On Wed, 12 Sep 2018, Thomas Gleixner wrote: > > case X86_BUG_SPECTRE_V2: > > - return sprintf(buf, "%s%s%s%s\n", > > spectre_v2_strings[spectre_v2_enabled], > > + mutex_lock(&spec_ctrl_mutex); > > + ret = sprintf(buf, "%s%s%s%s%s\n", > > spectre_v2_strings[spectre_v2_enabled], > > boot_cpu_has(X86_FEATURE_USE_IBPB) ? ", IBPB" : > > "", > > boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", > > IBRS_FW" : "", > > + (x86_spec_ctrl_base & SPEC_CTRL_STIBP) ? ", > > STIBP" : "", > > spectre_v2_module_string()); > > + mutex_unlock(&spec_ctrl_mutex); > > The mutex for this printing is overkill. It's a read after all and if there > is a concurrent SMT control fiddling going on then you have a chance of > getting the wrong information as well.
Yeah; I was just happy to be able to stick second use of it there, with the first one being basically useless as well :) > I'll zap it. Absolutely feel free to. Thanks, -- Jiri Kosina SUSE Labs
