Messages in this thread Patch in this message | | | From | Andy Lutomirski <> | Subject | [PATCH v4 1/5] uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME | Date | Fri, 21 Nov 2014 13:26:07 -0800 |
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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.
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andy Lutomirski <luto@amacapital.net> --- 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) /* 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
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