vmw_balloon: fix inflation of 64-bit GFNs

When balloon batching is not supported by the hypervisor, the guest frame number (GFN) must fit in 32-bit. However, due to a bug, this check was mistakenly ignored. In practice, when total RAM is greater than 16TB, the balloon does not work currently, making this bug unlikely to happen. Fixes: ef0f8f1 ("VMware balloon: partially inline vmballoon_reserve_page.") Cc: [email protected] Reviewed-by: Xavier Deguillard <[email protected]> Signed-off-by: Nadav Amit <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
numbqq · Jul 3, 2018 · 0975569 · 0975569
1 parent 10f1466
commit 0975569
Showing 1 changed file with 7 additions and 6 deletions.
diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
@@ -450,7 +450,7 @@ static int vmballoon_send_lock_page(struct vmballoon *b, unsigned long pfn,
 
 	pfn32 = (u32)pfn;
 	if (pfn32 != pfn)
-		return -1;
+		return -EINVAL;
 
 	STATS_INC(b->stats.lock[false]);
 
@@ -460,7 +460,7 @@ static int vmballoon_send_lock_page(struct vmballoon *b, unsigned long pfn,
 
 	pr_debug("%s - ppn %lx, hv returns %ld\n", __func__, pfn, status);
 	STATS_INC(b->stats.lock_fail[false]);
-	return 1;
+	return -EIO;
 }
 
 static int vmballoon_send_batched_lock(struct vmballoon *b,
@@ -597,11 +597,12 @@ static int vmballoon_lock_page(struct vmballoon *b, unsigned int num_pages,
 
 	locked = vmballoon_send_lock_page(b, page_to_pfn(page), &hv_status,
 								target);
-	if (locked > 0) {
+	if (locked) {
 		STATS_INC(b->stats.refused_alloc[false]);
 
-		if (hv_status == VMW_BALLOON_ERROR_RESET ||
-				hv_status == VMW_BALLOON_ERROR_PPN_NOTNEEDED) {
+		if (locked == -EIO &&
+		    (hv_status == VMW_BALLOON_ERROR_RESET ||
+		     hv_status == VMW_BALLOON_ERROR_PPN_NOTNEEDED)) {
 			vmballoon_free_page(page, false);
 			return -EIO;
 		}
@@ -617,7 +618,7 @@ static int vmballoon_lock_page(struct vmballoon *b, unsigned int num_pages,
 		} else {
 			vmballoon_free_page(page, false);
 		}
-		return -EIO;
+		return locked;
 	}
 
 	/* track allocated page */