[PATCH] KVM: x86: dynamically allocate large struct in em_fxrstor
From: Nick Desaulniers
Date: Wed May 24 2017 - 02:27:26 EST
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 <nick.desaulniers@xxxxxxxxx>
---
arch/x86/kvm/emulate.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 0816ab2e8adc..1d7c9ceeff56 100644
--- 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);
+ if (!fx_state)
+ return -ENOMEM;
+
+ rc = segmented_read_std(ctxt, ctxt->memop.addr.mem, fx_state, 512);
if (rc != X86EMUL_CONTINUE)
- return rc;
+ goto out;
- if (fx_state.mxcsr >> 16)
- return emulate_gp(ctxt, 0);
+ if (fx_state->mxcsr >> 16) {
+ rc = emulate_gp(ctxt, 0);
+ goto out;
+ }
ctxt->ops->get_fpu(ctxt);
if (ctxt->mode < X86EMUL_MODE_PROT64)
- rc = fxrstor_fixup(ctxt, &fx_state);
+ rc = fxrstor_fixup(ctxt, fx_state);
if (rc == X86EMUL_CONTINUE)
- rc = asm_safe("fxrstor %[fx]", : [fx] "m"(fx_state));
+ rc = asm_safe("fxrstor %[fx]", : [fx] "m"(*fx_state));
ctxt->ops->put_fpu(ctxt);
+out:
+ kfree(fx_state);
return rc;
}
--
2.11.0