@@ -24,6 +24,9 @@
#endif
#define arch_max_pkey() pkeys_total
+#define AMR_RD_BIT 0x1UL
+#define AMR_WR_BIT 0x2UL
+#define IAMR_EX_BIT 0x1UL
#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \
VM_PKEY_BIT3 | VM_PKEY_BIT4)
#define AMR_BITS_PER_PKEY 2
@@ -123,10 +126,14 @@ static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
return 0;
}
+extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
+ unsigned long init_val);
static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
unsigned long init_val)
{
- return 0;
+ if (!pkey_inited)
+ return -EINVAL;
+ return __arch_set_user_pkey_access(tsk, pkey, init_val);
}
static inline void pkey_mm_init(struct mm_struct *mm)
@@ -12,6 +12,7 @@
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
+#include <asm/mman.h>
#include <linux/pkeys.h> /* PKEY_* */
bool pkey_inited;
@@ -63,6 +64,11 @@ void __init pkey_initialize(void)
#define PKEY_REG_BITS (sizeof(u64)*8)
#define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey+1) * AMR_BITS_PER_PKEY))
+static bool is_pkey_enabled(int pkey)
+{
+ return !!(read_uamor() & (0x3ul << pkeyshift(pkey)));
+}
+
static inline void init_amr(int pkey, u8 init_bits)
{
u64 new_amr_bits = (((u64)init_bits & 0x3UL) << pkeyshift(pkey));
@@ -105,3 +111,25 @@ void __arch_deactivate_pkey(int pkey)
{
pkey_status_change(pkey, false);
}
+
+/*
+ * set the access right in AMR IAMR and UAMOR register
+ * for @pkey to that specified in @init_val.
+ */
+int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
+ unsigned long init_val)
+{
+ u64 new_amr_bits = 0x0ul;
+
+ if (!is_pkey_enabled(pkey))
+ return -EINVAL;
+
+ /* Set the bits we need in AMR: */
+ if (init_val & PKEY_DISABLE_ACCESS)
+ new_amr_bits |= AMR_RD_BIT | AMR_WR_BIT;
+ else if (init_val & PKEY_DISABLE_WRITE)
+ new_amr_bits |= AMR_WR_BIT;
+
+ init_amr(pkey, new_amr_bits);
+ return 0;
+}
This patch provides the detailed implementation for a user to allocate a key and enable it in the hardware. It provides the plumbing, but it cannot be used till the system call is implemented. The next patch will do so. Signed-off-by: Ram Pai <linuxram@us.ibm.com> --- arch/powerpc/include/asm/pkeys.h | 9 ++++++++- arch/powerpc/mm/pkeys.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+), 1 deletions(-)