On Sun, Nov 20, 2011 at 04:49:50PM -0500, David Miller wrote: > From: Jurij Smakov <jurij@xxxxxxxxx> > Date: Sat, 19 Nov 2011 13:40:57 +0000 > > > I'm debugging a problem for which kprobes may potentially provide > > useful information, in particular I would like to examine local > > registers at some point in the kernel code. Unfortunately, while > > trying to accomplish that I ran into an issue I can't quite explain: > > whenever I try to access %fp register (a.k.a. %i6) from kprobe using > > regs->u_regs[UREG_FP], I get an unaligned value, which makes me think > > that it's incorrect somehow. > > On 64-bit sparc, the stack is "biased" by 2047 bytes. > > This is so that more of the stack frame is reachable relative to %fp > using 13-bit signed immediate offsets, which are usable with the address > of load and store instructions. > > Grep for "STACK_BIAS" under arch/sparc Thanks for the explanation. -- Jurij Smakov jurij@xxxxxxxxx Key: http://www.wooyd.org/pgpkey/ KeyID: C99E03CC -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
