| Message ID | 1501459946-11619-13-git-send-email-linuxram@us.ibm.com (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
Hi Ram, On 31/07/2017 02:12, Ram Pai wrote: > arch independent code calls arch_override_mprotect_pkey() > to return a pkey that best matches the requested protection. > > This patch provides the implementation. > > Signed-off-by: Ram Pai <linuxram@us.ibm.com> > --- > arch/powerpc/include/asm/mmu_context.h | 5 +++ > arch/powerpc/include/asm/pkeys.h | 17 ++++++++++- > arch/powerpc/mm/pkeys.c | 47 ++++++++++++++++++++++++++++++++ > 3 files changed, 67 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h > index 4705dab..7232484 100644 > --- a/arch/powerpc/include/asm/mmu_context.h > +++ b/arch/powerpc/include/asm/mmu_context.h > @@ -185,6 +185,11 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, > #ifndef CONFIG_PPC64_MEMORY_PROTECTION_KEYS > #define pkey_initialize() > #define pkey_mm_init(mm) > + > +static inline int vma_pkey(struct vm_area_struct *vma) > +{ > + return 0; > +} > #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > > #endif /* __KERNEL__ */ > diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h > index a715a08..03f7ea2 100644 > --- a/arch/powerpc/include/asm/pkeys.h > +++ b/arch/powerpc/include/asm/pkeys.h > @@ -46,6 +46,16 @@ static inline u64 pkey_to_vmflag_bits(u16 pkey) > ((pkey & 0x10UL) ? VM_PKEY_BIT4 : 0x0UL)); > } > > +#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \ > + VM_PKEY_BIT3 | VM_PKEY_BIT4) > + > +static inline int vma_pkey(struct vm_area_struct *vma) > +{ > + if (!pkey_inited) > + return 0; > + return (vma->vm_flags & ARCH_VM_PKEY_FLAGS) >> VM_PKEY_SHIFT; > +} > + > #define arch_max_pkey() pkeys_total > #define AMR_RD_BIT 0x1UL > #define AMR_WR_BIT 0x2UL > @@ -146,11 +156,14 @@ static inline int execute_only_pkey(struct mm_struct *mm) > return __execute_only_pkey(mm); > } > > - > +extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma, > + int prot, int pkey); > static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, > int prot, int pkey) > { > - return 0; > + if (!pkey_inited) > + return 0; > + return __arch_override_mprotect_pkey(vma, prot, pkey); > } > > extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, > diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c > index 25749bf..edcbf48 100644 > --- a/arch/powerpc/mm/pkeys.c > +++ b/arch/powerpc/mm/pkeys.c > @@ -154,3 +154,50 @@ int __execute_only_pkey(struct mm_struct *mm) > mm->context.execute_only_pkey = execute_only_pkey; > return execute_only_pkey; > } > + > +static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma) > +{ > + /* Do this check first since the vm_flags should be hot */ > + if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC) > + return false; > + > + return (vma_pkey(vma) == vma->vm_mm->context.execute_only_pkey); > +} > + > +/* > + * This should only be called for *plain* mprotect calls. > + */ > +int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot, > + int pkey) > +{ > + /* > + * Is this an mprotect_pkey() call? If so, never > + * override the value that came from the user. > + */ > + if (pkey != -1) > + return pkey; This check should be moved in arch_override_mprotect_pkey() in arch/powerpc/include/asm/pkeys.h > + > + /* > + * If the currently associated pkey is execute-only, > + * but the requested protection requires read or write, > + * move it back to the default pkey. > + */ > + if (vma_is_pkey_exec_only(vma) && > + (prot & (PROT_READ|PROT_WRITE))) > + return 0; > + > + /* > + * the requested protection is execute-only. Hence > + * lets use a execute-only pkey. > + */ > + if (prot == PROT_EXEC) { > + pkey = execute_only_pkey(vma->vm_mm); > + if (pkey > 0) > + return pkey; > + } > + > + /* > + * nothing to override. > + */ > + return vma_pkey(vma); > +} >
