Subject: [PATCH v5 02/10] powerpc/signal: Add unsafe_copy_{vsx, fpr}_from_user()

From: "Christopher M. Riedl" <[email-masked]>
Date: Wed, 3 Feb 2021 12:43:15 -0600

Reuse the "safe" implementation from signal.c except for calling
unsafe_copy_from_user() to copy into a local buffer.

Signed-off-by: Christopher M. Riedl <[email-masked]>
---
 arch/powerpc/kernel/signal.h | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index 2559a681536e..7dfc536c78ef 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -53,6 +53,30 @@ unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
 				&buf[i], label);\
 } while (0)
 
+#define unsafe_copy_fpr_from_user(task, from, label)	do {		\
+	struct task_struct *__t = task;					\
+	u64 __user *__f = (u64 __user *)from;				\
+	u64 buf[ELF_NFPREG];						\
+	int i;								\
+									\
+	unsafe_copy_from_user(buf, __f, sizeof(buf), label);		\
+	for (i = 0; i < ELF_NFPREG - 1; i++)				\
+		__t->thread.TS_FPR(i) = buf[i];				\
+	__t->thread.fp_state.fpscr = buf[i];				\
+} while (0)
+
+#define unsafe_copy_vsx_from_user(task, from, label)	do {		\
+	struct task_struct *__t = task;					\
+	u64 __user *__f = (u64 __user *)from;				\
+	u64 buf[ELF_NVSRHALFREG];					\
+	int i;								\
+									\
+	unsafe_copy_from_user(buf, __f, sizeof(buf), label);		\
+	for (i = 0; i < ELF_NVSRHALFREG ; i++)				\
+		__t->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];	\
+} while (0)
+
+
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 #define unsafe_copy_ckfpr_to_user(to, task, label)	do {		\
 	struct task_struct *__t = task;					\
@@ -80,6 +104,10 @@ unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
 	unsafe_copy_to_user(to, (task)->thread.fp_state.fpr,	\
 			    ELF_NFPREG * sizeof(double), label)
 
+#define unsafe_copy_fpr_from_user(task, from, label)			\
+	unsafe_copy_from_user((task)->thread.fp_state.fpr, from,	\
+			    ELF_NFPREG * sizeof(double), label)
+
 static inline unsigned long
 copy_fpr_to_user(void __user *to, struct task_struct *task)
 {
@@ -115,6 +143,8 @@ copy_ckfpr_from_user(struct task_struct *task, void __user *from)
 #else
 #define unsafe_copy_fpr_to_user(to, task, label) do { } while (0)
 
+#define unsafe_copy_fpr_from_user(task, from, label) do { } while (0)
+
 static inline unsigned long
 copy_fpr_to_user(void __user *to, struct task_struct *task)
 {
-- 
2.26.1