* [PATCH 27/37] mm, multi-arch: pass a protection key in to calc_vm_flag_bits()
2015-11-17 3:35 [PATCH 00/37] x86: Memory Protection Keys Dave Hansen
@ 2015-11-17 3:35 ` Dave Hansen
2015-11-17 3:35 ` [PATCH 29/37] mm: implement new mprotect_key() system call Dave Hansen
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Dave Hansen @ 2015-11-17 3:35 UTC (permalink / raw)
To: linux-kernel; +Cc: x86, Dave Hansen, dave.hansen, linux-api, linux-arch
From: Dave Hansen <dave.hansen@linux.intel.com>
This plumbs a protection key through calc_vm_flag_bits(). We
could have 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.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-api@vger.kernel.org
Cc: linux-arch@vger.kernel.org
---
b/arch/powerpc/include/asm/mman.h | 5 +++--
b/drivers/char/agp/frontend.c | 2 +-
b/drivers/staging/android/ashmem.c | 4 ++--
b/include/linux/mman.h | 6 +++---
b/mm/mmap.c | 2 +-
b/mm/mprotect.c | 2 +-
b/mm/nommu.c | 2 +-
7 files changed, 12 insertions(+), 11 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 2015-11-16 12:36:26.421490430 -0800
+++ b/arch/powerpc/include/asm/mman.h 2015-11-16 12:36:26.434491019 -0800
@@ -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 2015-11-16 12:36:26.423490520 -0800
+++ b/drivers/char/agp/frontend.c 2015-11-16 12:36:26.435491065 -0800
@@ -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 2015-11-16 12:36:26.424490566 -0800
+++ b/drivers/staging/android/ashmem.c 2015-11-16 12:36:26.435491065 -0800
@@ -372,8 +372,8 @@ 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 2015-11-16 12:36:26.426490656 -0800
+++ b/include/linux/mman.h 2015-11-16 12:36:26.436491110 -0800
@@ -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 2015-11-16 12:36:26.428490747 -0800
+++ b/mm/mmap.c 2015-11-16 12:36:26.437491156 -0800
@@ -1309,7 +1309,7 @@ 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 2015-11-16 12:36:26.429490793 -0800
+++ b/mm/mprotect.c 2015-11-16 19:22:07.781660707 -0800
@@ -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(¤t->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 2015-11-16 12:36:26.431490883 -0800
+++ b/mm/nommu.c 2015-11-16 12:36:26.438491201 -0800
@@ -1081,7 +1081,7 @@ 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)) {
_
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH 29/37] mm: implement new mprotect_key() system call
2015-11-17 3:35 [PATCH 00/37] x86: Memory Protection Keys Dave Hansen
2015-11-17 3:35 ` [PATCH 27/37] mm, multi-arch: pass a protection key in to calc_vm_flag_bits() Dave Hansen
@ 2015-11-17 3:35 ` Dave Hansen
2015-11-17 3:35 ` [PATCH 31/37] x86: wire up " Dave Hansen
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Dave Hansen @ 2015-11-17 3:35 UTC (permalink / raw)
To: linux-kernel; +Cc: x86, Dave Hansen, dave.hansen, linux-api
From: Dave Hansen <dave.hansen@linux.intel.com>
mprotect_key() is just like mprotect, except it also takes a
protection key as an argument. On systems that do not support
protection keys, it still works, but requires that key=0.
Otherwise it does exactly what mprotect does.
I expect it to get used like this, if you want to guarantee that
any mapping you create can *never* be accessed without the right
protection keys set up.
pkey_deny_access(11); // random pkey
int real_prot = PROT_READ|PROT_WRITE;
ptr = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
ret = mprotect_key(ptr, PAGE_SIZE, real_prot, 11);
This way, there is *no* window where the mapping is accessible
since it was always either PROT_NONE or had a protection key set.
We settled on 'unsigned long' for the type of the key here. We
only need 4 bits on x86 today, but I figured that other
architectures might need some more space.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-api@vger.kernel.org
---
b/arch/x86/include/asm/mmu_context.h | 10 +++++++--
b/include/linux/pkeys.h | 7 +++++-
b/mm/Kconfig | 7 ++++++
b/mm/mprotect.c | 36 +++++++++++++++++++++++++++++------
4 files changed, 51 insertions(+), 9 deletions(-)
diff -puN arch/x86/include/asm/mmu_context.h~pkeys-85-mprotect_pkey arch/x86/include/asm/mmu_context.h
--- a/arch/x86/include/asm/mmu_context.h~pkeys-85-mprotect_pkey 2015-11-16 12:36:28.811598913 -0800
+++ b/arch/x86/include/asm/mmu_context.h 2015-11-16 19:22:01.920396860 -0800
@@ -4,6 +4,7 @@
#include <asm/desc.h>
#include <linux/atomic.h>
#include <linux/mm_types.h>
+#include <linux/pkeys.h>
#include <trace/events/tlb.h>
@@ -243,10 +244,14 @@ static inline void arch_unmap(struct mm_
mpx_notify_unmap(mm, vma, start, end);
}
+#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+/*
+ * If the config option is off, we get the generic version from
+ * include/linux/pkeys.h.
