 08:35:10PM -0700, Paul E. McKenney wrote:
Hello!

This series provides a /proc interface parallel to /proc/cmdline that
provides only those kernel boot parameters that were provided by the
bootloader in a new /proc/cmdline_load. This is especially important
when these parameters are presented to the boot loader by automation
that might gather them from diverse sources, and also when a kexec-based
reboot process pulls the kernel boot parameters from /proc. If such a
reboot process uses /proc/cmdline, the kernel parameters from the image
are replicated on every reboot, which can be frustrating when the new
kernel has different embedded kernel boot parameters.

Why put these in /proc? Because they is quite similar to /proc/cmdline,
so it makes sense to put it in the same place that /proc/cmdline is
located.

1. Update /proc/cmdline documentation to include boot config.

2. fs/proc: Add /proc/cmdline_load for boot loader arguments.

3. Add /proc/bootconfig to proc.rst.

Changes since v1:

o Dropped /proc/cmdline_image in favor of the existing
/proc/bootconfig.

o Pulled in fixes from Stephen and Arnd.

o Added documentation for /proc/bootconfig.

Thanx, Paul

------------------------------------------------------------------------

Documentation/filesystems/proc.rst | 2 ++
b/Documentation/filesystems/proc.rst | 3 ++-
b/fs/proc/cmdline.c | 13 +++++++++++++
b/include/linux/init.h | 3 ++-
b/init/main.c | 2 +-
5 files changed, 20 insertions(+), 3 deletions(-)