Merge tag 'for-linus-20191129' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "I wasn't going to send this one off so soon, but unfortunately one of
  the fixes from the previous pull broke the build on some archs. So I'm
  sending this sooner rather than later. This contains:

   - Add highmem.h include for io_uring, because of the kmap() additions
     from last round. For some reason the build bot didn't spot this
     even though it sat for days.

   - Three minor ';' removals

   - Add support for the Beurer CD-on-a-chip device

   - Make io_uring work on MMU-less archs"

* tag 'for-linus-20191129' of git://git.kernel.dk/linux-block:
  io_uring: fix missing kmap() declaration on powerpc
  ataflop: Remove unneeded semicolon
  block: sunvdc: Remove unneeded semicolon
  drbd: Remove unneeded semicolon
  io_uring: add mapping support for NOMMU archs
  sr_vendor: support Beurer GL50 evo CD-on-a-chip devices.
  cdrom: respect device capabilities during opening action

1 files changed, 52 insertions, 6 deletions

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 2c2e8c25da01..ec53aa7cdc94 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -69,6 +69,7 @@
 #include <linux/nospec.h>
 #include <linux/sizes.h>
 #include <linux/hugetlb.h>
+#include <linux/highmem.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/io_uring.h>
@@ -4469,12 +4470,11 @@ 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;
 
@@ -4487,17 +4487,59 @@ 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)
@@ -4568,6 +4610,10 @@ 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,
 };