+ */
static inline int vma_pkey(struct vm_area_struct *vma)
{
u16 pkey = 0;
-#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
unsigned long vma_pkey_mask = VM_PKEY_BIT0 | VM_PKEY_BIT1 |
VM_PKEY_BIT2 | VM_PKEY_BIT3;
/*
@@ -259,9 +264,10 @@ static inline int vma_pkey(struct vm_are
*/
pkey = (vma->vm_flags >> vm_pkey_shift) &
(vma_pkey_mask >> vm_pkey_shift);
-#endif
+
return pkey;
}
+#endif
static inline bool __pkru_allows_pkey(u16 pkey, bool write)
{
diff -puN include/linux/pkeys.h~pkeys-85-mprotect_pkey include/linux/pkeys.h
--- a/include/linux/pkeys.h~pkeys-85-mprotect_pkey 2015-11-16 12:36:28.812598958 -0800
+++ b/include/linux/pkeys.h 2015-11-16 19:22:05.259547173 -0800
@@ -2,10 +2,10 @@
#define _LINUX_PKEYS_H
#include <linux/mm_types.h>
-#include <asm/mmu_context.h>
#ifdef CONFIG_ARCH_HAS_PKEYS
#include <asm/pkeys.h>
+#include <asm/mmu_context.h>
#else /* ! CONFIG_ARCH_HAS_PKEYS */
/*
@@ -17,6 +17,11 @@ static inline bool arch_validate_pkey(in
{
return true;
}
+
+static inline int vma_pkey(struct vm_area_struct *vma)
+{
+ return 0;
+}
#endif /* ! CONFIG_ARCH_HAS_PKEYS */
#endif /* _LINUX_PKEYS_H */
diff -puN mm/Kconfig~pkeys-85-mprotect_pkey mm/Kconfig
--- a/mm/Kconfig~pkeys-85-mprotect_pkey 2015-11-16 12:36:28.814599049 -0800
+++ b/mm/Kconfig 2015-11-16 19:22:03.862484284 -0800
@@ -673,3 +673,10 @@ config ARCH_USES_HIGH_VMA_FLAGS
bool
config ARCH_HAS_PKEYS
bool
+
+config NR_PROTECTION_KEYS
+ int
+ # Everything supports a _single_ key, so allow folks to
+ # at least call APIs that take keys, but require that the
+ # key be 0.
+ default 1
diff -puN mm/mprotect.c~pkeys-85-mprotect_pkey mm/mprotect.c
--- a/mm/mprotect.c~pkeys-85-mprotect_pkey 2015-11-16 12:36:28.816599140 -0800
+++ b/mm/mprotect.c 2015-11-16 19:22:05.259547173 -0800
@@ -24,6 +24,7 @@
#include <linux/migrate.h>
#include <linux/perf_event.h>
#include <linux/ksm.h>
+#include <linux/pkeys.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
@@ -344,10 +345,13 @@ fail:
return error;
}
-SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
- unsigned long, prot)
+/*
+ * pkey=-1 when doing a legacy mprotect()
+ */
+static int do_mprotect_pkey(unsigned long start, size_t len,
+ unsigned long prot, int pkey)
{
- unsigned long vm_flags, nstart, end, tmp, reqprot;
+ unsigned long nstart, end, tmp, reqprot;
struct vm_area_struct *vma, *prev;
int error = -EINVAL;
const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP);
@@ -373,8 +377,6 @@ SYSCALL_DEFINE3(mprotect, unsigned long,
if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
prot |= PROT_EXEC;
- vm_flags = calc_vm_prot_bits(prot, 0);
-
down_write(¤t->mm->mmap_sem);
vma = find_vma(current->mm, start);
@@ -407,7 +409,14 @@ SYSCALL_DEFINE3(mprotect, unsigned long,
/* Here we know that vma->vm_start <= nstart < vma->vm_end. */
- newflags = vm_flags;
+ /*
+ * If this is a vanilla, non-pkey mprotect, inherit the
+ * pkey from the VMA we are working on.
+ */
+ if (pkey == -1)
+ newflags = calc_vm_prot_bits(prot, vma_pkey(vma));
+ else
+ newflags = calc_vm_prot_bits(prot, pkey);
newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
/* newflags >> 4 shift VM_MAY% in place of VM_% */
@@ -443,3 +452,18 @@ out:
up_write(¤t->mm->mmap_sem);
return error;
}
+
+SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
+ unsigned long, prot)
+{
+ return do_mprotect_pkey(start, len, prot, -1);
+}
+
+SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len,
+ unsigned long, prot, int, pkey)
+{
+ if (!arch_validate_pkey(pkey))
+ return -EINVAL;
+
+ return do_mprotect_pkey(start, len, prot, pkey);
+}
_
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH 31/37] x86: wire up mprotect_key() system call
2015-11-17 3:35 [PATCH 00/37] x86: Memory Protection Keys Dave Hansen
2015-11-17 3:35 ` [PATCH 27/37] mm, multi-arch: pass a protection key in to calc_vm_flag_bits() Dave Hansen
2015-11-17 3:35 ` [PATCH 29/37] mm: implement new mprotect_key() system call Dave Hansen
@ 2015-11-17 3:35 ` Dave Hansen
2015-11-17 3:35 ` [PATCH 34/37] x86, pkeys: allocation/free syscalls Dave Hansen
