[PATCH 4.4 067/135] sparc64: fix misuses of access_process_vm() in genregs32_[sg]et()

[Sasha Levin <sashal@xxxxxxxxxx>]

From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

[ Upstream commit 142cd25293f6a7ecbdff4fb0af17de6438d46433 ]

We do need access_process_vm() to access the target's reg_window.
However, access to caller's memory (storing the result in
genregs32_get(), fetching the new values in case of genregs32_set())
should be done by normal uaccess primitives.

Fixes: ad4f95764040 ([SPARC64]: Fix user accesses in regset code.)
Cc: stable@xxxxxxxxxx
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/sparc/kernel/ptrace_64.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/arch/sparc/kernel/ptrace_64.c b/arch/sparc/kernel/ptrace_64.c
index c1566170964f3..829592d5efe0b 100644
--- a/arch/sparc/kernel/ptrace_64.c
+++ b/arch/sparc/kernel/ptrace_64.c
@@ -534,13 +534,8 @@ static int genregs32_get(struct task_struct *target,
 						      &reg, sizeof(reg), 0)
 				    != sizeof(reg))
 					return -EFAULT;
-				if (access_process_vm(target,
-						      (unsigned long) u,
-						      &reg, sizeof(reg), 1)
-				    != sizeof(reg))
+				if (put_user(reg, u++))
 					return -EFAULT;
-				pos++;
-				u++;
 			}
 		}
 	}
@@ -639,11 +634,7 @@ static int genregs32_set(struct task_struct *target,
 			}
 		} else {
 			for (; count > 0 && pos < 32; count--) {
-				if (access_process_vm(target,
-						      (unsigned long)
-						      u,
-						      &reg, sizeof(reg), 0)
-				    != sizeof(reg))
+				if (get_user(reg, u++))
 					return -EFAULT;
 				if (access_process_vm(target,
 						      (unsigned long)
-- 
2.25.1