cvs commit: src/sys/kern subr_kdb.c

[Bruce Evans]

On Wed, 26 Oct 2005, Peter Wemm wrote:

> peter       2005-10-26 22:40:07 UTC
>
>  FreeBSD src repository
>
>  Modified files:
>    sys/kern             subr_kdb.c
>  Log:
>  Commit something we found useful at work at one point.  Add sysctls for
>  debug.kdb.panic and debug.kdb.trap alongside the existing debug.kdb.enter
>  sysctl.  'panic' causes a panic, and 'trap' causes a page fault.  We used
>  these to ensure that crash dumps succeed from those two common failure
>  modes.  This avoids the need for creating a 'panic' kld module.

This has nothing to do with kdb, so it doesn't belong here.  Panics and
traps just happen to invoke a debugger if a debugger is configured.
Panics should have even less to do with kdb -- the existence of the
panic command in ddb is a bug, since debugger context is special and
not suitable for calling panic(); e.g., sync() in panic() only ever worked
because of other bugs (ddb keeps^Wkept interrupts disabled but sync()
requires interrupts to do i/o).

Bruce