In eal_intr_proc_rxtx_intr, negative value may be used as argument to a
function expecting a positive value. If 'read' returns EAGAIN as example, the
bytes_read updates to a negative value which continue be passed as argument for
the next 'read'.
Coverity issue: 107115
927 do {
3. negative_return_fn: Function read(fd, &buf, bytes_read) returns a
negative number.
4. var_assign: Assigning: signed variable bytes_read = read.
CID 107115 (#1 of 1): Argument cannot be negative
(NEGATIVE_RETURNS)9. negative_returns: bytes_read is passed to a parameter
that cannot be negative.
928 bytes_read = read(fd, &buf, bytes_read);
Fixes: c9f3ec1a0f3f ("eal/linux: add Rx interrupt control function")
Signed-off-by: Cunming Liang <cunming.liang at intel.com>
---
lib/librte_eal/linuxapp/eal/eal_interrupts.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/lib/librte_eal/linuxapp/eal/eal_interrupts.c
b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
index 470d6a1..06b26a9 100644
--- a/lib/librte_eal/linuxapp/eal/eal_interrupts.c
+++ b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
@@ -901,6 +901,7 @@ eal_intr_proc_rxtx_intr(int fd, const struct
rte_intr_handle *intr_handle)
{
union rte_intr_read_buffer buf;
int bytes_read = 1;
+ int nbytes;
switch (intr_handle->type) {
case RTE_INTR_HANDLE_UIO:
@@ -925,15 +926,15 @@ eal_intr_proc_rxtx_intr(int fd, const struct
rte_intr_handle *intr_handle)
* for epoll_wait.
*/
do {
- bytes_read = read(fd, &buf, bytes_read);
- if (bytes_read < 0) {
+ nbytes = read(fd, &buf, bytes_read);
+ if (nbytes < 0) {
if (errno == EINTR || errno == EWOULDBLOCK ||
errno == EAGAIN)
continue;
RTE_LOG(ERR, EAL,
"Error reading from fd %d: %s\n",
fd, strerror(errno));
- } else if (bytes_read == 0)
+ } else if (nbytes == 0)
RTE_LOG(ERR, EAL, "Read nothing from fd %d\n", fd);
return;
} while (1);
--
2.4.3
