The patch titled
Subject: selftests: vm: pkeys: add helpers for pkey bits
has been added to the -mm tree. Its filename is
selftests-vm-pkeys-add-helpers-for-pkey-bits.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/selftests-vm-pkeys-add-helpers-for-pkey-bits.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/selftests-vm-pkeys-add-helpers-for-pkey-bits.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Sandipan Das <sandipan@xxxxxxxxxxxxx>
Subject: selftests: vm: pkeys: add helpers for pkey bits
This introduces some functions that help with setting or clearing bits of
a particular pkey. This also adds an abstraction for getting a pkey's bit
position in the pkey register as this may vary across architectures.
Link: http://lkml.kernel.org/r/2ad9705f4f68ca7e72155cc583415e5a979546f1.1585646528.git.sandipan@xxxxxxxxxxxxx
Signed-off-by: Sandipan Das <sandipan@xxxxxxxxxxxxx>
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: "Desnes A. Nunes do Rosario" <desnesn@xxxxxxxxxxxxxxxxxx>
Cc: Florian Weimer <fweimer@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Ram Pai <linuxram@xxxxxxxxxx>
Cc: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Michal Suchanek <msuchanek@xxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/vm/pkey-helpers.h | 22 +++++++++++
tools/testing/selftests/vm/pkey-x86.h | 5 ++
tools/testing/selftests/vm/protection_keys.c | 32 ++++-------------
3 files changed, 36 insertions(+), 23 deletions(-)
--- a/tools/testing/selftests/vm/pkey-helpers.h~selftests-vm-pkeys-add-helpers-for-pkey-bits
+++ a/tools/testing/selftests/vm/pkey-helpers.h
@@ -80,6 +80,28 @@ extern void abort_hooks(void);
#error Architecture not supported
#endif /* arch */
+#define PKEY_MASK (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE)
+
+static inline u64 set_pkey_bits(u64 reg, int pkey, u64 flags)
+{
+ u32 shift = pkey_bit_position(pkey);
+ /* mask out bits from pkey in old value */
+ reg &= ~((u64)PKEY_MASK << shift);
+ /* OR in new bits for pkey */
+ reg |= (flags & PKEY_MASK) << shift;
+ return reg;
+}
+
+static inline u64 get_pkey_bits(u64 reg, int pkey)
+{
+ u32 shift = pkey_bit_position(pkey);
+ /*
+ * shift down the relevant bits to the lowest two, then
+ * mask off all the other higher bits
+ */
+ return ((reg >> shift) & PKEY_MASK);
+}
+
extern u64 shadow_pkey_reg;
static inline u64 _read_pkey_reg(int line)
--- a/tools/testing/selftests/vm/pkey-x86.h~selftests-vm-pkeys-add-helpers-for-pkey-bits
+++ a/tools/testing/selftests/vm/pkey-x86.h
@@ -118,6 +118,11 @@ static inline int cpu_has_pku(void)
return 1;
}
+static inline u32 pkey_bit_position(int pkey)
+{
+ return pkey * PKEY_BITS_PER_PKEY;
+}
+
#define XSTATE_PKEY_BIT (9)
#define XSTATE_PKEY 0x200
--- a/tools/testing/selftests/vm/protection_keys.c~selftests-vm-pkeys-add-helpers-for-pkey-bits
+++ a/tools/testing/selftests/vm/protection_keys.c
@@ -334,25 +334,13 @@ pid_t fork_lazy_child(void)
static u32 hw_pkey_get(int pkey, unsigned long flags)
{
- u32 mask = (PKEY_DISABLE_ACCESS|PKEY_DISABLE_WRITE);
u64 pkey_reg = __read_pkey_reg();
- u64 shifted_pkey_reg;
- u32 masked_pkey_reg;
dprintf1("%s(pkey=%d, flags=%lx) = %x / %d\n",
__func__, pkey, flags, 0, 0);
dprintf2("%s() raw pkey_reg: %016llx\n", __func__, pkey_reg);
- shifted_pkey_reg = (pkey_reg >> (pkey * PKEY_BITS_PER_PKEY));
- dprintf2("%s() shifted_pkey_reg: %016llx\n", __func__,
- shifted_pkey_reg);
- masked_pkey_reg = shifted_pkey_reg & mask;
- dprintf2("%s() masked pkey_reg: %x\n", __func__, masked_pkey_reg);
- /*
- * shift down the relevant bits to the lowest two, then
- * mask off all the other high bits.
- */
- return masked_pkey_reg;
+ return (u32) get_pkey_bits(pkey_reg, pkey);
}
static int hw_pkey_set(int pkey, unsigned long rights, unsigned long flags)
@@ -364,12 +352,8 @@ static int hw_pkey_set(int pkey, unsigne
/* make sure that 'rights' only contains the bits we expect: */
assert(!(rights & ~mask));
- /* copy old pkey_reg */
- new_pkey_reg = old_pkey_reg;
- /* mask out bits from pkey in old value: */
- new_pkey_reg &= ~(mask << (pkey * PKEY_BITS_PER_PKEY));
- /* OR in new bits for pkey: */
- new_pkey_reg |= (rights << (pkey * PKEY_BITS_PER_PKEY));
+ /* modify bits accordingly in old pkey_reg and assign it */
+ new_pkey_reg = set_pkey_bits(old_pkey_reg, pkey, rights);
__write_pkey_reg(new_pkey_reg);
@@ -403,7 +387,7 @@ void pkey_disable_set(int pkey, int flag
ret = hw_pkey_set(pkey, pkey_rights, syscall_flags);
assert(!ret);
/* pkey_reg and flags have the same format */
- shadow_pkey_reg |= flags << (pkey * 2);
+ shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
dprintf1("%s(%d) shadow: 0x%016llx\n",
__func__, pkey, shadow_pkey_reg);
@@ -437,7 +421,7 @@ void pkey_disable_clear(int pkey, int fl
pkey_rights |= flags;
ret = hw_pkey_set(pkey, pkey_rights, 0);
- shadow_pkey_reg &= ~(flags << (pkey * 2));
+ shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
pkey_assert(ret >= 0);
pkey_rights = hw_pkey_get(pkey, syscall_flags);
@@ -513,7 +497,8 @@ int alloc_pkey(void)
shadow_pkey_reg);
if (ret) {
/* clear both the bits: */
- shadow_pkey_reg &= ~(0x3 << (ret * 2));
+ shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, ret,
+ ~PKEY_MASK);
dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016llx"
" shadow: 0x%016llx\n",
__func__,
@@ -523,7 +508,8 @@ int alloc_pkey(void)
* move the new state in from init_val
* (remember, we cheated and init_val == pkey_reg format)
*/
- shadow_pkey_reg |= (init_val << (ret * 2));
+ shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, ret,
+ init_val);
}
dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016llx"
" shadow: 0x%016llx\n",
_
Patches currently in -mm which might be from sandipan@xxxxxxxxxxxxx are
selftests-vm-pkeys-use-sane-types-for-pkey-register.patch
selftests-vm-pkeys-add-helpers-for-pkey-bits.patch
selftests-vm-pkeys-use-the-correct-huge-page-size.patch
selftests-vm-pkeys-use-the-correct-page-size-on-powerpc.patch
selftests-vm-pkeys-fix-multilib-builds-for-x86.patch
