From: Bodo Stroesser Date: Sat, 7 May 2005 04:30:54 +0000 (-0700) Subject: [PATCH] uml: Fix process exit race X-Git-Tag: v2.6.12-rc4~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0f7e663dea7f0e22f3b2d07156c5e9d2e8656610;p=pandora-kernel.git [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 Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed