On Thu, Feb 14, 2013 at 11:21:12AM -0800, H. Peter Anvin wrote: > On 02/14/2013 11:18 AM, Oleg Nesterov wrote: > > On 02/14, H. Peter Anvin wrote: > >> > >> On 02/14/2013 07:00 AM, Oleg Nesterov wrote: > >>> On 02/14, Denys Vlasenko wrote: > >>>> > >>>> Determining personality of a ptraced process is a murky area. > >>>> On x86, for years strace was looking at segment selectors, > >>>> which is conceptually wrong: see, for example, > >>>> https://lkml.org/lkml/2012/1/18/320 > >>>> > >> > >> One proposal that keeps being on the table is to export a regset with > >> metadatam, including process mode at launch (i386, x86-64, x32). > > > > Yes... but if this metadata includes TS_COMPAT-is-set, then strace should > > do PTRACE_GETREGSET(REGSET_META) + PTRACE_GETREGSET(REGSET_GENERAL) every > > time. Or REGSET_META should include META+GENERAL. > > > > IOW, it is not clear to me what this "meta" should actually report. > > That is one of the things that needs to be nailed down. In particular, > what are the things people need.
Indeed, having some "official" way for compat bit retrieval would be a great thing for us (c/r camp) since we've just met the same problem. And at moment I sticked for the same trick as gdb does (cs/ds test). But, guys, if only I'm not missing something completely obvious, can't we simply provide task-compat bit to userspace in say /proc/pid/stat or something? Then the strace/gdb would be able to always know if the tracee is actually in compat mode. Or I miss something fundamental here? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
