driver core: debug for bad dev_attr_show() return value.
Try to find the culprit who caused
http://bugzilla.kernel.org/show_bug.cgi?id=10150
Cc: <balajirrao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 7de543d..24198ad0 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -19,6 +19,7 @@
#include <linux/kdev_t.h>
#include <linux/notifier.h>
#include <linux/genhd.h>
+#include <linux/kallsyms.h>
#include <asm/semaphore.h>
#include "base.h"
@@ -68,6 +69,10 @@
if (dev_attr->show)
ret = dev_attr->show(dev, dev_attr, buf);
+ if (ret >= (ssize_t)PAGE_SIZE) {
+ print_symbol("dev_attr_show: %s returned bad count\n",
+ (unsigned long)dev_attr->show);
+ }
return ret;
}
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index a271c87..baa663e 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -12,6 +12,7 @@
#include <linux/module.h>
#include <linux/kobject.h>
+#include <linux/kallsyms.h>
#include <linux/namei.h>
#include <linux/poll.h>
#include <linux/list.h>
@@ -86,7 +87,12 @@
* The code works fine with PAGE_SIZE return but it's likely to
* indicate truncated result or overflow in normal use cases.
*/
- BUG_ON(count >= (ssize_t)PAGE_SIZE);
+ if (count >= (ssize_t)PAGE_SIZE) {
+ print_symbol("fill_read_buffer: %s returned bad count\n",
+ (unsigned long)ops->show);
+ /* Try to struggle along */
+ count = PAGE_SIZE - 1;
+ }
if (count >= 0) {
buffer->needs_read_fill = 0;
buffer->count = count;
