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From: Kefeng Wang <wangkefeng.wang@huawei.com>
To: Russell King <linux@armlinux.org.uk>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>
Cc: Alexander Potapenko <glider@google.com>,
	Marco Elver <elver@google.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: [PATCH v2 2/3] ARM: mm: Provide is_write_fault()
Date: Wed, 3 Nov 2021 21:38:44 +0800	[thread overview]
Message-ID: <20211103133845.78528-3-wangkefeng.wang@huawei.com> (raw)
In-Reply-To: <20211103133845.78528-1-wangkefeng.wang@huawei.com>

The function will check whether the fault is caused by a write access.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 arch/arm/mm/fault.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index bc8779d54a64..f7ab6dabe89f 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -207,6 +207,11 @@ static inline bool is_permission_fault(unsigned int fsr)
 	return false;
 }
 
+static inline bool is_write_fault(unsigned int fsr)
+{
+	return (fsr & FSR_WRITE) && !(fsr & FSR_CM);
+}
+
 static vm_fault_t __kprobes
 __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int flags,
 		unsigned long vma_flags, struct pt_regs *regs)
@@ -261,7 +266,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	if (user_mode(regs))
 		flags |= FAULT_FLAG_USER;
 
-	if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) {
+	if (is_write_fault(fsr)) {
 		flags |= FAULT_FLAG_WRITE;
 		vm_flags = VM_WRITE;
 	}
-- 
2.26.2


  parent reply	other threads:[~2021-11-03 13:26 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-03 13:38 [PATCH v2 0/3] ARM: Support KFENCE feature Kefeng Wang
2021-11-03 13:38 ` [PATCH v2 1/3] ARM: mm: Provide set_memory_valid() Kefeng Wang
2021-11-03 13:38 ` Kefeng Wang [this message]
2021-11-03 13:38 ` [PATCH v2 3/3] ARM: Support KFENCE for ARM Kefeng Wang
2021-11-03 16:22   ` Alexander Potapenko
2021-11-04  1:14     ` Kefeng Wang
2021-11-04  7:00 ` [PATCH v2 0/3] ARM: Support KFENCE feature Marco Elver
2021-11-04  7:17   ` Kefeng Wang
2021-11-04 12:12 ` Russell King (Oracle)
2021-11-04 12:38   ` Kefeng Wang

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