The kernel commit 2f859d0dad8 ("s390/smp: reduce size of struct pcpu") for linux-4.0 removed the "async_stack" and "panic_stack" members from "struct pcpu". So now the only option to find out the stack address is using "struct lowcore" (again). Unfortunately we don't get the exact address because since commit dc7ee00d477 ("s390: lowcore stack pointer offsets") the stack frame overhead is already subtracted from the addresses. Therefore we have to roundup the stack address to PAGE_SIZE. Signed-off-by: Michael Holzheu <holzheu(a)linux.vnet.ibm.com&gt; --- s390x.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/s390x.c +++ b/s390x.c @@ -1027,8 +1027,6 @@ static unsigned long get_int_stack_pcpu( { unsigned long addr; - if (!MEMBER_EXISTS("pcpu", stack_name)) - return 0; addr = symbol_value("pcpu_devices") + cpu * STRUCT_SIZE("pcpu") + MEMBER_OFFSET("pcpu", stack_name); return readmem_ul(addr) + INT_STACK_SIZE; @@ -1041,7 +1039,8 @@ static unsigned long get_int_stack_lc(ch { if (!MEMBER_EXISTS(lc_struct, stack_name)) return 0; - return ULONG(lc + MEMBER_OFFSET(lc_struct, stack_name)); + return roundup(ULONG(lc + MEMBER_OFFSET(lc_struct, stack_name)), + PAGESIZE()); } /* @@ -1057,7 +1056,7 @@ static void get_int_stack(char *stack_na stack_addr = symbol_value("restart_stack"); stack_addr = readmem_ul(stack_addr); } else { - if (symbol_exists("pcpu_devices")) + if (symbol_exists("pcpu_devices") && MEMBER_EXISTS("pcpu", stack_name)) stack_addr = get_int_stack_pcpu(stack_name, cpu); else stack_addr = get_int_stack_lc(stack_name, lc);