2015-11-17 3:36 ` [PATCH 35/37] x86, pkeys: add pkey set/get syscalls Dave Hansen
4 siblings, 0 replies; 6+ messages in thread
From: Dave Hansen @ 2015-11-17 3:35 UTC (permalink / raw)
To: linux-kernel; +Cc: x86, Dave Hansen, dave.hansen, linux-api
From: Dave Hansen <dave.hansen@linux.intel.com>
This is all that we need to get the new system call itself
working on x86.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-api@vger.kernel.org
---
b/arch/x86/entry/syscalls/syscall_32.tbl | 1 +
b/arch/x86/entry/syscalls/syscall_64.tbl | 1 +
b/arch/x86/include/uapi/asm/mman.h | 6 ++++++
b/mm/Kconfig | 1 +
4 files changed, 9 insertions(+)
diff -puN arch/x86/entry/syscalls/syscall_32.tbl~pkeys-16-x86-mprotect_key arch/x86/entry/syscalls/syscall_32.tbl
--- a/arch/x86/entry/syscalls/syscall_32.tbl~pkeys-16-x86-mprotect_key 2015-11-16 12:36:30.650682386 -0800
+++ b/arch/x86/entry/syscalls/syscall_32.tbl 2015-11-16 19:21:56.328145123 -0800
@@ -383,3 +383,4 @@
374 i386 userfaultfd sys_userfaultfd
375 i386 membarrier sys_membarrier
376 i386 mlock2 sys_mlock2
+377 i386 pkey_mprotect sys_pkey_mprotect
diff -puN arch/x86/entry/syscalls/syscall_64.tbl~pkeys-16-x86-mprotect_key arch/x86/entry/syscalls/syscall_64.tbl
--- a/arch/x86/entry/syscalls/syscall_64.tbl~pkeys-16-x86-mprotect_key 2015-11-16 12:36:30.652682477 -0800
+++ b/arch/x86/entry/syscalls/syscall_64.tbl 2015-11-16 19:21:56.328145123 -0800
@@ -332,6 +332,7 @@
323 common userfaultfd sys_userfaultfd
324 common membarrier sys_membarrier
325 common mlock2 sys_mlock2
+326 common pkey_mprotect sys_pkey_mprotect
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff -puN arch/x86/include/uapi/asm/mman.h~pkeys-16-x86-mprotect_key arch/x86/include/uapi/asm/mman.h
--- a/arch/x86/include/uapi/asm/mman.h~pkeys-16-x86-mprotect_key 2015-11-16 12:36:30.653682522 -0800
+++ b/arch/x86/include/uapi/asm/mman.h 2015-11-16 12:36:30.659682794 -0800
@@ -20,6 +20,12 @@
((vm_flags) & VM_PKEY_BIT1 ? _PAGE_PKEY_BIT1 : 0) | \
((vm_flags) & VM_PKEY_BIT2 ? _PAGE_PKEY_BIT2 : 0) | \
((vm_flags) & VM_PKEY_BIT3 ? _PAGE_PKEY_BIT3 : 0))
+
+#define arch_calc_vm_prot_bits(prot, key) ( \
+ ((key) & 0x1 ? VM_PKEY_BIT0 : 0) | \
+ ((key) & 0x2 ? VM_PKEY_BIT1 : 0) | \
+ ((key) & 0x4 ? VM_PKEY_BIT2 : 0) | \
+ ((key) & 0x8 ? VM_PKEY_BIT3 : 0))
#endif
#include <asm-generic/mman.h>
diff -puN mm/Kconfig~pkeys-16-x86-mprotect_key mm/Kconfig
--- a/mm/Kconfig~pkeys-16-x86-mprotect_key 2015-11-16 12:36:30.655682613 -0800
+++ b/mm/Kconfig 2015-11-16 12:36:30.659682794 -0800
@@ -679,4 +679,5 @@ config NR_PROTECTION_KEYS
# Everything supports a _single_ key, so allow folks to
# at least call APIs that take keys, but require that the
# key be 0.
+ default 16 if X86_INTEL_MEMORY_PROTECTION_KEYS
default 1
_
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 34/37] x86, pkeys: allocation/free syscalls
2015-11-17 3:35 [PATCH 00/37] x86: Memory Protection Keys Dave Hansen
` (2 preceding siblings ...)
2015-11-17 3:35 ` [PATCH 31/37] x86: wire up " Dave Hansen
@ 2015-11-17 3:35 ` Dave Hansen
2015-11-17 3:36 ` [PATCH 35/37] x86, pkeys: add pkey set/get syscalls Dave Hansen
4 siblings, 0 replies; 6+ messages in thread
From: Dave Hansen @ 2015-11-17 3:35 UTC (permalink / raw)
To: linux-kernel; +Cc: x86, Dave Hansen, dave.hansen, linux-api
From: Dave Hansen <dave.hansen@linux.intel.com>
This patch adds two new system calls:
int pkey_alloc(unsigned long flags, unsigned long init_access_rights)
int pkey_free(int pkey);
These establish which protection keys are valid for use by
userspace. A key which was not obtained by pkey_alloc() may not
be passed to pkey_mprotect().
In addition, the 'init_access_rights' argument to pkey_alloc() specifies
the rights that will be established for the returned pkey. For instance
pkey = pkey_alloc(flags, PKEY_DENY_WRITE);
will return with the bits set in PKRU such that writing to 'pkey' is
already denied. This keeps userspace from needing to have knowledge
about manipulating PKRU. It is still free to do so if it wishes, but
it is no longer required.
