Hi Will, On Mon, May 13, 2024 at 06:30:05PM +0100, Will Deacon wrote: > On Fri, May 10, 2024 at 12:26:39PM +0100, Pierre-Clément Tosi wrote: > > [...] > > > > Use SYM_TYPED_FUNC_START() for __pkvm_init_switch_pgd, as nVHE can't > > call it directly and must use a PA function pointer from C (because it > > is part of the idmap page), which would trigger a kCFI failure if the > > type ID wasn't present. > > > > Signed-off-by: Pierre-Clément Tosi <ptosi@xxxxxxxxxx> > > --- > > arch/arm64/include/asm/esr.h | 6 ++++++ > > arch/arm64/kvm/handle_exit.c | 11 +++++++++++ > > arch/arm64/kvm/hyp/nvhe/Makefile | 6 +++--- > > arch/arm64/kvm/hyp/nvhe/hyp-init.S | 6 +++++- > > 4 files changed, 25 insertions(+), 4 deletions(-) > > > > [...] > > > > diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S > > index 5a15737b4233..33fb5732ab83 100644 > > --- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S > > +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S > > @@ -5,6 +5,7 @@ > > */ > > > > #include <linux/arm-smccc.h> > > +#include <linux/cfi_types.h> > > #include <linux/linkage.h> > > > > #include <asm/alternative.h> > > @@ -268,8 +269,11 @@ SYM_CODE_END(__kvm_handle_stub_hvc) > > /* > > * void __pkvm_init_switch_pgd(struct kvm_nvhe_init_params *params, > > * void (*finalize_fn)(void)); > > + * > > + * SYM_TYPED_FUNC_START() allows C to call this ID-mapped function indirectly > > + * using a physical pointer without triggering a kCFI failure. > > */ > > -SYM_FUNC_START(__pkvm_init_switch_pgd) > > +SYM_TYPED_FUNC_START(__pkvm_init_switch_pgd) > > /* Load the inputs from the VA pointer before turning the MMU off */ > > ldr x5, [x0, #NVHE_INIT_PGD_PA] > > ldr x0, [x0, #NVHE_INIT_STACK_HYP_VA] > > Unrelated hunk? No, this is needed to prevent a kCFI failure at EL2. Please let me know if the comment and commit message aren't clear enough. > > Will
