linux-kernel - [PATCH v3 2/6] ARM: mm: Kill task_struct argument for __do_page

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Date:   Thu, 10 Jun 2021 20:35:52 +0800
From:   Kefeng Wang <wangkefeng.wang@...wei.com>
To:     Russell King <linux@...linux.org.uk>,
        <linux-arm-kernel@...ts.infradead.org>
CC:     Catalin Marinas <catalin.marinas@....com>,
        <linux-kernel@...r.kernel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Jungseung Lee <js07.lee@...il.com>,
        Will Deacon <will@...nel.org>,
        Kefeng Wang <wangkefeng.wang@...wei.com>
Subject: [PATCH v3 2/6] ARM: mm: Kill task_struct argument for __do_page_fault()

The __do_page_fault() won't use task_struct argument, kill it
and also use current->mm directly in do_page_fault().

No functional change.

Signed-off-by: Kefeng Wang <wangkefeng.wang@...wei.com>
---
 arch/arm/mm/fault.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 662ac3ca3c8a..249db395bdf0 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -202,8 +202,7 @@ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
 
 static vm_fault_t __kprobes
 __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
-		unsigned int flags, struct task_struct *tsk,
-		struct pt_regs *regs)
+		unsigned int flags, struct pt_regs *regs)
 {
 	struct vm_area_struct *vma = find_vma(mm, addr);
 	if (unlikely(!vma))
@@ -231,8 +230,7 @@ __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
 static int __kprobes
 do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
-	struct task_struct *tsk;
-	struct mm_struct *mm;
+	struct mm_struct *mm = current->mm;
 	int sig, code;
 	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_DEFAULT;
@@ -240,8 +238,6 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	if (kprobe_page_fault(regs, fsr))
 		return 0;
 
-	tsk = current;
-	mm  = tsk->mm;
 
 	/* Enable interrupts if they were enabled in the parent context. */
 	if (interrupts_enabled(regs))
@@ -285,7 +281,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 #endif
 	}
 
-	fault = __do_page_fault(mm, addr, fsr, flags, tsk, regs);
+	fault = __do_page_fault(mm, addr, fsr, flags, regs);
 
 	/* If we need to retry but a fatal signal is pending, handle the
 	 * signal first. We do not need to release the mmap_lock because
-- 
2.26.2