On Tue, 28 Apr 2020 22:31:30 +1000, Michael Ellerman wrote:
> Aneesh increased the size of struct pt_regs by 16 bytes and started
> seeing this WARN_ON:
>
> smp: Bringing up secondary CPUs ...
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 0 at arch/powerpc/kernel/process.c:455
> giveup_all+0xb4/0x110
> Modules linked in:
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted
> 5.7.0-rc2-gcc-8.2.0-1.g8f6a41f-default+ #318
> NIP: c00000000001a2b4 LR: c00000000001a29c CTR: c0000000031d0000
> REGS: c0000000026d3980 TRAP: 0700 Not tainted
> (5.7.0-rc2-gcc-8.2.0-1.g8f6a41f-default+)
> MSR: 800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 48048224
> XER: 00000000
> CFAR: c000000000019cc8 IRQMASK: 1
> GPR00: c00000000001a264 c0000000026d3c20 c0000000026d7200 800000000280b033
> GPR04: 0000000000000001 0000000000000000 0000000000000077 30206d7372203164
> GPR08: 0000000000002000 0000000002002000 800000000280b033 3230303030303030
> GPR12: 0000000000008800 c0000000031d0000 0000000000800050 0000000002000066
> GPR16: 000000000309a1a0 000000000309a4b0 000000000309a2d8 000000000309a890
> GPR20: 00000000030d0098 c00000000264da40 00000000fd620000 c0000000ff798080
> GPR24: c00000000264edf0 c0000001007469f0 00000000fd620000 c0000000020e5e90
> GPR28: c00000000264edf0 c00000000264d200 000000001db60000 c00000000264d200
> NIP [c00000000001a2b4] giveup_all+0xb4/0x110
> LR [c00000000001a29c] giveup_all+0x9c/0x110
> Call Trace:
> [c0000000026d3c20] [c00000000001a264] giveup_all+0x64/0x110 (unreliable)
> [c0000000026d3c90] [c00000000001ae34] __switch_to+0x104/0x480
> [c0000000026d3cf0] [c000000000e0b8a0] __schedule+0x320/0x970
> [c0000000026d3dd0] [c000000000e0c518] schedule_idle+0x38/0x70
> [c0000000026d3df0] [c00000000019c7c8] do_idle+0x248/0x3f0
> [c0000000026d3e70] [c00000000019cbb8] cpu_startup_entry+0x38/0x40
> [c0000000026d3ea0] [c000000000011bb0] rest_init+0xe0/0xf8
> [c0000000026d3ed0] [c000000002004820] start_kernel+0x990/0x9e0
> [c0000000026d3f90] [c00000000000c49c] start_here_common+0x1c/0x400
>
> [...]
Applied to powerpc/next.
[1/1] powerpc/64: Don't initialise init_task->thread.regs
https://git.kernel.org/powerpc/c/7ffa8b7dc11752827329e4e84a574ea6aaf24716
cheers
