> -----Original Message----- > From: Amit S. Kale [mailto:[EMAIL PROTECTED] > Sent: Thursday, May 17, 2007 11:38 AM > To: kgdb-bugreport@lists.sourceforge.net > Cc: Wessel, Jason; Tom Rini > Subject: Re: [Kgdb-bugreport] [PATCH] Further fix to single > step user->kernel > > > If the single-step bit is cleared, user space execution will > resume normally. > Once that happens, there is no way for gdb to forcefully get > control back. > Worse still: during this userspace and subsequently kernel > space resume, all other processors may locked on kgdb entry.
I was able to use gdb to break back in after the auto continue. > > One more problem is gdb removes breakpoints before a single > step. So user-space and then kernel-space code will execute > without breakpoints with this code. > In the 6.6 release I used, gdb plants all the breakpoints prior to single step in the case that a single step results in a resume. > Current kgdb code is definitely broken in this context. I > believe we can't fix it (either with following code or > otherwise). We may be better off panicing the way you'd done > in yesterday's code. > -Amit Another possibility was to stop the kernel at the user space instruction. I had tested that as well, and that made gdb happy, but you end up an instruction for which you can not back trace correctly because you have some arbitrary code in user land which has no fram pointer back to the under lying kernel code. Originally that is why I thought a continue would be the best operation. Either way I still print a warning to explain what happened. Jason. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Kgdb-bugreport mailing list Kgdb-bugreport@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