The kernel does _not_ enforce that this interface must be used for
changes to PKRU, even for keys it does not control.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-api@vger.kernel.org
---
b/arch/x86/entry/syscalls/syscall_32.tbl | 2
b/arch/x86/entry/syscalls/syscall_64.tbl | 2
b/arch/x86/include/asm/mmu.h | 7 ++
b/arch/x86/include/asm/mmu_context.h | 8 +++
b/arch/x86/include/asm/pgtable.h | 5 +-
b/arch/x86/include/asm/pkeys.h | 55 ++++++++++++++++++++++
b/arch/x86/kernel/fpu/xstate.c | 75 +++++++++++++++++++++++++++++++
b/include/asm-generic/mm_hooks.h | 1
b/include/linux/pkeys.h | 23 +++++++++
b/include/uapi/asm-generic/mman-common.h | 5 ++
b/mm/mprotect.c | 55 ++++++++++++++++++++++
11 files changed, 236 insertions(+), 2 deletions(-)
diff -puN arch/x86/entry/syscalls/syscall_32.tbl~pkey-allocation-syscalls arch/x86/entry/syscalls/syscall_32.tbl
--- a/arch/x86/entry/syscalls/syscall_32.tbl~pkey-allocation-syscalls 2015-11-16 12:36:32.972787782 -0800
+++ b/arch/x86/entry/syscalls/syscall_32.tbl 2015-11-16 19:21:52.519973697 -0800
@@ -384,3 +384,5 @@
375 i386 membarrier sys_membarrier
376 i386 mlock2 sys_mlock2
377 i386 pkey_mprotect sys_pkey_mprotect
+378 i386 pkey_alloc sys_pkey_alloc
+379 i386 pkey_free sys_pkey_free
diff -puN arch/x86/entry/syscalls/syscall_64.tbl~pkey-allocation-syscalls arch/x86/entry/syscalls/syscall_64.tbl
--- a/arch/x86/entry/syscalls/syscall_64.tbl~pkey-allocation-syscalls 2015-11-16 12:36:32.973787828 -0800
+++ b/arch/x86/entry/syscalls/syscall_64.tbl 2015-11-16 19:21:52.520973742 -0800
@@ -333,6 +333,8 @@
324 common membarrier sys_membarrier
325 common mlock2 sys_mlock2
326 common pkey_mprotect sys_pkey_mprotect
+327 common pkey_alloc sys_pkey_alloc
+328 common pkey_free sys_pkey_free
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff -puN arch/x86/include/asm/mmu_context.h~pkey-allocation-syscalls arch/x86/include/asm/mmu_context.h
--- a/arch/x86/include/asm/mmu_context.h~pkey-allocation-syscalls 2015-11-16 12:36:32.975787919 -0800
+++ b/arch/x86/include/asm/mmu_context.h 2015-11-16 19:21:52.520973742 -0800
@@ -108,7 +108,12 @@ static inline void enter_lazy_tlb(struct
static inline int init_new_context(struct task_struct *tsk,
struct mm_struct *mm)
{
+#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+ /* pkey 0 is the default and always allocated */
+ mm->context.pkey_allocation_map = 0x1;
+#endif
init_new_context_ldt(tsk, mm);
+
return 0;
}
static inline void destroy_context(struct mm_struct *mm)
@@ -333,4 +338,7 @@ static inline bool arch_pte_access_permi
return __pkru_allows_pkey(pte_flags_pkey(pte_flags(pte)), write);
}
+extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
+ unsigned long init_val);
+
#endif /* _ASM_X86_MMU_CONTEXT_H */
diff -puN arch/x86/include/asm/mmu.h~pkey-allocation-syscalls arch/x86/include/asm/mmu.h
--- a/arch/x86/include/asm/mmu.h~pkey-allocation-syscalls 2015-11-16 12:36:32.976787964 -0800
+++ b/arch/x86/include/asm/mmu.h 2015-11-16 12:36:32.992788690 -0800
@@ -22,6 +22,13 @@ typedef struct {
void __user *vdso;
atomic_t perf_rdpmc_allowed; /* nonzero if rdpmc is allowed */
+#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+ /*
+ * One bit per protection key says whether userspace can
+ * use it or not. protected by mmap_sem.
+ */
+ u16 pkey_allocation_map;
+#endif
} mm_context_t;
#ifdef CONFIG_SMP
diff -puN arch/x86/include/asm/pgtable.h~pkey-allocation-syscalls arch/x86/include/asm/pgtable.h
--- a/arch/x86/include/asm/pgtable.h~pkey-allocation-syscalls 2015-11-16 12:36:32.978788055 -0800
+++ b/arch/x86/include/asm/pgtable.h 2015-11-16 12:36:32.992788690 -0800
@@ -912,16 +912,17 @@ static inline pte_t pte_swp_clear_soft_d
#define PKRU_AD_BIT 0x1
#define PKRU_WD_BIT 0x2
+#define PKRU_BITS_PER_PKEY 2
static inline bool __pkru_allows_read(u32 pkru, u16 pkey)
{
- int pkru_pkey_bits = pkey * 2;
+ int pkru_pkey_bits = pkey * PKRU_BITS_PER_PKEY;
return !(pkru & (PKRU_AD_BIT << pkru_pkey_bits));
}
static inline bool __pkru_allows_write(u32 pkru, u16 pkey)
{
- int pkru_pkey_bits = pkey * 2;
+ int pkru_pkey_bits = pkey * PKRU_BITS_PER_PKEY;
/*
* Access-disable disables writes too so we need to check
* both bits here.