On Wed, Oct 18, 2017 at 05:58:18PM +0200, Laurent Dufour wrote: > Hi Ram, > > On 31/07/2017 02:12, Ram Pai wrote: > > arch independent code calls arch_override_mprotect_pkey() > > to return a pkey that best matches the requested protection. > > > > This patch provides the implementation. > > > > Signed-off-by: Ram Pai <linuxram@us.ibm.com> > > --- > > arch/powerpc/include/asm/mmu_context.h | 5 +++ > > arch/powerpc/include/asm/pkeys.h | 17 ++++++++++- > > arch/powerpc/mm/pkeys.c | 47 ++++++++++++++++++++++++++++++++ > > 3 files changed, 67 insertions(+), 2 deletions(-) > > > > diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h > > index 4705dab..7232484 100644 > > --- a/arch/powerpc/include/asm/mmu_context.h > > +++ b/arch/powerpc/include/asm/mmu_context.h > > @@ -185,6 +185,11 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, > > #ifndef CONFIG_PPC64_MEMORY_PROTECTION_KEYS > > #define pkey_initialize() > > #define pkey_mm_init(mm) > > + > > +static inline int vma_pkey(struct vm_area_struct *vma) > > +{ > > + return 0; > > +} > > #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > > > > #endif /* __KERNEL__ */ > > diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h > > index a715a08..03f7ea2 100644 > > --- a/arch/powerpc/include/asm/pkeys.h > > +++ b/arch/powerpc/include/asm/pkeys.h > > @@ -46,6 +46,16 @@ static inline u64 pkey_to_vmflag_bits(u16 pkey) > > ((pkey & 0x10UL) ? VM_PKEY_BIT4 : 0x0UL)); > > } > > > > +#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \ > > + VM_PKEY_BIT3 | VM_PKEY_BIT4) > > + > > +static inline int vma_pkey(struct vm_area_struct *vma) > > +{ > > + if (!pkey_inited) > > + return 0; > > + return (vma->vm_flags & ARCH_VM_PKEY_FLAGS) >> VM_PKEY_SHIFT; > > +} > > + > > #define arch_max_pkey() pkeys_total > > #define AMR_RD_BIT 0x1UL > > #define AMR_WR_BIT 0x2UL > > @@ -146,11 +156,14 @@ static inline int execute_only_pkey(struct mm_struct *mm) > > return __execute_only_pkey(mm); > > } > > > > - > > +extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma, > > + int prot, int pkey); > > static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, > > int prot, int pkey) > > { > > - return 0; > > + if (!pkey_inited) > > + return 0; > > + return __arch_override_mprotect_pkey(vma, prot, pkey); > > } > > > > extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, > > diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c > > index 25749bf..edcbf48 100644 > > --- a/arch/powerpc/mm/pkeys.c > > +++ b/arch/powerpc/mm/pkeys.c > > @@ -154,3 +154,50 @@ int __execute_only_pkey(struct mm_struct *mm) > > mm->context.execute_only_pkey = execute_only_pkey; > > return execute_only_pkey; > > } > > + > > +static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma) > > +{ > > + /* Do this check first since the vm_flags should be hot */ > > + if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC) > > + return false; > > + > > + return (vma_pkey(vma) == vma->vm_mm->context.execute_only_pkey); > > +} > > + > > +/* > > + * This should only be called for *plain* mprotect calls. > > + */ > > +int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot, > > + int pkey) > > +{ > > + /* > > + * Is this an mprotect_pkey() call? If so, never > > + * override the value that came from the user. > > + */ > > + if (pkey != -1) > > + return pkey; > > This check should be moved in arch_override_mprotect_pkey() in > arch/powerpc/include/asm/pkeys.h ok. will do. > > > + > > + /* > > + * If the currently associated pkey is execute-only, > > + * but the requested protection requires read or write, > > + * move it back to the default pkey. > > + */ > > + if (vma_is_pkey_exec_only(vma) && > > + (prot & (PROT_READ|PROT_WRITE))) > > + return 0; > > + > > + /* > > + * the requested protection is execute-only. Hence > > + * lets use a execute-only pkey. > > + */ > > + if (prot == PROT_EXEC) { > > + pkey = execute_only_pkey(vma->vm_mm); > > + if (pkey > 0) > > + return pkey; > > + } > > + > > + /* > > + * nothing to override. > > + */ > > + return vma_pkey(vma); > > +} > > Thanks,
