Le 21/07/2022 à 12:00, Dan Carpenter a écrit :
On Thu, Jul 21, 2022 at 11:02:22AM +0200, Christophe JAILLET wrote:
find_first_zero_bit() returns MAX_COPPS_PER_PORT at max here.
So 'idx' should be tested with ">=" or the test can't match.
Fixes: 7b20b2be51e1 ("ASoC: qdsp6: q6adm: Add q6adm driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
sound/soc/qcom/qdsp6/q6adm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/soc/qcom/qdsp6/q6adm.c b/sound/soc/qcom/qdsp6/q6adm.c
index 01f383888b62..1530e98df165 100644
--- a/sound/soc/qcom/qdsp6/q6adm.c
+++ b/sound/soc/qcom/qdsp6/q6adm.c
@@ -217,7 +217,7 @@ static struct q6copp *q6adm_alloc_copp(struct q6adm *adm, int port_idx)
idx = find_first_zero_bit(&adm->copp_bitmap[port_idx],
MAX_COPPS_PER_PORT);
- if (idx > MAX_COPPS_PER_PORT)
+ if (idx >= MAX_COPPS_PER_PORT)
return ERR_PTR(-EBUSY);
Harshit asked me to write a Smatch check to prevent this bug in the
future. I got his email before I got your patch. :P Attached.
Well, well, well...
Easy to say afterwards. You got 58 mins to write it. :).
sound/soc/qcom/qdsp6/q6adm.c:220 q6adm_alloc_copp() warn: impossible find_next_bit condition
I'll probably try to make this check more generic, but even the simple
find_first_zero_bit() version will probably find bugs in the future and
it was pretty simple to write.
You could add find_last_bit(), find_next_zero_bit_le() and
find_next_bit_le().
regards,
dan carpenter
A reduced version of mine was:
@@
expression e1, e2;
statement S;
@@
(
* e1 = find_first_bit(...);
|
* e1 = find_last_bit(...);
|
[... snip ...]
)
...
if (e1 > e2)
S
(and it takes only a few seconds to scan the whole kernel :) )
