Merge branch 'akpm' (patches from Andrew)

Merge some more updates from Andrew Morton: - various hotfixes and minor things - hch's use_mm/unuse_mm clearnups Subsystems affected by this patch series: mm/hugetlb, scripts, kcov, lib, nilfs, checkpatch, lib, mm/debug, ocfs2, lib, misc. * emailed patches from Andrew Morton <[email protected]>: kernel: set USER_DS in kthread_use_mm kernel: better document the use_mm/unuse_mm API contract kernel: move use_mm/unuse_mm to kthread.c kernel: move use_mm/unuse_mm to kthread.c stacktrace: cleanup inconsistent variable type lib: test get_count_order/long in test_bitops.c mm: add comments on pglist_data zones ocfs2: fix spelling mistake and grammar mm/debug_vm_pgtable: fix kernel crash by checking for THP support lib: fix bitmap_parse() on 64-bit big endian archs checkpatch: correct check for kernel parameters doc nilfs2: fix null pointer dereference at nilfs_segctor_do_construct() lib/lz4/lz4_decompress.c: document deliberate use of `&' kcov: check kcov_softirq in kcov_remote_stop() scripts/spelling: add a few more typos khugepaged: selftests: fix timeout condition in wait_for_scan()
vieko · Jun 11, 2020 · 623f6dc · 623f6dc
2 parents 5cd221e + 37c54f9
commit 623f6dc
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Showing 35 changed files with 215 additions and 148 deletions.
diff --git a/arch/powerpc/platforms/powernv/vas-fault.c b/arch/powerpc/platforms/powernv/vas-fault.c
@@ -127,7 +127,7 @@ static void update_csb(struct vas_window *window,
 		return;
 	}
 
-	use_mm(window->mm);
+	kthread_use_mm(window->mm);
 	rc = copy_to_user(csb_addr, &csb, sizeof(csb));
 	/*
 	 * User space polls on csb.flags (first byte). So add barrier
@@ -139,7 +139,7 @@ static void update_csb(struct vas_window *window,
 		smp_mb();
 		rc = copy_to_user(csb_addr, &csb, sizeof(u8));
 	}
-	unuse_mm(window->mm);
+	kthread_unuse_mm(window->mm);
 	put_task_struct(tsk);
 
 	/* Success */

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -27,6 +27,7 @@
 
 #include <linux/types.h>
 #include <linux/mm.h>
+#include <linux/kthread.h>
 #include <linux/workqueue.h>
 #include <kgd_kfd_interface.h>
 #include <drm/ttm/ttm_execbuf_util.h>
@@ -196,9 +197,9 @@ uint8_t amdgpu_amdkfd_get_xgmi_hops_count(struct kgd_dev *dst, struct kgd_dev *s
 			if ((mmptr) == current->mm) {			\
 				valid = !get_user((dst), (wptr));	\
 			} else if (current->mm == NULL) {		\
-				use_mm(mmptr);				\
+				kthread_use_mm(mmptr);			\
 				valid = !get_user((dst), (wptr));	\
-				unuse_mm(mmptr);			\
+				kthread_unuse_mm(mmptr);		\
 			}						\
 			pagefault_enable();				\
 		}							\

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
@@ -22,7 +22,6 @@
 #include <linux/module.h>
 #include <linux/fdtable.h>
 #include <linux/uaccess.h>
-#include <linux/mmu_context.h>
 #include <linux/firmware.h>
 #include "amdgpu.h"
 #include "amdgpu_amdkfd.h"

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
@@ -19,7 +19,6 @@
  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  */
-#include <linux/mmu_context.h>
 #include "amdgpu.h"
 #include "amdgpu_amdkfd.h"
 #include "gc/gc_10_1_0_offset.h"

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
@@ -20,8 +20,6 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#include <linux/mmu_context.h>
-
 #include "amdgpu.h"
 #include "amdgpu_amdkfd.h"
 #include "cikd.h"

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
@@ -20,8 +20,6 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#include <linux/mmu_context.h>
-
 #include "amdgpu.h"
 #include "amdgpu_amdkfd.h"
 #include "gfx_v8_0.h"

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
@@ -19,8 +19,6 @@
  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  */
-#include <linux/mmu_context.h>
-
 #include "amdgpu.h"
 #include "amdgpu_amdkfd.h"
 #include "gc/gc_9_0_offset.h"

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -31,7 +31,7 @@
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/mm.h>
-#include <linux/mmu_context.h>
+#include <linux/kthread.h>
 #include <linux/sched/mm.h>
 #include <linux/types.h>
 #include <linux/list.h>

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
@@ -32,7 +32,7 @@
 #include <linux/usb/functionfs.h>
 
 #include <linux/aio.h>
-#include <linux/mmu_context.h>
+#include <linux/kthread.h>
 #include <linux/poll.h>
 #include <linux/eventfd.h>
 
