[PATCH] powerpc/book3s64/radix: Avoid WARN_ON in destroy_context

[Michael Ellerman]

On Wed, 2019-09-18 at 14:01:03 UTC, "Aneesh Kumar K.V" wrote:
> On failed task initialization due to memory allocation failures,
> we can call into destroy_context with process_tb entry set. This patch
> forces the process_tb entry to zero in destroy_context. With
> this patch, we lose the ability to track if we are destroying a context
> without flushing the process table entry.
> 
>  WARNING: CPU: 4 PID: 6368 at arch/powerpc/mm/mmu_context_book3s64.c:246 destroy_context+0x58/0x340
>  NIP [c0000000000875f8] destroy_context+0x58/0x340
>  LR [c00000000013da18] __mmdrop+0x78/0x270
>  Call Trace:
>  [c000000f7db77c80] [c00000000013da18] __mmdrop+0x78/0x270
>  [c000000f7db77cf0] [c0000000004d6a34] __do_execve_file.isra.13+0xbd4/0x1000
>  [c000000f7db77e00] [c0000000004d7428] sys_execve+0x58/0x70
>  [c000000f7db77e30] [c00000000000b388] system_call+0x5c/0x70
> 
> Reported-by: Priya M.A <priyama2 at in.ibm.com>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/7aec584eaf1cc1a527dcbe7d80f2e44e3bfcfe1d

cheers