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authorLinus Torvalds <torvalds@linux-foundation.org>2017-10-23 06:35:01 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2017-10-23 06:35:01 -0400
commit17e7637f5947284cd7f41c1b26ff8cbee9a794a4 (patch)
tree571c0ee5fec7224ba63dded321df818c88fd9994 /drivers
parent5805992184f97b7797f24b74d511825f8992861e (diff)
parentae65c8510f3319dfb2114cc48d476b81232e27b3 (diff)
Merge tag 'char-misc-4.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH: "Here are four small fixes for 4.14-rc6. Three of them are binder driver fixes for reported issues, and the last one is a hyperv driver bugfix. Nothing major, but good fixes to get into 4.14-final. All of these have been in linux-next with no reported issues" * tag 'char-misc-4.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: android: binder: Fix null ptr dereference in debug msg android: binder: Don't get mm from task vmbus: hvsock: add proper sync for vmbus_hvsock_device_unregister() binder: call poll_wait() unconditionally.
Diffstat (limited to 'drivers')
-rw-r--r--drivers/android/binder.c11
-rw-r--r--drivers/android/binder_alloc.c24
-rw-r--r--drivers/android/binder_alloc.h1
-rw-r--r--drivers/hv/channel_mgmt.c5
4 files changed, 15 insertions, 26 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 0621a95b8597..fddf76ef5bd6 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3662,12 +3662,6 @@ static void binder_stat_br(struct binder_proc *proc,
}
}
-static int binder_has_thread_work(struct binder_thread *thread)
-{
- return !binder_worklist_empty(thread->proc, &thread->todo) ||
- thread->looper_need_return;
-}
-
static int binder_put_node_cmd(struct binder_proc *proc,
struct binder_thread *thread,
void __user **ptrp,
@@ -4297,12 +4291,9 @@ static unsigned int binder_poll(struct file *filp,
binder_inner_proc_unlock(thread->proc);
- if (binder_has_work(thread, wait_for_proc_work))
- return POLLIN;
-
poll_wait(filp, &thread->wait, wait);
- if (binder_has_thread_work(thread))
+ if (binder_has_work(thread, wait_for_proc_work))
return POLLIN;
return 0;
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 064f5e31ec55..c2819a3d58a6 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -215,17 +215,12 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
}
}
- if (!vma && need_mm)
- mm = get_task_mm(alloc->tsk);
+ if (!vma && need_mm && mmget_not_zero(alloc->vma_vm_mm))
+ mm = alloc->vma_vm_mm;
if (mm) {
down_write(&mm->mmap_sem);
vma = alloc->vma;
- if (vma && mm != alloc->vma_vm_mm) {
- pr_err("%d: vma mm and task mm mismatch\n",
- alloc->pid);
- vma = NULL;
- }
}
if (!vma && need_mm) {
@@ -565,7 +560,7 @@ static void binder_delete_free_buffer(struct binder_alloc *alloc,
binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
"%d: merge free, buffer %pK do not share page with %pK or %pK\n",
alloc->pid, buffer->data,
- prev->data, next->data);
+ prev->data, next ? next->data : NULL);
binder_update_page_range(alloc, 0, buffer_start_page(buffer),
buffer_start_page(buffer) + PAGE_SIZE,
NULL);
@@ -720,6 +715,7 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
barrier();
alloc->vma = vma;
alloc->vma_vm_mm = vma->vm_mm;
+ mmgrab(alloc->vma_vm_mm);
return 0;
@@ -795,6 +791,8 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc)
vfree(alloc->buffer);
}
mutex_unlock(&alloc->mutex);
+ if (alloc->vma_vm_mm)
+ mmdrop(alloc->vma_vm_mm);
binder_alloc_debug(BINDER_DEBUG_OPEN_CLOSE,
"%s: %d buffers %d, pages %d\n",
@@ -889,7 +887,6 @@ int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
void binder_alloc_vma_close(struct binder_alloc *alloc)
{
WRITE_ONCE(alloc->vma, NULL);
- WRITE_ONCE(alloc->vma_vm_mm, NULL);
}
/**
@@ -926,9 +923,9 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
vma = alloc->vma;
if (vma) {
- mm = get_task_mm(alloc->tsk);
- if (!mm)
- goto err_get_task_mm_failed;
+ if (!mmget_not_zero(alloc->vma_vm_mm))
+ goto err_mmget;
+ mm = alloc->vma_vm_mm;
if (!down_write_trylock(&mm->mmap_sem))
goto err_down_write_mmap_sem_failed;
}
@@ -963,7 +960,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
err_down_write_mmap_sem_failed:
mmput_async(mm);
-err_get_task_mm_failed:
+err_mmget:
err_page_already_freed:
mutex_unlock(&alloc->mutex);
err_get_alloc_mutex_failed:
@@ -1002,7 +999,6 @@ struct shrinker binder_shrinker = {
*/
void binder_alloc_init(struct binder_alloc *alloc)
{
- alloc->tsk = current->group_leader;
alloc->pid = current->group_leader->pid;
mutex_init(&alloc->mutex);
INIT_LIST_HEAD(&alloc->buffers);
diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h
index a3a3602c689c..2dd33b6df104 100644
--- a/drivers/android/binder_alloc.h
+++ b/drivers/android/binder_alloc.h
@@ -100,7 +100,6 @@ struct binder_lru_page {
*/
struct binder_alloc {
struct mutex mutex;
- struct task_struct *tsk;
struct vm_area_struct *vma;
struct mm_struct *vma_vm_mm;
void *buffer;
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 018d2e0f8ec5..379b0df123be 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -937,7 +937,10 @@ void vmbus_hvsock_device_unregister(struct vmbus_channel *channel)
{
BUG_ON(!is_hvsock_channel(channel));
- channel->rescind = true;
+ /* We always get a rescind msg when a connection is closed. */
+ while (!READ_ONCE(channel->probe_done) || !READ_ONCE(channel->rescind))
+ msleep(1);
+
vmbus_device_unregister(channel->device_obj);
}
EXPORT_SYMBOL_GPL(vmbus_hvsock_device_unregister);

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