@@ -824,13 +824,9 @@ static void ffs_user_copy_worker(struct work_struct *work)
 	bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
 
 	if (io_data->read && ret > 0) {
-		mm_segment_t oldfs = get_fs();
-
-		set_fs(USER_DS);
-		use_mm(io_data->mm);
+		kthread_use_mm(io_data->mm);
 		ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data);
-		unuse_mm(io_data->mm);
-		set_fs(oldfs);
+		kthread_unuse_mm(io_data->mm);
 	}
 
 	io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);

diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
@@ -21,7 +21,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/poll.h>
-#include <linux/mmu_context.h>
+#include <linux/kthread.h>
 #include <linux/aio.h>
 #include <linux/uio.h>
 #include <linux/refcount.h>
@@ -462,9 +462,9 @@ static void ep_user_copy_worker(struct work_struct *work)
 	struct kiocb *iocb = priv->iocb;
 	size_t ret;
 
-	use_mm(mm);
+	kthread_use_mm(mm);
 	ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
-	unuse_mm(mm);
+	kthread_unuse_mm(mm);
 	if (!ret)
 		ret = -EFAULT;
 

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
@@ -27,7 +27,7 @@
 #include <linux/iommu.h>
 #include <linux/module.h>
 #include <linux/mm.h>
-#include <linux/mmu_context.h>
+#include <linux/kthread.h>
 #include <linux/rbtree.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/mm.h>
@@ -2817,7 +2817,7 @@ static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu,
 		return -EPERM;
 
 	if (kthread)
-		use_mm(mm);
+		kthread_use_mm(mm);
 	else if (current->mm != mm)
 		goto out;
 
@@ -2844,7 +2844,7 @@ static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu,
 		*copied = copy_from_user(data, (void __user *)vaddr,
 					   count) ? 0 : count;
 	if (kthread)
-		unuse_mm(mm);
+		kthread_unuse_mm(mm);
 out:
 	mmput(mm);
 	return *copied ? 0 : -EFAULT;

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
@@ -14,7 +14,6 @@
 #include <linux/vhost.h>
 #include <linux/uio.h>
 #include <linux/mm.h>
-#include <linux/mmu_context.h>
 #include <linux/miscdevice.h>
 #include <linux/mutex.h>
 #include <linux/poll.h>
@@ -335,10 +334,8 @@ static int vhost_worker(void *data)
 	struct vhost_dev *dev = data;
 	struct vhost_work *work, *work_next;
 	struct llist_node *node;
-	mm_segment_t oldfs = get_fs();
 
-	set_fs(USER_DS);
-	use_mm(dev->mm);
+	kthread_use_mm(dev->mm);
 
 	for (;;) {
 		/* mb paired w/ kthread_stop */
@@ -366,8 +363,7 @@ static int vhost_worker(void *data)
 				schedule();
 		}
 	}
-	unuse_mm(dev->mm);
-	set_fs(oldfs);
+	kthread_unuse_mm(dev->mm);
 	return 0;
 }
 

diff --git a/fs/aio.c b/fs/aio.c
@@ -27,7 +27,6 @@
 #include <linux/file.h>
 #include <linux/mm.h>
 #include <linux/mman.h>
-#include <linux/mmu_context.h>
 #include <linux/percpu.h>
 #include <linux/slab.h>
 #include <linux/timer.h>

diff --git a/fs/io-wq.c b/fs/io-wq.c
@@ -10,7 +10,6 @@
 #include <linux/errno.h>
 #include <linux/sched/signal.h>
 #include <linux/mm.h>
-#include <linux/mmu_context.h>
 #include <linux/sched/mm.h>
 #include <linux/percpu.h>
 #include <linux/slab.h>
@@ -170,8 +169,7 @@ static bool __io_worker_unuse(struct io_wqe *wqe, struct io_worker *worker)
 			dropped_lock = true;
 		}
 		__set_current_state(TASK_RUNNING);
-		set_fs(KERNEL_DS);
-		unuse_mm(worker->mm);
+		kthread_unuse_mm(worker->mm);
 		mmput(worker->mm);
 		worker->mm = NULL;
 	}
@@ -418,18 +416,15 @@ static struct io_wq_work *io_get_next_work(struct io_wqe *wqe)
 static void io_wq_switch_mm(struct io_worker *worker, struct io_wq_work *work)
 {
 	if (worker->mm) {
-		unuse_mm(worker->mm);
+		kthread_unuse_mm(worker->mm);
 		mmput(worker->mm);
 		worker->mm = NULL;
 	}
-	if (!work->mm) {
-		set_fs(KERNEL_DS);
+	if (!work->mm)
 		return;
-	}
+
 	if (mmget_not_zero(work->mm)) {
-		use_mm(work->mm);
-		if (!worker->mm)
-			set_fs(USER_DS);
+		kthread_use_mm(work->mm);
 		worker->mm = work->mm;
 		/* hang on to this mm */
 		work->mm = NULL;

