On 2/22/19 15:39, Jan Beulich wrote: >>>> On 21.02.19 at 09:16, <nmant...@amazon.de> wrote: >> --- a/xen/arch/x86/hvm/hvm.c >> +++ b/xen/arch/x86/hvm/hvm.c >> @@ -4109,6 +4109,13 @@ static int hvmop_set_param( >> if ( a.index >= HVM_NR_PARAMS ) >> return -EINVAL; >> >> + /* >> + * Make sure the guest controlled value a.index is bounded even during >> + * speculative execution. >> + */ >> + a.index = array_index_nospec(a.index, HVM_NR_PARAMS); >> + block_speculation(); >> + >> d = rcu_lock_domain_by_any_id(a.domid); >> if ( d == NULL ) >> return -ESRCH; >> @@ -4375,6 +4382,13 @@ static int hvmop_get_param( >> if ( a.index >= HVM_NR_PARAMS ) >> return -EINVAL; >> >> + /* >> + * Make sure the guest controlled value a.index is bounded even during >> + * speculative execution. >> + */ >> + a.index = array_index_nospec(a.index, HVM_NR_PARAMS); >> + block_speculation(); > Please can the comments briefly explain the otherwise apparently > pointless redundancy of both constructs?
Sure, I will add some reasoning. Best, Norbert Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich Ust-ID: DE 289 237 879 Eingetragen am Amtsgericht Charlottenburg HRB 149173 B _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
