On Wed, 7 Sep 2011 08:38:18 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > On Tue, 06 Sep 2011 19:50:09 +0200 > Anders <aeriksson2@xxxxxxxxx> wrote: > > > On 09/05/11 02:49, KAMEZAWA Hiroyuki wrote: > > > On Sun, 04 Sep 2011 20:49:42 +0200 > > > Anders <aeriksson2@xxxxxxxxx> wrote: > > > > > > > I've got kdump setup to collect oopes. I found this in the log. Not sure > > > > what it's related to. > > > > > > > > > > > <4>[47900.533010] [<ffffffff810ab79f>] ? > > > > mem_cgroup_count_vm_event+0x15/0x67 > > > > <4>[47900.533010] [<ffffffff810987e5>] ? handle_mm_fault+0x3b/0x1e8 > > > > <4>[47900.533010] [<ffffffff81049bb3>] ? sched_clock_local+0x13/0x76 > > > > <4>[47900.533010] [<ffffffff8101bdb0>] ? do_page_fault+0x31a/0x33f > > > > <4>[47900.533010] [<ffffffff81022b80>] ? check_preempt_curr+0x36/0x62 > > > > <4>[47900.533010] [<ffffffff8104bb23>] ? ktime_get_ts+0x65/0xa6 > > > > <4>[47900.533010] [<ffffffff810bfd2c>] ? > > > > poll_select_copy_remaining+0xce/0xed > > > > <4>[47900.533010] [<ffffffff814c4b4f>] ? page_fault+0x1f/0x30 > > > > > > I'll check memcg but...not sure what parts in above log are garbage. > > > At quick glance, mem_cgroup_count_vm_event() does enough NULL check > > > but faulted address was.. > > > > > > > <0>[47900.533010] CR2: ffffc5217e257cf0 > > > > > > This seems not NULL referencing. > > > > > > #define VMALLOC_START _AC(0xffffc90000000000, UL) > > > #define VMALLOC_END _AC(0xffffe8ffffffffff, UL) > > > > > > This is not vmalloc area...hmm. could you show your disassemble of > > > mem_cgroup_count_vm_event() ? and .config ? > > > > > How do I disassembe it? > > > > # make mm/memcontrol.o > # objdump -d memcontrol.o > file > > please cut out mem_cgroup_count_vm_event() from dumpped file. > Sorry, I made mistake ..the log says <1>[47900.533010] RIP [<ffffffff81097d18>] handle_pte_fault+0x24/0x70a <4>[47900.533010] RSP <ffff880024c27db8> <0>[47900.533010] CR2: ffffc5217e257cf0 <4>[47900.533010] RSP: 0000:ffff880024c27db8 EFLAGS: 00010296 <4>[47900.533010] RAX: 0000000000000cf0 RBX: ffff88006c3b2a68 RCX: ffffc5217e257cf0 <4>[47900.533010] RDX: 000000000059effe RSI: ffff88006c3b2a68 RDI: ffff88006d6d2ac0 <4>[47900.533010] RBP: ffffc5217e257cf0 R08: ffff880024d3b010 R09: 0000000000000028 Hm. CR2==RBP...then accessing RBP caused the fault. But it seems this RBP was accessed in this function before reaching EIP. your .config says CONFIG_HAVE_FUNCTION_TRACER=y CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST=y CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST=y CONFIG_HAVE_DYNAMIC_FTRACE=y CONFIG_HAVE_FTRACE_MCOUNT_RECORD=y CONFIG_HAVE_SYSCALL_TRACEPOINTS=y CONFIG_HAVE_C_RECORDMCOUNT=y In my binary, ffffffff8113b820 <handle_pte_fault>: ffffffff8113b820: 55 push %rbp ffffffff8113b821: 48 89 e5 mov %rsp,%rbp ffffffff8113b824: 48 81 ec c0 00 00 00 sub $0xc0,%rsp ffffffff8113b82b: 48 89 5d d8 mov %rbx,-0x28(%rbp) ffffffff8113b82f: 4c 89 65 e0 mov %r12,-0x20(%rbp) ffffffff8113b833: 4c 89 6d e8 mov %r13,-0x18(%rbp) ffffffff8113b837: 4c 89 75 f0 mov %r14,-0x10(%rbp) ffffffff8113b83b: 4c 89 7d f8 mov %r15,-0x8(%rbp) ffffffff8113b83f: e8 fc d4 47 00 callq ffffffff815b8d40 <mcount> ffffffff8113b844: 4c 89 45 b8 mov %r8,-0x48(%rbp) ffffffff8113b848: 4c 8b 29 mov (%rcx),%r13 handle_pte_fault + 0x24 is just after mcount. And caused fault by accessing %rbp...returning from a funciton ? Hmm...problem with tracing ? I'm sorry if I misunderstand something. Anyway, CCing ftrace guys for getting information. Thanks, -Kame -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>