| Message ID | 20231124163510.1835740-12-joey.gouly@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Permission Overlay Extension | expand |
On Fri, Nov 24, 2023 at 04:34:56PM +0000, Joey Gouly wrote: > diff --git a/arch/arm64/include/asm/pkeys.h b/arch/arm64/include/asm/pkeys.h > new file mode 100644 > index 000000000000..5761fb48fd53 > --- /dev/null > +++ b/arch/arm64/include/asm/pkeys.h > @@ -0,0 +1,54 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright (C) 2023 Arm Ltd. > + * > + * Based on arch/x86/include/asm/pkeys.h > +*/ > + > +#ifndef _ASM_ARM64_PKEYS_H > +#define _ASM_ARM64_PKEYS_H > + > +#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2) > + > +#define arch_max_pkey() 0 > + > +int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, > + unsigned long init_val); > + > +static inline bool arch_pkeys_enabled(void) > +{ > + return false; > +} > + > +static inline int vma_pkey(struct vm_area_struct *vma) > +{ > + return -1; > +} What's the point of these dummies? I guess they'll be populated later but I haven't reached that point. Could we not just leave them out for now and add the complete version directly? This would work better with an earlier comment to move the Kconfig entry towards the end of the series. Also, they don't seem to match the generic include/linux/pkeys.h dummies. For example, vma_pkey() returns 0 in the generic version, -1 here. Should they actually match?
Hi, Thanks to you and Mark for the comments so far! On Thu, Dec 07, 2023 at 03:25:17PM +0000, Catalin Marinas wrote: > On Fri, Nov 24, 2023 at 04:34:56PM +0000, Joey Gouly wrote: > > diff --git a/arch/arm64/include/asm/pkeys.h b/arch/arm64/include/asm/pkeys.h > > new file mode 100644 > > index 000000000000..5761fb48fd53 > > --- /dev/null > > +++ b/arch/arm64/include/asm/pkeys.h > > @@ -0,0 +1,54 @@ > > +/* SPDX-License-Identifier: GPL-2.0 */ > > +/* > > + * Copyright (C) 2023 Arm Ltd. > > + * > > + * Based on arch/x86/include/asm/pkeys.h > > +*/ > > + > > +#ifndef _ASM_ARM64_PKEYS_H > > +#define _ASM_ARM64_PKEYS_H > > + > > +#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2) > > + > > +#define arch_max_pkey() 0 > > + > > +int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, > > + unsigned long init_val); > > + > > +static inline bool arch_pkeys_enabled(void) > > +{ > > + return false; > > +} > > + > > +static inline int vma_pkey(struct vm_area_struct *vma) > > +{ > > + return -1; > > +} > > What's the point of these dummies? I guess they'll be populated later > but I haven't reached that point. Could we not just leave them out for > now and add the complete version directly? This would work better with > an earlier comment to move the Kconfig entry towards the end of the > series. I think the suggestion to move the Kconfig to the end is good, and I agree that it will probably remove these dummy implementations. > > Also, they don't seem to match the generic include/linux/pkeys.h > dummies. For example, vma_pkey() returns 0 in the generic version, -1 > here. Should they actually match? If for some reason I need to keep them after the Kconfig move, I will look into this further. Thanks, Joey
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index d7df6c603190..72a71a9834dd 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2082,6 +2082,8 @@ menu "ARMv8.9 architectural features" config ARM64_POE prompt "Permission Overlay Extension" def_bool y + select ARCH_USES_HIGH_VMA_FLAGS + select ARCH_HAS_PKEYS help The Permission Overlay Extension is used to implement Memory Protection Keys. Memory Protection Keys provides a mechanism for diff --git a/arch/arm64/include/asm/pkeys.h b/arch/arm64/include/asm/pkeys.h new file mode 100644 index 000000000000..5761fb48fd53 --- /dev/null +++ b/arch/arm64/include/asm/pkeys.h @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2023 Arm Ltd. + * + * Based on arch/x86/include/asm/pkeys.h +*/ + +#ifndef _ASM_ARM64_PKEYS_H +#define _ASM_ARM64_PKEYS_H + +#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2) + +#define arch_max_pkey() 0 + +int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, + unsigned long init_val); + +static inline bool arch_pkeys_enabled(void) +{ + return false; +} + +static inline int vma_pkey(struct vm_area_struct *vma) +{ + return -1; +} + +static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, + int prot, int pkey) +{ + return -1; +} + +static inline int execute_only_pkey(struct mm_struct *mm) +{ + return -1; +} + +static inline bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey) +{ + return false; +} + +static inline int mm_pkey_alloc(struct mm_struct *mm) +{ + return -1; +} + +static inline int mm_pkey_free(struct mm_struct *mm, int pkey) +{ + return -EINVAL; +} + +#endif /* _ASM_ARM64_PKEYS_H */ diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 15f6347d23b6..f7bf41eae904 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1486,3 +1486,10 @@ void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte { set_pte_at(vma->vm_mm, addr, ptep, pte); } + +#ifdef CONFIG_ARCH_HAS_PKEYS +int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, unsigned long init_val) +{ + return -ENOSPC; +} +#endif
Enable the ARCH_HAS_PKEYS config, but provide dummy functions for the entire interface. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> --- arch/arm64/Kconfig | 2 ++ arch/arm64/include/asm/pkeys.h | 54 ++++++++++++++++++++++++++++++++++ arch/arm64/mm/mmu.c | 7 +++++ 3 files changed, 63 insertions(+) create mode 100644 arch/arm64/include/asm/pkeys.h