Hi, I am seeing the attached crash when running a realview-pb-a8 image with realview_defconfig in qemu. bisect wasn't successful, but a commit analysis identified commit 'drivers/perf: arm_pmu: make info messages more verbose' as the culprit. Reverting this commit fixes the problem. The code roughly looks as follows. int arm_pmu_device_probe() { ... if (node && ..) { } else { } if (ret) { pr_info("%s: failed to probe PMU! Error %i\n", node->full_name, ret); goto out_free; } .... out_free: pr_info("%s: failed to register PMU devices! Error %i\n", node->full_name, ret); .... } Note that 'node' is dereferenced even though it was previously checked if it is NULL. The configuration I am testing does not use devicetree. Can you use dev_info() instead ? Thanks, Guenter --- Crash log: Unable to handle kernel NULL pointer dereference at virtual address 0000000c pgd = c0004000 [0000000c] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.5.0-next-20160317 #1 Hardware name: ARM-RealView PB-A8 task: df427600 ti: df428000 task.ti: df428000 PC is at arm_pmu_device_probe+0x11c/0x6ec LR is at smp_call_function_single+0xe8/0x164 pc : [<c03bc2d0>] lr : [<c0180260>] psr: a0000053 sp : df429e40 ip : df428000 fp : 00000000 r10: df4aa200 r9 : 00000090 r8 : c0500d5c r7 : c05015c8 r6 : fffffffa r5 : c08457f8 r4 : c080a5d8 r3 : 00000000 r2 : fffffffa r1 : df429df8 r0 : c05e6214 Flags: NzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 70004059 DAC: 00000051 Process swapper/0 (pid: 1, stack limit = 0xdf428210) Stack: (0xdf429e40 to 0xdf42a000) 9e40: 00000000 c05ce464 00000000 00000001 00000090 ffffffed c080a5e8 fffffdfb 9e60: c0806a1c c0806a1c 00000090 00000000 00000000 c02f95b4 c02f9564 c080a5e8 9e80: c0844630 c0844638 00000000 c02f7f04 00000000 c080a5e8 c0806a1c c080a61c 9ea0: 00000000 c0704714 00000000 c02f8040 00000000 c0806a1c c02f7f94 c02f6504 9ec0: df41785c df47bcb4 c0806a1c df4ec300 c081afc8 c02f74d0 c05b859c a0000053 9ee0: c0806a1c c0806a1c c080514c df58e780 c082b400 c02f885c c02f915c c080514c 9f00: c080514c c0101744 0000005f 00000000 00000000 00000000 00000000 c022645c 9f20: 00000000 c0810320 c061bb48 c0512b18 00000090 c0136c3c 00000000 c05db800 9f40: c061b008 00000000 00000006 00000006 c08102e8 dfffc1c0 c0733bb8 00000006 9f60: c0728830 c082b400 c07005a4 00000090 c072883c c0700d70 00000006 00000006 9f80: 00000000 c07005a4 00000000 c04ad914 00000000 00000000 00000000 00000000 9fa0: 00000000 c04ad91c 00000000 c0107830 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 [<c03bc2d0>] (arm_pmu_device_probe) from [<c02f95b4>] (platform_drv_probe+0x50/0xb0) [<c02f95b4>] (platform_drv_probe) from [<c02f7f04>] (driver_probe_device+0x218/0x2a8) [<c02f7f04>] (driver_probe_device) from [<c02f8040>] (__driver_attach+0xac/0xb0) [<c02f8040>] (__driver_attach) from [<c02f6504>] (bus_for_each_dev+0x54/0x88) [<c02f6504>] (bus_for_each_dev) from [<c02f74d0>] (bus_add_driver+0xe4/0x1f4) [<c02f74d0>] (bus_add_driver) from [<c02f885c>] (driver_register+0x78/0xf4) [<c02f885c>] (driver_register) from [<c0101744>] (do_one_initcall+0x80/0x1d8) [<c0101744>] (do_one_initcall) from [<c0700d70>] (kernel_init_freeable+0x118/0x1ec) [<c0700d70>] (kernel_init_freeable) from [<c04ad91c>] (kernel_init+0x8/0x110) [<c04ad91c>] (kernel_init) from [<c0107830>] (ret_from_fork+0x14/0x24) Code: e3e0600b e59d3008 e1a02006 e59f03cc (e593100c) ---[ end trace bfac761a54ea927f ]--- -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html