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/tt/include/mode_kern-tt.h | 1 - 1 file changed, 1 deletion(-) (limited to 'arch/um/kernel/tt/include') diff --git a/arch/um/kernel/tt/include/mode_kern-tt.h b/arch/um/kernel/tt/include/mode_kern-tt.h index 28aaab3448fa..e0ca0e0b2516 100644 --- a/arch/um/kernel/tt/include/mode_kern-tt.h +++ b/arch/um/kernel/tt/include/mode_kern-tt.h @@ -19,7 +19,6 @@ extern int copy_thread_tt(int nr, unsigned long clone_flags, unsigned long sp, unsigned long stack_top, struct task_struct *p, struct pt_regs *regs); extern void release_thread_tt(struct task_struct *task); -extern void exit_thread_tt(void); extern void initial_thread_cb_tt(void (*proc)(void *), void *arg); extern void init_idle_tt(void); extern void flush_tlb_kernel_range_tt(unsigned long start, unsigned long end); -- cgit v1.2.1