Re: [RFC PATCH RESEND] x86/cpu: Avoid endless loop to get the number of cache leaves

From: Borislav Petkov
Date: Thu Dec 06 2018 - 05:37:47 EST


On Thu, Dec 06, 2018 at 03:26:13PM +0800, Pu Wen wrote:
> To get the number of cache leaves on AMD or Hygon platform, it should
> get the value of cpuid leaf 0x8000001d. But on certain broken platform
> such as a not fullly implemented virtual platform(for example Xen),
> the value of the cpuid leaf will nerver be CTYPE_NULL, so the kernel
> will run into an endless loop.
>
> To fix this problem, add a new enum type CTYPE_MAX to limit the maximum
> cpuid accessing.
>
> Signed-off-by: Pu Wen <puwen@xxxxxxxx>
> ---
> arch/x86/kernel/cpu/cacheinfo.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)

Did you not see my reply to this last time?

https://lkml.kernel.org/r/20181115172155.GB25056@xxxxxxx

--
Regards/Gruss,
Boris.

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