diff --git a/fs/io_uring.c b/fs/io_uring.c
@@ -55,7 +55,6 @@
 #include <linux/fdtable.h>
 #include <linux/mm.h>
 #include <linux/mman.h>
-#include <linux/mmu_context.h>
 #include <linux/percpu.h>
 #include <linux/slab.h>
 #include <linux/kthread.h>
@@ -5867,7 +5866,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
 	if (io_op_defs[req->opcode].needs_mm && !current->mm) {
 		if (unlikely(!mmget_not_zero(ctx->sqo_mm)))
 			return -EFAULT;
-		use_mm(ctx->sqo_mm);
+		kthread_use_mm(ctx->sqo_mm);
 	}
 
 	sqe_flags = READ_ONCE(sqe->flags);
@@ -5981,7 +5980,7 @@ static inline void io_sq_thread_drop_mm(struct io_ring_ctx *ctx)
 	struct mm_struct *mm = current->mm;
 
 	if (mm) {
-		unuse_mm(mm);
+		kthread_unuse_mm(mm);
 		mmput(mm);
 	}
 }
@@ -5990,15 +5989,12 @@ static int io_sq_thread(void *data)
 {
 	struct io_ring_ctx *ctx = data;
 	const struct cred *old_cred;
-	mm_segment_t old_fs;
 	DEFINE_WAIT(wait);
 	unsigned long timeout;
 	int ret = 0;
 
 	complete(&ctx->sq_thread_comp);
 
-	old_fs = get_fs();
-	set_fs(USER_DS);
 	old_cred = override_creds(ctx->creds);
 
 	timeout = jiffies + ctx->sq_thread_idle;
@@ -6103,7 +6099,6 @@ static int io_sq_thread(void *data)
 	if (current->task_works)
 		task_work_run();
 
-	set_fs(old_fs);
 	io_sq_thread_drop_mm(ctx);
 	revert_creds(old_cred);
 

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
@@ -2780,6 +2780,8 @@ int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
 	if (!nilfs->ns_writer)
 		return -ENOMEM;
 
+	inode_attach_wb(nilfs->ns_bdev->bd_inode, NULL);
+
 	err = nilfs_segctor_start_thread(nilfs->ns_writer);
 	if (err) {
 		kfree(nilfs->ns_writer);

diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c
@@ -62,7 +62,7 @@ static vm_fault_t __ocfs2_page_mkwrite(struct file *file,
 	last_index = (size - 1) >> PAGE_SHIFT;
 
 	/*
-	 * There are cases that lead to the page no longer bebongs to the
+	 * There are cases that lead to the page no longer belonging to the
 	 * mapping.
 	 * 1) pagecache truncates locally due to memory pressure.
 	 * 2) pagecache truncates when another is taking EX lock against 

diff --git a/include/linux/kthread.h b/include/linux/kthread.h
@@ -5,6 +5,8 @@
 #include <linux/err.h>
 #include <linux/sched.h>
 
+struct mm_struct;
+
 __printf(4, 5)
 struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
 					   void *data,
@@ -199,6 +201,9 @@ bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
 
 void kthread_destroy_worker(struct kthread_worker *worker);
 
+void kthread_use_mm(struct mm_struct *mm);
+void kthread_unuse_mm(struct mm_struct *mm);
+
 struct cgroup_subsys_state;
 
 #ifdef CONFIG_BLK_CGROUP

diff --git a/include/linux/mmu_context.h b/include/linux/mmu_context.h
@@ -4,11 +4,6 @@
 
 #include <asm/mmu_context.h>
 
-struct mm_struct;
-
-void use_mm(struct mm_struct *mm);
-void unuse_mm(struct mm_struct *mm);
-
 /* Architectures that care about IRQ state in switch_mm can override this. */
 #ifndef switch_mm_irqs_off
 # define switch_mm_irqs_off switch_mm

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
@@ -660,9 +660,21 @@ struct deferred_split {
  * per-zone basis.
  */
 typedef struct pglist_data {
+	/*
+	 * node_zones contains just the zones for THIS node. Not all of the
+	 * zones may be populated, but it is the full list. It is referenced by
+	 * this node's node_zonelists as well as other node's node_zonelists.
+	 */
 	struct zone node_zones[MAX_NR_ZONES];
+
+	/*
+	 * node_zonelists contains references to all zones in all nodes.
+	 * Generally the first zones will be references to this node's
+	 * node_zones.
+	 */
 	struct zonelist node_zonelists[MAX_ZONELISTS];
-	int nr_zones;
+
+	int nr_zones; /* number of populated zones in this node */
 #ifdef CONFIG_FLAT_NODE_MEM_MAP	/* means !SPARSEMEM */
 	struct page *node_mem_map;
 #ifdef CONFIG_PAGE_EXTENSION

diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h
@@ -64,7 +64,7 @@ void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
 struct stack_trace {
 	unsigned int nr_entries, max_entries;
 	unsigned long *entries;
-	int skip;	/* input argument: How many entries to skip */
+	unsigned int skip;	/* input argument: How many entries to skip */
 };
 
 extern void save_stack_trace(struct stack_trace *trace);