powerpc/mm: Use _PAGE_READ to indicate Read access

This splits the _PAGE_RW bit into _PAGE_READ and _PAGE_WRITE. It also
removes the dependency on _PAGE_USER for implying read only. Few things
to note here is that, we have read implied with write and execute
permission. Hence we should always find _PAGE_READ set on hash pte
fault.

We still can't switch PROT_NONE to !(_PAGE_RWX). Auto numa depends on
marking a prot none pte _PAGE_WRITE. (For more details look at
b191f9b106 "mm: numa: preserve PTE write permissions across a NUMA
hinting fault")

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Aneesh Kumar K.V 2016-04-29 23:25:30 +10:00 committed by Michael Ellerman
parent ee3caed37d
commit c7d54842de
14 changed files with 49 additions and 37 deletions

View File

@ -291,10 +291,10 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp)
{
if ((pmd_val(*pmdp) & _PAGE_RW) == 0)
if ((pmd_val(*pmdp) & _PAGE_WRITE) == 0)
return;
pmd_hugepage_update(mm, addr, pmdp, _PAGE_RW, 0);
pmd_hugepage_update(mm, addr, pmdp, _PAGE_WRITE, 0);
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

View File

@ -16,8 +16,10 @@
#define _PAGE_BIT_SWAP_TYPE 0
#define _PAGE_EXEC 0x00001 /* execute permission */
#define _PAGE_RW 0x00002 /* read & write access allowed */
#define _PAGE_WRITE 0x00002 /* write access allowed */
#define _PAGE_READ 0x00004 /* read access allowed */
#define _PAGE_RW (_PAGE_READ | _PAGE_WRITE)
#define _PAGE_RWX (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)
#define _PAGE_USER 0x00008 /* page may be accessed by userspace */
#define _PAGE_GUARDED 0x00010 /* G: guarded (side-effect) page */
/* M (memory coherence) is always set in the HPTE, so we don't need it here */
@ -145,8 +147,8 @@
*/
#define PAGE_PROT_BITS (_PAGE_GUARDED | _PAGE_COHERENT | _PAGE_NO_CACHE | \
_PAGE_WRITETHRU | _PAGE_4K_PFN | \
_PAGE_USER | _PAGE_ACCESSED | \
_PAGE_RW | _PAGE_DIRTY | _PAGE_EXEC | \
_PAGE_USER | _PAGE_ACCESSED | _PAGE_READ |\
_PAGE_WRITE | _PAGE_DIRTY | _PAGE_EXEC | \
_PAGE_SOFT_DIRTY)
/*
* We define 2 sets of base prot bits, one for basic pages (ie,
@ -171,10 +173,12 @@
#define PAGE_SHARED __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
#define PAGE_SHARED_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | \
_PAGE_EXEC)
#define PAGE_COPY __pgprot(_PAGE_BASE | _PAGE_USER )
#define PAGE_COPY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
#define PAGE_READONLY __pgprot(_PAGE_BASE | _PAGE_USER )
#define PAGE_READONLY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
#define PAGE_COPY __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_READ)
#define PAGE_COPY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_READ| \
_PAGE_EXEC)
#define PAGE_READONLY __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_READ)
#define PAGE_READONLY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_READ| \
_PAGE_EXEC)
#define __P000 PAGE_NONE
#define __P001 PAGE_READONLY
@ -296,19 +300,19 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
if ((pte_val(*ptep) & _PAGE_RW) == 0)
if ((pte_val(*ptep) & _PAGE_WRITE) == 0)
return;
pte_update(mm, addr, ptep, _PAGE_RW, 0, 0);
pte_update(mm, addr, ptep, _PAGE_WRITE, 0, 0);
}
static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
if ((pte_val(*ptep) & _PAGE_RW) == 0)
if ((pte_val(*ptep) & _PAGE_WRITE) == 0)
return;
pte_update(mm, addr, ptep, _PAGE_RW, 0, 1);
pte_update(mm, addr, ptep, _PAGE_WRITE, 0, 1);
}
/*
@ -349,7 +353,7 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry)
{
__be64 old, tmp, val, mask;
mask = cpu_to_be64(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW |
mask = cpu_to_be64(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_READ | _PAGE_WRITE |
_PAGE_EXEC | _PAGE_SOFT_DIRTY);
val = pte_raw(entry) & mask;
@ -384,7 +388,7 @@ static inline unsigned long pgd_page_vaddr(pgd_t pgd)
/* Generic accessors to PTE bits */
static inline int pte_write(pte_t pte) { return !!(pte_val(pte) & _PAGE_RW);}
static inline int pte_write(pte_t pte) { return !!(pte_val(pte) & _PAGE_WRITE);}
static inline int pte_dirty(pte_t pte) { return !!(pte_val(pte) & _PAGE_DIRTY); }
static inline int pte_young(pte_t pte) { return !!(pte_val(pte) & _PAGE_ACCESSED); }
static inline int pte_special(pte_t pte) { return !!(pte_val(pte) & _PAGE_SPECIAL); }
@ -445,7 +449,7 @@ static inline unsigned long pte_pfn(pte_t pte)
/* Generic modifiers for PTE bits */
static inline pte_t pte_wrprotect(pte_t pte)
{
return __pte(pte_val(pte) & ~_PAGE_RW);
return __pte(pte_val(pte) & ~_PAGE_WRITE);
}
static inline pte_t pte_mkclean(pte_t pte)
@ -460,6 +464,9 @@ static inline pte_t pte_mkold(pte_t pte)
static inline pte_t pte_mkwrite(pte_t pte)
{
/*
* write implies read, hence set both
*/
return __pte(pte_val(pte) | _PAGE_RW);
}

