Date: Sat, 23 Nov 2002 23:46:41 +0000 From: Doug Rabson <dfr@nlsystems.com> To: Marcel Moolenaar <marcel@xcllnt.net> Cc: Perforce Change Reviews <perforce@freebsd.org> Subject: Re: PERFORCE change 21417 for review Message-ID: <200211232346.41171.dfr@nlsystems.com> In-Reply-To: <20021123230017.GB8744@dhcp01.pn.xcllnt.net> References: <200211232017.gANKHAAk090869@repoman.freebsd.org> <200211232250.38412.dfr@nlsystems.com> <20021123230017.GB8744@dhcp01.pn.xcllnt.net>
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On Saturday 23 November 2002 11:00 pm, Marcel Moolenaar wrote: > On Sat, Nov 23, 2002 at 10:50:38PM +0000, Doug Rabson wrote: > > On Saturday 23 November 2002 8:17 pm, Marcel Moolenaar wrote: > > > http://perforce.freebsd.org/chv.cgi?CH=21417 > > > > > > Change 21417 by marcel@marcel_nfs on 2002/11/23 12:17:09 > > > > > > Raw, untested implementation of EPC syscalls. > > > > This seems to be missing the bit after calling syscall() which > > checks for a full exception_restore, e.g. after an execve and also > > the check for calling ast(), e.g. after a signal. > > Yes. > > [snip] > > > One other thing after re-familiarising myself with exception.s. You > > have added unwind records to all the kernel IVT entry points. This > > is quite unhelpful when trying to debug kernel faults. The previous > > version which manually unwound past the exception to the code which > > faulted was extremely useful and saved me a lot of time in > > debugging. Can we have it back please :-). > > If we want to use unwinding to get to the register state of the > process, we can never unwind over the exception code. It's probably > much easier to restart unwinding after it stopped at the exception > entry point. This would also hold for signal handlers. Would a DDB > command to resume unwinding work? I think it would be ok to just put back the code in db_stack_trace_cmd() which spots kernel entry points and resets the unwind state based on the contents of the appropriate stack frame. That would give complete stack traces in DDB without disturbing the real unwind records. -- Doug Rabson Mail: dfr@nlsystems.com Phone: +44 20 8348 6160 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe p4-projects" in the body of the messagehelp
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