Re: [perf/x86/RAPL] BUG: unable to handle kernel NULL pointer dereference at 00000028

From: Fengguang Wu
Date: Wed Jul 30 2014 - 01:53:42 EST


On Wed, Jul 30, 2014 at 06:45:58AM +0200, Stephane Eranian wrote:
> On Wed, Jul 30, 2014 at 6:00 AM, Fengguang Wu <fengguang.wu@xxxxxxxxx> wrote:
> > Greetings,
> >
> > 0day kernel testing robot got the below dmesg and the first bad commit is
> >
> Is this booting a guest kernel or native?

It's a guest kernel.

> What is the host CPU?

The host CPU is E5-2680, Sandy Bridge-EP.

Thanks,
Fengguang

> > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > commit 4788e5b4b2338f85fa42a712a182d8afd65d7c58
> > Author: Stephane Eranian <eranian@xxxxxxxxxx>
> > AuthorDate: Tue Nov 12 17:58:50 2013 +0100
> > Commit: Ingo Molnar <mingo@xxxxxxxxxx>
> > CommitDate: Wed Nov 27 11:16:40 2013 +0100
> >
> > perf/x86: Add Intel RAPL PMU support
> >
> > This patch adds a new uncore PMU to expose the Intel
> > RAPL energy consumption counters. Up to 3 counters,
> > each counting a particular RAPL event are exposed.
> >
> > The RAPL counters are available on Intel SandyBridge,
> > IvyBridge, Haswell. The server skus add a 3rd counter.
> >
> > The following events are available and exposed in sysfs:
> >
> > - power/energy-cores: power consumption of all cores on socket
> > - power/energy-pkg: power consumption of all cores + LLc cache
> > - power/energy-dram: power consumption of DRAM (servers only)
> >
> > For each event both the unit (Joules) and scale (2^-32 J)
> > is exposed in sysfs for use by perf stat and other tools.
> > The files are:
> >
> > /sys/devices/power/events/energy-*.unit
> > /sys/devices/power/events/energy-*.scale
> >
> > The RAPL PMU is uncore by nature and is implemented such
> > that it only works in system-wide mode. Measuring only
> > one CPU per socket is sufficient. The /sys/devices/power/cpumask
> > file can be used by tools to figure out which CPUs to monitor
> > by default. For instance, on a 2-socket system, 2 CPUs
> > (one on each socket) will be shown.
> >
> > All the counters measure in the same unit (exposed via sysfs).
> > The perf_events API exposes all RAPL counters as 64-bit integers
> > counting in unit of 1/2^32 Joules (about 0.23 nJ). User level tools
> > must convert the counts by multiplying them by 2^-32 to obtain
> > Joules. The reason for this is that the kernel avoids
> > doing floating point math whenever possible because it is
> > expensive (user floating-point state must be saved). The method
> > used avoids kernel floating-point usage. There is no loss of
> > precision. Thanks to PeterZ for suggesting this approach.
> >
> > To convert the raw count in Watt:
> > W = C * 2.3 / (1e10 * time)
> > or ldexp(C, -32).
> >
> > RAPL PMU is a new standalone PMU which registers with the
> > perf_event core subsystem. The PMU type (attr->type) is
> > dynamically allocated and is available from /sys/device/power/type.
> >
> > Sampling is not supported by the RAPL PMU. There is no
> > privilege level filtering either.
> >
> > Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
> > Reviewed-by: Maria Dimakopoulou <maria.n.dimakopoulou@xxxxxxxxx>
> > Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> > Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > Cc: acme@xxxxxxxxxx
> > Cc: jolsa@xxxxxxxxxx
> > Cc: zheng.z.yan@xxxxxxxxx
> > Cc: bp@xxxxxxxxx
> > Link: http://lkml.kernel.org/r/1384275531-10892-4-git-send-email-eranian@xxxxxxxxxx
> > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
> >
> > +-----------------------------------------------------------+------------+------------+---------------+
> > | | 410136f5dd | 4788e5b4b2 | next-20140724 |
