This introduces some functions that help with setting
or fetching 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.
cc: Dave Hansen <dave.hansen@xxxxxxxxx>
cc: Florian Weimer <fweimer@xxxxxxxxxx>
cc: Ram Pai <linuxram@xxxxxxxxxx>
Signed-off-by: Sandipan Das <sandipan@xxxxxxxxxxxxx>
---
tools/testing/selftests/vm/pkey-helpers.h | 23 ++++++++++++++
tools/testing/selftests/vm/pkey-x86.h | 5 +++
tools/testing/selftests/vm/protection_keys.c | 32 ++++++--------------
3 files changed, 37 insertions(+), 23 deletions(-)
diff --git a/tools/testing/selftests/vm/pkey-helpers.h b/tools/testing/selftests/vm/pkey-helpers.h
index 2a1a0240f684..bd90a49a3229 100644
--- a/tools/testing/selftests/vm/pkey-helpers.h
+++ b/tools/testing/selftests/vm/pkey-helpers.h
@@ -80,6 +80,29 @@ extern void abort_hooks(void);
#error Architecture not supported
#endif /* arch */
+#define PKEY_MASK (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE)
+
+static inline pkey_reg_t set_pkey_bits(pkey_reg_t reg, int pkey,
+ pkey_reg_t flags)
+{
+ u32 shift = pkey_bit_position(pkey);
+ /* mask out bits from pkey in old value */
+ reg &= ~((pkey_reg_t)PKEY_MASK << shift);
+ /* OR in new bits for pkey */
+ reg |= (flags & PKEY_MASK) << shift;
+ return reg;
+}
+
+static inline pkey_reg_t get_pkey_bits(pkey_reg_t 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 pkey_reg_t shadow_pkey_reg;
static inline pkey_reg_t _read_pkey_reg(int line)
diff --git a/tools/testing/selftests/vm/pkey-x86.h b/tools/testing/selftests/vm/pkey-x86.h
index 5f40901219d3..4937f48f77cc 100644
--- a/tools/testing/selftests/vm/pkey-x86.h
+++ b/tools/testing/selftests/vm/pkey-x86.h
@@ -120,6 +120,11 @@ 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
diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index 7e2148662fa4..b474d4fbe92b 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -333,25 +333,13 @@ pid_t fork_lazy_child(void)
static u32 hw_pkey_get(int pkey, unsigned long flags)
{
- u32 mask = (PKEY_DISABLE_ACCESS|PKEY_DISABLE_WRITE);
pkey_reg_t pkey_reg = __read_pkey_reg();
- pkey_reg_t 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: "PKEY_REG_FMT"\n", __func__, pkey_reg);
- shifted_pkey_reg = (pkey_reg >> (pkey * PKEY_BITS_PER_PKEY));
- dprintf2("%s() shifted_pkey_reg: "PKEY_REG_FMT"\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)
@@ -363,12 +351,8 @@ static int hw_pkey_set(int pkey, unsigned long rights, unsigned long flags)
/* 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);
@@ -402,7 +386,7 @@ void pkey_disable_set(int pkey, int flags)
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"PKEY_REG_FMT"\n",
__func__, pkey, shadow_pkey_reg);
@@ -436,7 +420,7 @@ void pkey_disable_clear(int pkey, int flags)
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);
@@ -512,7 +496,8 @@ 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"PKEY_REG_FMT
" shadow: 0x"PKEY_REG_FMT"\n",
__func__,
@@ -522,7 +507,8 @@ 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"PKEY_REG_FMT
" shadow: 0x"PKEY_REG_FMT"\n",
--
2.17.1
