On Fri, 29 Oct 2021 17:10:45 +0200, Christophe Leroy wrote:
> Until now, all tests involving CONFIG_STRICT_KERNEL_RWX were done with
> DEBUG_RODATA_TEST to check the result. But now that
> CONFIG_STRICT_KERNEL_RWX is selected by default, it came without
> CONFIG_DEBUG_RODATA_TEST and led to the following Oops
>
> [ 6.830908] Freeing unused kernel image (initmem) memory: 352K
> [ 6.840077] BUG: Unable to handle kernel data access on write at 0xc1285200
> [ 6.846836] Faulting instruction address: 0xc0004b6c
> [ 6.851745] Oops: Kernel access of bad area, sig: 11 [#1]
> [ 6.857075] BE PAGE_SIZE=16K PREEMPT CMPC885
> [ 6.861348] SAF3000 DIE NOTIFICATION
> [ 6.864830] CPU: 0 PID: 1 Comm: swapper Not tainted
> 5.15.0-rc5-s3k-dev-02255-g2747d7b7916f #451
> [ 6.873429] NIP: c0004b6c LR: c0004b60 CTR: 00000000
> [ 6.878419] REGS: c902be60 TRAP: 0300 Not tainted
> (5.15.0-rc5-s3k-dev-02255-g2747d7b7916f)
> [ 6.886852] MSR: 00009032 <EE,ME,IR,DR,RI> CR: 53000335 XER: 8000ff40
> [ 6.893564] DAR: c1285200 DSISR: 82000000
> [ 6.893564] GPR00: 0c000000 c902bf20 c20f4000 08000000 00000001 04001f00
> c1800000 00000035
> [ 6.893564] GPR08: ff0001ff c1280000 00000002 c0004b60 00001000 00000000
> c0004b1c 00000000
> [ 6.893564] GPR16: 00000000 00000000 00000000 00000000 00000000 00000000
> 00000000 00000000
> [ 6.893564] GPR24: 00000000 00000000 00000000 00000000 00000000 00000000
> 00000000 c1060000
> [ 6.932034] NIP [c0004b6c] kernel_init+0x50/0x138
> [ 6.936682] LR [c0004b60] kernel_init+0x44/0x138
> [ 6.941245] Call Trace:
> [ 6.943653] [c902bf20] [c0004b60] kernel_init+0x44/0x138 (unreliable)
> [ 6.950022] [c902bf30] [c001122c] ret_from_kernel_thread+0x5c/0x64
> [ 6.956135] Instruction dump:
> [ 6.959060] 48ffc521 48045469 4800d8cd 3d20c086 89295fa0 2c090000 41820058
> 480796c9
> [ 6.966890] 4800e48d 3d20c128 39400002 3fe0c106 <91495200> 3bff8000
> 4806fa1d 481f7d75
> [ 6.974902] ---[ end trace 1e397bacba4aa610 ]---
>
> [...]
Applied to powerpc/next.
[1/1] powerpc/8xx: Fix Oops with STRICT_KERNEL_RWX without DEBUG_RODATA_TEST
https://git.kernel.org/powerpc/c/c12ab8dbc492b992e1ea717db933cee568780c47
cheers
