HID: allocate hid_parser in a proper way

hid_parser is non-trivially large structure, so it should be allocated
using vmalloc() to avoid unsuccessful allocations when memory fragmentation
is too high.
This structue has a very short life, it's destroyed as soon as the report
descriptor has been completely parsed.

This should be considered a temporary solution, until the hid_parser is
rewritten to consume less memory during report descriptor parsing.

Acked-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 9 insertions, 7 deletions

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index f4ee1afe488f..e5894a75a6f3 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -26,6 +26,7 @@
 #include <asm/byteorder.h>
 #include <linux/input.h>
 #include <linux/wait.h>
+#include <linux/vmalloc.h>
 
 #include <linux/hid.h>
 #include <linux/hiddev.h>
@@ -654,12 +655,13 @@ struct hid_device *hid_parse_report(__u8 *start, unsigned size)
         memcpy(device->rdesc, start, size);
         device->rsize = size;
 
-        if (!(parser = kzalloc(sizeof(struct hid_parser), GFP_KERNEL))) {
+        if (!(parser = vmalloc(sizeof(struct hid_parser)))) {
                 kfree(device->rdesc);
                 kfree(device->collection);
                 kfree(device);
                 return NULL;
         }
+        memset(parser, 0, sizeof(struct hid_parser));
         parser->device = device;
 
         end = start + size;
@@ -668,7 +670,7 @@ struct hid_device *hid_parse_report(__u8 *start, unsigned size)
                 if (item.format != HID_ITEM_FORMAT_SHORT) {
                         dbg("unexpected long global item");
                         hid_free_device(device);
-                        kfree(parser);
+                        vfree(parser);
                         return NULL;
                 }
 
@@ -676,7 +678,7 @@ struct hid_device *hid_parse_report(__u8 *start, unsigned size)
                         dbg("item %u %u %u %u parsing failed\n",
                                 item.format, (unsigned)item.size, (unsigned)item.type, (unsigned)item.tag);
                         hid_free_device(device);
-                        kfree(parser);
+                        vfree(parser);
                         return NULL;
                 }
 
@@ -684,23 +686,23 @@ struct hid_device *hid_parse_report(__u8 *start, unsigned size)
                         if (parser->collection_stack_ptr) {
                                 dbg("unbalanced collection at end of report description");
                                 hid_free_device(device);
-                                kfree(parser);
+                                vfree(parser);
                                 return NULL;
                         }
                         if (parser->local.delimiter_depth) {
                                 dbg("unbalanced delimiter at end of report description");
                                 hid_free_device(device);
-                                kfree(parser);
+                                vfree(parser);
                                 return NULL;
                         }
-                        kfree(parser);
+                        vfree(parser);
                         return device;
                 }
         }
 
         dbg("item fetching failed at offset %d\n", (int)(end - start));
         hid_free_device(device);
-        kfree(parser);
+        vfree(parser);
         return NULL;
 }
 EXPORT_SYMBOL_GPL(hid_parse_report);