riscv/mm/fault: Move bad area handling to bad_area() (a51271d9) · Commits · 戴 / test

arch/riscv/mm/fault.c

+40 −27

Original line number	Diff line number	Diff line
		@@ -37,6 +37,22 @@ static inline void no_context(struct pt_regs *regs, unsigned long addr)
		do_exit(SIGKILL);
		}

		static inline void bad_area(struct pt_regs regs, struct mm_struct mm, int code, unsigned long addr)
		{
		/*
		* Something tried to access memory that isn't in our memory map.
		* Fix it, but check if it's kernel or user first.
		*/
		mmap_read_unlock(mm);
		/* User mode accesses just cause a SIGSEGV */
		if (user_mode(regs)) {
		do_trap(regs, SIGSEGV, code, addr);
		return;
		}

		no_context(regs, addr);
		}

		/*
		* This routine handles page faults. It determines the address and the
		* problem, and then passes it off to one of the appropriate routines.
		@@ -90,14 +106,20 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
		retry:
		mmap_read_lock(mm);
		vma = find_vma(mm, addr);
		if (unlikely(!vma))
		goto bad_area;
		if (unlikely(!vma)) {
		bad_area(regs, mm, code, addr);
		return;
		}
		if (likely(vma->vm_start <= addr))
		goto good_area;
		if (unlikely(!(vma->vm_flags & VM_GROWSDOWN)))
		goto bad_area;
		if (unlikely(expand_stack(vma, addr)))
		goto bad_area;
		if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) {
		bad_area(regs, mm, code, addr);
		return;
		}
		if (unlikely(expand_stack(vma, addr))) {
		bad_area(regs, mm, code, addr);
		return;
		}

		/*
		* Ok, we have a good vm_area for this memory access, so
		@@ -108,16 +130,22 @@ good_area:

		switch (cause) {
		case EXC_INST_PAGE_FAULT:
		if (!(vma->vm_flags & VM_EXEC))
		goto bad_area;
		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))
		goto bad_area;
		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))
		goto bad_area;
		if (!(vma->vm_flags & VM_WRITE)) {
		bad_area(regs, mm, code, addr);
		return;
		}
		flags \|= FAULT_FLAG_WRITE;
		break;
		default:
		@@ -161,21 +189,6 @@ good_area:
		mmap_read_unlock(mm);
		return;

		/*
		* Something tried to access memory that isn't in our memory map.
		* Fix it, but check if it's kernel or user first.
		*/
		bad_area:
		mmap_read_unlock(mm);
		/* User mode accesses just cause a SIGSEGV */
		if (user_mode(regs)) {
		do_trap(regs, SIGSEGV, code, addr);
		return;
		}

		no_context(regs, addr);
		return;

		/*
		* We ran out of memory, call the OOM killer, and return the userspace
		* (which will retry the fault, or kill us if we got oom-killed).

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