diff options
Diffstat (limited to 'arch/powerpc/kernel/ptrace/ptrace-view.c')
| -rw-r--r-- | arch/powerpc/kernel/ptrace/ptrace-view.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/ptrace/ptrace-view.c b/arch/powerpc/kernel/ptrace/ptrace-view.c index 13208a9a02ca..19823a250aa0 100644 --- a/arch/powerpc/kernel/ptrace/ptrace-view.c +++ b/arch/powerpc/kernel/ptrace/ptrace-view.c @@ -470,13 +470,15 @@ static int pkey_active(struct task_struct *target, const struct user_regset *reg static int pkey_get(struct task_struct *target, const struct user_regset *regset, struct membuf to) { + int ret; + BUILD_BUG_ON(TSO(amr) + sizeof(unsigned long) != TSO(iamr)); - BUILD_BUG_ON(TSO(iamr) + sizeof(unsigned long) != TSO(uamor)); if (!arch_pkeys_enabled()) return -ENODEV; - return membuf_write(&to, &target->thread.amr, ELF_NPKEY * sizeof(unsigned long)); + membuf_write(&to, &target->thread.amr, 2 * sizeof(unsigned long)); + return membuf_store(&to, default_uamor); } static int pkey_set(struct task_struct *target, const struct user_regset *regset, @@ -498,9 +500,17 @@ static int pkey_set(struct task_struct *target, const struct user_regset *regset if (ret) return ret; - /* UAMOR determines which bits of the AMR can be set from userspace. */ - target->thread.amr = (new_amr & target->thread.uamor) | - (target->thread.amr & ~target->thread.uamor); + /* + * UAMOR determines which bits of the AMR can be set from userspace. + * UAMOR value 0b11 indicates that the AMR value can be modified + * from userspace. If the kernel is using a specific key, we avoid + * userspace modifying the AMR value for that key by masking them + * via UAMOR 0b00. + * + * Pick the AMR values for the keys that kernel is using. This + * will be indicated by the ~default_uamor bits. + */ + target->thread.amr = (new_amr & default_uamor) | (target->thread.amr & ~default_uamor); return 0; } |