linux-toradex.git/kernel/signal.c, branch v2.6.27-rc1

tracehook: force signal_pending()

2008-07-26T19:00:09+00:00

This defines a new hook tracehook_force_sigpending() that lets tracing
code decide to force TIF_SIGPENDING on in recalc_sigpending().

This is not used yet, so it compiles away to nothing for now.  It lays the
groundwork for new tracing code that can interrupt a task synthetically
without actually sending a signal.

Signed-off-by: Roland McGrath 
Cc: Oleg Nesterov 
Reviewed-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tracehook: death

2008-07-26T19:00:09+00:00

This moves the ptrace logic in task death (exit_notify) into tracehook.h
inlines.  Some code is rearranged slightly to make things nicer.  There is
no change, only cleanup.

There is one hook called with the tasklist_lock write-locked, as ptrace
needs.  There is also a new hook called after exit_state changes and
without locks.  This is a better place for tracing work to be in the
future, since it doesn't delay the whole system with locking.

Signed-off-by: Roland McGrath 
Cc: Oleg Nesterov 
Reviewed-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tracehook: job control

2008-07-26T19:00:09+00:00

This defines the tracehook_notify_jctl() hook to formalize the ptrace
effects on the job control notifications.  There is no change, only
cleanup.

Signed-off-by: Roland McGrath 
Cc: Oleg Nesterov 
Reviewed-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tracehook: get_signal_to_deliver

2008-07-26T19:00:09+00:00

This defines the tracehook_get_signal() hook to allow tracing code to slip
in before normal signal dequeuing.  This lays the groundwork for new
tracing features that can inject synthetic signals outside the normal
queue or control the disposition of delivered signals.  The calling
convention lets tracehook_get_signal() decide both exactly what will
happen and what signal number to report in the handler/exit.

Signed-off-by: Roland McGrath 
Cc: Oleg Nesterov 
Reviewed-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tracehook: tracehook_consider_fatal_signal

2008-07-26T19:00:09+00:00

This defines tracehook_consider_fatal_signal() has a fine-grained hook for
deciding to skip the special cases for a fatal signal, as ptrace does.
There is no change, only cleanup.

Signed-off-by: Roland McGrath 
Cc: Oleg Nesterov 
Reviewed-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tracehook: tracehook_consider_ignored_signal

2008-07-26T19:00:09+00:00

This defines tracehook_consider_ignored_signal() has a fine-grained hook
for deciding to prevent the normal short-circuit of sending an ignored
signal, as ptrace does.  There is no change, only cleanup.

Signed-off-by: Roland McGrath 
Cc: Oleg Nesterov 
Reviewed-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tracehook: unexport ptrace_notify

2008-07-26T19:00:08+00:00

The ptrace_notify() function should not be called by any modules.  It was
only ever exported to be called by binfmt exec functions.  But that is no
longer necessary since fs/exec.c deals with that generically now.  There
should be no calls to ptrace_notify() from outside the core kernel.

Signed-off-by: Roland McGrath 
Cc: Oleg Nesterov 
Reviewed-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

pidns: remove now unused kill_proc function

2008-07-25T17:53:45+00:00

This function operated on a pid_t to kill a task, which is no longer valid
in a containerized system.

It has finally lost all its users and we can safely remove it from the
tree.

Signed-off-by: Pavel Emelyanov 
Cc: Oleg Nesterov 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

coredump: move mm->core_waiters into struct core_state

2008-07-25T17:53:39+00:00

Move mm->core_waiters into "struct core_state" allocated on stack.  This
shrinks mm_struct a little bit and allows further changes.

This patch mostly does s/core_waiters/core_state.  The only essential
change is that coredump_wait() must clear mm->core_state before return.

The coredump_wait()'s path is uglified and .text grows by 30 bytes, this
is fixed by the next patch.

Signed-off-by: Oleg Nesterov 
Cc: Roland McGrath 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ptrace: simplify ptrace_stop()->sigkill_pending() path

2008-07-25T17:53:39+00:00

1. SIGKILL can't be blocked, remove this check from sigkill_pending().

2. When ptrace_stop() sees sigkill_pending() == T, it can just return.
   Kill "int killed" and simplify the code. This also is more correct,
   the tracer shouldn't see us in TASK_TRACED if we are not going to
   stop.

I strongly believe this code needs further changes.  We should do the "was
this task killed" check unconditionally, currently it depends on
arch_ptrace_stop_needed().  On the other hand, sigkill_pending() isn't
very clever.  If the task was killed tkill(SIGKILL), the signal can be
already dequeued if the caller is do_exit().

Signed-off-by: Oleg Nesterov 
Cc: Roland McGrath 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds