[Devel] [PATCH ckpt-v15] allocate checkpoint headers with kzalloc

Nathan Lynch ntl at pobox.com
Wed May 13 08:55:59 PDT 2009

In a checkpoint image I noticed a lot of 0x6b (POISON_FREE) bytes
corresponding to checkpoint_restart_block -- this indicates that we
would write uninitialized kernel memory to the image in cases where
slab allocator debugging is not enabled[1].

Use kzalloc in ckpt_hdr_get.

[1] slub's debug mode apparently initializes allocated buffers to
POISON_FREE instead of POISON_INUSE, which confused me for a bit.
Maybe I don't understand the intended meanings of the poison values.

Signed-off-by: Nathan Lynch <ntl at pobox.com>
 checkpoint/sys.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/checkpoint/sys.c b/checkpoint/sys.c
index 255ebc1..34a226c 100644
--- a/checkpoint/sys.c
+++ b/checkpoint/sys.c
@@ -117,7 +117,7 @@ int ckpt_kread(struct ckpt_ctx *ctx, void *addr, int count)
 void *ckpt_hdr_get(struct ckpt_ctx *ctx, int len)
-	return kmalloc(len, GFP_KERNEL);
+	return kzalloc(len, GFP_KERNEL);

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