> > +-----------------------------------------------------------+------------+------------+---------------+
> > | boot_successes | 1000 | 751 | 78 |
> > | boot_failures | 0 | 149 | 3 |
> > | BUG:unable_to_handle_kernel_NULL_pointer_dereference | 0 | 132 | 2 |
> > | Oops | 0 | 132 | 2 |
> > | EIP_is_at_rapl_pmu_init | 0 | 132 | |
> > | Kernel_panic-not_syncing:Attempted_to_kill_init_exitcode= | 0 | 132 | 2 |
> > | backtrace:rapl_pmu_init | 0 | 132 | |
> > | backtrace:kernel_init_freeable | 0 | 132 | 2 |
> > | BUG:kernel_boot_hang | 0 | 17 | 1 |
> > | EIP_is_at_validate_chain | 0 | 0 | 2 |
> > | backtrace:free_reserved_area | 0 | 0 | 2 |
> > | backtrace:free_init_pages | 0 | 0 | 2 |
> > | backtrace:populate_rootfs | 0 | 0 | 2 |
> > +-----------------------------------------------------------+------------+------------+---------------+
> >
> > [ 0.613305] PCI: CLS 0 bytes, default 64
> > [ 0.614699] Unpacking initramfs...
> > [ 0.732188] Freeing initrd memory: 3276K (d3cbd000 - d3ff0000)
> > [ 0.733895] BUG: unable to handle kernel NULL pointer dereference at 00000028
> > [ 0.735603] IP: [<c09b20cb>] rapl_pmu_init+0x11e/0x139
> > [ 0.736012] *pdpt = 0000000000000000 *pde = f000ff53f000ff53
> > [ 0.736012] Oops: 0000 [#1] PREEMPT
> > [ 0.736012] Modules linked in:
> > [ 0.736012] CPU: 0 PID: 1 Comm: swapper Not tainted 3.12.0-05711-g4788e5b #11
> > [ 0.736012] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
> > [ 0.736012] task: d244c020 ti: d244e000 task.ti: d244e000
> > [ 0.736012] EIP: 0060:[<c09b20cb>] EFLAGS: 00010202 CPU: 0
> > [ 0.736012] EIP is at rapl_pmu_init+0x11e/0x139
> > [ 0.736012] EAX: 00000000 EBX: 00000000 ECX: 00000000 EDX: 00000001
> > [ 0.736012] ESI: c09b1fad EDI: 000000cc EBP: d244ff00 ESP: d244fef0
> > [ 0.736012] DS: 007b ES: 007b FS: 0000 GS: 00e0 SS: 0068
> > [ 0.736012] CR0: 80050033 CR2: 00000028 CR3: 00a16000 CR4: 000406b0
> > [ 0.736012] Stack:
> > [ 0.736012] c04ddabe 00000000 00000002 00000000 d244ff74 c0200477 c0251b16 d244ff2c
> > [ 0.736012] c025467d d3ff63cb d244ff34 c02410cb d3ff63cb d244ff00 c09aa512 c080d71c
> > [ 0.736012] 000000cc d244ff74 c02412d5 c0829fe0 00000286 c023b6d8 00000246 00060006
> > [ 0.736012] Call Trace:
> > [ 0.736012] [<c04ddabe>] ? register_syscore_ops+0x32/0x35
> > [ 0.736012] [<c0200477>] do_one_initcall+0xdf/0x138
> > [ 0.736012] [<c0251b16>] ? lock_release_holdtime.part.20+0x93/0xf8
> > [ 0.736012] [<c025467d>] ? trace_hardirqs_on_caller+0xeb/0x1ad
> > [ 0.736012] [<c02410cb>] ? parameq+0x13/0x5e
> > [ 0.736012] [<c09aa512>] ? repair_env_string+0x12/0x51
> > [ 0.736012] [<c02412d5>] ? parse_args+0x1bf/0x2f8
> > [ 0.736012] [<c023b6d8>] ? __usermodehelper_set_disable_depth+0x3e/0x44
> > [ 0.736012] [<c09aab46>] kernel_init_freeable+0xde/0x178
> > [ 0.736012] [<c09aa500>] ? do_early_param+0x78/0x78
> > [ 0.736012] [<c064bd10>] kernel_init+0xb/0xed
> > [ 0.736012] [<c0249199>] ? schedule_tail+0xc/0x3a
> > [ 0.736012] [<c0659637>] ret_from_kernel_thread+0x1b/0x28
> > [ 0.736012] [<c064bd05>] ? rest_init+0xb5/0xb5
> > [ 0.736012] Code: 99 87 ff 89 5c 24 04 c7 04 24 90 bf 76 c0 e8 dd e9 c9 ff 83 c8 ff eb 28 a1 44 bc a1 c0 f3 0f b8 c0 90 89 44 24 08 a1 80 73 82 c0 <8b> 40 28 89 44 24 04 c7 04 24 d4 bf 76 c0 e8 b2 e9 c9 ff 31 c0
> > [ 0.736012] EIP: [<c09b20cb>] rapl_pmu_init+0x11e/0x139 SS:ESP 0068:d244fef0
> > [ 0.736012] CR2: 0000000000000028
> > [ 0.736012] ---[ end trace 0a81712c9fb36a0a ]---
> > [ 0.736012] swapper (1) used greatest stack depth: 5800 bytes left
> >
> > git bisect start v3.14 v3.13 --
> > git bisect bad 09df7c4c8097ca4a11393b1edd4997d786daad52 # 16:18 0- 3 x86: Remove CONFIG_X86_OOSTORE
