[dpdk-dev] [PATCH v3 1/3] examples/vm_power_manager: fix string truncation warning

[Bruce Richardson <bruce.richardson@intel.com>]

When compiling on ubuntu 20.04, a warning was issued about possible
truncation of the path string for the power management socket.

channel_manager.c: In function ‘add_all_channels’:
channel_manager.c:470:41: warning: ‘%s’ directive output may be truncated writing up to 255 bytes into a region of size 90 [-Wformat-truncation=]
  470 |     sizeof(chan_info->channel_path), "%s%s",
      |                                         ^~

This can be fixed by adding in an explicit truncation check to the code and
handling it appropriately.

Fixes: e8ae9b662506 ("examples/vm_power: channel manager and monitor in host")
Cc: stable@dpdk.org

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: David Hunt <david.hunt@intel.com>
---
 examples/vm_power_manager/channel_manager.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/examples/vm_power_manager/channel_manager.c b/examples/vm_power_manager/channel_manager.c
index 74a2a677e..a26315051 100644
--- a/examples/vm_power_manager/channel_manager.c
+++ b/examples/vm_power_manager/channel_manager.c
@@ -467,9 +467,15 @@ add_all_channels(const char *vm_name)
 			continue;
 		}
 
-		snprintf(chan_info->channel_path,
+		if ((size_t)snprintf(chan_info->channel_path,
 				sizeof(chan_info->channel_path), "%s%s",
-				CHANNEL_MGR_SOCKET_PATH, dir->d_name);
+				CHANNEL_MGR_SOCKET_PATH, dir->d_name)
+					>= sizeof(chan_info->channel_path)) {
+			RTE_LOG(ERR, CHANNEL_MANAGER, "Pathname too long for channel '%s%s'\n",
+					CHANNEL_MGR_SOCKET_PATH, dir->d_name);
+			rte_free(chan_info);
+			continue;
+		}
 
 		if (setup_channel_info(&vm_info, &chan_info, channel_num) < 0) {
 			rte_free(chan_info);
-- 
2.25.1