| Message ID | 20240712075022.48276-1-flyingpeng@tencent.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] KVM/x86: make function emulator_do_task_switch as noinline_for_stack | expand |
On Fri, Jul 12, 2024, flyingpenghao@gmail.com wrote: > From: Peng Hao <flyingpeng@tencent.com> > > When KASAN is enabled and built with clang: > clang report > arch/x86/kvm/emulate.c:3022:5: error: stack frame size (2488) exceeds limit (2048) in 'emulator_task_switch' [-Werror,-Wframe-larger-than] > int emulator_task_switch(struct x86_emulate_ctxt *ctxt, > ^ > > since emulator_do_task_switch() consumes a lot of stack space, mark it as > noinline_for_stack to prevent it from blowing up emulator_task_switch()'s > stack size. No, sprinkling noinline to combat KASAN stack frame sizes is not a maintainable approach. Practically speaking, KASAN + -Werror + FRAME_WARN=2048 is not a sane config. > Signed-off-by: Peng Hao <flyingpeng@tencent.com> > --- > arch/x86/kvm/emulate.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c > index 5d4c86133453..bbc185b9725d 100644 > --- a/arch/x86/kvm/emulate.c > +++ b/arch/x86/kvm/emulate.c > @@ -2918,7 +2918,7 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt, u16 old_tss_sel, > return load_state_from_tss32(ctxt, &tss_seg); > } > > -static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, > +static noinline_for_stack int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, > u16 tss_selector, int idt_index, int reason, > bool has_error_code, u32 error_code) > { > -- > 2.27.0 >
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 5d4c86133453..bbc185b9725d 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2918,7 +2918,7 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt, u16 old_tss_sel, return load_state_from_tss32(ctxt, &tss_seg); } -static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, +static noinline_for_stack int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, u16 tss_selector, int idt_index, int reason, bool has_error_code, u32 error_code) {