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From: Kefeng Wang <wangkefeng.wang@huawei.com>
To: Russell King <linux@armlinux.org.uk>,
	<linux-arm-kernel@lists.infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	<linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Jungseung Lee <js07.lee@gmail.com>,
	Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: [PATCH v2 1/7] ARM: mm: Rafactor the __do_page_fault()
Date: Wed, 2 Jun 2021 15:02:40 +0800	[thread overview]
Message-ID: <20210602070246.83990-2-wangkefeng.wang@huawei.com> (raw)
In-Reply-To: <20210602070246.83990-1-wangkefeng.wang@huawei.com>

Clean up the multiple goto statements and drops local variable
vm_fault_t fault, which will make the __do_page_fault() much
more readability.

No functional change.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 arch/arm/mm/fault.c | 34 +++++++++++++---------------------
 1 file changed, 13 insertions(+), 21 deletions(-)

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index efa402025031..662ac3ca3c8a 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -205,35 +205,27 @@ __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
 		unsigned int flags, struct task_struct *tsk,
 		struct pt_regs *regs)
 {
-	struct vm_area_struct *vma;
-	vm_fault_t fault;
-
-	vma = find_vma(mm, addr);
-	fault = VM_FAULT_BADMAP;
+	struct vm_area_struct *vma = find_vma(mm, addr);
 	if (unlikely(!vma))
-		goto out;
-	if (unlikely(vma->vm_start > addr))
-		goto check_stack;
+		return VM_FAULT_BADMAP;
+
+	if (unlikely(vma->vm_start > addr)) {
+		if (!(vma->vm_flags & VM_GROWSDOWN))
+			return VM_FAULT_BADMAP;
+		if (addr < FIRST_USER_ADDRESS)
+			return VM_FAULT_BADMAP;
+		if (expand_stack(vma, addr))
+			return VM_FAULT_BADMAP;
+	}
 
 	/*
 	 * Ok, we have a good vm_area for this
 	 * memory access, so we can handle it.
 	 */
-good_area:
-	if (access_error(fsr, vma)) {
-		fault = VM_FAULT_BADACCESS;
-		goto out;
-	}
+	if (access_error(fsr, vma))
+		return VM_FAULT_BADACCESS;
 
 	return handle_mm_fault(vma, addr & PAGE_MASK, flags, regs);
-
-check_stack:
-	/* Don't allow expansion below FIRST_USER_ADDRESS */
-	if (vma->vm_flags & VM_GROWSDOWN &&
-	    addr >= FIRST_USER_ADDRESS && !expand_stack(vma, addr))
-		goto good_area;
-out:
-	return fault;
 }
 
 static int __kprobes
-- 
2.26.2


  reply	other threads:[~2021-06-02  6:53 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-02  7:02 [PATCH v2 0/7] ARM: mm: cleanup page fault and fix pxn process issue Kefeng Wang
2021-06-02  7:02 ` Kefeng Wang [this message]
2021-06-02 10:29   ` [PATCH v2 1/7] ARM: mm: Rafactor the __do_page_fault() Russell King (Oracle)
2021-06-02  7:02 ` [PATCH v2 2/7] ARM: mm: Kill task_struct argument for __do_page_fault() Kefeng Wang
2021-06-02 10:31   ` Russell King (Oracle)
2021-06-02  7:02 ` [PATCH v2 3/7] ARM: mm: Cleanup access_error() Kefeng Wang
2021-06-02 10:39   ` Russell King (Oracle)
2021-06-02  7:02 ` [PATCH v2 4/7] ARM: mm: print out correct page table entries Kefeng Wang
2021-06-02 10:44   ` Russell King (Oracle)
2021-06-02 11:24     ` Kefeng Wang
2021-06-02  7:02 ` [PATCH v2 5/7] ARM: mm: Print physical address of page table base in show_pte() Kefeng Wang
2021-06-02 10:47   ` Russell King (Oracle)
2021-06-02 11:25     ` Kefeng Wang
2021-06-02  7:02 ` [PATCH v2 6/7] ARM: mm: Provide die_kernel_fault() helper Kefeng Wang
2021-06-02 10:49   ` Russell King (Oracle)
2021-06-02  7:02 ` [PATCH v2 7/7] ARM: mm: Fix PXN process with LPAE feature Kefeng Wang
2021-06-02 10:52   ` Russell King (Oracle)
2021-06-02 15:13     ` Kefeng Wang
2021-06-02 15:58       ` Russell King (Oracle)
2021-06-03  9:38         ` Kefeng Wang
2021-06-07  8:32           ` Kefeng Wang

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