Hello list, The PSR.lp bit of kernel thread kondemand sometimes would be set, then causes set_pstate PAL call fails with invalid argument. I tracked down to the place that the PSR.lp was set in do_notify_resume_user. I don't understand why not use task->thread.on_ustack to check if on user stack.in the first place. For optimization? Signed-off-by: Yu Luming <luming.yu@xxxxxxxxx> ptrace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- linux-2.6.18.ia64/include/asm-ia64/ptrace.h.0 2007-09-28 21:41:19.000000000 +0800
+++ linux-2.6.18.ia64/include/asm-ia64/ptrace.h 2007-09-28 21:41:40.000000000 +0800
@@ -257,7 +257,7 @@
# define task_pt_regs(t) (((struct pt_regs *) ((char *) (t) + IA64_STK_OFFSET)) - 1)
# define ia64_psr(regs) ((struct ia64_psr *) &(regs)->cr_ipsr)
# define user_mode(regs) (((struct ia64_psr *) &(regs)->cr_ipsr)->cpl != 0)
-# define user_stack(task,regs) ((long) regs - (long) task == IA64_STK_OFFSET - sizeof(*regs))
+# define user_stack(task,regs) (task->thread.on_ustack)
# define fsys_mode(task,regs) \
({ \
struct task_struct *_task = (task); \
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