View File

@ -198,3 +198,8 @@ extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
/* Advertise support for _PAGE_SPECIAL */
#define __HAVE_ARCH_PTE_SPECIAL
#ifndef _PAGE_READ
/* if not defined, we should not find _PAGE_WRITE too */
#define _PAGE_READ 0
#define _PAGE_WRITE _PAGE_RW
#endif

View File

@ -45,7 +45,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
* also add _PAGE_COMBO
*/
new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
if (access & _PAGE_RW)
if (access & _PAGE_WRITE)
new_pte |= _PAGE_DIRTY;
} while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));

View File

@ -77,7 +77,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
* also add _PAGE_COMBO
*/
new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED | _PAGE_COMBO;
if (access & _PAGE_RW)
if (access & _PAGE_WRITE)
new_pte |= _PAGE_DIRTY;
} while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));
@ -251,7 +251,7 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
* a write access.
*/
new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
if (access & _PAGE_RW)
if (access & _PAGE_WRITE)
new_pte |= _PAGE_DIRTY;
} while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));

View File

@ -175,8 +175,9 @@ unsigned long htab_convert_pte_flags(unsigned long pteflags)
* or PP=0x3 for read-only (including writeable but clean pages).
*/
if (pteflags & _PAGE_USER) {
rflags |= 0x2;
if (!((pteflags & _PAGE_RW) && (pteflags & _PAGE_DIRTY)))
if (pteflags & _PAGE_RWX)
rflags |= 0x2;
if (!((pteflags & _PAGE_WRITE) && (pteflags & _PAGE_DIRTY)))
rflags |= 0x1;
}
/*
@ -1209,7 +1210,7 @@ EXPORT_SYMBOL_GPL(hash_page);
int __hash_page(unsigned long ea, unsigned long msr, unsigned long trap,
unsigned long dsisr)
{
unsigned long access = _PAGE_PRESENT;
unsigned long access = _PAGE_PRESENT | _PAGE_READ;
unsigned long flags = 0;
struct mm_struct *mm = current->mm;
@ -1220,7 +1221,7 @@ int __hash_page(unsigned long ea, unsigned long msr, unsigned long trap,
flags |= HPTE_NOHPTE_UPDATE;
if (dsisr & DSISR_ISSTORE)
access |= _PAGE_RW;
access |= _PAGE_WRITE;
/*
* We need to set the _PAGE_USER bit if MSR_PR is set or if we are
* accessing a userspace segment (even from the kernel). We assume