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 4705dab..7232484 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -185,6 +185,11 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, #ifndef CONFIG_PPC64_MEMORY_PROTECTION_KEYS #define pkey_initialize() #define pkey_mm_init(mm) + +static inline int vma_pkey(struct vm_area_struct *vma) +{ + return 0; +} #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ #endif /* __KERNEL__ */ diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h index a715a08..03f7ea2 100644 --- a/arch/powerpc/include/asm/pkeys.h +++ b/arch/powerpc/include/asm/pkeys.h @@ -46,6 +46,16 @@ static inline u64 pkey_to_vmflag_bits(u16 pkey) ((pkey & 0x10UL) ? VM_PKEY_BIT4 : 0x0UL)); } +#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \ + VM_PKEY_BIT3 | VM_PKEY_BIT4) + +static inline int vma_pkey(struct vm_area_struct *vma) +{ + if (!pkey_inited) + return 0; + return (vma->vm_flags & ARCH_VM_PKEY_FLAGS) >> VM_PKEY_SHIFT; +} + #define arch_max_pkey() pkeys_total #define AMR_RD_BIT 0x1UL #define AMR_WR_BIT 0x2UL @@ -146,11 +156,14 @@ static inline int execute_only_pkey(struct mm_struct *mm) return __execute_only_pkey(mm); } - +extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma, + int prot, int pkey); static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot, int pkey) { - return 0; + if (!pkey_inited) + return 0; + return __arch_override_mprotect_pkey(vma, prot, pkey); } extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c index 25749bf..edcbf48 100644 --- a/arch/powerpc/mm/pkeys.c +++ b/arch/powerpc/mm/pkeys.c @@ -154,3 +154,50 @@ int __execute_only_pkey(struct mm_struct *mm) mm->context.execute_only_pkey = execute_only_pkey; return execute_only_pkey; } + +static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma) +{ + /* Do this check first since the vm_flags should be hot */ + if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC) + return false; + + return (vma_pkey(vma) == vma->vm_mm->context.execute_only_pkey); +} + +/* + * This should only be called for *plain* mprotect calls. + */ +int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot, + int pkey) +{ + /* + * Is this an mprotect_pkey() call? If so, never + * override the value that came from the user. + */ + if (pkey != -1) + return pkey; + + /* + * If the currently associated pkey is execute-only, + * but the requested protection requires read or write, + * move it back to the default pkey. + */ + if (vma_is_pkey_exec_only(vma) && + (prot & (PROT_READ|PROT_WRITE))) + return 0; + + /* + * the requested protection is execute-only. Hence + * lets use a execute-only pkey. + */ + if (prot == PROT_EXEC) { + pkey = execute_only_pkey(vma->vm_mm); + if (pkey > 0) + return pkey; + } + + /* + * nothing to override. + */ + return vma_pkey(vma); +}
arch independent code calls arch_override_mprotect_pkey() to return a pkey that best matches the requested protection. This patch provides the implementation. Signed-off-by: Ram Pai <linuxram@us.ibm.com> --- arch/powerpc/include/asm/mmu_context.h | 5 +++ arch/powerpc/include/asm/pkeys.h | 17 ++++++++++- arch/powerpc/mm/pkeys.c | 47 ++++++++++++++++++++++++++++++++ 3 files changed, 67 insertions(+), 2 deletions(-)