Merge branch 'agp-patches' of master.kernel.org:/pub/scm/linux/kernel…

…/git/airlied/agp-2.6 * 'agp-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied/agp-2.6: fix use after free in amd create gatt pages AGP fix race condition between unmapping and freeing pages
git-mirror · Oct 15, 2007 · 3d06f7a · 3d06f7a
2 parents 13626cb + bdc3e60
commit 3d06f7a
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Showing 7 changed files with 50 additions and 34 deletions.
diff --git a/drivers/char/agp/agp.h b/drivers/char/agp/agp.h
@@ -58,6 +58,9 @@ struct gatt_mask {
 	 * devices this will probably be ignored */
 };
 
+#define AGP_PAGE_DESTROY_UNMAP 1
+#define AGP_PAGE_DESTROY_FREE 2
+
 struct aper_size_info_8 {
 	int size;
 	int num_entries;
@@ -113,7 +116,7 @@ struct agp_bridge_driver {
 	struct agp_memory *(*alloc_by_type) (size_t, int);
 	void (*free_by_type)(struct agp_memory *);
 	void *(*agp_alloc_page)(struct agp_bridge_data *);
-	void (*agp_destroy_page)(void *);
+	void (*agp_destroy_page)(void *, int flags);
         int (*agp_type_to_mask_type) (struct agp_bridge_data *, int);
 };
 
@@ -267,7 +270,7 @@ int agp_generic_remove_memory(struct agp_memory *mem, off_t pg_start, int type);
 struct agp_memory *agp_generic_alloc_by_type(size_t page_count, int type);
 void agp_generic_free_by_type(struct agp_memory *curr);
 void *agp_generic_alloc_page(struct agp_bridge_data *bridge);
-void agp_generic_destroy_page(void *addr);
+void agp_generic_destroy_page(void *addr, int flags);
 void agp_free_key(int key);
 int agp_num_entries(void);
 u32 agp_collect_device_status(struct agp_bridge_data *bridge, u32 mode, u32 command);

diff --git a/drivers/char/agp/ali-agp.c b/drivers/char/agp/ali-agp.c
@@ -156,29 +156,34 @@ static void *m1541_alloc_page(struct agp_bridge_data *bridge)
 	return addr;
 }
 
-static void ali_destroy_page(void * addr)
+static void ali_destroy_page(void * addr, int flags)
 {
 	if (addr) {
-		global_cache_flush();	/* is this really needed?  --hch */
-		agp_generic_destroy_page(addr);
-		global_flush_tlb();
+		if (flags & AGP_PAGE_DESTROY_UNMAP) {
+			global_cache_flush();	/* is this really needed?  --hch */
+			agp_generic_destroy_page(addr, flags);
+			global_flush_tlb();
+		} else
+			agp_generic_destroy_page(addr, flags);
 	}
 }
 
-static void m1541_destroy_page(void * addr)
+static void m1541_destroy_page(void * addr, int flags)
 {
 	u32 temp;
 
 	if (addr == NULL)
 		return;
 
-	global_cache_flush();
+	if (flags & AGP_PAGE_DESTROY_UNMAP) {
+		global_cache_flush();
 
-	pci_read_config_dword(agp_bridge->dev, ALI_CACHE_FLUSH_CTRL, &temp);
-	pci_write_config_dword(agp_bridge->dev, ALI_CACHE_FLUSH_CTRL,
-			(((temp & ALI_CACHE_FLUSH_ADDR_MASK) |
-			  virt_to_gart(addr)) | ALI_CACHE_FLUSH_EN));
-	agp_generic_destroy_page(addr);
+		pci_read_config_dword(agp_bridge->dev, ALI_CACHE_FLUSH_CTRL, &temp);
+		pci_write_config_dword(agp_bridge->dev, ALI_CACHE_FLUSH_CTRL,
+				       (((temp & ALI_CACHE_FLUSH_ADDR_MASK) |
+					 virt_to_gart(addr)) | ALI_CACHE_FLUSH_EN));
+	}
+	agp_generic_destroy_page(addr, flags);
 }
 
