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linux/arch/um/kernel/tt/include
Bodo Stroesser 0f7e663dea [PATCH] uml: Fix process exit race
tt-mode closes switch_pipes in exit_thread_tt and kills processes in
switch_to_tt, if the exit_state is EXIT_DEAD or EXIT_ZOMBIE.

In very rare cases the exiting process can be scheduled out after having set
exit_state and closed switch_pipes (from release_task it calls proc_pid_flush,
which might sleep).  If this process is to be restarted, UML failes in
switch_to_tt with:

   write of switch_pipe failed, err = 9

We fix this by closing switch_pipes not in exit_thread_tt, but later in
release_thread_tt.  Additionally, we set switch_pipe[0] = 0 after closing.
switch_to_tt must not kill "from" process depending on its exit_state, but
must kill it after release_thread was processed only, so it examines
switch_pipe[0] for its decision.

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-06 22:09:30 -07:00
..
debug.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mmu-tt.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mode_kern-tt.h [PATCH] uml: Fix process exit race 2005-05-06 22:09:30 -07:00
mode-tt.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
tt.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
uaccess-tt.h [PATCH] uml: __deprecated makes build unnecessarily noisy 2005-05-06 22:09:28 -07:00