On Tue, Jul 16, 2024 at 02:35:48PM +0530, Anshuman Khandual wrote: > > > On 5/3/24 18:31, Joey Gouly wrote: > > Modify arch_calc_vm_prot_bits() and vm_get_page_prot() such that the pkey > > value is set in the vm_flags and then into the pgprot value. > > > > Signed-off-by: Joey Gouly <joey.gouly@xxxxxxx> > > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > > Cc: Will Deacon <will@xxxxxxxxxx> > > --- > > arch/arm64/include/asm/mman.h | 8 +++++++- > > arch/arm64/mm/mmap.c | 9 +++++++++ > > 2 files changed, 16 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h > > index 5966ee4a6154..ecb2d18dc4d7 100644 > > --- a/arch/arm64/include/asm/mman.h > > +++ b/arch/arm64/include/asm/mman.h > > @@ -7,7 +7,7 @@ > > #include <uapi/asm/mman.h> > > > > static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, > > - unsigned long pkey __always_unused) > > + unsigned long pkey) > > { > > unsigned long ret = 0; > > > > @@ -17,6 +17,12 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, > > if (system_supports_mte() && (prot & PROT_MTE)) > > ret |= VM_MTE; > > > > +#if defined(CONFIG_ARCH_HAS_PKEYS) > > + ret |= pkey & 0x1 ? VM_PKEY_BIT0 : 0; > > + ret |= pkey & 0x2 ? VM_PKEY_BIT1 : 0; > > + ret |= pkey & 0x4 ? VM_PKEY_BIT2 : 0; > > 0x1, 0x2, 0x4 here are standard bit positions for their corresponding > VM_KEY_XXX based protection values ? Although this is similar to what > x86 is doing currently, hence just trying to understand if these bit > positions here are related to the user visible ABI, which should be > standardized ? The bit positions of VM_PKEY_BIT* aren't user visible. This is converting the value of the `pkey` that was passed to the mprotect, into the internal flags. I might replace those hex values with BIT(0), BIT(1), BIT(2), might be clearer. > > Agree with previous comments about the need for system_supports_poe() > based additional check for the above code block. > > > +#endif > > + > > return ret; > > } > > #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey) > > diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c > > index 642bdf908b22..86eda6bc7893 100644 > > --- a/arch/arm64/mm/mmap.c > > +++ b/arch/arm64/mm/mmap.c > > @@ -102,6 +102,15 @@ pgprot_t vm_get_page_prot(unsigned long vm_flags) > > if (vm_flags & VM_MTE) > > prot |= PTE_ATTRINDX(MT_NORMAL_TAGGED); > > > > +#ifdef CONFIG_ARCH_HAS_PKEYS > > + if (vm_flags & VM_PKEY_BIT0) > > + prot |= PTE_PO_IDX_0; > > + if (vm_flags & VM_PKEY_BIT1) > > + prot |= PTE_PO_IDX_1; > > + if (vm_flags & VM_PKEY_BIT2) > > + prot |= PTE_PO_IDX_2; > > +#endif > > + > > return __pgprot(prot); > > } > > EXPORT_SYMBOL(vm_get_page_prot); > Thanks, Joey