View File

@ -47,7 +47,7 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
* a write access
*/
new_pmd = old_pmd | _PAGE_BUSY | _PAGE_ACCESSED;
if (access & _PAGE_RW)
if (access & _PAGE_WRITE)
new_pmd |= _PAGE_DIRTY;
} while (!pmd_xchg(pmdp, __pmd(old_pmd), __pmd(new_pmd)));

View File

@ -55,7 +55,7 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
/* Try to lock the PTE, add ACCESSED and DIRTY if it was
* a write access */
new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
if (access & _PAGE_RW)
if (access & _PAGE_WRITE)
new_pte |= _PAGE_DIRTY;
} while(!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));

View File

@ -1003,9 +1003,9 @@ int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
end = pte_end;
pte = READ_ONCE(*ptep);
mask = _PAGE_PRESENT | _PAGE_USER;
mask = _PAGE_PRESENT | _PAGE_USER | _PAGE_READ;
if (write)
mask |= _PAGE_RW;
mask |= _PAGE_WRITE;
if ((pte_val(pte) & mask) != mask)
return 0;

View File

@ -177,8 +177,8 @@ void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
* _PAGE_PRESENT, but we can be sure that it is not in hpte.
* Hence we can use set_pte_at for them.
*/
VM_WARN_ON((pte_val(*ptep) & (_PAGE_PRESENT | _PAGE_USER)) ==
(_PAGE_PRESENT | _PAGE_USER));
VM_WARN_ON(pte_present(*ptep) && !pte_protnone(*ptep));
/*
* Add the pte bit when tryint set a pte
*/

View File

@ -277,7 +277,7 @@ void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size,
void *caller = __builtin_return_address(0);
/* writeable implies dirty for kernel addresses */
if (flags & _PAGE_RW)
if (flags & _PAGE_WRITE)
flags |= _PAGE_DIRTY;
/* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
@ -676,8 +676,7 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
#ifdef CONFIG_DEBUG_VM
WARN_ON((pmd_val(*pmdp) & (_PAGE_PRESENT | _PAGE_USER)) ==
(_PAGE_PRESENT | _PAGE_USER));
WARN_ON(pte_present(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
assert_spin_locked(&mm->page_table_lock);
WARN_ON(!pmd_trans_huge(pmd));
#endif

View File

@ -197,7 +197,7 @@ static int __spu_trap_data_map(struct spu *spu, unsigned long ea, u64 dsisr)
(REGION_ID(ea) != USER_REGION_ID)) {
spin_unlock(&spu->register_lock);
ret = hash_page(ea, _PAGE_PRESENT, 0x300, dsisr);
ret = hash_page(ea, _PAGE_PRESENT | _PAGE_READ, 0x300, dsisr);
spin_lock(&spu->register_lock);
if (!ret) {

View File

@ -141,8 +141,8 @@ int spufs_handle_class1(struct spu_context *ctx)
/* we must not hold the lock when entering copro_handle_mm_fault */
spu_release(ctx);
access = (_PAGE_PRESENT | _PAGE_USER);
access |= (dsisr & MFC_DSISR_ACCESS_PUT) ? _PAGE_RW : 0UL;
access = (_PAGE_PRESENT | _PAGE_READ | _PAGE_USER);
access |= (dsisr & MFC_DSISR_ACCESS_PUT) ? _PAGE_WRITE : 0UL;
local_irq_save(flags);
ret = hash_page(ea, access, 0x300, dsisr);
local_irq_restore(flags);

View File

@ -149,9 +149,9 @@ static void cxl_handle_page_fault(struct cxl_context *ctx,
* update_mmu_cache() will not have loaded the hash since current->trap
* is not a 0x400 or 0x300, so just call hash_page_mm() here.
*/
access = _PAGE_PRESENT;
access = _PAGE_PRESENT | _PAGE_READ;
if (dsisr & CXL_PSL_DSISR_An_S)
access |= _PAGE_RW;
access |= _PAGE_WRITE;
if ((!ctx->kernel) || (REGION_ID(dar) == USER_REGION_ID))
access |= _PAGE_USER;