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@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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.
@@ -511,7 +506,7 @@ 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) {
@@ -551,11 +546,11 @@ 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);
 		}