| Message ID | 1504910713-7094-26-git-send-email-linuxram@us.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | powerpc: Free up RPAGE_RSV bits | expand |
On Fri, 8 Sep 2017 15:45:05 -0700 Ram Pai <linuxram@us.ibm.com> wrote: > helper function that checks if the read/write/execute is allowed > on the pte. > > Signed-off-by: Ram Pai <linuxram@us.ibm.com> > --- > arch/powerpc/include/asm/book3s/64/pgtable.h | 4 +++ > arch/powerpc/include/asm/pkeys.h | 12 +++++++++++ > arch/powerpc/mm/pkeys.c | 28 ++++++++++++++++++++++++++ > 3 files changed, 44 insertions(+), 0 deletions(-) > > diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h > index 5935d4e..bd244b3 100644 > --- a/arch/powerpc/include/asm/book3s/64/pgtable.h > +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h > @@ -492,6 +492,10 @@ static inline void write_uamor(u64 value) > mtspr(SPRN_UAMOR, value); > } > > +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS > +extern bool arch_pte_access_permitted(u64 pte, bool write, bool execute); > +#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > + > #define __HAVE_ARCH_PTEP_GET_AND_CLEAR > static inline pte_t ptep_get_and_clear(struct mm_struct *mm, > unsigned long addr, pte_t *ptep) > diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h > index cd3924c..50522a0 100644 > --- a/arch/powerpc/include/asm/pkeys.h > +++ b/arch/powerpc/include/asm/pkeys.h > @@ -80,6 +80,18 @@ static inline u64 pte_to_hpte_pkey_bits(u64 pteflags) > ((pteflags & H_PAGE_PKEY_BIT4) ? HPTE_R_KEY_BIT4 : 0x0UL)); > } > > +static inline u16 pte_to_pkey_bits(u64 pteflags) > +{ > + if (!pkey_inited) > + return 0x0UL; > + > + return (((pteflags & H_PAGE_PKEY_BIT0) ? 0x10 : 0x0UL) | > + ((pteflags & H_PAGE_PKEY_BIT1) ? 0x8 : 0x0UL) | > + ((pteflags & H_PAGE_PKEY_BIT2) ? 0x4 : 0x0UL) | > + ((pteflags & H_PAGE_PKEY_BIT3) ? 0x2 : 0x0UL) | > + ((pteflags & H_PAGE_PKEY_BIT4) ? 0x1 : 0x0UL)); > +} > + > #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \ > VM_PKEY_BIT3 | VM_PKEY_BIT4) > #define AMR_BITS_PER_PKEY 2 > diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c > index fb1a76a..24589d9 100644 > --- a/arch/powerpc/mm/pkeys.c > +++ b/arch/powerpc/mm/pkeys.c > @@ -292,3 +292,31 @@ int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot, > */ > return vma_pkey(vma); > } > + > +static bool pkey_access_permitted(int pkey, bool write, bool execute) > +{ > + int pkey_shift; > + u64 amr; > + > + if (!pkey) > + return true; Why would we have pkey set to 0, it's reserved. Why do we return true? > + > + pkey_shift = pkeyshift(pkey); > + if (!(read_uamor() & (0x3UL << pkey_shift))) > + return true; > + > + if (execute && !(read_iamr() & (IAMR_EX_BIT << pkey_shift))) > + return true; > + > + amr = read_amr(); /* delay reading amr uptil absolutely needed*/ > + return ((!write && !(amr & (AMR_RD_BIT << pkey_shift))) || > + (write && !(amr & (AMR_WR_BIT << pkey_shift)))); > +} > + > +bool arch_pte_access_permitted(u64 pte, bool write, bool execute) > +{ > + if (!pkey_inited) > + return true; Again, don't like the pkey_inited bits :) > + return pkey_access_permitted(pte_to_pkey_bits(pte), > + write, execute); > +} Balbir Singh
On Wed, Oct 18, 2017 at 03:48:31PM +1100, Balbir Singh wrote: > On Fri, 8 Sep 2017 15:45:05 -0700 > Ram Pai <linuxram@us.ibm.com> wrote: > > > helper function that checks if the read/write/execute is allowed > > on the pte. > > > > Signed-off-by: Ram Pai <linuxram@us.ibm.com> > > --- > > arch/powerpc/include/asm/book3s/64/pgtable.h | 4 +++ > > arch/powerpc/include/asm/pkeys.h | 12 +++++++++++ > > arch/powerpc/mm/pkeys.c | 28 ++++++++++++++++++++++++++ > > 3 files changed, 44 insertions(+), 0 deletions(-) > > > > diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h > > index 5935d4e..bd244b3 100644 > > --- a/arch/powerpc/include/asm/book3s/64/pgtable.h > > +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h > > @@ -492,6 +492,10 @@ static inline void write_uamor(u64 value) > > mtspr(SPRN_UAMOR, value); > > } > > > > +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS > > +extern bool arch_pte_access_permitted(u64 pte, bool write, bool execute); > > +#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > > + > > #define __HAVE_ARCH_PTEP_GET_AND_CLEAR > > static inline pte_t ptep_get_and_clear(struct mm_struct *mm, > > unsigned long addr, pte_t *ptep) > > diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h > > index cd3924c..50522a0 100644 > > --- a/arch/powerpc/include/asm/pkeys.h > > +++ b/arch/powerpc/include/asm/pkeys.h > > @@ -80,6 +80,18 @@ static inline u64 pte_to_hpte_pkey_bits(u64 pteflags) > > ((pteflags & H_PAGE_PKEY_BIT4) ? HPTE_R_KEY_BIT4 : 0x0UL)); > > } > > > > +static inline u16 pte_to_pkey_bits(u64 pteflags) > > +{ > > + if (!pkey_inited) > > + return 0x0UL; > > + > > + return (((pteflags & H_PAGE_PKEY_BIT0) ? 