 

diff --git a/drivers/char/agp/amd-k7-agp.c b/drivers/char/agp/amd-k7-agp.c
@@ -100,21 +100,16 @@ static int amd_create_gatt_pages(int nr_tables)
 
 	for (i = 0; i < nr_tables; i++) {
 		entry = kzalloc(sizeof(struct amd_page_map), GFP_KERNEL);
+		tables[i] = entry;
 		if (entry == NULL) {
-			while (i > 0) {
-				kfree(tables[i-1]);
-				i--;
-			}
-			kfree(tables);
 			retval = -ENOMEM;
 			break;
 		}
-		tables[i] = entry;
 		retval = amd_create_page_map(entry);
 		if (retval != 0)
 			break;
 	}
-	amd_irongate_private.num_tables = nr_tables;
+	amd_irongate_private.num_tables = i;
 	amd_irongate_private.gatt_pages = tables;
 
 	if (retval != 0)

diff --git a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c
@@ -189,9 +189,11 @@ static int agp_backend_initialize(struct agp_bridge_data *bridge)
 
 err_out:
 	if (bridge->driver->needs_scratch_page) {
-		bridge->driver->agp_destroy_page(
-				gart_to_virt(bridge->scratch_page_real));
+		bridge->driver->agp_destroy_page(gart_to_virt(bridge->scratch_page_real),
+						 AGP_PAGE_DESTROY_UNMAP);
 		flush_agp_mappings();
+		bridge->driver->agp_destroy_page(gart_to_virt(bridge->scratch_page_real),
+						 AGP_PAGE_DESTROY_FREE);
 	}
 	if (got_gatt)
 		bridge->driver->free_gatt_table(bridge);
@@ -215,9 +217,11 @@ static void agp_backend_cleanup(struct agp_bridge_data *bridge)
 
 	if (bridge->driver->agp_destroy_page &&
 	    bridge->driver->needs_scratch_page) {
-		bridge->driver->agp_destroy_page(
-				gart_to_virt(bridge->scratch_page_real));
+		bridge->driver->agp_destroy_page(gart_to_virt(bridge->scratch_page_real),
+						 AGP_PAGE_DESTROY_UNMAP);
 		flush_agp_mappings();
+		bridge->driver->agp_destroy_page(gart_to_virt(bridge->scratch_page_real),
+						 AGP_PAGE_DESTROY_FREE);
 	}
 }
 

diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
@@ -195,9 +195,12 @@ void agp_free_memory(struct agp_memory *curr)
 	}
 	if (curr->page_count != 0) {
 		for (i = 0; i < curr->page_count; i++) {
-			curr->bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[i]));
+			curr->bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[i]), AGP_PAGE_DESTROY_UNMAP);
 		}
 		flush_agp_mappings();
+		for (i = 0; i < curr->page_count; i++) {
+			curr->bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[i]), AGP_PAGE_DESTROY_FREE);
+		}
 	}
 	agp_free_key(curr->key);
 	agp_free_page_array(curr);
@@ -1176,18 +1179,22 @@ void *agp_generic_alloc_page(struct agp_bridge_data *bridge)
 EXPORT_SYMBOL(agp_generic_alloc_page);
 
 
-void agp_generic_destroy_page(void *addr)
+void agp_generic_destroy_page(void *addr, int flags)
 {
 	struct page *page;
 
 	if (addr == NULL)
 		return;
 
 	page = virt_to_page(addr);
-	unmap_page_from_agp(page);
-	put_page(page);
-	free_page((unsigned long)addr);
-	atomic_dec(&agp_bridge->current_memory_agp);
+	if (flags & AGP_PAGE_DESTROY_UNMAP)
+		unmap_page_from_agp(page);
+
+	if (flags & AGP_PAGE_DESTROY_FREE) {
+		put_page(page);
+		free_page((unsigned long)addr);
+		atomic_dec(&agp_bridge->current_memory_agp);
+	}
 }
 EXPORT_SYMBOL(agp_generic_destroy_page);
 

diff --git a/drivers/char/agp/i460-agp.c b/drivers/char/agp/i460-agp.c
@@ -536,10 +536,10 @@ static void *i460_alloc_page (struct agp_bridge_data *bridge)
 	return page;
 }
 
-static void i460_destroy_page (void *page)
+static void i460_destroy_page (void *page, int flags)
 {
 	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT) {
-		agp_generic_destroy_page(page);
+		agp_generic_destroy_page(page, flags);
 		global_flush_tlb();
 	}
 }

diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
@@ -400,9 +400,11 @@ static void intel_i810_free_by_type(struct agp_memory *curr)
 		if (curr->page_count == 4)
 			i8xx_destroy_pages(gart_to_virt(curr->memory[0]));
 		else {
-			agp_bridge->driver->agp_destroy_page(
-				 gart_to_virt(curr->memory[0]));
+			agp_bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[0]),
+							     AGP_PAGE_DESTROY_UNMAP);
 			global_flush_tlb();
+			agp_bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[0]),
+							     AGP_PAGE_DESTROY_FREE);
 		}
 		agp_free_page_array(curr);
 	}