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>

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index f4ee1af..e5894a7 100644 (file)
--- 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);