1 files changed, 23 insertions, 9 deletions

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 3e926b9c0641..9fde010c945f 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -655,11 +655,16 @@ static int compat_gpr_get(struct task_struct *target,
                         reg = task_pt_regs(target)->regs[idx];
                 }
 
-                ret = copy_to_user(ubuf, &reg, sizeof(reg));
-                if (ret)
-                        break;
-
-                ubuf += sizeof(reg);
+                if (kbuf) {
+                        memcpy(kbuf, &reg, sizeof(reg));
+                        kbuf += sizeof(reg);
+                } else {
+                        ret = copy_to_user(ubuf, &reg, sizeof(reg));
+                        if (ret)
+                                break;
+
+                        ubuf += sizeof(reg);
+                }
         }
 
         return ret;
@@ -689,11 +694,16 @@ static int compat_gpr_set(struct task_struct *target,
                 unsigned int idx = start + i;
                 compat_ulong_t reg;
 
-                ret = copy_from_user(&reg, ubuf, sizeof(reg));
-                if (ret)
-                        return ret;
+                if (kbuf) {
+                        memcpy(&reg, kbuf, sizeof(reg));
+                        kbuf += sizeof(reg);
+                } else {
+                        ret = copy_from_user(&reg, ubuf, sizeof(reg));
+                        if (ret)
+                                return ret;
 
-                ubuf += sizeof(reg);
+                        ubuf += sizeof(reg);
+                }
 
                 switch (idx) {
                 case 15:
@@ -827,6 +837,7 @@ static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
                                     compat_ulong_t val)
 {
         int ret;
+        mm_segment_t old_fs = get_fs();
 
         if (off & 3 || off >= COMPAT_USER_SZ)
                 return -EIO;
@@ -834,10 +845,13 @@ static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
         if (off >= sizeof(compat_elf_gregset_t))
                 return 0;
 
+        set_fs(KERNEL_DS);
         ret = copy_regset_from_user(tsk, &user_aarch32_view,
                                     REGSET_COMPAT_GPR, off,
                                     sizeof(compat_ulong_t),
                                     &val);
+        set_fs(old_fs);
+
         return ret;
 }