diff mbox series

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

Message ID 20240402075142.196265-2-wangkefeng.wang@huawei.com (mailing list archive)
State New, archived
Headers show
Series arch/mm/fault: accelerate pagefault when badaccess | expand

Commit Message

Kefeng Wang April 2, 2024, 7:51 a.m. UTC 
The __do_page_fault() only check vma->flags and call handle_mm_fault(),
and only called by do_page_fault(), let's squash it into do_page_fault()
to cleanup code.

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

Comments

Suren Baghdasaryan April 3, 2024, 5:11 a.m. UTC | #1 
On Tue, Apr 2, 2024 at 12:53 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>
> The __do_page_fault() only check vma->flags and call handle_mm_fault(),
> and only called by do_page_fault(), let's squash it into do_page_fault()
> to cleanup code.
>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>

Reviewed-by: Suren Baghdasaryan <surenb@google.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
>
Catalin Marinas April 3, 2024, 6:24 p.m. UTC | #2 
On Tue, Apr 02, 2024 at 03:51:36PM +0800, Kefeng Wang wrote:
> The __do_page_fault() only check vma->flags and call handle_mm_fault(),
> and only called by do_page_fault(), let's squash it into do_page_fault()
> to cleanup code.
> 
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
diff mbox series

Patch

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)) {