4: 000000000000000a 0000000000000000 0000000000000001 0000000000000012 GPR28: c000000fa5c04f80 00000000000008bc c0000000015c0a28 000000000000022e [ 18.824792] NIP [c000000000052f40] .memcpy_power7+0x5a0/0x7c4 [ 18.824797] LR [c00000000020b874] .pcpu_free_area+0x174/0x2d0 [ 18.824800] Call Trace: [ 18.824803] [c000001f1fef7a10] [c000000000052c14] .memcpy_power7+0x274/0x7c4 (unreliable) [ 18.824809] [c000001f1fef7b10] [c00000000020b874] .pcpu_free_area+0x174/0x2d0 [ 18.824813] [c000001f1fef7bb0] [c00000000020ba88] .free_percpu+0xb8/0x1b0 [ 18.824819] [c000001f1fef7c50] [c00000000043d144] .throtl_pd_exit+0x94/0xd0 [ 18.824824] [c000001f1fef7cf0] [c00000000043acf8] .blkg_free+0x88/0xe0 [ 18.824829] [c000001f1fef7d90] [c00000000018c048] .rcu_process_callbacks+0x2e8/0x8a0 [ 18.824835] [c000001f1fef7e90] [c0000000000a8ce8] .__do_softirq+0x158/0x4d0 [ 18.824840] [c000001f1fef7f90] [c000000000025ecc] .call_do_softirq+0x14/0x24 [ 18.824845] [c000000fa7483650] [c000000000010e80] .do_softirq+0x160/0x1a0 [ 18.824850] [c000000fa74836f0] [c0000000000a94a4] .irq_exit+0xf4/0x120 [ 18.824854] [c000000fa7483780] [c000000000020c44] .timer_interrupt+0x154/0x4d0 [ 18.824859] [c000000fa7483830] [c000000000003be0] decrementer_common+0x160/0x180 [ 18.824866] --- Exception: 901 at .plpar_hcall_norets+0x84/0xd4 [ 18.824866] LR = .check_and_cede_processor+0x48/0x80 [ 18.824871] [c000000fa7483b20] [c00000000007f018] .check_and_cede_processor+0x18/0x80 (unreliable) [ 18.824877] [c000000fa7483b90] [c00000000007f104] .dedicated_cede_loop+0x84/0x150 [ 18.824883] [c000000fa7483c50] [c0000000006bc030] .cpuidle_enter+0x30/0x50 [ 18.824887] [c000000fa7483cc0] [c0000000006bc9f4] .cpuidle_idle_call+0x104/0x720 [ 18.824892] [c000000fa7483d80] [c000000000070af8] .pSeries_idle+0x18/0x40 [ 18.824897] [c000000fa7483df0] [c000000000019084] .cpu_idle+0x1a4/0x380 [ 18.824902] [c000000fa7483ec0] [c0000000008a4c18] .start_secondary+0x520/0x528 [ 18.824907] [c000000fa7483f90] [c0000000000093f0] .start_secondary_prolog+0x10/0x14 [ 18.824911] Instruction dump: [ 18.824914] 38840008 90030000 90e30004 38630008 7ca62850 7cc300d0 78c7e102 7cf01120 [ 18.824923] 78c60660 39200010 39400020 39600030 <7e00200c> 7c0020ce 38840010 409f001c [ 18.824935] ---[ end trace 0bb95124affaaa45 ]--- [ 18.825046] Unrecoverable VMX/Altivec Unavailable Exception f20 at c000000000052d08 I believe the right fix is to make memcpy match usercopy and not use cr1. Signed-off-by: Nishanth Aravamudan Signed-off-by: Benjamin Herrenschmidt CC: [v3.6] &>x