Re: [PATCH] printk: Userspace format enumeration support

Chris Down writes:

quoted

quoted

3. `KERN_SOH + level' can appear in other places than just printk strings

KERN_SOH is just ASCII '\001' -- it's not distinctive or unique, even when
paired with a check for something that looks like a level after it. For this
reason, your proposed patch results in a non-trivial amount of non-printk
related garbage in its output. For example:

    % binutils/strings -k /tmp/vmlinux | head -5
    3L)s
    3L)s
    c,[]A\
    c(L)c
    d$pL)d$`u4

Fundamentally, one cannot use a tool which just determines whether something is
printable to determine semantic intent.

$ kernel_strings --kernel --section ".rodata" vmlinux

I got exactly 0.

"It works on my computer" is not a valid testing methodology, 
especially for something as complex as the Linux kernel. It's 
especially not a valid rebuttal to someone demonstrating that it 
clearly doesn't work on theirs.

Even filtering to the .rodata section, there's plenty of garbage just 
in the first five cases:

   % binutils/strings --kernel --section ".rodata" /tmp/vmlinux | head -5
   3******* Your BIOS seems to not contain a fix for K8 errata #93
   1>pBC)
   dTRAC
   6Run %s as init process
   7calling  %pS @ %i

Clearly there are cases that you are not considering. My kernel config 
is attached if you want to try and replicate, but regardless, it's 
really not valid to say "it works for me" in response to someone 
showing that it doesn't.

Attached.