On Jul 22 2016 11:39, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Sakamoto [mailto:o-takashi@sakamocchi.jp] Sent: Friday, July 22, 2016 10:16 AM To: mengdong.lin@linux.intel.com; alsa-devel@alsa-project.org; broonie@kernel.org Cc: tiwai@suse.de; Lin, Mengdong; Girdwood, Liam R; Nc, Shreyas Subject: Re: [PATCH v2 2/2] topology: Fix the missing referenced elem ptr when merging private data
On Jul 22 2016 10:47, mengdong.lin@linux.intel.com wrote:
From: Mengdong Lin mengdong.lin@linux.intel.com
tplg_copy_data() should set the valid referenced data element pointer on success. The caller will double check this pointer for all kinds of references, including controls and data.
Signed-off-by: Mengdong Lin mengdong.lin@linux.intel.com
diff --git a/src/topology/data.c b/src/topology/data.c index 768fc27..e7793b2 100644 --- a/src/topology/data.c +++ b/src/topology/data.c @@ -1078,6 +1078,8 @@ int tplg_copy_data(snd_tplg_t *tplg, struct
tplg_elem *elem,
ref_elem->compound_elem = 1; memcpy(priv->data + old_priv_data_size, ref_elem->data->data, priv_data_size);
- ref->elem = ref_elem; return 0; }
Is this really OK when the found topology element has no private data? In this case, ref->elem has no assignment at return.
No. This is my mistake. Thanks for finding this bug.
ref->elem should still be assigned for this case. I will make it like this:
/* overlook empty private data */ if (!ref_elem->data || !ref_elem->data->size) { ref->elem = ref_elem; return 0; }
Let us split data merging code to an explicit function? Then:
if (ref_elem->data != NULL && ref_elem->data->size > 0) { err = merge_private_data(elem, ref_elem); if (err < 0) return err; } ref->elem = ref_elem; return 0;
(Here, I expect compiler optimization to merge the new function to caller implicitly.)
Regards
Takashi Sakamoto