svn commit: r290454 - in stable: 10/sys/dev/drm2/i915 9/sys/dev/drm2/i915

[John Baldwin]

Author: jhb
Date: Fri Nov  6 16:48:33 2015
New Revision: 290454
URL: https://svnweb.freebsd.org/changeset/base/290454

Log:
  MFC 288452,289719:
  
  288452:
  Most error cases in i915_gem_do_execbuffer() jump to one of two labels to
  release resources (such as unholding pages) when errors occur.  Some
  recently added error checks return immediately instead of jumping to a
  label resulting in leaks.  Fix these to jump to a label to do cleanup
  instead.
  
  Note that stable/9 does not have the "recently added" error checks, but
  it does have some older error checks (that were are no longer present
  in stable/10 and head) that have the same bug and this fixes those
  instead.
  
  289719:
  i915_gem_do_execbuffer() holds the pages backing each relocation region for
  various reasons while executing user commands.  After these commands are
  completed, the pages backing the relocation regions are unheld.
  
  Since relocation regions do not have to be page aligned, the code in
  validate_exec_list() allocates 2 extra page pointers in the array of
  held pages populated by vm_fault_quick_hold_pages().  However, the cleanup
  code that unheld the pages always assumed that only the buffer size /
  PAGE_SIZE pages were used.  This meant that non-page aligned buffers would
  not unheld the last 1 or 2 pages in the list.  Fix this by saving the
  number of held pages returned by vm_fault_quick_hold_pages() for each
  relocation region and using this count during cleanup.

Modified:
  stable/9/sys/dev/drm2/i915/i915_gem_execbuffer.c
Directory Properties:
  stable/9/sys/   (props changed)
  stable/9/sys/dev/   (props changed)

Changes in other areas also in this revision:
Modified:
  stable/10/sys/dev/drm2/i915/i915_gem_execbuffer.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/9/sys/dev/drm2/i915/i915_gem_execbuffer.c
==============================================================================
--- stable/9/sys/dev/drm2/i915/i915_gem_execbuffer.c	Fri Nov  6 16:43:22 2015	(r290453)
+++ stable/9/sys/dev/drm2/i915/i915_gem_execbuffer.c	Fri Nov  6 16:48:33 2015	(r290454)
@@ -953,13 +953,15 @@ i915_gem_check_execbuffer(struct drm_i91
 
 static int
 validate_exec_list(struct drm_i915_gem_exec_object2 *exec, int count,
-    vm_page_t ***map)
+    vm_page_t ***map, int **maplen)
 {
 	vm_page_t *ma;
 	int i, length, page_count;
 
 	/* XXXKIB various limits checking is missing there */
 	*map = malloc(count * sizeof(*ma), DRM_I915_GEM, M_WAITOK | M_ZERO);
+	*maplen = malloc(count * sizeof(*maplen), DRM_I915_GEM, M_WAITOK |
+	    M_ZERO);
 	for (i = 0; i < count; i++) {
 		/* First check for malicious input causing overflow */
 		if (exec[i].relocation_count >
@@ -981,9 +983,10 @@ validate_exec_list(struct drm_i915_gem_e
 		page_count = howmany(length, PAGE_SIZE) + 2;
 		ma = (*map)[i] = malloc(page_count * sizeof(vm_page_t),
 		    DRM_I915_GEM, M_WAITOK | M_ZERO);
-		if (vm_fault_quick_hold_pages(&curproc->p_vmspace->vm_map,
-		    exec[i].relocs_ptr, length, VM_PROT_READ | VM_PROT_WRITE,
-		    ma, page_count) == -1) {
+		(*maplen)[i] = vm_fault_quick_hold_pages(
+		    &curproc->p_vmspace->vm_map, exec[i].relocs_ptr, length,
+		    VM_PROT_READ | VM_PROT_WRITE, ma, page_count);
+		if ((*maplen)[i] == -1) {
 			free(ma, DRM_I915_GEM);
 			(*map)[i] = NULL;
 			return (-EFAULT);
@@ -1130,6 +1133,7 @@ i915_gem_do_execbuffer(struct drm_device
 	struct drm_clip_rect *cliprects = NULL;
 	struct intel_ring_buffer *ring;
 	vm_page_t **relocs_ma;
+	int *relocs_len;
 	u32 exec_start, exec_len;
 	u32 seqno;
 	u32 mask;
@@ -1143,7 +1147,8 @@ i915_gem_do_execbuffer(struct drm_device
 	if (args->batch_len == 0)
 		return (0);
 
-	ret = validate_exec_list(exec, args->buffer_count, &relocs_ma);
+	ret = validate_exec_list(exec, args->buffer_count, &relocs_ma,
+	    &relocs_len);
 	if (ret != 0)
 		goto pre_struct_lock_err;
 
@@ -1155,14 +1160,16 @@ i915_gem_do_execbuffer(struct drm_device
 	case I915_EXEC_BSD:
 		if (!HAS_BSD(dev)) {
 			DRM_DEBUG("execbuf with invalid ring (BSD)\n");
-			return -EINVAL;
+			ret = -EINVAL;
+			goto pre_struct_lock_err;
 		}
 		ring = &dev_priv->rings[VCS];
 		break;
 	case I915_EXEC_BLT:
 		if (!HAS_BLT(dev)) {
 			DRM_DEBUG("execbuf with invalid ring (BLT)\n");
-			return -EINVAL;
+			ret = -EINVAL;
+			goto pre_struct_lock_err;
 		}
 		ring = &dev_priv->rings[BCS];
 		break;
@@ -1390,13 +1397,11 @@ struct_lock_err:
 pre_struct_lock_err:
 	for (i = 0; i < args->buffer_count; i++) {
 		if (relocs_ma[i] != NULL) {
-			vm_page_unhold_pages(relocs_ma[i], howmany(
-			    exec[i].relocation_count *
-			    sizeof(struct drm_i915_gem_relocation_entry),
-			    PAGE_SIZE));
+			vm_page_unhold_pages(relocs_ma[i], relocs_len[i]);
 			free(relocs_ma[i], DRM_I915_GEM);
 		}
 	}
+	free(relocs_len, DRM_I915_GEM);
 	free(relocs_ma, DRM_I915_GEM);
 	free(cliprects, DRM_I915_GEM);
 	return ret;