lkml.org 
[lkml]   [2013]   [Nov]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH] devres: Freeing the drs after all release() are called
From
Date

In release_nodes(), it will call dr->node.release() and kfree
dr one by one.

But sometimes the previous dr maybe be used by next .release(),
such as:
[50314.855534] [<c12b172f>] ? synchronize_irq+0x3f/0xb0
[50314.861193] [<c12b18e9>] __free_irq+0x149/0x200
[50314.866367] [<c12b19e3>] free_irq+0x43/0xa0
[50314.871152] [<c12b4864>] devm_irq_release+0x14/0x20
[50314.876713] [<c169e806>] release_nodes+0x136/0x1b0
[50314.882178] [<c169ee79>] devres_release_all+0x39/0x60
[50314.887935] [<c169b411>] __device_release_driver+0x71/0xd0

the free_irq() will sync the last irq handling, which maybe use
freed dr, then it will cause memory corruption.

Here split the dr kfreeing actions after all dr->node.release().

Signed-off-by: Liu, Chuansheng <chuansheng.liu@intel.com>
---
drivers/base/devres.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index 507379e..66ff0be 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -490,9 +490,11 @@ static int release_nodes(struct device *dev, struct list_head *first,
list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
devres_log(dev, &dr->node, "REL");
dr->node.release(dev, dr->data);
- kfree(dr);
}

+ list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry)
+ kfree(dr);
+
return cnt;
}

--
1.7.9.5




\
 
 \ /
  Last update: 2013-11-06 08:21    [W:0.058 / U:2.304 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site