On Thu, Jan 25, 2024 at 11:15:44AM +0000, Sudeep Holla wrote:
On Tue, Dec 12, 2023 at 02:25:16PM -0800, Ricardo Neri wrote:
Before determining the validity of the last-level cache info, ensure that it has been allocated. Simply checking for non-zero cache_leaves() is not sufficient, as some architectures (e.g., Intel processors) have non-zero cache_leaves() before allocation.
Dereferencing NULL cacheinfo can occur in update_per_cpu_data_slice_size(). This function iterates over all online CPUs. However, a CPU may have come online recently, but its cacheinfo may not have been allocated yet.
Cc: Andreas Herrmann aherrmann@suse.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Chen Yu yu.c.chen@intel.com Cc: Huang Ying ying.huang@intel.com Cc: Len Brown len.brown@intel.com Cc: Radu Rendec rrendec@redhat.com Cc: Pierre Gondois Pierre.Gondois@arm.com Cc: Pu Wen puwen@hygon.cn Cc: "Rafael J. Wysocki" rafael.j.wysocki@intel.com Cc: Sudeep Holla sudeep.holla@arm.com
If you respin, you can address the below minor nit. I am fine as is as well.
Reviewed-by: Sudeep Holla sudeep.holla@arm.com
Thank you for your review Sudeep!
[...]
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index f1e79263fe61..967c5cf3fb1d 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -61,6 +61,9 @@ bool last_level_cache_is_valid(unsigned int cpu) if (!cache_leaves(cpu)) return false;
- if (!per_cpu_cacheinfo(cpu))
return false;[nit] You can even combine this with above if condition.
Sure, I can take care of this if a new version is needed as per feedback from the x86 maintainers.