On Thu, 16 Jul 2020 09:37:04 +1000, Anton Blanchard wrote:
> The code in vdso_cpu_init that exposes the cpu and numa node to
> userspace via SPRG_VDSO incorrctly masks the cpu to 12 bits. This means
> that any kernel running on a box with more than 4096 threads (NR_CPUS
> advertises a limit of of 8192 cpus) would expose userspace to two cpu
> contexts running at the same time with the same cpu number.
>
> Note: I'm not aware of any distro shipping a kernel with support for more
> than 4096 threads today, nor of any system image that currently exceeds
> 4096 threads. Found via code browsing.
Applied to powerpc/next.
[1/1] powerpc/vdso: Fix vdso cpu truncation
https://git.kernel.org/powerpc/c/a9f675f950a07d5c1dbcbb97aabac56f5ed085e3
cheers