diff -puN arch/x86/include/asm/pkeys.h~pkey-allocation-syscalls arch/x86/include/asm/pkeys.h
--- a/arch/x86/include/asm/pkeys.h~pkey-allocation-syscalls 2015-11-16 12:36:32.979788100 -0800
+++ b/arch/x86/include/asm/pkeys.h 2015-11-16 19:21:52.520973742 -0800
@@ -7,6 +7,61 @@
#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | VM_PKEY_BIT3)
+#define mm_pkey_allocation_map(mm) (mm->context.pkey_allocation_map)
+#define mm_set_pkey_allocated(mm, pkey) do { \
+ mm_pkey_allocation_map(mm) |= (1 << pkey); \
+} while (0)
+#define mm_set_pkey_free(mm, pkey) do { \
+ mm_pkey_allocation_map(mm) &= ~(1 << pkey); \
+} while (0)
+
+static inline
+bool mm_pkey_is_allocated(struct mm_struct *mm, unsigned long pkey)
+{
+ if (!arch_validate_pkey(pkey))
+ return true;
+
+ return mm_pkey_allocation_map(mm) & (1 << pkey);
+}
+
+static inline
+int mm_pkey_alloc(struct mm_struct *mm)
+{
+ int all_pkeys_mask = ((1 << arch_max_pkey()) - 1);
+ int ret;
+
+ /*
+ * Are we out of pkeys? We must handle this specially
+ * because ffz() behavior is undefined if there are no
+ * zeros.
+ */
+ if (mm_pkey_allocation_map(mm) == all_pkeys_mask)
+ return -1;
+
+ ret = ffz(mm_pkey_allocation_map(mm));
+
+ mm_set_pkey_allocated(mm, ret);
+
+ return ret;
+}
+
+static inline
+int mm_pkey_free(struct mm_struct *mm, int pkey)
+{
+ /*
+ * pkey 0 is special, always allocated and can never
+ * be freed.
+ */
+ if (!pkey || !arch_validate_pkey(pkey))
+ return -EINVAL;
+ if (!mm_pkey_is_allocated(mm, pkey))
+ return -EINVAL;
+
+ mm_set_pkey_free(mm, pkey);
+
+ return 0;
+}
+
#endif /*_ASM_X86_PKEYS_H */
diff -puN arch/x86/kernel/fpu/xstate.c~pkey-allocation-syscalls arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~pkey-allocation-syscalls 2015-11-16 12:36:32.981788191 -0800
+++ b/arch/x86/kernel/fpu/xstate.c 2015-11-16 19:21:52.521973787 -0800
@@ -5,6 +5,8 @@
*/
#include <linux/compat.h>
#include <linux/cpu.h>
+#include <linux/mman.h>
+#include <linux/pkeys.h>
#include <asm/fpu/api.h>
#include <asm/fpu/internal.h>
@@ -775,6 +777,7 @@ const void *get_xsave_field_ptr(int xsav
return get_xsave_addr(&fpu->state.xsave, xsave_state);
}
+#ifdef CONFIG_ARCH_HAS_PKEYS
/*
* Set xfeatures (aka XSTATE_BV) bit for a feature that we want
@@ -864,6 +867,78 @@ static void fpu__xfeature_set_state(int
preempt_disable();
fpu__restore(fpu);
preempt_enable();
+}
+
+#define NR_VALID_PKRU_BITS (CONFIG_NR_PROTECTION_KEYS * 2)
+#define PKRU_VALID_MASK (NR_VALID_PKRU_BITS - 1)
+
+/*
+ * This will go out and modify the XSAVE buffer so that PKRU is
+ * set to a particular state for access to 'pkey'.
+ *
+ * PKRU state does affect kernel access to user memory. We do
+ * not modfiy PKRU *itself* here, only the XSAVE state that will
+ * be restored in to PKRU when we return back to userspace.
+ */
+int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
+ unsigned long init_val)
+{
+ struct xregs_state *xsave = &tsk->thread.fpu.state.xsave;
+ struct pkru_state *old_pkru_state;
+ struct pkru_state new_pkru_state;
+ int pkey_shift = (pkey * PKRU_BITS_PER_PKEY);
+ u32 new_pkru_bits = 0;
+
+ if (!arch_validate_pkey(pkey))
+ return -EINVAL;
+ /*
+ * This check implies XSAVE support. OSPKE only gets
+ * set if we enable XSAVE and we enable PKU in XCR0.
+ */
+ if (!boot_cpu_has(X86_FEATURE_OSPKE))
+ return -EINVAL;
+
+ /* Set the bits we need in PKRU */
+ if (init_val & PKEY_DISABLE_ACCESS)
+ new_pkru_bits |= PKRU_AD_BIT;
+ if (init_val & PKEY_DISABLE_WRITE)
+ new_pkru_bits |= PKRU_WD_BIT;
+
+ /* Shift the bits in to the correct place in PKRU for pkey. */
+ new_pkru_bits <<= pkey_shift;
+
+ /* Locate old copy of the state in the xsave buffer */
+ old_pkru_state = get_xsave_addr(xsave, XFEATURE_MASK_PKRU);
+
+ /*
+ * When state is not in the buffer, it is in the init
+ * state, set it manually. Otherwise, copy out the old
+ * state.
