Commit 6be5ceb0 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

VM: add "vm_mmap()" helper function 



This continues the theme started with vm_brk() and vm_munmap():
vm_mmap() does the same thing as do_mmap(), but additionally does the
required VM locking.

This uninlines (and rewrites it to be clearer) do_mmap(), which sadly
duplicates it in mm/mmap.c and mm/nommu.c.  But that way we don't have
to export our internal do_mmap_pgoff() function.

Some day we hopefully don't have to export do_mmap() either, if all
modular users can become the simpler vm_mmap() instead.  We're actually
very close to that already, with the notable exception of the (broken)
use in i810, and a couple of stragglers in binfmt_elf.

Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a46ef99d

arch/tile/kernel/single_step.c

+1 −3
Original line number Diff line number Diff line
@@ -346,12 +346,10 @@ void single_step_once(struct pt_regs *regs) 
		}



		/* allocate a cache line of writable, executable memory */

		down_write(&current->mm->mmap_sem);

		buffer = (void __user *) do_mmap(NULL, 0, 64,

		buffer = (void __user *) vm_mmap(NULL, 0, 64,

					  PROT_EXEC | PROT_READ | PROT_WRITE,

					  MAP_PRIVATE | MAP_ANONYMOUS,

					  0);

		up_write(&current->mm->mmap_sem);



		if (IS_ERR((void __force *)buffer)) {

			kfree(state);

arch/x86/ia32/ia32_aout.c

+3 −9
Original line number Diff line number Diff line
@@ -379,26 +379,22 @@ static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs) 
			goto beyond_if;

		}



		down_write(&current->mm->mmap_sem);

		error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,

		error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,

				PROT_READ | PROT_EXEC,

				MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |

				MAP_EXECUTABLE | MAP_32BIT,

				fd_offset);

		up_write(&current->mm->mmap_sem);



		if (error != N_TXTADDR(ex)) {

			send_sig(SIGKILL, current, 0);

			return error;

		}



		down_write(&current->mm->mmap_sem);

		error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,

		error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,

				PROT_READ | PROT_WRITE | PROT_EXEC,

				MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |

				MAP_EXECUTABLE | MAP_32BIT,

				fd_offset + ex.a_text);

		up_write(&current->mm->mmap_sem);

		if (error != N_DATADDR(ex)) {

			send_sig(SIGKILL, current, 0);

			return error;
@@ -482,12 +478,10 @@ static int load_aout_library(struct file *file) 
		goto out;

	}

	/* Now use mmap to map the library into memory. */

	down_write(&current->mm->mmap_sem);

	error = do_mmap(file, start_addr, ex.a_text + ex.a_data,

	error = vm_mmap(file, start_addr, ex.a_text + ex.a_data,

			PROT_READ | PROT_WRITE | PROT_EXEC,

			MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_32BIT,

			N_TXTOFF(ex));

	up_write(&current->mm->mmap_sem);

	retval = error;

	if (error != start_addr)

		goto out;

arch/x86/kvm/x86.c

+1 −3
Original line number Diff line number Diff line
@@ -6336,13 +6336,11 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, 
		if (npages && !old.rmap) {

			unsigned long userspace_addr;



			down_write(&current->mm->mmap_sem);

			userspace_addr = do_mmap(NULL, 0,

			userspace_addr = vm_mmap(NULL, 0,

						 npages * PAGE_SIZE,

						 PROT_READ | PROT_WRITE,

						 map_flags,

						 0);

			up_write(&current->mm->mmap_sem);



			if (IS_ERR((void *)userspace_addr))

				return PTR_ERR((void *)userspace_addr);

drivers/gpu/drm/drm_bufs.c

+4 −8
Original line number Diff line number Diff line
@@ -1510,8 +1510,8 @@ int drm_freebufs(struct drm_device *dev, void *data, 
 * \param arg pointer to a drm_buf_map structure.

 * \return zero on success or a negative number on failure.

 *

 * Maps the AGP, SG or PCI buffer region with do_mmap(), and copies information

 * about each buffer into user space. For PCI buffers, it calls do_mmap() with

 * Maps the AGP, SG or PCI buffer region with vm_mmap(), and copies information

 * about each buffer into user space. For PCI buffers, it calls vm_mmap() with

 * offset equal to 0, which drm_mmap() interpretes as PCI buffers and calls

 * drm_mmap_dma().

 */
@@ -1553,18 +1553,14 @@ int drm_mapbufs(struct drm_device *dev, void *data, 
				retcode = -EINVAL;

				goto done;

			}

			down_write(&current->mm->mmap_sem);

			virtual = do_mmap(file_priv->filp, 0, map->size,

			virtual = vm_mmap(file_priv->filp, 0, map->size,

					  PROT_READ | PROT_WRITE,

					  MAP_SHARED,

					  token);

			up_write(&current->mm->mmap_sem);

		} else {

			down_write(&current->mm->mmap_sem);

			virtual = do_mmap(file_priv->filp, 0, dma->byte_count,

			virtual = vm_mmap(file_priv->filp, 0, dma->byte_count,

					  PROT_READ | PROT_WRITE,

					  MAP_SHARED, 0);

			up_write(&current->mm->mmap_sem);

		}

		if (virtual > -1024UL) {

			/* Real error */

drivers/gpu/drm/exynos/exynos_drm_gem.c

+1 −3
Original line number Diff line number Diff line
@@ -581,10 +581,8 @@ int exynos_drm_gem_mmap_ioctl(struct drm_device *dev, void *data, 
	obj->filp->f_op = &exynos_drm_gem_fops;

	obj->filp->private_data = obj;



	down_write(&current->mm->mmap_sem);

	addr = do_mmap(obj->filp, 0, args->size,

	addr = vm_mmap(obj->filp, 0, args->size,

			PROT_READ | PROT_WRITE, MAP_SHARED, 0);

	up_write(&current->mm->mmap_sem);



	drm_gem_object_unreference_unlocked(obj);

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