From: "H. Peter Anvin" <hpa@xxxxxxxxx> Subject: Re: sigreturn on sparc64 Date: Wed, 24 May 2006 14:23:58 -0700 > David Miller wrote: > > > > GLIBC is the source of all knowledge :-) > > > > libc/sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c > > > > In there you'll see that you have to set the sa_restorer > > to NULL and pass in the "stub" address minus 8, as the > > 4th argument to rt_sigation system call. > > > > Minus 8 :) Talk about weirdness... :-/ The stub is "returned to" directly from the signal handler itself using the "retl" instruction, which jumps to the value of "register %i7 plus 8". We stick the passed in stub address directly into the %i7 register of the signal handler frame, that's why you need to subtract 8 for the system call argument. - 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