+ */
+ if (!old_pkru_state)
+ new_pkru_state.pkru = 0;
+ else
+ new_pkru_state.pkru = old_pkru_state->pkru;
+
+ /* mask off any old bits in place */
+ new_pkru_state.pkru &= ~((PKRU_AD_BIT|PKRU_WD_BIT) << pkey_shift);
+ /* Set the newly-requested bits */
+ new_pkru_state.pkru |= new_pkru_bits;
+
+ /*
+ * We could theoretically live without zeroing pkru.pad.
+ * The current XSAVE feature state definition says that
+ * only bytes 0->3 are used. But we do not want to
+ * chance leaking kernel stack out to userspace in case a
+ * memcpy() of the whole xsave buffer was done.
+ *
+ * They're in the same cacheline anyway.
+ */
+ new_pkru_state.pad = 0;
+
+ fpu__xfeature_set_state(XFEATURE_MASK_PKRU, &new_pkru_state,
+ sizeof(new_pkru_state));
return 0;
}
+#endif /* CONFIG_ARCH_HAS_PKEYS */
diff -puN include/asm-generic/mm_hooks.h~pkey-allocation-syscalls include/asm-generic/mm_hooks.h
--- a/include/asm-generic/mm_hooks.h~pkey-allocation-syscalls 2015-11-16 12:36:32.983788282 -0800
+++ b/include/asm-generic/mm_hooks.h 2015-11-16 12:36:32.993788735 -0800
@@ -38,4 +38,5 @@ static inline bool arch_pte_access_permi
/* by default, allow everything */
return true;
}
+
#endif /* _ASM_GENERIC_MM_HOOKS_H */
diff -puN include/linux/pkeys.h~pkey-allocation-syscalls include/linux/pkeys.h
--- a/include/linux/pkeys.h~pkey-allocation-syscalls 2015-11-16 12:36:32.984788327 -0800
+++ b/include/linux/pkeys.h 2015-11-16 19:21:52.521973787 -0800
@@ -23,6 +23,29 @@ static inline int vma_pkey(struct vm_are
{
return 0;
}
+
+static inline bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey)
+{
+ return (pkey == 0);
+}
+
+static inline int mm_pkey_alloc(struct mm_struct *mm)
+{
+ return -1;
+}
+
+static inline int mm_pkey_free(struct mm_struct *mm, int pkey)
+{
+ WARN_ONCE(1, "free of protection key when disabled");
+ return -EINVAL;
+}
+
+static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
+ unsigned long init_val)
+{
+ return 0;
+}
+
#endif /* ! CONFIG_ARCH_HAS_PKEYS */
#endif /* _LINUX_PKEYS_H */
diff -puN include/uapi/asm-generic/mman-common.h~pkey-allocation-syscalls include/uapi/asm-generic/mman-common.h
--- a/include/uapi/asm-generic/mman-common.h~pkey-allocation-syscalls 2015-11-16 12:36:32.986788418 -0800
+++ b/include/uapi/asm-generic/mman-common.h 2015-11-16 12:36:32.994788781 -0800
@@ -71,4 +71,9 @@
#define MAP_HUGE_SHIFT 26
#define MAP_HUGE_MASK 0x3f
+#define PKEY_DISABLE_ACCESS 0x1
+#define PKEY_DISABLE_WRITE 0x2
+#define PKEY_ACCESS_MASK (PKEY_DISABLE_ACCESS |\
+ PKEY_DISABLE_WRITE)
+
#endif /* __ASM_GENERIC_MMAN_COMMON_H */
diff -puN mm/mprotect.c~pkey-allocation-syscalls mm/mprotect.c
--- a/mm/mprotect.c~pkey-allocation-syscalls 2015-11-16 12:36:32.988788509 -0800
+++ b/mm/mprotect.c 2015-11-16 19:21:52.522973832 -0800
@@ -23,11 +23,13 @@
#include <linux/mmu_notifier.h>
#include <linux/migrate.h>
#include <linux/perf_event.h>
+#include <linux/pkeys.h>
#include <linux/ksm.h>
#include <linux/pkeys.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
+#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
#include "internal.h"
@@ -379,6 +381,14 @@ static int do_mprotect_pkey(unsigned lon
down_write(¤t->mm->mmap_sem);
+ /*
+ * If userspace did not allocate the pkey, do not let
+ * them use it here.
+ */
+ error = -EINVAL;
+ if (!mm_pkey_is_allocated(current->mm, pkey))
+ goto out;
+
vma = find_vma(current->mm, start);
error = -ENOMEM;
if (!vma)
@@ -474,3 +484,48 @@ SYSCALL_DEFINE4(pkey_mprotect, unsigned
return do_mprotect_pkey(start, len, prot, pkey);
}
+
+SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val)
+{
+ int pkey;
+ int ret;
+
+ /* No flags supported yet. */
+ if (flags)
+ return -EINVAL;
+ /* check for unsupported init values */
+ if (init_val & ~PKEY_ACCESS_MASK)
+ return -EINVAL;
+
+ down_write(¤t->mm->mmap_sem);
+ pkey = mm_pkey_alloc(current->mm);
+
+ ret = -ENOSPC;
+ if (pkey == -1)
+ goto out;
+
+ ret = arch_set_user_pkey_access(current, pkey, init_val);
+ if (ret) {
+ mm_pkey_free(current->mm, pkey);
+ goto out;
+ }
+ ret = pkey;
+out:
+ up_write(¤t->mm->mmap_sem);
+ return ret;
+}
+
+SYSCALL_DEFINE1(pkey_free, int, pkey)
+{
+ int ret;
+
+ down_write(¤t->mm->mmap_sem);
+ ret = mm_pkey_free(current->mm, pkey);
+ up_write(¤t->mm->mmap_sem);
+
+ /*
+ * We could provie warnings or errors if any VMA still
+ * has the pkey set here.
