io_uring: add mapping support for NOMMU archs (6c5c240e) · Commits · 戴 / test

fs/io_uring.c

+51 −6

Original line number	Diff line number	Diff line
		@@ -4402,12 +4402,11 @@ static int io_uring_flush(struct file file, void data)
		return 0;
		}

		static int io_uring_mmap(struct file file, struct vm_area_struct vma)
		static void io_uring_validate_mmap_request(struct file file,
		loff_t pgoff, size_t sz)
		{
		loff_t offset = (loff_t) vma->vm_pgoff << PAGE_SHIFT;
		unsigned long sz = vma->vm_end - vma->vm_start;
		struct io_ring_ctx *ctx = file->private_data;
		unsigned long pfn;
		loff_t offset = pgoff << PAGE_SHIFT;
		struct page *page;
		void *ptr;

		@@ -4420,17 +4419,59 @@ static int io_uring_mmap(struct file file, struct vm_area_struct vma)
		ptr = ctx->sq_sqes;
		break;
		default:
		return -EINVAL;
		return ERR_PTR(-EINVAL);
		}

		page = virt_to_head_page(ptr);
		if (sz > page_size(page))
		return -EINVAL;
		return ERR_PTR(-EINVAL);

		return ptr;
		}

		#ifdef CONFIG_MMU

		static int io_uring_mmap(struct file file, struct vm_area_struct vma)
		{
		size_t sz = vma->vm_end - vma->vm_start;
		unsigned long pfn;
		void *ptr;

		ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz);
		if (IS_ERR(ptr))
		return PTR_ERR(ptr);

		pfn = virt_to_phys(ptr) >> PAGE_SHIFT;
		return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot);
		}

		#else /* !CONFIG_MMU */

		static int io_uring_mmap(struct file file, struct vm_area_struct vma)
		{
		return vma->vm_flags & (VM_SHARED \| VM_MAYSHARE) ? 0 : -EINVAL;
		}

		static unsigned int io_uring_nommu_mmap_capabilities(struct file *file)
		{
		return NOMMU_MAP_DIRECT \| NOMMU_MAP_READ \| NOMMU_MAP_WRITE;
		}

		static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,
		unsigned long addr, unsigned long len,
		unsigned long pgoff, unsigned long flags)
		{
		void *ptr;

		ptr = io_uring_validate_mmap_request(file, pgoff, len);
		if (IS_ERR(ptr))
		return PTR_ERR(ptr);

		return (unsigned long) ptr;
		}

		#endif /* !CONFIG_MMU */

		SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
		u32, min_complete, u32, flags, const sigset_t __user *, sig,
		size_t, sigsz)
		@@ -4501,6 +4542,10 @@ static const struct file_operations io_uring_fops = {
		.release = io_uring_release,
		.flush = io_uring_flush,
		.mmap = io_uring_mmap,
		#ifndef CONFIG_MMU
		.get_unmapped_area = io_uring_nommu_get_unmapped_area,
		.mmap_capabilities = io_uring_nommu_mmap_capabilities,
		#endif
		.poll = io_uring_poll,
		.fasync = io_uring_fasync,
		};

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