LoongArch: Add pad structure members for explicit alignment

This is done in order to easily calculate the number of breakpoints
in hw_break_get.

Signed-off-by: Qing Zhang <zhangqing@loongson.cn>

arch/loongarch/include/uapi/asm/ptrace.h

@@ -47,11 +47,12 @@ struct user_fp_state {
 };
 
 struct user_watch_state {
-	uint16_t dbg_info;
+	uint64_t dbg_info;
 	struct {
 		uint64_t    addr;
 		uint64_t    mask;
 		uint32_t    ctrl;
+		uint32_t    pad;
 	} dbg_regs[8];
 };
 

arch/loongarch/kernel/ptrace.c

@@ -391,10 +391,10 @@ static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 	return 0;
 }
 
-static int ptrace_hbp_get_resource_info(unsigned int note_type, u16 *info)
+static int ptrace_hbp_get_resource_info(unsigned int note_type, u64 *info)
 {
 	u8 num;
-	u16 reg = 0;
+	u64 reg = 0;
 
 	switch (note_type) {
 	case NT_LOONGARCH_HW_BREAK:
@@ -532,7 +532,7 @@ static int hw_break_get(struct task_struct *target,
 			const struct user_regset *regset,
 			struct membuf to)
 {
-	u16 info;
+	u64 info;
 	u32 ctrl;
 	u64 addr, mask;
 	int ret, idx = 0;
@@ -562,6 +562,7 @@ static int hw_break_get(struct task_struct *target,
 		membuf_store(&to, addr);
 		membuf_store(&to, mask);
 		membuf_store(&to, ctrl);
+		membuf_zero(&to, sizeof(u32));
 		idx++;
 	}
 
@@ -578,7 +579,7 @@ static int hw_break_set(struct task_struct *target,
 	int ret, idx = 0, offset, limit;
 	unsigned int note_type = regset->core_note_type;
 
-	/* Resource info */
+	/* Resource info and pad */
 	offset = offsetof(struct user_watch_state, dbg_regs);
 	user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 
@@ -620,6 +621,10 @@ static int hw_break_set(struct task_struct *target,
 		if (ret)
 			return ret;
 		offset += PTRACE_HBP_CTRL_SZ;
+
+		user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+					  offset, offset + PTRACE_HBP_PAD_SZ);
+		offset += PTRACE_HBP_PAD_SZ;
 		idx++;
 	}