4.5-stable review patch. If anyone has any objections, please let me know.
------------------ From: Heiko Carstens <[email protected]> commit 8f100bb1ff27873dd71f636da670e503b9ade3c6 upstream. Add the missing lpp magic initialization for cpu 0. Without this all samples on cpu 0 do not have the most significant bit set in the program parameter field, which we use to distinguish between guest and host samples if the pid is also 0. We did initialize the lpp magic in the absolute zero lowcore but forgot that when switching to the allocated lowcore on cpu 0 only. Reported-by: Shu Juan Zhang <[email protected]> Acked-by: Christian Borntraeger <[email protected]> Fixes: e22cf8ca6f75 ("s390/cpumf: rework program parameter setting to detect guest samples") Signed-off-by: Heiko Carstens <[email protected]> Signed-off-by: Martin Schwidefsky <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/s390/kernel/setup.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -327,6 +327,7 @@ static void __init setup_lowcore(void) + PAGE_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); lc->current_task = (unsigned long) init_thread_union.thread_info.task; lc->thread_info = (unsigned long) &init_thread_union; + lc->lpp = LPP_MAGIC; lc->machine_flags = S390_lowcore.machine_flags; lc->stfl_fac_list = S390_lowcore.stfl_fac_list; memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
