From afb8c6fee8ce9b54b9c810eea0597ef6a876abb7 Mon Sep 17 00:00:00 2001
From: Pekka Enberg <penberg@kernel.org>
Date: Tue, 25 Aug 2020 19:41:17 +0300
Subject: [PATCH] riscv/mm/fault: Move access error check to function
Move the access error check into a access_error() function to simplify
the control flow in do_page_fault().
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
arch/riscv/mm/fault.c | 48 ++++++++++++++++++++++++-------------------
1 file changed, 27 insertions(+), 21 deletions(-)
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index bdc70d3d507f1..a23eaf5ce95c8 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -156,6 +156,30 @@ static void inline vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
local_flush_tlb_page(addr);
}
+static inline bool access_error(unsigned long cause, struct vm_area_struct *vma)
+{
+ switch (cause) {
+ case EXC_INST_PAGE_FAULT:
+ if (!(vma->vm_flags & VM_EXEC)) {
+ return true;
+ }
+ break;
+ case EXC_LOAD_PAGE_FAULT:
+ if (!(vma->vm_flags & VM_READ)) {
+ return true;
+ }
+ break;
+ case EXC_STORE_PAGE_FAULT:
+ if (!(vma->vm_flags & VM_WRITE)) {
+ return true;
+ }
+ break;
+ default:
+ panic("%s: unhandled cause %lu", __func__, cause);
+ }
+ return false;
+}
+
/*
* This routine handles page faults. It determines the address and the
* problem, and then passes it off to one of the appropriate routines.
@@ -236,27 +260,9 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
good_area:
code = SEGV_ACCERR;
- switch (cause) {
- case EXC_INST_PAGE_FAULT:
- if (!(vma->vm_flags & VM_EXEC)) {
- bad_area(regs, mm, code, addr);
- return;
- }
- break;
- case EXC_LOAD_PAGE_FAULT:
- if (!(vma->vm_flags & VM_READ)) {
- bad_area(regs, mm, code, addr);
- return;
- }
- break;
- case EXC_STORE_PAGE_FAULT:
- if (!(vma->vm_flags & VM_WRITE)) {
- bad_area(regs, mm, code, addr);
- return;
- }
- break;
- default:
- panic("%s: unhandled cause %lu", __func__, cause);
+ if (unlikely(access_error(cause, vma))) {
+ bad_area(regs, mm, code, addr);
+ return;
}
/*
--
GitLab