Hi, There is a bug in os_free_irq_by_cb, when the first element of active_fds list is free, the value of active_fds is not updated, just value in stack is updated.
The intresting thing is that without this patch, a poweroff in user mode linux guest will halt the host linux system.It seems that after the tracing thread is dead, the syscall to sys_reboot of the traced thread is executed by host. I don't know if it is another bug. Signed-off-by: Lepton Wu <[EMAIL PROTECTED]> diff -X linux-2.6.22.6/Documentation/dontdiff -pru linux-2.6.22.6/arch/um/include/os.h linux-2.6.22.6-lepton/arch/um/include/os.h --- linux-2.6.22.6/arch/um/include/os.h 2007-09-14 17:41:10.000000000 +0800 +++ linux-2.6.22.6-lepton/arch/um/include/os.h 2007-09-22 12:15:28.000000000 +0800 @@ -325,7 +325,7 @@ extern void reboot_skas(void); extern int os_waiting_for_events(struct irq_fd *active_fds); extern int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds); extern void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg, - struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2); + struct irq_fd **active_fds_ptr, struct irq_fd ***last_irq_ptr2); extern void os_free_irq_later(struct irq_fd *active_fds, int irq, void *dev_id); extern int os_get_pollfd(int i); diff -X linux-2.6.22.6/Documentation/dontdiff -pru linux-2.6.22.6/arch/um/kernel/irq.c linux-2.6.22.6-lepton/arch/um/kernel/irq.c --- linux-2.6.22.6/arch/um/kernel/irq.c 2007-09-14 17:41:10.000000000 +0800 +++ linux-2.6.22.6-lepton/arch/um/kernel/irq.c 2007-09-22 12:15:05.000000000 +0800 @@ -218,7 +218,7 @@ static void free_irq_by_cb(int (*test)(s unsigned long flags; spin_lock_irqsave(&irq_lock, flags); - os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr); + os_free_irq_by_cb(test, arg, &active_fds, &last_irq_ptr); spin_unlock_irqrestore(&irq_lock, flags); } diff -X linux-2.6.22.6/Documentation/dontdiff -pru linux-2.6.22.6/arch/um/os-Linux/irq.c linux-2.6.22.6-lepton/arch/um/os-Linux/irq.c --- linux-2.6.22.6/arch/um/os-Linux/irq.c 2007-09-14 17:41:10.000000000 +0800 +++ linux-2.6.22.6-lepton/arch/um/os-Linux/irq.c 2007-09-22 12:15:42.000000000 +0800 @@ -84,12 +84,12 @@ int os_create_pollfd(int fd, int events, } void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg, - struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2) + struct irq_fd **active_fds_ptr, struct irq_fd ***last_irq_ptr2) { struct irq_fd **prev; int i = 0; - prev = &active_fds; + prev = active_fds_ptr; while (*prev != NULL) { if ((*test)(*prev, arg)) { struct irq_fd *old_fd = *prev; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/