* Andy Lutomirski <[email protected]> [2014-11-13 23:01:12]: > On Thu, Nov 13, 2014 at 10:08 PM, Srikar Dronamraju > <[email protected]> wrote: > > * Andy Lutomirski <[email protected]> [2014-11-13 14:31:21]: > > > >> x86 call do_notify_resume on paranoid returns if TIF_UPROBE is set > >> but not on non-paranoid returns. I suspect that this is a mistake > >> and that the code only works because int3 is paranoid. > >> > >> Setting _TIF_NOTIFY_RESUME in the uprobe code was probably a > >> workaround for the x86 bug. With that bug fixed, we can remove > > > >> _TIF_NOTIFY_RESUME from the uprobes code. > >> > >> Cc: Srikar Dronamraju <[email protected]> > >> Reported-by: Oleg Nesterov <[email protected]> > >> Signed-off-by: Andy Lutomirski <[email protected]> > >> --- > >> arch/x86/include/asm/thread_info.h | 2 +- > >> kernel/events/uprobes.c | 1 - > >> 2 files changed, 1 insertion(+), 2 deletions(-) > >> > >> diff --git a/arch/x86/include/asm/thread_info.h > >> b/arch/x86/include/asm/thread_info.h > >> index 854053889d4d..547e344a6dc6 100644 > >> --- a/arch/x86/include/asm/thread_info.h > >> +++ b/arch/x86/include/asm/thread_info.h > >> @@ -141,7 +141,7 @@ struct thread_info { > >> /* Only used for 64 bit */ > >> #define _TIF_DO_NOTIFY_MASK \ > >> (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \ > >> - _TIF_USER_RETURN_NOTIFY) > >> + _TIF_USER_RETURN_NOTIFY | _TIF_UPROBE) > > > > > > The comment above says only for 64 bit. So would this still work for > > i386? > > > > i386 seems to look at _TIF_WORK_MASK (which includes _TIF_UPROBE) for > everything except syscalls and at _TIF_WORK_SYSCALL_EXIT for syscall > return (which does not include _TIF_UPROBE). Is that okay? >
Ok.. That expains (please add my ack to your v3) Acked-by: Srikar Dronamraju <[email protected]> > --Andy > > >> > >> /* flags to check in __switch_to() */ > >> #define _TIF_WORK_CTXSW > >> \ > >> diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > >> index 1d0af8a2c646..ed8f2cde34c5 100644 > >> --- a/kernel/events/uprobes.c > >> +++ b/kernel/events/uprobes.c > >> @@ -1640,7 +1640,6 @@ bool uprobe_deny_signal(void) > >> if (__fatal_signal_pending(t) || > >> arch_uprobe_xol_was_trapped(t)) { > >> utask->state = UTASK_SSTEP_TRAPPED; > >> set_tsk_thread_flag(t, TIF_UPROBE); > >> - set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); > >> } > >> } > >> > >> -- > >> 1.9.3 > >> > > > > -- > > Thanks and Regards > > Srikar Dronamraju > > > > > > -- > Andy Lutomirski > AMA Capital Management, LLC > -- Thanks and Regards Srikar Dronamraju -- 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/
