[PATCH 19/26] [NEWSYSCALL] mm, multi-arch: pass a protection key in to calc_vm_flag_bits()

From: Dave Hansen
Date: Wed Sep 16 2015 - 13:58:44 EST



This plumbs a protection key through calc_vm_flag_bits().
We could of done this in calc_vm_prot_bits(), but I did not
feel super strongly which way to go. It was pretty arbitrary
which one to use.

---

b/arch/powerpc/include/asm/mman.h | 5 +++--
b/drivers/char/agp/frontend.c | 2 +-
b/drivers/staging/android/ashmem.c | 7 ++++---
b/include/linux/mman.h | 6 +++---
b/mm/mmap.c | 2 +-
b/mm/mprotect.c | 2 +-
b/mm/nommu.c | 2 +-
7 files changed, 14 insertions(+), 12 deletions(-)

diff -puN arch/powerpc/include/asm/mman.h~pkeys-84-calc_vm_prot_bits arch/powerpc/include/asm/mman.h
--- a/arch/powerpc/include/asm/mman.h~pkeys-84-calc_vm_prot_bits 2015-09-16 10:48:19.704348642 -0700
+++ b/arch/powerpc/include/asm/mman.h 2015-09-16 10:48:19.717349232 -0700
@@ -18,11 +18,12 @@
* This file is included by linux/mman.h, so we can't use cacl_vm_prot_bits()
* here. How important is the optimization?
*/
-static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot)
+static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
+ unsigned long pkey)
{
return (prot & PROT_SAO) ? VM_SAO : 0;
}
-#define arch_calc_vm_prot_bits(prot) arch_calc_vm_prot_bits(prot)
+#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)

static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
{
diff -puN drivers/char/agp/frontend.c~pkeys-84-calc_vm_prot_bits drivers/char/agp/frontend.c
--- a/drivers/char/agp/frontend.c~pkeys-84-calc_vm_prot_bits 2015-09-16 10:48:19.706348733 -0700
+++ b/drivers/char/agp/frontend.c 2015-09-16 10:48:19.718349277 -0700
@@ -156,7 +156,7 @@ static pgprot_t agp_convert_mmap_flags(i
{
unsigned long prot_bits;

- prot_bits = calc_vm_prot_bits(prot) | VM_SHARED;
+ prot_bits = calc_vm_prot_bits(prot, 0) | VM_SHARED;
return vm_get_page_prot(prot_bits);
}

diff -puN drivers/staging/android/ashmem.c~pkeys-84-calc_vm_prot_bits drivers/staging/android/ashmem.c
--- a/drivers/staging/android/ashmem.c~pkeys-84-calc_vm_prot_bits 2015-09-16 10:48:19.707348778 -0700
+++ b/drivers/staging/android/ashmem.c 2015-09-16 10:48:19.718349277 -0700
@@ -351,7 +351,8 @@ out:
return ret;
}

-static inline vm_flags_t calc_vm_may_flags(unsigned long prot)
+static inline vm_flags_t calc_vm_may_flags(unsigned long prot,
+ unsigned long pkey)
{
return _calc_vm_trans(prot, PROT_READ, VM_MAYREAD) |
_calc_vm_trans(prot, PROT_WRITE, VM_MAYWRITE) |
@@ -372,8 +373,8 @@ static int ashmem_mmap(struct file *file
}

/* requested protection bits must match our allowed protection mask */
- if (unlikely((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask)) &
- calc_vm_prot_bits(PROT_MASK))) {
+ if (unlikely((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask, 0)) &
+ calc_vm_prot_bits(PROT_MASK, 0))) {
ret = -EPERM;
goto out;
}
diff -puN include/linux/mman.h~pkeys-84-calc_vm_prot_bits include/linux/mman.h
--- a/include/linux/mman.h~pkeys-84-calc_vm_prot_bits 2015-09-16 10:48:19.709348869 -0700
+++ b/include/linux/mman.h 2015-09-16 10:48:19.719349322 -0700
@@ -35,7 +35,7 @@ static inline void vm_unacct_memory(long
*/

#ifndef arch_calc_vm_prot_bits
-#define arch_calc_vm_prot_bits(prot) 0
+#define arch_calc_vm_prot_bits(prot, pkey) 0
#endif

#ifndef arch_vm_get_page_prot
@@ -70,12 +70,12 @@ static inline int arch_validate_prot(uns
* Combine the mmap "prot" argument into "vm_flags" used internally.
*/
static inline unsigned long
-calc_vm_prot_bits(unsigned long prot)
+calc_vm_prot_bits(unsigned long prot, unsigned long pkey)
{
return _calc_vm_trans(prot, PROT_READ, VM_READ ) |
_calc_vm_trans(prot, PROT_WRITE, VM_WRITE) |
_calc_vm_trans(prot, PROT_EXEC, VM_EXEC) |
- arch_calc_vm_prot_bits(prot);
+ arch_calc_vm_prot_bits(prot, pkey);
}

/*
diff -puN mm/mmap.c~pkeys-84-calc_vm_prot_bits mm/mmap.c
--- a/mm/mmap.c~pkeys-84-calc_vm_prot_bits 2015-09-16 10:48:19.711348959 -0700
+++ b/mm/mmap.c 2015-09-16 10:48:19.720349367 -0700
@@ -1311,7 +1311,7 @@ unsigned long do_mmap(struct file *file,
* to. we assume access permissions have been handled by the open
* of the memory object, so we don't do any here.
*/
- vm_flags |= calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags) |
+ vm_flags |= calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags) |
mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;

if (flags & MAP_LOCKED)
diff -puN mm/mprotect.c~pkeys-84-calc_vm_prot_bits mm/mprotect.c
--- a/mm/mprotect.c~pkeys-84-calc_vm_prot_bits 2015-09-16 10:48:19.712349005 -0700
+++ b/mm/mprotect.c 2015-09-16 10:48:19.720349367 -0700
@@ -373,7 +373,7 @@ SYSCALL_DEFINE3(mprotect, unsigned long,
if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
prot |= PROT_EXEC;

- vm_flags = calc_vm_prot_bits(prot);
+ vm_flags = calc_vm_prot_bits(prot, 0);

down_write(&current->mm->mmap_sem);

diff -puN mm/nommu.c~pkeys-84-calc_vm_prot_bits mm/nommu.c
--- a/mm/nommu.c~pkeys-84-calc_vm_prot_bits 2015-09-16 10:48:19.714349096 -0700
+++ b/mm/nommu.c 2015-09-16 10:48:19.721349413 -0700
@@ -1084,7 +1084,7 @@ static unsigned long determine_vm_flags(
{
unsigned long vm_flags;

- vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags);
+ vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags);
/* vm_flags |= mm->def_flags; */

if (!(capabilities & NOMMU_MAP_DIRECT)) {
_
--
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