HEADS UP: Standalone kernel debug files moving out of /boot/kernel/

Julian Elischer julian at freebsd.org
Fri Oct 31 05:11:08 UTC 2014

On 10/31/14, 1:41 AM, Garance A Drosehn wrote:
> On 30 Oct 2014, at 12:49, Ed Maste wrote:
>> On 30 October 2014 02:20, John-Mark Gurney <jmg at funkthat.com> wrote:
>>> Oh, make sure that make install (or installkernel) properly handles
>>> moving the debug data too... i.e. kernel to kernel.old...
>> Yes, in the case that /boot/kernel is moved to /boot/kernel.old
>> /usr/lib/debug/boot/kernel is moved to /usr/lib/debug/boot/kernel.old.
> I definitely like the idea of moving the debug symbols out to /usr/lib/debug
> I'm another person who sometimes has multiple kernels sitting in /boot
> (which is one reason I'd like the debug symbols elsewhere!).  I may
> shuffle those around by hand, and I'm sure I won't remember to shuffle
> around information under /usr/lib/debug.  I also do things like
>    cp -rp kernel kernel-PreBigChange
> where I save away a copy of the kernel for possible fallback (at some
> unknown future date), but I wouldn't need two copies of the debug info.
> When we build a kernel, could we tag it with some unique-ID (by putting
> that ID in a plain-text file inside the kernel's directory), and then
> that unique-ID could be used for finding the correct debug info under
> /usr/lib/debug?  This way we wouldn't need to move around any of the
> debug info under /usr/lib/debug.  And we could tell which sets of
> debug info should be removed by comparing the existing sets of debug
> info with the kernel-unique-ID's which still exist under /boot.
I'd put the debug symbls somewhere with a unique name and than add a 
symlink from the installed directory..
(and an ID file)
So /boot/kernel.old/symbols points to 
when you move the directory back to /boot/kernel, it STILL points to 
the right place..
occasionally remove all directories in /usr/lib/debug/kernelsymbols.* 
that are not pointed to by
a symlink in /boot/*/symbols.
An option could make the symlink relative for chroot/jail/nfs issues..

> If debug tools need to have the debug-info for the booted kernel to
> be in a fixed location, then maybe the boot-up process could create
> a symlink from some fixed pathname to the correct debug info for the
> kernel which the system booted up on.

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