0x10 : 0x0UL) | > > + ((pteflags & H_PAGE_PKEY_BIT1) ? 0x8 : 0x0UL) | > > + ((pteflags & H_PAGE_PKEY_BIT2) ? 0x4 : 0x0UL) | > > + ((pteflags & H_PAGE_PKEY_BIT3) ? 0x2 : 0x0UL) | > > + ((pteflags & H_PAGE_PKEY_BIT4) ? 0x1 : 0x0UL)); > > +} > > + > > #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \ > > VM_PKEY_BIT3 | VM_PKEY_BIT4) > > #define AMR_BITS_PER_PKEY 2 > > diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c > > index fb1a76a..24589d9 100644 > > --- a/arch/powerpc/mm/pkeys.c > > +++ b/arch/powerpc/mm/pkeys.c > > @@ -292,3 +292,31 @@ int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot, > > */ > > return vma_pkey(vma); > > } > > + > > +static bool pkey_access_permitted(int pkey, bool write, bool execute) > > +{ > > + int pkey_shift; > > + u64 amr; > > + > > + if (!pkey) > > + return true; > > Why would we have pkey set to 0, it's reserved. Why do we return true? pkey 0 is reserved in some weird sense. it is the default key which is omnipresent, which cannot be allocated or freed, but can be used any time and allows read/write/execute at all times. > > > + > > + pkey_shift = pkeyshift(pkey); > > + if (!(read_uamor() & (0x3UL << pkey_shift))) > > + return true; > > + > > + if (execute && !(read_iamr() & (IAMR_EX_BIT << pkey_shift))) > > + return true; > > + > > + amr = read_amr(); /* delay reading amr uptil absolutely needed*/ > > + return ((!write && !(amr & (AMR_RD_BIT << pkey_shift))) || > > + (write && !(amr & (AMR_WR_BIT << pkey_shift)))); > > +} > > + > > +bool arch_pte_access_permitted(u64 pte, bool write, bool execute) > > +{ > > + if (!pkey_inited) > > + return true; > > Again, don't like the pkey_inited bits :) suggest something. :) running out of ideas ;) > > > + return pkey_access_permitted(pte_to_pkey_bits(pte), > > + write, execute); > > +} > > Balbir Singh
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index 5935d4e..bd244b3 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -492,6 +492,10 @@ static inline void write_uamor(u64 value) mtspr(SPRN_UAMOR, value); } +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS +extern bool arch_pte_access_permitted(u64 pte, bool write, bool execute); +#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ + #define __HAVE_ARCH_PTEP_GET_AND_CLEAR static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h index cd3924c..50522a0 100644 --- a/arch/powerpc/include/asm/pkeys.h +++ b/arch/powerpc/include/asm/pkeys.h @@ -80,6 +80,18 @@ static inline u64 pte_to_hpte_pkey_bits(u64 pteflags) ((pteflags & H_PAGE_PKEY_BIT4) ? HPTE_R_KEY_BIT4 : 0x0UL)); } +static inline u16 pte_to_pkey_bits(u64 pteflags) +{ + if (!pkey_inited) + return 0x0UL; + + return (((pteflags & H_PAGE_PKEY_BIT0) ? 0x10 : 0x0UL) | + ((pteflags & H_PAGE_PKEY_BIT1) ? 0x8 : 0x0UL) | + ((pteflags & H_PAGE_PKEY_BIT2) ? 0x4 : 0x0UL) | + ((pteflags & H_PAGE_PKEY_BIT3) ? 0x2 : 0x0UL) | + ((pteflags & H_PAGE_PKEY_BIT4) ? 0x1 : 0x0UL)); +} + #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \ VM_PKEY_BIT3 | VM_PKEY_BIT4) #define AMR_BITS_PER_PKEY 2 diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c index fb1a76a..24589d9 100644 --- a/arch/powerpc/mm/pkeys.c +++ b/arch/powerpc/mm/pkeys.c @@ -292,3 +292,31 @@ int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot, */ return vma_pkey(vma); } + +static bool pkey_access_permitted(int pkey, bool write, bool execute) +{ + int pkey_shift; + u64 amr; + + if (!pkey) + return true; + + pkey_shift = pkeyshift(pkey); + if (!(read_uamor() & (0x3UL << pkey_shift))) + return true; + + if (execute && !(read_iamr() & (IAMR_EX_BIT << pkey_shift))) + return true; + + amr = read_amr(); /* delay reading amr uptil absolutely needed*/ + return ((!write && !(amr & (AMR_RD_BIT << pkey_shift))) || + (write && !(amr & (AMR_WR_BIT << pkey_shift)))); +} + +bool arch_pte_access_permitted(u64 pte, bool write, bool execute) +{ + if (!pkey_inited) + return true; + return pkey_access_permitted(pte_to_pkey_bits(pte), + write, execute); +}
helper function that checks if the read/write/execute is allowed on the pte. Signed-off-by: Ram Pai <linuxram@us.ibm.com> --- arch/powerpc/include/asm/book3s/64/pgtable.h | 4 +++ arch/powerpc/include/asm/pkeys.h | 12 +++++++++++ arch/powerpc/mm/pkeys.c | 28 ++++++++++++++++++++++++++ 3 files changed, 44 insertions(+), 0 deletions(-)