+ */
+ return ret;
+}
_
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH 35/37] x86, pkeys: add pkey set/get syscalls
2015-11-17 3:35 [PATCH 00/37] x86: Memory Protection Keys Dave Hansen
` (3 preceding siblings ...)
2015-11-17 3:35 ` [PATCH 34/37] x86, pkeys: allocation/free syscalls Dave Hansen
@ 2015-11-17 3:36 ` Dave Hansen
4 siblings, 0 replies; 6+ messages in thread
From: Dave Hansen @ 2015-11-17 3:36 UTC (permalink / raw)
To: linux-kernel; +Cc: x86, Dave Hansen, dave.hansen, linux-api
From: Dave Hansen <dave.hansen@linux.intel.com>
This establishes two more system calls for protection key management:
unsigned long pkey_get(int pkey);
int pkey_set(int pkey, unsigned long access_rights);
The return value from pkey_get() and the 'access_rights' passed
to pkey_set() are the same format: a bitmask containing
PKEY_DENY_WRITE and/or PKEY_DENY_ACCESS, or nothing set at all.
These replace userspace's direct use of rdpkru/wrpkru.
With current hardware, the kernel can not enforce that it has
control over a given key. But, this at least allows the kernel
to indicate to userspace that userspace does not control a given
protection key.
The kernel does _not_ enforce that this interface must be used for
changes to PKRU, even for keys it has not "allocated".
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-api@vger.kernel.org
---
b/arch/x86/entry/syscalls/syscall_32.tbl | 2 +
b/arch/x86/entry/syscalls/syscall_64.tbl | 2 +
b/arch/x86/include/asm/mmu_context.h | 2 +
b/arch/x86/include/asm/pkeys.h | 2 -
b/arch/x86/kernel/fpu/xstate.c | 55 +++++++++++++++++++++++++++++--
b/include/linux/pkeys.h | 8 ++++
b/mm/mprotect.c | 34 +++++++++++++++++++
7 files changed, 102 insertions(+), 3 deletions(-)
diff -puN arch/x86/entry/syscalls/syscall_32.tbl~pkey-syscalls-set-get arch/x86/entry/syscalls/syscall_32.tbl
--- a/arch/x86/entry/syscalls/syscall_32.tbl~pkey-syscalls-set-get 2015-11-16 12:36:34.851873071 -0800
+++ b/arch/x86/entry/syscalls/syscall_32.tbl 2015-11-16 12:36:34.863873616 -0800
@@ -386,3 +386,5 @@
377 i386 pkey_mprotect sys_pkey_mprotect
378 i386 pkey_alloc sys_pkey_alloc
379 i386 pkey_free sys_pkey_free
+380 i386 pkey_get sys_pkey_get
+381 i386 pkey_set sys_pkey_set
diff -puN arch/x86/entry/syscalls/syscall_64.tbl~pkey-syscalls-set-get arch/x86/entry/syscalls/syscall_64.tbl
--- a/arch/x86/entry/syscalls/syscall_64.tbl~pkey-syscalls-set-get 2015-11-16 12:36:34.852873116 -0800
+++ b/arch/x86/entry/syscalls/syscall_64.tbl 2015-11-16 12:36:34.864873661 -0800
@@ -335,6 +335,8 @@
326 common pkey_mprotect sys_pkey_mprotect
327 common pkey_alloc sys_pkey_alloc
328 common pkey_free sys_pkey_free
+329 common pkey_get sys_pkey_get
+330 common pkey_set sys_pkey_set
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff -puN arch/x86/include/asm/mmu_context.h~pkey-syscalls-set-get arch/x86/include/asm/mmu_context.h
--- a/arch/x86/include/asm/mmu_context.h~pkey-syscalls-set-get 2015-11-16 12:36:34.854873207 -0800
+++ b/arch/x86/include/asm/mmu_context.h 2015-11-16 12:36:34.864873661 -0800
@@ -340,5 +340,7 @@ static inline bool arch_pte_access_permi
extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
unsigned long init_val);
+extern unsigned long arch_get_user_pkey_access(struct task_struct *tsk,
+ int pkey);
#endif /* _ASM_X86_MMU_CONTEXT_H */
diff -puN arch/x86/include/asm/pkeys.h~pkey-syscalls-set-get arch/x86/include/asm/pkeys.h
--- a/arch/x86/include/asm/pkeys.h~pkey-syscalls-set-get 2015-11-16 12:36:34.855873253 -0800
+++ b/arch/x86/include/asm/pkeys.h 2015-11-16 19:14:09.231117816 -0800
@@ -16,7 +16,7 @@
} while (0)
static inline
-bool mm_pkey_is_allocated(struct mm_struct *mm, unsigned long pkey)
+bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey)
{
if (!arch_validate_pkey(pkey))
return true;
diff -puN arch/x86/kernel/fpu/xstate.c~pkey-syscalls-set-get arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~pkey-syscalls-set-get 2015-11-16 12:36:34.857873343 -0800
+++ b/arch/x86/kernel/fpu/xstate.c 2015-11-16 12:36:34.865873706 -0800
@@ -687,7 +687,7 @@ void fpu__resume_cpu(void)
*
* Note: does not work for compacted buffers.
