[PATCH v2] Subject: eal: remove unnecessary argv[0] handling

[Stephen Hemminger <stephen@networkplumber.org>]

The rte_eal_init function only evalutes argv[0] to determine
the program name to pass to the log init function.
This is both unnecessary and in a corner case a problem.

It is possible to run a program with argc=0 and argv[0]=NULL.
This would cause rte_eal_init() to dereference a null pointer.
Not a really useful feature, but better for DPDK get a SEGV
if it doesn't need to.

Parsing argv[0] is unnecessary because the function openlog()
already determines the log identifier from program name if
NULL is passed.

openlog man page:
    The string pointed to by ident is prepended to every message, and is
    typically set to the program name. If ident is NULL, the program name
    is used.  (POSIX.1-2008 does not specify the behavior when ident is
    NULL.)

Since eal_log_init() is internal just drop the unused argument.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
 lib/eal/common/eal_log.h  | 2 +-
 lib/eal/linux/eal.c       | 6 +-----
 lib/eal/linux/eal_log.c   | 4 ++--
 lib/eal/windows/eal.c     | 2 +-
 lib/eal/windows/eal_log.c | 2 +-
 5 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/lib/eal/common/eal_log.h b/lib/eal/common/eal_log.h
index c784fa604389..d0282b3258da 100644
--- a/lib/eal/common/eal_log.h
+++ b/lib/eal/common/eal_log.h
@@ -11,7 +11,7 @@
 /*
  * Initialize the default log stream.
  */
-int eal_log_init(const char *id, int facility);
+int eal_log_init(int facility);
 
 /*
  * Determine where log data is written when no call to rte_openlog_stream.
diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
index 9c8395ab14d0..a6e8c5793334 100644
--- a/lib/eal/linux/eal.c
+++ b/lib/eal/linux/eal.c
@@ -966,8 +966,6 @@ rte_eal_init(int argc, char **argv)
 	pthread_t thread_id;
 	static uint32_t run_once;
 	uint32_t has_run = 0;
-	const char *p;
-	static char logid[PATH_MAX];
 	char cpuset[RTE_CPU_AFFINITY_STR_LEN];
 	char thread_name[RTE_MAX_THREAD_NAME_LEN];
 	bool phys_addrs;
@@ -989,8 +987,6 @@ rte_eal_init(int argc, char **argv)
 		return -1;
 	}
 
-	p = strrchr(argv[0], '/');
-	strlcpy(logid, p ? p + 1 : argv[0], sizeof(logid));
 	thread_id = pthread_self();
 
 	eal_reset_internal_config(internal_conf);
@@ -1165,7 +1161,7 @@ rte_eal_init(int argc, char **argv)
 #endif
 	}
 
-	if (eal_log_init(logid, internal_conf->syslog_facility) < 0) {
+	if (eal_log_init(internal_conf->syslog_facility) < 0) {
 		rte_eal_init_alert("Cannot init logging.");
 		rte_errno = ENOMEM;
 		__atomic_store_n(&run_once, 0, __ATOMIC_RELAXED);
diff --git a/lib/eal/linux/eal_log.c b/lib/eal/linux/eal_log.c
index c0aa1007c4df..e5cc10737b37 100644
--- a/lib/eal/linux/eal_log.c
+++ b/lib/eal/linux/eal_log.c
@@ -46,7 +46,7 @@ static cookie_io_functions_t console_log_func = {
  * once memzones are available.
  */
 int
-eal_log_init(const char *id, int facility)
+eal_log_init(int facility)
 {
 	FILE *log_stream;
 
@@ -54,7 +54,7 @@ eal_log_init(const char *id, int facility)
 	if (log_stream == NULL)
 		return -1;
 
-	openlog(id, LOG_NDELAY | LOG_PID, facility);
+	openlog(NULL, LOG_NDELAY | LOG_PID, facility);
 
 	eal_log_set_default(log_stream);
 
diff --git a/lib/eal/windows/eal.c b/lib/eal/windows/eal.c
index ca3c41aaa7f1..3133a934dd3c 100644
--- a/lib/eal/windows/eal.c
+++ b/lib/eal/windows/eal.c
@@ -280,7 +280,7 @@ rte_eal_init(int argc, char **argv)
 	enum rte_iova_mode iova_mode;
 	int ret;
 
-	eal_log_init(NULL, 0);
+	eal_log_init(0);
 
 	eal_log_level_parse(argc, argv);
 
diff --git a/lib/eal/windows/eal_log.c b/lib/eal/windows/eal_log.c
index d4ea47f1c824..df995c337998 100644
--- a/lib/eal/windows/eal_log.c
+++ b/lib/eal/windows/eal_log.c
@@ -8,7 +8,7 @@
 
 /* set the log to default function, called during eal init process. */
 int
-eal_log_init(__rte_unused const char *id, __rte_unused int facility)
+eal_log_init(__rte_unused int facility)
 {
 	rte_openlog_stream(stderr);
 
-- 
2.34.1