From 0f7e663dea7f0e22f3b2d07156c5e9d2e8656610 Mon Sep 17 00:00:00 2001 From: Bodo Stroesser Date: Fri, 6 May 2005 21:30:54 -0700 Subject: [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 --- arch/um/kernel/process_kern.c | 1 - 1 file changed, 1 deletion(-) (limited to 'arch/um/kernel/process_kern.c') diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process_kern.c index 3dcb080c44a0..c1adf7ba3fd1 100644 --- a/arch/um/kernel/process_kern.c +++ b/arch/um/kernel/process_kern.c @@ -142,7 +142,6 @@ void release_thread(struct task_struct *task) void exit_thread(void) { - CHOOSE_MODE(exit_thread_tt(), exit_thread_skas()); unprotect_stack((unsigned long) current_thread); } -- cgit v1.2.3