[PATCH v2 1/7] arm64: mm: cleanup __do_page_fault()

Kefeng Wang wangkefeng.wang at huawei.com
Wed Apr 3 01:37:59 PDT 2024


The __do_page_fault() only calls handle_mm_fault() after vm_flags
checked, and it is only called by do_page_fault(), let's squash
it into do_page_fault() to cleanup code.

Reviewed-by: Suren Baghdasaryan <surenb at google.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang at huawei.com>
---
 arch/arm64/mm/fault.c | 27 +++++++--------------------
 1 file changed, 7 insertions(+), 20 deletions(-)

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 8251e2fea9c7..9bb9f395351a 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -486,25 +486,6 @@ static void do_bad_area(unsigned long far, unsigned long esr,
 	}
 }
 
-#define VM_FAULT_BADMAP		((__force vm_fault_t)0x010000)
-#define VM_FAULT_BADACCESS	((__force vm_fault_t)0x020000)
-
-static vm_fault_t __do_page_fault(struct mm_struct *mm,
-				  struct vm_area_struct *vma, unsigned long addr,
-				  unsigned int mm_flags, unsigned long vm_flags,
-				  struct pt_regs *regs)
-{
-	/*
-	 * Ok, we have a good vm_area for this memory access, so we can handle
-	 * it.
-	 * Check that the permissions on the VMA allow for the fault which
-	 * occurred.
-	 */
-	if (!(vma->vm_flags & vm_flags))
-		return VM_FAULT_BADACCESS;
-	return handle_mm_fault(vma, addr, mm_flags, regs);
-}
-
 static bool is_el0_instruction_abort(unsigned long esr)
 {
 	return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW;
@@ -519,6 +500,9 @@ static bool is_write_abort(unsigned long esr)
 	return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM);
 }
 
+#define VM_FAULT_BADMAP		((__force vm_fault_t)0x010000)
+#define VM_FAULT_BADACCESS	((__force vm_fault_t)0x020000)
+
 static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
 				   struct pt_regs *regs)
 {
@@ -617,7 +601,10 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
 		goto done;
 	}
 
-	fault = __do_page_fault(mm, vma, addr, mm_flags, vm_flags, regs);
+	if (!(vma->vm_flags & vm_flags))
+		fault = VM_FAULT_BADACCESS;
+	else
+		fault = handle_mm_fault(vma, addr, mm_flags, regs);
 
 	/* Quick path to respond to signals */
 	if (fault_signal_pending(fault, regs)) {
-- 
2.27.0




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