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From:   Qing Zhang <zhangqing@loongson.cn>
To:     Huacai Chen <chenhuacai@kernel.org>,
        WANG Xuerui <kernel@xen0n.name>
Cc:     Jiaxun Yang <jiaxun.yang@flygoat.com>, loongarch@lists.linux.dev,
        linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] LoongArch: Add pad structure members for explicit alignment
Date:   Tue, 18 Apr 2023 17:13:48 +0800
Message-Id: <20230418091348.9239-1-zhangqing@loongson.cn>
MIME-Version: 1.0
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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 |  3 ++-
 arch/loongarch/kernel/ptrace.c           | 13 +++++++++----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/arch/loongarch/include/uapi/asm/ptrace.h b/arch/loongarch/include/uapi/asm/ptrace.h
index 2282ae1fd3b6..06e3be52cb04 100644
--- a/arch/loongarch/include/uapi/asm/ptrace.h
+++ b/arch/loongarch/include/uapi/asm/ptrace.h
@@ -57,11 +57,12 @@ struct user_lasx_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];
 };
 
diff --git a/arch/loongarch/kernel/ptrace.c b/arch/loongarch/kernel/ptrace.c
index 0c7c41e41cad..9c3bc1bbf2ff 100644
--- a/arch/loongarch/kernel/ptrace.c
+++ b/arch/loongarch/kernel/ptrace.c
@@ -475,10 +475,10 @@ 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:
@@ -616,7 +616,7 @@ 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;
@@ -646,6 +646,7 @@ 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++;
 	}
 
@@ -662,7 +663,7 @@ 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);
 
@@ -704,6 +705,10 @@ 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++;
 	}
 
-- 
2.20.1