[dpdk-dev] [PATCH] test: make multiprocess launch error more informative

[Anatoly Burakov <anatoly.burakov@intel.com>]

Currently, if there is no procfs mounted, test application will
fail to run any multiprocess-related autotests (EAL flags etc.)
without a clear explanation as to why this happens.

Add a check specifically for that condition, as well as add a
general stringified error message to rte_panic.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 app/test/process.h | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/app/test/process.h b/app/test/process.h
index 513bc9420..128ce4121 100644
--- a/app/test/process.h
+++ b/app/test/process.h
@@ -5,12 +5,16 @@
 #ifndef _PROCESS_H_
 #define _PROCESS_H_
 
+#include <errno.h>  /* errno */
 #include <limits.h> /* PATH_MAX */
 #include <libgen.h> /* basename et al */
 #include <stdlib.h> /* NULL */
+#include <string.h> /* strerror */
 #include <unistd.h> /* readlink */
 #include <sys/wait.h>
 
+#include <rte_string_fns.h> /* strlcpy */
+
 #ifdef RTE_EXEC_ENV_FREEBSD
 #define self "curproc"
 #define exe "file"
@@ -67,8 +71,15 @@ process_dup(const char *const argv[], int numargs, const char *env_value)
 		/* set the environment variable */
 		if (setenv(RECURSIVE_ENV_VAR, env_value, 1) != 0)
 			rte_panic("Cannot export environment variable\n");
-		if (execv("/proc/" self "/" exe, argv_cpy) < 0)
-			rte_panic("Cannot exec\n");
+
+		strlcpy(path, "/proc/" self "/" exe, sizeof(path));
+		if (execv(path, argv_cpy) < 0) {
+			if (errno == ENOENT) {
+				printf("Could not find '%s', is procfs mounted?\n",
+						path);
+			}
+			rte_panic("Cannot exec: %s\n", strerror(errno));
+		}
 	}
 	/* parent process does a wait */
 #ifdef RTE_LIBRTE_PDUMP
-- 
2.17.1