Re: [PATCH RFC bootconfig] 2/2] fs/proc: Add /proc/cmdline_image for embedded arguments

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On Sat, 29 Jul 2023 08:41:46 -0700
"Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote:

> On Sat, Jul 29, 2023 at 11:23:46PM +0900, Masami Hiramatsu wrote:
> > Hi Paul,
> > 
> > On Thu, 27 Jul 2023 20:37:01 -0700
> > "Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote:
> > 
> > > In kernels built with CONFIG_BOOT_CONFIG_FORCE=y, /proc/cmdline will show
> > > all kernel boot parameters, both those supplied by the boot loader and
> > > those embedded in the kernel image.  This works well for those who just
> > > want to see all of the kernel boot parameters, but is not helpful to those
> > > who need to see only those parameters that were embedded into the kernel
> > > image.  This is especially important in situations where there are many
> > > kernel images for different kernel versions and kernel configurations,
> > > all of which opens the door to a great deal of human error.
> > 
> > There is /proc/bootconfig file which shows all bootconfig entries and is
> > formatted as easily filter by grep (or any other line-based commands).
> > (e.g. `grep ^kernel\\. /proc/cmdline` will filter all kernel cmdline
> > parameters in the bootconfig)
> > Could you clarify the reason why you need a dump of bootconfig file?
> 
> Because I was unaware of /proc/bootconfig?  ;-)

Oh :)

> 
> So how about if I replace this patch of mine with the following?

Yes, I missed to update the proc.rst. Thanks!

> 
> And thank you for pointing me at /proc/bootconfig.
> 
> 							Thanx, Paul
> 
> ------------------------------------------------------------------------
> 
> diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
> index 98c43c5ef1ee..832d66d4e396 100644
> --- a/Documentation/filesystems/proc.rst
> +++ b/Documentation/filesystems/proc.rst
> @@ -684,6 +684,7 @@ files are there, and which are missing.
>   File         Content
>   ============ ===============================================================
>   apm          Advanced power management info
> + bootconfig   Kernel command line obtained from boot config	(5.5)
>   buddyinfo    Kernel memory allocator information (see text)	(2.5)
>   bus          Directory containing bus specific information
>   cmdline      Kernel command line, both from bootloader and embedded


-- 
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>