Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 27 Oct 2005 15:58:44 +1000 (EST)
From:      Bruce Evans <bde@zeta.org.au>
To:        Peter Wemm <peter@freebsd.org>
Cc:        cvs-src@freebsd.org, src-committers@freebsd.org, cvs-all@freebsd.org
Subject:   Re: cvs commit: src/sys/kern subr_kdb.c
Message-ID:  <20051027155314.A24293@delplex.bde.org>
In-Reply-To: <200510262240.j9QMe7l0011003@repoman.freebsd.org>
References:  <200510262240.j9QMe7l0011003@repoman.freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help
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



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20051027155314.A24293>