Unwinding a running task has proven problematic. In one instance, the running task was attempting to unwind itself and received an interrupt between when get_wchan allocated local variables on the stack and when unw_init_from_blocked_task was called which resulted in unw_init_frame_info to place this tasks task_struct pointer over the switch stack's ar_bspstore entry. Signed-off-by: Robin Holt <holt@xxxxxxx> Index: linux-tot-20070517/arch/ia64/kernel/process.c =================================================================== --- linux-tot-20070517.orig/arch/ia64/kernel/process.c 2007-05-18 10:14:45.485516967 -0500 +++ linux-tot-20070517/arch/ia64/kernel/process.c 2007-05-18 10:15:10.340573728 -0500 @@ -763,6 +763,9 @@ get_wchan (struct task_struct *p) unsigned long ip; int count = 0; + if (!p || p == current || p->state == TASK_RUNNING) + return 0; + /* * Note: p may not be a blocked task (it could be current or * another process running on some other CPU. Rather than @@ -773,6 +776,8 @@ get_wchan (struct task_struct *p) */ unw_init_from_blocked_task(&info, p); do { + if (p->state == TASK_RUNNING) + return 0; if (unw_unwind(&info) < 0) return 0; unw_get_ip(&info, &ip); - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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