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From: Stephen Hemminger <stephen@networkplumber.org>
To: dev@dpdk.org
Cc: Stephen Hemminger <stephen@networkplumber.org>,
	Stephen Hemminger <sthemmin@microsoft.com>
Subject: [PATCH] eal: remove unnecessary argv[0] handling
Date: Wed,  2 Feb 2022 11:47:39 -0800	[thread overview]
Message-ID: <20220202194738.404876-1-stephen@networkplumber.org> (raw)

The rte_eal_init function looks at 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.

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

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.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
 lib/eal/linux/eal.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
index 60b49248388e..6bc7cdf440b8 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(NULL, internal_conf->syslog_facility) < 0) {
 		rte_eal_init_alert("Cannot init logging.");
 		rte_errno = ENOMEM;
 		__atomic_store_n(&run_once, 0, __ATOMIC_RELAXED);
-- 
2.34.1


             reply	other threads:[~2022-02-02 19:48 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-02 19:47 Stephen Hemminger [this message]
2022-02-09 14:58 ` Thomas Monjalon
2022-02-09 15:36   ` Stephen Hemminger
2022-02-09 15:45   ` Stephen Hemminger
2022-02-09 18:51     ` Thomas Monjalon
2022-02-09 19:29       ` Stephen Hemminger
2022-02-10  7:57         ` Thomas Monjalon
2022-02-09 15:54 ` [PATCH v2] Subject: " Stephen Hemminger
2022-02-09 20:41 ` [PATCH v3] eal: simplify " Stephen Hemminger

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