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.
cc: Dave Hansen dave.hansen@intel.com cc: Florian Weimer fweimer@redhat.com cc: Ram Pai linuxram@us.ibm.com cc: Thiago Jung Bauermann bauerman@linux.ibm.com Signed-off-by: Sandipan Das sandipan@linux.ibm.com --- 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(-)
diff --git a/tools/testing/selftests/vm/pkey-helpers.h b/tools/testing/selftests/vm/pkey-helpers.h index cc3491a6df2d..df4b46050393 100644 --- a/tools/testing/selftests/vm/pkey-helpers.h +++ b/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) diff --git a/tools/testing/selftests/vm/pkey-x86.h b/tools/testing/selftests/vm/pkey-x86.h index dc34ae21e714..f05e45ecaffb 100644 --- a/tools/testing/selftests/vm/pkey-x86.h +++ b/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
diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c index f36e9e7789ce..3ce5a87804ab 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); 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: %016lx\n", __func__, pkey_reg);
- shifted_pkey_reg = (pkey_reg >> (pkey * PKEY_BITS_PER_PKEY)); - dprintf2("%s() shifted_pkey_reg: %016lx\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%016lx\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%016lx" " shadow: 0x%016lx\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%016lx" " shadow: 0x%016lx\n",