[Bug runtime/15080] New: The kernel function 'signal_wake_up' is gone

[Bug runtime/15080] New: The kernel function 'signal_wake_up' is gone

[dsmith at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=15080

             Bug #: 15080
           Summary: The kernel function 'signal_wake_up' is gone
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: runtime
        AssignedTo: systemtap@sourceware.org
        ReportedBy: dsmith@redhat.com
    Classification: Unclassified


In today's rawhide kernel, 3.8.0-0.rc4.git5.1.fc19.x86_64, the kernel function
'signal_wake_up' is no longer present. This causes a couple of problems:

- the tapset/linux/signal.stp tapset defines 'signal.wakeup' as an alias for
'signal_wake_up'

- the utrace replacement code in runtime/stp_utrace.c uses 'signal_wake_up' to
help interrupt a target task

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[Bug runtime/15080] The kernel function 'signal_wake_up' is gone

[dsmith at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=15080

--- Comment #1 from David Smith <dsmith at redhat dot com> 2013-01-29 16:53:17 UTC ---
Looks like the following commit is the culprit:

commit 910ffdb18a6408e14febbb6e4b6840fd2c928c82
Author: Oleg Nesterov <oleg@redhat.com>
Date:   Mon Jan 21 20:47:41 2013 +0100

    ptrace: introduce signal_wake_up_state() and ptrace_signal_wake_up()

    Cleanup and preparation for the next change.

    signal_wake_up(resume => true) is overused. None of ptrace/jctl callers
    actually want to wakeup a TASK_WAKEKILL task, but they can't specify the
    necessary mask.

    Turn signal_wake_up() into signal_wake_up_state(state), reintroduce
    signal_wake_up() as a trivial helper, and add ptrace_signal_wake_up()
    which adds __TASK_TRACED.

    This way ptrace_signal_wake_up() can work "inside" ptrace_request()
    even if the tracee doesn't have the TASK_WAKEKILL bit set.

    Signed-off-by: Oleg Nesterov <oleg@redhat.com>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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[Bug runtime/15080] The kernel function 'signal_wake_up' is gone

[dsmith at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=15080

David Smith <dsmith at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED

--- Comment #2 from David Smith <dsmith at redhat dot com> 2013-01-30 16:31:46 UTC ---
Commit dfdbaa3 fixes this problem.

The new code should handle kernels with and without signal_wake_up_state().

Note that the tapset changes look reasonable, but because of bad debuginfo stap
can't access the arguments of signal_wake_up_state().

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