On Sat, 16 Jul 2011 03:25:47 +0000 "Chen, Tiejun" <tiejun.c...@windriver.com> wrote:
> > -----Original Message----- > > From: Scott Wood [mailto:scottw...@freescale.com] > > Sent: Saturday, July 16, 2011 2:43 AM > > To: Chen, Tiejun > > Cc: Kumar Gala; linuxppc-...@ozlabs.org > > Subject: Re: [v3 PATCH 1/1] booke/kprobe: make program > > exception to use one dedicated exception stack > > > > On Fri, 15 Jul 2011 13:28:15 +0800 > > tiejun.chen <tiejun.c...@windriver.com> wrote: > > > > > Kumar Gala wrote: > > > > I'm still very confused why we need a unique stack frame > > for kprobe/program exceptions on book-e devices. > > > > > > Its a bug at least for Book-E. > > > > But why only booke? There's nothing booke-specific about the > > I don't mean this is reproduced only on booke, so I use 'at least' carefully > to notice we really see this problem on booke. > > > stwu instruction. > > Please note this root cause to this bug is not related to how to emulate stwu > instruction. That should be issued from the overlap between an exception > frame and the kprobed function stack frame on booke. Would you like to see > that example I showed? As I understand it, the problem comes from the fact that stwu combines the creation of a stack frame with storing into that stack frame. If they were separate instructions you'd have a new exception frame at a lower address by the time you actually store to the non-exception frame. -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
