1 files changed, 61 insertions, 49 deletions

diff --git a/drivers/infiniband/hw/hfi1/user_exp_rcv.c b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
index 4e417ed08b09..2619a7a9f27c 100644
--- a/drivers/infiniband/hw/hfi1/user_exp_rcv.c
+++ b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
@@ -215,16 +215,11 @@ static void unpin_rcv_pages(struct hfi1_filedata *fd,
 static int pin_rcv_pages(struct hfi1_filedata *fd, struct tid_user_buf *tidbuf)
 {
 	int pinned;
-	unsigned int npages;
+	unsigned int npages = tidbuf->npages;
 	unsigned long vaddr = tidbuf->vaddr;
 	struct page **pages = NULL;
 	struct hfi1_devdata *dd = fd->uctxt->dd;
 
-	/* Get the number of pages the user buffer spans */
-	npages = num_user_pages(vaddr, tidbuf->length);
-	if (!npages)
-		return -EINVAL;
-
 	if (npages > fd->uctxt->expected_count) {
 		dd_dev_err(dd, "Expected buffer too big\n");
 		return -EINVAL;
@@ -258,7 +253,6 @@ static int pin_rcv_pages(struct hfi1_filedata *fd, struct tid_user_buf *tidbuf)
 		return pinned;
 	}
 	tidbuf->pages = pages;
-	tidbuf->npages = npages;
 	fd->tid_n_pinned += pinned;
 	return pinned;
 }
@@ -325,6 +319,8 @@ int hfi1_user_exp_rcv_setup(struct hfi1_filedata *fd,
 
 	if (!PAGE_ALIGNED(tinfo->vaddr))
 		return -EINVAL;
+	if (tinfo->length == 0)
+		return -EINVAL;
 
 	tidbuf = kzalloc(sizeof(*tidbuf), GFP_KERNEL);
 	if (!tidbuf)
@@ -332,43 +328,42 @@ int hfi1_user_exp_rcv_setup(struct hfi1_filedata *fd,
 
 	tidbuf->vaddr = tinfo->vaddr;
 	tidbuf->length = tinfo->length;
+	tidbuf->npages = num_user_pages(tidbuf->vaddr, tidbuf->length);
 	tidbuf->psets = kcalloc(uctxt->expected_count, sizeof(*tidbuf->psets),
 				GFP_KERNEL);
 	if (!tidbuf->psets) {
-		kfree(tidbuf);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto fail_release_mem;
 	}
 
 	pinned = pin_rcv_pages(fd, tidbuf);
 	if (pinned <= 0) {
-		kfree(tidbuf->psets);
-		kfree(tidbuf);
-		return pinned;
+		ret = (pinned < 0) ? pinned : -ENOSPC;
+		goto fail_unpin;
 	}
 
 	/* Find sets of physically contiguous pages */
 	tidbuf->n_psets = find_phys_blocks(tidbuf, pinned);
 
-	/*
-	 * We don't need to access this under a lock since tid_used is per
-	 * process and the same process cannot be in hfi1_user_exp_rcv_clear()
-	 * and hfi1_user_exp_rcv_setup() at the same time.
-	 */
+	/* Reserve the number of expected tids to be used. */
 	spin_lock(&fd->tid_lock);
 	if (fd->tid_used + tidbuf->n_psets > fd->tid_limit)
 		pageset_count = fd->tid_limit - fd->tid_used;
 	else
 		pageset_count = tidbuf->n_psets;
+	fd->tid_used += pageset_count;
 	spin_unlock(&fd->tid_lock);
 
-	if (!pageset_count)
-		goto bail;
+	if (!pageset_count) {
+		ret = -ENOSPC;
+		goto fail_unreserve;
+	}
 
 	ngroups = pageset_count / dd->rcv_entries.group_size;
 	tidlist = kcalloc(pageset_count, sizeof(*tidlist), GFP_KERNEL);
 	if (!tidlist) {
 		ret = -ENOMEM;
-		goto nomem;
+		goto fail_unreserve;
 	}
 
 	tididx = 0;
@@ -464,43 +459,60 @@ int hfi1_user_exp_rcv_setup(struct hfi1_filedata *fd,
 	}
 unlock:
 	mutex_unlock(&uctxt->exp_mutex);
-nomem:
 	hfi1_cdbg(TID, "total mapped: tidpairs:%u pages:%u (%d)", tididx,
 		  mapped_pages, ret);
-	if (tididx) {
-		spin_lock(&fd->tid_lock);
-		fd->tid_used += tididx;
-		spin_unlock(&fd->tid_lock);
-		tinfo->tidcnt = tididx;
-		tinfo->length = mapped_pages * PAGE_SIZE;
-
-		if (copy_to_user(u64_to_user_ptr(tinfo->tidlist),
-				 tidlist, sizeof(tidlist[0]) * tididx)) {
-			/*
-			 * On failure to copy to the user level, we need to undo
-			 * everything done so far so we don't leak resources.
-			 */
-			tinfo->tidlist = (unsigned long)&tidlist;
-			hfi1_user_exp_rcv_clear(fd, tinfo);
-			tinfo->tidlist = 0;
-			ret = -EFAULT;
-			goto bail;
-		}
+
+	/* fail if nothing was programmed, set error if none provided */
+	if (tididx == 0) {
+		if (ret >= 0)
+			ret = -ENOSPC;
+		goto fail_unreserve;
 	}
 
-	/*
-	 * If not everything was mapped (due to insufficient RcvArray entries,
-	 * for example), unpin all unmapped pages so we can pin them nex time.
-	 */
-	if (mapped_pages != pinned)
-		unpin_rcv_pages(fd, tidbuf, NULL, mapped_pages,
-				(pinned - mapped_pages), false);
-bail:
+	/* adjust reserved tid_used to actual count */
+	spin_lock(&fd->tid_lock);
+	fd->tid_used -= pageset_count - tididx;
+	spin_unlock(&fd->tid_lock);
+
+	/* unpin all pages not covered by a TID */
+	unpin_rcv_pages(fd, tidbuf, NULL, mapped_pages, pinned - mapped_pages,
+			false);
+
+	tinfo->tidcnt = tididx;
+	tinfo->length = mapped_pages * PAGE_SIZE;
+
+	if (copy_to_user(u64_to_user_ptr(tinfo->tidlist),
+			 tidlist, sizeof(tidlist[0]) * tididx)) {
+		ret = -EFAULT;
+		goto fail_unprogram;
+	}
+
+	kfree(tidbuf->pages);
 	kfree(tidbuf->psets);
+	kfree(tidbuf);
 	kfree(tidlist);
+	return 0;
+
+fail_unprogram:
+	/* unprogram, unmap, and unpin all allocated TIDs */
+	tinfo->tidlist = (unsigned long)tidlist;
+	hfi1_user_exp_rcv_clear(fd, tinfo);
+	tinfo->tidlist = 0;
+	pinned = 0;		/* nothing left to unpin */
+	pageset_count = 0;	/* nothing left reserved */
+fail_unreserve:
+	spin_lock(&fd->tid_lock);
+	fd->tid_used -= pageset_count;
+	spin_unlock(&fd->tid_lock);
+fail_unpin:
+	if (pinned > 0)
+		unpin_rcv_pages(fd, tidbuf, NULL, 0, pinned, false);
+fail_release_mem:
 	kfree(tidbuf->pages);
+	kfree(tidbuf->psets);
 	kfree(tidbuf);
-	return ret > 0 ? 0 : ret;
+	kfree(tidlist);
+	return ret;
 }
 
 int hfi1_user_exp_rcv_clear(struct hfi1_filedata *fd,