[PATCH V8 03/44] x86/pkeys: Create pkeys_common.h

ira.weiny
2022-01-27T17:55:37Z

From: Ira Weiny <ira.weiny@intel.com>

Protection Keys User (PKU) and Protection Keys Supervisor (PKS) work in
similar fashions and can share common defines. Specifically PKS and PKU
each have:

1. A single control register
2. The same number of keys
3. The same number of bits in the register per key
4. Access and Write disable in the same bit locations

Given the above, share all the macros that synthesize and manipulate
register values between the two features. Share these defines by moving
them into a new header, change their names to reflect the common use,
and include the header where needed.

Also while editing the code remove the use of 'we' from comments being
touched.

NOTE the checkpatch errors are ignored for the init_pkru_value to
align the values in the code.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes from v7:
Rebased onto latest
---
arch/x86/include/asm/pkeys_common.h | 11 +++++++++++
arch/x86/include/asm/pkru.h | 20 ++++++++------------
arch/x86/kernel/fpu/xstate.c | 10 +++++-----
arch/x86/mm/pkeys.c | 14 ++++++--------
4 files changed, 30 insertions(+), 25 deletions(-)
create mode 100644 arch/x86/include/asm/pkeys_common.h

diff --git a/arch/x86/include/asm/pkeys_common.h b/arch/x86/include/asm/pkeys_common.h
new file mode 100644
index 000000000000..08c736669244
--- /dev/null
+++ b/arch/x86/include/asm/pkeys_common.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_PKEYS_COMMON_H
+#define _ASM_X86_PKEYS_COMMON_H
+
+#define PKR_AD_BIT 0x1u
+#define PKR_WD_BIT 0x2u
+#define PKR_BITS_PER_PKEY 2
+
+#define PKR_AD_KEY(pkey) (PKR_AD_BIT << ((pkey) * PKR_BITS_PER_PKEY))
+
+#endif /*_ASM_X86_PKEYS_COMMON_H */
diff --git a/arch/x86/include/asm/pkru.h b/arch/x86/include/asm/pkru.h
index 74f0a2d34ffd..06980dd42946 100644
--- a/arch/x86/include/asm/pkru.h
+++ b/arch/x86/include/asm/pkru.h
@@ -3,10 +3,7 @@
#define _ASM_X86_PKRU_H

#include <asm/cpufeature.h>
-
-#define PKRU_AD_BIT 0x1u
-#define PKRU_WD_BIT 0x2u
-#define PKRU_BITS_PER_PKEY 2
+#include <asm/pkeys_common.h>

#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
extern u32 init_pkru_value;
@@ -18,18 +15,17 @@ extern u32 init_pkru_value;

static inline bool __pkru_allows_read(u32 pkru, u16 pkey)
{
- int pkru_pkey_bits = pkey * PKRU_BITS_PER_PKEY;
- return !(pkru & (PKRU_AD_BIT << pkru_pkey_bits));
+ int pkru_pkey_bits = pkey * PKR_BITS_PER_PKEY;
+
+ return !(pkru & (PKR_AD_BIT << pkru_pkey_bits));
}

static inline bool __pkru_allows_write(u32 pkru, u16 pkey)
{
- int pkru_pkey_bits = pkey * PKRU_BITS_PER_PKEY;
- /*
- * Access-disable disables writes too so we need to check
- * both bits here.
- */
- return !(pkru & ((PKRU_AD_BIT|PKRU_WD_BIT) << pkru_pkey_bits));
+ int pkru_pkey_bits = pkey * PKR_BITS_PER_PKEY;
+
+ /* Access-disable disables writes too so check both bits here. */
+ return !(pkru & ((PKR_AD_BIT|PKR_WD_BIT) << pkru_pkey_bits));
}

static inline u32 read_pkru(void)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 02b3ddaf4f75..d8ddd306d225 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -1089,19 +1089,19 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
if (WARN_ON_ONCE(pkey >= arch_max_pkey()))
return -EINVAL;

- /* Set the bits we need in PKRU: */
+ /* Set the bits needed in PKRU: */
if (init_val & PKEY_DISABLE_ACCESS)
- new_pkru_bits |= PKRU_AD_BIT;
+ new_pkru_bits |= PKR_AD_BIT;
if (init_val & PKEY_DISABLE_WRITE)
- new_pkru_bits |= PKRU_WD_BIT;
+ new_pkru_bits |= PKR_WD_BIT;

/* Shift the bits in to the correct place in PKRU for pkey: */
- pkey_shift = pkey * PKRU_BITS_PER_PKEY;
+ pkey_shift = pkey * PKR_BITS_PER_PKEY;
new_pkru_bits <<= pkey_shift;

/* Get old PKRU and mask off any old bits in place: */
old_pkru = read_pkru();
- old_pkru &= ~((PKRU_AD_BIT|PKRU_WD_BIT) << pkey_shift);
+ old_pkru &= ~((PKR_AD_BIT|PKR_WD_BIT) << pkey_shift);

/* Write old part along with new part: */
write_pkru(old_pkru | new_pkru_bits);
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index e44e938885b7..aa7042f272fb 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -110,19 +110,17 @@ int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot, int pkey
return vma_pkey(vma);
}

-#define PKRU_AD_KEY(pkey) (PKRU_AD_BIT << ((pkey) * PKRU_BITS_PER_PKEY))
-
/*
* Make the default PKRU value (at execve() time) as restrictive
* as possible. This ensures that any threads clone()'d early
* in the process's lifetime will not accidentally get access
* to data which is pkey-protected later on.
*/
-u32 init_pkru_value = PKRU_AD_KEY( 1) | PKRU_AD_KEY( 2) | PKRU_AD_KEY( 3) |
- PKRU_AD_KEY( 4) | PKRU_AD_KEY( 5) | PKRU_AD_KEY( 6) |
- PKRU_AD_KEY( 7) | PKRU_AD_KEY( 8) | PKRU_AD_KEY( 9) |
- PKRU_AD_KEY(10) | PKRU_AD_KEY(11) | PKRU_AD_KEY(12) |
- PKRU_AD_KEY(13) | PKRU_AD_KEY(14) | PKRU_AD_KEY(15);
+u32 init_pkru_value = PKR_AD_KEY( 1) | PKR_AD_KEY( 2) | PKR_AD_KEY( 3) |
+ PKR_AD_KEY( 4) | PKR_AD_KEY( 5) | PKR_AD_KEY( 6) |
+ PKR_AD_KEY( 7) | PKR_AD_KEY( 8) | PKR_AD_KEY( 9) |
+ PKR_AD_KEY(10) | PKR_AD_KEY(11) | PKR_AD_KEY(12) |
+ PKR_AD_KEY(13) | PKR_AD_KEY(14) | PKR_AD_KEY(15);

static ssize_t init_pkru_read_file(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
@@ -155,7 +153,7 @@ static ssize_t init_pkru_write_file(struct file *file,
* up immediately if someone attempts to disable access
* or writes to pkey 0.
*/
- if (new_init_pkru & (PKRU_AD_BIT|PKRU_WD_BIT))
+ if (new_init_pkru & (PKR_AD_BIT|PKR_WD_BIT))
return -EINVAL;

WRITE_ONCE(init_pkru_value, new_init_pkru);
--
2.31.1