[SPARC64]: Fix user accesses in regset code.

If target is not current we need to use access_process_vm().

Noticed by Roland McGrath.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 115 insertions, 21 deletions

diff --git a/arch/sparc64/kernel/ptrace.c b/arch/sparc64/kernel/ptrace.c
index aaae865e7932..7963595c77cc 100644
--- a/arch/sparc64/kernel/ptrace.c
+++ b/arch/sparc64/kernel/ptrace.c
@@ -138,8 +138,17 @@ static int genregs64_get(struct task_struct *target,
                         (regs->u_regs[UREG_I6] + STACK_BIAS);
                 unsigned long window[16];
 
-                if (copy_from_user(window, reg_window, sizeof(window)))
-                        return -EFAULT;
+                if (target == current) {
+                        if (copy_from_user(window, reg_window, sizeof(window)))
+                                return -EFAULT;
+                } else {
+                        if (access_process_vm(target,
+                                              (unsigned long) reg_window,
+                                              window,
+                                              sizeof(window), 0) !=
+                            sizeof(window))
+                                return -EFAULT;
+                }
 
                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
                                           window,
@@ -190,16 +199,37 @@ static int genregs64_set(struct task_struct *target,
                         (regs->u_regs[UREG_I6] + STACK_BIAS);
                 unsigned long window[16];
 
-                if (copy_from_user(window, reg_window, sizeof(window)))
-                        return -EFAULT;
+                if (target == current) {
+                        if (copy_from_user(window, reg_window, sizeof(window)))
+                                return -EFAULT;
+                } else {
+                        if (access_process_vm(target,
+                                              (unsigned long) reg_window,
+                                              window,
+                                              sizeof(window), 0) !=
+                            sizeof(window))
+                                return -EFAULT;
+                }
 
                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                          window,
                                          16 * sizeof(u64),
                                          32 * sizeof(u64));
-                if (!ret &&
-                    copy_to_user(reg_window, window, sizeof(window)))
-                        return -EFAULT;
+                if (!ret) {
+                        if (target == current) {
+                                if (copy_to_user(reg_window, window,
+                                                 sizeof(window)))
+                                        return -EFAULT;
+                        } else {
+                                if (access_process_vm(target,
+                                                      (unsigned long)
+                                                      reg_window,
+                                                      window,
+                                                      sizeof(window), 1) !=
+                                    sizeof(window))
+                                        return -EFAULT;
+                        }
+                }
         }
 
         if (!ret && count > 0) {
@@ -412,9 +442,22 @@ static int genregs32_get(struct task_struct *target,
                         *k++ = regs->u_regs[pos++];
 
                 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
-                for (; count > 0 && pos < 32; count--) {
-                        if (get_user(*k++, &reg_window[pos++]))
-                                return -EFAULT;
+                if (target == current) {
+                        for (; count > 0 && pos < 32; count--) {
+                                if (get_user(*k++, &reg_window[pos++]))
+                                        return -EFAULT;
+                        }
+                } else {
+                        for (; count > 0 && pos < 32; count--) {
+                                if (access_process_vm(target,
+                                                      (unsigned long)
+                                                      &reg_window[pos],
+                                                      k, sizeof(*k), 0)
+                                    != sizeof(*k))
+                                        return -EFAULT;
+                                k++;
+                                pos++;
+                        }
                 }
         } else {
                 for (; count > 0 && pos < 16; count--) {
@@ -423,10 +466,28 @@ static int genregs32_get(struct task_struct *target,
                 }
 
                 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
-                for (; count > 0 && pos < 32; count--) {
-                        if (get_user(reg, &reg_window[pos++]) ||
-                            put_user(reg, u++))
-                                return -EFAULT;
+                if (target == current) {
+                        for (; count > 0 && pos < 32; count--) {
+                                if (get_user(reg, &reg_window[pos++]) ||
+                                    put_user(reg, u++))
+                                        return -EFAULT;
+                        }
+                } else {
+                        for (; count > 0 && pos < 32; count--) {
+                                if (access_process_vm(target,
+                                                      (unsigned long)
+                                                      &reg_window[pos],
+                                                      &reg, sizeof(reg), 0)
+                                    != sizeof(reg))
+                                        return -EFAULT;
+                                if (access_process_vm(target,
+                                                      (unsigned long) u,
+                                                      &reg, sizeof(reg), 1)
+                                    != sizeof(reg))
+                                        return -EFAULT;
+                                pos++;
+                                u++;
+                        }
                 }
         }
         while (count > 0) {
@@ -488,9 +549,23 @@ static int genregs32_set(struct task_struct *target,
                         regs->u_regs[pos++] = *k++;
 
                 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
-                for (; count > 0 && pos < 32; count--) {
-                        if (put_user(*k++, &reg_window[pos++]))
-                                return -EFAULT;
+                if (target == current) {
+                        for (; count > 0 && pos < 32; count--) {
+                                if (put_user(*k++, &reg_window[pos++]))
+                                        return -EFAULT;
+                        }
+                } else {
+                        for (; count > 0 && pos < 32; count--) {
+                                if (access_process_vm(target,
+                                                      (unsigned long)
+                                                      &reg_window[pos],
+                                                      (void *) k,
+                                                      sizeof(*k), 1)
+                                    != sizeof(*k))
+                                        return -EFAULT;
+                                k++;
+                                pos++;
+                        }
                 }
         } else {
                 for (; count > 0 && pos < 16; count--) {
@@ -500,10 +575,29 @@ static int genregs32_set(struct task_struct *target,
                 }
 
                 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
-                for (; count > 0 && pos < 32; count--) {
-                        if (get_user(reg, u++) ||
-                            put_user(reg, &reg_window[pos++]))
-                                return -EFAULT;
+                if (target == current) {
+                        for (; count > 0 && pos < 32; count--) {
+                                if (get_user(reg, u++) ||
+                                    put_user(reg, &reg_window[pos++]))
+                                        return -EFAULT;
+                        }
+                } else {
+                        for (; count > 0 && pos < 32; count--) {
+                                if (access_process_vm(target,
+                                                      (unsigned long)
+                                                      u,
+                                                      &reg, sizeof(reg), 0)
+                                    != sizeof(reg))
+                                        return -EFAULT;
+                                if (access_process_vm(target,
+                                                      (unsigned long)
+                                                      &reg_window[pos],
+                                                      &reg, sizeof(reg), 1)
+                                    != sizeof(reg))
+                                        return -EFAULT;
+                                pos++;
+                                u++;
+                        }
                 }
         }
         while (count > 0) {