On 11.02.2022 10:02, Roger Pau Monné wrote: > On Fri, Feb 11, 2022 at 08:23:27AM +0100, Norbert Manthey wrote: >> When re-identifying CPU data, we might use uninitialized data when >> checking for the cache line property to adapt the cache >> alignment. The data that depends on this uninitialized read is >> currently not forwarded. >> >> To avoid problems in the future, initialize the data cpuinfo >> structure before re-identifying the CPU again. >> >> The trace to hit the uninitialized read reported by Coverity is: >> >> bool recheck_cpu_features(unsigned int cpu) >> ... >> struct cpuinfo_x86 c; >> ... >> identify_cpu(&c); >> >> void identify_cpu(struct cpuinfo_x86 *c) >> ... >> generic_identify(c) >> >> static void generic_identify(struct cpuinfo_x86 *c) >> ... > > Would it be more appropriate for generic_identify to also set > x86_cache_alignment like it's done in early_cpu_init? > > generic_identify already re-fetches a bunch of stuff that's also > set by early_cpu_init for the BSP.
This would be an option, but how sure are you that there isn't (going to be) another field with similar properties? We better wouldn't require _everything_ to be re-filled in generic_identify(). Jan
