[PATCH 02/11] misc: st_core: Protect unsigned value against becoming negative

Lee Jones
2014-08-28T13:14:36Z

Coverity reported:
This less-than-zero comparison of an unsigned value is never true.

In answer to that, we only ever decrement if protos_registered is
positive. We can subsequently remove the paranoid checking during
unregister.

Cc: gregkh@linuxfoundation.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
drivers/misc/ti-st/st_core.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
index 1972d57a..54be83d 100644
--- a/drivers/misc/ti-st/st_core.c
+++ b/drivers/misc/ti-st/st_core.c
@@ -153,8 +153,9 @@ static void st_reg_complete(struct st_data_s *st_gdata, char err)
(st_gdata->list[i]->priv_data, err);
pr_info("protocol %d's cb sent %d\n", i, err);
if (err) { /* cleanup registered protocol */
- st_gdata->protos_registered--;
st_gdata->is_registered[i] = false;
+ if (st_gdata->protos_registered)
+ st_gdata->protos_registered--;
}
}
}
@@ -639,14 +640,12 @@ long st_unregister(struct st_proto_s *proto)
return -EPROTONOSUPPORT;
}

- st_gdata->protos_registered--;
+ if (st_gdata->protos_registered)
+ st_gdata->protos_registered--;
+
remove_channel_from_table(st_gdata, proto);
spin_unlock_irqrestore(&st_gdata->lock, flags);

- /* paranoid check */
- if (st_gdata->protos_registered < ST_EMPTY)
- st_gdata->protos_registered = ST_EMPTY;
-
if ((st_gdata->protos_registered == ST_EMPTY) &&
(!test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
pr_info(" all chnl_ids unregistered ");
--
1.9.1