[PATCH 4.9 117/128] sparc64: fix misuses of access_process_vm() in genregs32_[sg]et()

From: Al Viro viro@zeniv.linux.org.uk

commit 142cd25293f6a7ecbdff4fb0af17de6438d46433 upstream.

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@kernel.org Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- arch/sparc/kernel/ptrace_64.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-)

--- a/arch/sparc/kernel/ptrace_64.c +++ b/arch/sparc/kernel/ptrace_64.c @@ -533,19 +533,13 @@ static int genregs32_get(struct task_str for (; count > 0 && pos < 32; count--) { if (access_process_vm(target, (unsigned long) - &reg_window[pos], + &reg_window[pos++], &reg, sizeof(reg), FOLL_FORCE) != sizeof(reg)) return -EFAULT; - if (access_process_vm(target, - (unsigned long) u, - &reg, sizeof(reg), - FOLL_FORCE | FOLL_WRITE) - != sizeof(reg)) + if (put_user(reg, u++)) return -EFAULT; - pos++; - u++; } } } @@ -645,12 +639,7 @@ static int genregs32_set(struct task_str } } else { for (; count > 0 && pos < 32; count--) { - if (access_process_vm(target, - (unsigned long) - u, - &reg, sizeof(reg), - FOLL_FORCE) - != sizeof(reg)) + if (get_user(reg, u++)) return -EFAULT; if (access_process_vm(target, (unsigned long)