> > git bisect bad 15c81026204da897a05424c79263aea861a782cc # 16:24 2- 5 Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
> > git bisect bad a0fa1dd3cdbccec9597fe53b6177a9aa6e20f2f8 # 16:33 0- 15 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
> > git bisect good edde1fb8c41d0db7c8ce17fb32886da2e389b0cc # 17:48 900+ 0 Merge tag 'localmodconfig-v3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-kconfig
> > git bisect good a693c46e14c9fdadbcd68ddfa94a4f72495531a9 # 17:55 900+ 0 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
> > git bisect good 2cc3f16cad1561c6fc551aefff559e53726efc8b # 18:12 900+ 0 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
> > git bisect bad 9326657abe1a83ed4b4f396b923ca1217fd50cba # 18:21 9- 2 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
> > git bisect bad 7bb73553e2490ac6667387ee723e0faa61e9d999 # 18:38 0- 1 tools lib traceevent: Get rid of die() in reparent_op_arg()
> > git bisect bad 3d7c0144491bd8c21d53b43032274a85efdfe434 # 18:41 11- 4 perf tools: Add build and install plugins targets
> > git bisect bad ba1ddf42f3c3af111d3adee277534f73c1ef6a9b # 18:43 0- 15 perf script: Print mmap[2] events also
> > git bisect bad a8b4c7014cadfdacd4e1f4c963128593be6f20de # 18:49 0- 2 perf completion: Rename file to reflect zsh support
> > git bisect bad 4788e5b4b2338f85fa42a712a182d8afd65d7c58 # 18:53 0- 1 perf/x86: Add Intel RAPL PMU support
> > git bisect good c912dae60ae6f659455f239298110adc67a5f3e9 # 19:33 900+ 14 uprobes: Cleanup !CONFIG_UPROBES decls, unexport xol_area
> > git bisect good 09897d78dbc3a544426f2272b5601c62922ccab9 # 19:44 900+ 0 Merge branch 'uprobes/core' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/core
> > git bisect good 410136f5dd96b6013fe6d1011b523b1c247e1ccb # 19:52 900+ 0 tools/perf/stat: Add event unit and scale support
> > # first bad commit: [4788e5b4b2338f85fa42a712a182d8afd65d7c58] perf/x86: Add Intel RAPL PMU support
> > git bisect good 410136f5dd96b6013fe6d1011b523b1c247e1ccb # 19:56 1000+ 0 tools/perf/stat: Add event unit and scale support
> > git bisect bad 1a58d9909611972fd1c081bb04a9f7dc2571e612 # 19:58 0- 3 Add linux-next specific files for 20140724
> > git bisect bad 82e13c71bc655b6dc7110da4e164079dadb44892 # 20:07 448- 10 Merge branch 'for-3.16' of git://linux-nfs.org/~bfields/linux
> > git bisect bad 5a7439efd1c5c416f768fc550048ca130cf4bf99 # 20:14 2- 6 Add linux-next specific files for 20140725
> >
> >
> > This script may reproduce the error.
> >
> > ----------------------------------------------------------------------------
> > #!/bin/bash
> >
> > kernel=$1
> > initrd=yocto-minimal-i386.cgz
> >
> > wget --no-clobber https://github.com/fengguang/reproduce-kernel-bug/blob/master/initrd/$initrd
> >
> > kvm=(
> > qemu-system-x86_64
> > -enable-kvm
> > -cpu Haswell,+smep,+smap
> > -kernel $kernel
> > -initrd $initrd
> > -m 320
> > -smp 1
> > -net nic,vlan=1,model=e1000
> > -net user,vlan=1
> > -boot order=nc
> > -no-reboot
> > -watchdog i6300esb
> > -rtc base=localtime
> > -serial stdio
> > -display none
> > -monitor null
> > )
> >
> > append=(
> > hung_task_panic=1
> > earlyprintk=ttyS0,115200
> > debug
> > apic=debug
> > sysrq_always_enabled
> > rcupdate.rcu_cpu_stall_timeout=100
> > panic=10
> > softlockup_panic=1
> > nmi_watchdog=panic
> > prompt_ramdisk=0
> > console=ttyS0,115200
> > console=tty0
> > vga=normal
> > root=/dev/ram0
> > rw
> > drbd.minor_count=8
> > )
> >
> > "${kvm[@]}" --append "${append[*]}"
> > ----------------------------------------------------------------------------
> >
> > Thanks,
> > Fengguang
> >
> > _______________________________________________
> > LKP mailing list
> > LKP@xxxxxxxxxxxxxxx
> >
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