linux-kernel - [PATCH V2 2/4] arm64/mm: Drop task_struct argument from __do_page

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Date:   Mon,  3 Jun 2019 12:11:23 +0530
From:   Anshuman Khandual <anshuman.khandual@....com>
To:     linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Cc:     Anshuman Khandual <anshuman.khandual@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>,
        Mark Rutland <mark.rutland@....com>,
        James Morse <james.morse@....com>,
        Andrey Konovalov <andreyknvl@...gle.com>
Subject: [PATCH V2 2/4] arm64/mm: Drop task_struct argument from __do_page_fault()

The task_struct argument is not getting used in __do_page_fault(). Hence
just drop it and use current or cuurent->mm instead where ever required.
This does not change any functionality.

Signed-off-by: Anshuman Khandual <anshuman.khandual@....com>
Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will.deacon@....com>
Cc: Mark Rutland <mark.rutland@....com>
Cc: James Morse <james.morse@....com>
Cc: Andrey Konovalov <andreyknvl@...gle.com>
---
 arch/arm64/mm/fault.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index dc1cf32..da02678 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -395,8 +395,7 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re
 #define VM_FAULT_BADACCESS	0x020000
 
 static vm_fault_t __do_page_fault(struct mm_struct *mm, unsigned long addr,
-			   unsigned int mm_flags, unsigned long vm_flags,
-			   struct task_struct *tsk)
+			   unsigned int mm_flags, unsigned long vm_flags)
 {
 	struct vm_area_struct *vma;
 	vm_fault_t fault;
@@ -440,8 +439,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
 				   struct pt_regs *regs)
 {
 	const struct fault_info *inf;
-	struct task_struct *tsk;
-	struct mm_struct *mm;
+	struct mm_struct *mm = current->mm;
 	vm_fault_t fault, major = 0;
 	unsigned long vm_flags = VM_READ | VM_WRITE;
 	unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
@@ -449,9 +447,6 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
 	if (notify_page_fault(regs, esr))
 		return 0;
 
-	tsk = current;
-	mm  = tsk->mm;
-
 	/*
 	 * If we're in an interrupt or have no user context, we must not take
 	 * the fault.
@@ -510,7 +505,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
 #endif
 	}
 
-	fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk);
+	fault = __do_page_fault(mm, addr, mm_flags, vm_flags);
 	major |= fault & VM_FAULT_MAJOR;
 
 	if (fault & VM_FAULT_RETRY) {
@@ -550,11 +545,11 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
 		 * that point.
 		 */
 		if (major) {
-			tsk->maj_flt++;
+			current->maj_flt++;
 			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
 				      addr);
 		} else {
-			tsk->min_flt++;
+			current->min_flt++;
 			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs,
 				      addr);
 		}
-- 
2.7.4