2017-05-23 23:24-0700, Nick Desaulniers: > Fixes the warning: > > arch/x86/kvm/emulate.c:4018:12: warning: stack frame size of 1080 bytes in > function > 'em_fxrstor' [-Wframe-larger-than=] > static int em_fxrstor(struct x86_emulate_ctxt *ctxt) > ^ > > Found with CONFIG_FRAME_WARN set to 1024. > > Signed-off-by: Nick Desaulniers <[email protected]> > --- > diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c > @@ -4017,30 +4017,38 @@ static int fxrstor_fixup(struct x86_emulate_ctxt > *ctxt, > > static int em_fxrstor(struct x86_emulate_ctxt *ctxt) > { > - struct fxregs_state fx_state; > + struct fxregs_state *fx_state; > int rc; > > rc = check_fxsr(ctxt); > if (rc != X86EMUL_CONTINUE) > return rc; > > - rc = segmented_read_std(ctxt, ctxt->memop.addr.mem, &fx_state, 512); > + fx_state = kmalloc(sizeof(*fx_state), GFP_KERNEL); > + fx_state = kmalloc(sizeof(*fx_state), GFP_KERNEL);
fx_state must be 16 byte aligned and x86 ARCH_KMALLOC_MINALIGN is 8, so this needs manual correction. Also, please kmalloc also fxregs_state in fxrstor_fixup and em_fxsave so we again have only one storage type. > + if (!fx_state) > + return -ENOMEM; The caller does not understand -ENOMEM. The appropriate return value is X86EMUL_UNHANDLEABLE. > if (ctxt->mode < X86EMUL_MODE_PROT64) > - rc = fxrstor_fixup(ctxt, &fx_state); > + rc = fxrstor_fixup(ctxt, fx_state); Ah, fxrstor_fixup most likely got inlined and both of them put ~512 byte fxregs_state on the stack ... noinline attribute should solve the warning too. Thanks.
