Messages in this thread | | | From | Andy Lutomirski <> | Date | Fri, 25 Mar 2016 08:51:39 -0700 | Subject | Re: x32 processes, with CONFIG_X86_X32 not set |
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On Fri, Mar 25, 2016 at 8:48 AM, Dave Jones <davej@codemonkey.org.uk> wrote: > I had a trinity process get stuck last overnight. > The reason for it getting stuck is my bug (I think), but > there's an odd unrelated thing I noticed while debugging this.. > > $ strace -p 20966 > strace: Process 20966 attached > strace: [ Process PID=20966 runs in x32 mode. ] > > So I don't use that new-fangled x32 stuff. > I don't even have CONFIG_X86_X32 compiled in. > > Is this strace getting confused, or did we somehow screw > up the syscall entry code ? > > Dave >
I think you're just seeing an oddity of how x32 works. Unlike "compat", x32-ness of the current syscall isn't a special magic state variable; it's just but 31 in the syscall nr. So trying to do an x32 syscall on a non-x32 syscall should still show bit 31 set to ptracers, and the strace probably decodes this as being in x32 mode.
--Andy
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