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From:   Chen Ni <vulab@iscas.ac.cn>
To:     peterz@infradead.org, mingo@redhat.com, acme@kernel.org,
        mark.rutland@arm.com, alexander.shishkin@linux.intel.com,
        jolsa@redhat.com, namhyung@kernel.org
Cc:     linux-kernel@vger.kernel.org, Xu Wang <vulab@iscas.ac.cn>
Subject: [PATCH] kernel: events: use offset_in_page macro
Date:   Tue, 30 Jun 2020 07:42:58 +0000
Message-Id: <20200630074258.8301-1-vulab@iscas.ac.cn>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Xu Wang <vulab@iscas.ac.cn>

Use offset_in_page macro instead of (addr & ~PAGE_MASK).

Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
---
 kernel/events/uprobes.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index bb0862873dba..44d175d81ed6 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -244,14 +244,14 @@ bool __weak is_trap_insn(uprobe_opcode_t *insn)
 static void copy_from_page(struct page *page, unsigned long vaddr, void *dst, int len)
 {
 	void *kaddr = kmap_atomic(page);
-	memcpy(dst, kaddr + (vaddr & ~PAGE_MASK), len);
+	memcpy(dst, kaddr + offset_in_page(vaddr), len);
 	kunmap_atomic(kaddr);
 }
 
 static void copy_to_page(struct page *page, unsigned long vaddr, const void *src, int len)
 {
 	void *kaddr = kmap_atomic(page);
-	memcpy(kaddr + (vaddr & ~PAGE_MASK), src, len);
+	memcpy(kaddr + offset_in_page(vaddr), src, len);
 	kunmap_atomic(kaddr);
 }
 
@@ -387,7 +387,7 @@ __update_ref_ctr(struct mm_struct *mm, unsigned long vaddr, short d)
 	}
 
 	kaddr = kmap_atomic(page);
-	ptr = kaddr + (vaddr & ~PAGE_MASK);
+	ptr = kaddr + offset_in_page(vaddr);
 
 	if (unlikely(*ptr + d < 0)) {
 		pr_warn("ref_ctr going negative. vaddr: 0x%lx, "
-- 
2.17.1