Commit 3ecafda9 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'akpm' (patches from Andrew) 

Merge misc fixes from Andrew Morton:
 "16 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping
  mm/kmemleak.c: fix unused-function warning
  init: initialize jump labels before command line option parsing
  kernel/watchdog_hld.c: hard lockup message should end with a newline
  kcov: improve CONFIG_ARCH_HAS_KCOV help text
  mm: fix inactive list balancing between NUMA nodes and cgroups
  mm/hotplug: treat CMA pages as unmovable
  proc: fixup proc-pid-vm test
  proc: fix map_files test on F29
  mm/vmstat.c: fix /proc/vmstat format for CONFIG_DEBUG_TLBFLUSH=y CONFIG_SMP=n
  mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lock
  mm: swapoff: shmem_unuse() stop eviction without igrab()
  mm: swapoff: take notice of completion sooner
  mm: swapoff: remove too limiting SWAP_UNUSE_MAX_TRIES
  mm: swapoff: shmem_find_swap_entries() filter out other types
  slab: store tagged freelist for off-slab slabmgmt
parents b222e9af 04f5866e

drivers/base/memory.c

+1 −1
Original line number Diff line number Diff line
@@ -506,7 +506,7 @@ static ssize_t probe_store(struct device *dev, struct device_attribute *attr, 


	ret = lock_device_hotplug_sysfs();

	if (ret)

		goto out;

		return ret;



	nid = memory_add_physaddr_to_nid(phys_addr);

	ret = __add_memory(nid, phys_addr,

drivers/infiniband/core/uverbs_main.c

+3 −0
Original line number Diff line number Diff line
@@ -993,6 +993,8 @@ void uverbs_user_mmap_disassociate(struct ib_uverbs_file *ufile) 
		 * will only be one mm, so no big deal.

		 */

		down_write(&mm->mmap_sem);

		if (!mmget_still_valid(mm))

			goto skip_mm;

		mutex_lock(&ufile->umap_lock);

		list_for_each_entry_safe (priv, next_priv, &ufile->umaps,

					  list) {
@@ -1007,6 +1009,7 @@ void uverbs_user_mmap_disassociate(struct ib_uverbs_file *ufile) 
			vma->vm_flags &= ~(VM_SHARED | VM_MAYSHARE);

		}

		mutex_unlock(&ufile->umap_lock);

	skip_mm:

		up_write(&mm->mmap_sem);

		mmput(mm);

	}

fs/proc/task_mmu.c

+18 −0
Original line number Diff line number Diff line
@@ -1143,6 +1143,24 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, 
					count = -EINTR;

					goto out_mm;

				}

				/*

				 * Avoid to modify vma->vm_flags

				 * without locked ops while the

				 * coredump reads the vm_flags.

				 */

				if (!mmget_still_valid(mm)) {

					/*

					 * Silently return "count"

					 * like if get_task_mm()

					 * failed. FIXME: should this

					 * function have returned

					 * -ESRCH if get_task_mm()

					 * failed like if

					 * get_proc_task() fails?

					 */

					up_write(&mm->mmap_sem);

					goto out_mm;

				}

				for (vma = mm->mmap; vma; vma = vma->vm_next) {

					vma->vm_flags &= ~VM_SOFTDIRTY;

					vma_set_page_prot(vma);

fs/userfaultfd.c

+9 −0
Original line number Diff line number Diff line
@@ -629,6 +629,8 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx, 


		/* the various vma->vm_userfaultfd_ctx still points to it */

		down_write(&mm->mmap_sem);

		/* no task can run (and in turn coredump) yet */

		VM_WARN_ON(!mmget_still_valid(mm));

		for (vma = mm->mmap; vma; vma = vma->vm_next)

			if (vma->vm_userfaultfd_ctx.ctx == release_new_ctx) {

				vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
@@ -883,6 +885,8 @@ static int userfaultfd_release(struct inode *inode, struct file *file) 
	 * taking the mmap_sem for writing.

	 */

	down_write(&mm->mmap_sem);

	if (!mmget_still_valid(mm))

		goto skip_mm;

	prev = NULL;

	for (vma = mm->mmap; vma; vma = vma->vm_next) {

		cond_resched();
@@ -905,6 +909,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file) 
		vma->vm_flags = new_flags;

		vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;

	}

skip_mm:

	up_write(&mm->mmap_sem);

	mmput(mm);

wakeup:
@@ -1333,6 +1338,8 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, 
		goto out;



	down_write(&mm->mmap_sem);

	if (!mmget_still_valid(mm))

		goto out_unlock;

	vma = find_vma_prev(mm, start, &prev);

	if (!vma)

		goto out_unlock;
@@ -1520,6 +1527,8 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, 
		goto out;



	down_write(&mm->mmap_sem);

	if (!mmget_still_valid(mm))

		goto out_unlock;

	vma = find_vma_prev(mm, start, &prev);

	if (!vma)

		goto out_unlock;

include/linux/sched/mm.h

+21 −0
Original line number Diff line number Diff line
@@ -49,6 +49,27 @@ static inline void mmdrop(struct mm_struct *mm) 
		__mmdrop(mm);

}



/*

 * This has to be called after a get_task_mm()/mmget_not_zero()

 * followed by taking the mmap_sem for writing before modifying the

 * vmas or anything the coredump pretends not to change from under it.

 *

 * NOTE: find_extend_vma() called from GUP context is the only place

 * that can modify the "mm" (notably the vm_start/end) under mmap_sem

 * for reading and outside the context of the process, so it is also

 * the only case that holds the mmap_sem for reading that must call

 * this function. Generally if the mmap_sem is hold for reading

 * there's no need of this check after get_task_mm()/mmget_not_zero().

 *

 * This function can be obsoleted and the check can be removed, after

 * the coredump code will hold the mmap_sem for writing before

 * invoking the ->core_dump methods.

 */

static inline bool mmget_still_valid(struct mm_struct *mm)

{

	return likely(!mm->core_state);

}



/**

 * mmget() - Pin the address space associated with a &struct mm_struct.

 * @mm: The address space to pin.

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