*/
-void *__raw_xsave_addr(struct xregs_state *xsave, int xstate_feature_mask)
+static void *__raw_xsave_addr(struct xregs_state *xsave, int xstate_feature_mask)
{
int feature_nr = fls64(xstate_feature_mask) - 1;
@@ -871,6 +871,7 @@ static void fpu__xfeature_set_state(int
#define NR_VALID_PKRU_BITS (CONFIG_NR_PROTECTION_KEYS * 2)
#define PKRU_VALID_MASK (NR_VALID_PKRU_BITS - 1)
+#define PKRU_INIT_STATE 0
/*
* This will go out and modify the XSAVE buffer so that PKRU is
@@ -889,6 +890,9 @@ int arch_set_user_pkey_access(struct tas
int pkey_shift = (pkey * PKRU_BITS_PER_PKEY);
u32 new_pkru_bits = 0;
+ /* Only support manipulating current task for now */
+ if (tsk != current)
+ return -EINVAL;
if (!arch_validate_pkey(pkey))
return -EINVAL;
/*
@@ -916,7 +920,7 @@ int arch_set_user_pkey_access(struct tas
* state.
*/
if (!old_pkru_state)
- new_pkru_state.pkru = 0;
+ new_pkru_state.pkru = PKRU_INIT_STATE;
else
new_pkru_state.pkru = old_pkru_state->pkru;
@@ -941,4 +945,51 @@ int arch_set_user_pkey_access(struct tas
return 0;
}
+
+/*
+ * Figures out what the rights are currently for 'pkey'.
+ * Converts from PKRU's format to the user-visible PKEY_DISABLE_*
+ * format.
+ */
+unsigned long arch_get_user_pkey_access(struct task_struct *tsk, int pkey)
+{
+ struct fpu *fpu = ¤t->thread.fpu;
+ u32 pkru_reg;
+ int ret = 0;
+
+ /* Only support manipulating current task for now */
+ if (tsk != current)
+ return -1;
+ if (!boot_cpu_has(X86_FEATURE_OSPKE))
+ return -1;
+ /*
+ * The contents of PKRU itself are invalid. Consult the
+ * task's XSAVE buffer for PKRU contents. This is much
+ * more expensive than reading PKRU directly, but should
+ * be rare or impossible with eagerfpu mode.
+ */
+ if (!fpu->fpregs_active) {
+ struct xregs_state *xsave = &fpu->state.xsave;
+ struct pkru_state *pkru_state =
+ get_xsave_addr(xsave, XFEATURE_MASK_PKRU);
+ /*
+ * PKRU is in its init state and not present in
+ * the buffer in a saved form.
+ */
+ if (!pkru_state)
+ return PKRU_INIT_STATE;
+
+ return pkru_state->pkru;
+ }
+ /*
+ * Consult the user register directly.
+ */
+ pkru_reg = read_pkru();
+ if (!__pkru_allows_read(pkru_reg, pkey))
+ ret |= PKEY_DISABLE_ACCESS;
+ if (!__pkru_allows_write(pkru_reg, pkey))
+ ret |= PKEY_DISABLE_WRITE;
+
+ return ret;
+}
#endif /* CONFIG_ARCH_HAS_PKEYS */
diff -puN include/linux/pkeys.h~pkey-syscalls-set-get include/linux/pkeys.h
--- a/include/linux/pkeys.h~pkey-syscalls-set-get 2015-11-16 12:36:34.858873389 -0800
+++ b/include/linux/pkeys.h 2015-11-16 12:36:34.865873706 -0800
@@ -43,6 +43,14 @@ static inline int mm_pkey_free(struct mm
static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
unsigned long init_val)
{
+ return -EINVAL;
+}
+
+static inline
+unsigned long arch_get_user_pkey_access(struct task_struct *tsk, int pkey)
+{
+ if (pkey)
+ return -1;
return 0;
}
diff -puN mm/mprotect.c~pkey-syscalls-set-get mm/mprotect.c
--- a/mm/mprotect.c~pkey-syscalls-set-get 2015-11-16 12:36:34.860873479 -0800
+++ b/mm/mprotect.c 2015-11-16 12:36:34.865873706 -0800
@@ -529,3 +529,37 @@ SYSCALL_DEFINE1(pkey_free, int, pkey)
*/
return ret;
}
+
+SYSCALL_DEFINE1(pkey_get, int, pkey)
+{
+ unsigned long ret = 0;
+
+ down_write(¤t->mm->mmap_sem);
+ if (!mm_pkey_is_allocated(current->mm, pkey))
+ ret = -EBADF;
+ up_write(¤t->mm->mmap_sem);
+
+ if (ret)
+ return ret;
+
+ ret = arch_get_user_pkey_access(current, pkey);
+
+ return ret;
+}
+
+SYSCALL_DEFINE2(pkey_set, int, pkey, unsigned long, access_rights)
+{
+ unsigned long ret = 0;
+
+ down_write(¤t->mm->mmap_sem);
+ if (!mm_pkey_is_allocated(current->mm, pkey))
+ ret = -EBADF;
+ up_write(¤t->mm->mmap_sem);
+
+ if (ret)
+ return ret;
+
+ ret = arch_set_user_pkey_access(current, pkey, access_rights);
+
+ return ret;
+}
_
^ permalink raw reply [flat|nested] 6+ messages in thread