[dpdk-dev] [PATCH v3 14/14] eal: prevent different primary/secondary process versions

[Anatoly Burakov]

Currently, nothing stops DPDK to attempt to run primary and
secondary processes while having different versions. This
can lead to all sorts of weird behavior and makes it harder
to maintain compatibility without breaking ABI every once
in a while.

Fix it by explicitly disallowing running different DPDK
versions as primary and secondary processes.

Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
---
 lib/librte_eal/common/eal_common_mcfg.c | 15 +++++++++++++++
 lib/librte_eal/common/eal_memcfg.h      |  6 ++++++
 lib/librte_eal/freebsd/eal/eal.c        |  5 ++++-
 lib/librte_eal/linux/eal/eal.c          |  5 ++++-
 4 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_mcfg.c b/lib/librte_eal/common/eal_common_mcfg.c
index fe8d2b726..1825d9083 100644
--- a/lib/librte_eal/common/eal_common_mcfg.c
+++ b/lib/librte_eal/common/eal_common_mcfg.c
@@ -4,6 +4,7 @@
 
 #include <rte_config.h>
 #include <rte_eal_memconfig.h>
+#include <rte_version.h>
 
 #include "eal_internal_cfg.h"
 #include "eal_memcfg.h"
@@ -31,6 +32,18 @@ eal_mcfg_wait_complete(void)
 		rte_pause();
 }
 
+int
+eal_mcfg_check_version(void)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+
+	/* check if version from memconfig matches compiled in macro */
+	if (mcfg->version != RTE_VERSION)
+		return -1;
+
+	return 0;
+}
+
 void
 eal_mcfg_update_internal(void)
 {
@@ -47,6 +60,8 @@ eal_mcfg_update_from_internal(void)
 
 	mcfg->legacy_mem = internal_config.legacy_mem;
 	mcfg->single_file_segments = internal_config.single_file_segments;
+	/* record current DPDK version */
+	mcfg->version = RTE_VERSION;
 }
 
 void
diff --git a/lib/librte_eal/common/eal_memcfg.h b/lib/librte_eal/common/eal_memcfg.h
index d02ac1621..a3d4b7fd1 100644
--- a/lib/librte_eal/common/eal_memcfg.h
+++ b/lib/librte_eal/common/eal_memcfg.h
@@ -21,6 +21,8 @@
  */
 struct rte_mem_config {
 	volatile uint32_t magic;   /**< Magic number - Sanity check. */
+	uint32_t version;
+	/**< Prevent secondary processes using different DPDK versions. */
 
 	/* memory topology */
 	uint32_t nchannel;    /**< Number of channels (0 if unknown). */
@@ -80,6 +82,10 @@ eal_mcfg_update_from_internal(void);
 void
 eal_mcfg_wait_complete(void);
 
+/* check if DPDK version of current process matches one stored in the config */
+int
+eal_mcfg_check_version(void);
+
 /* set mem config as complete */
 void
 eal_mcfg_complete(void);
diff --git a/lib/librte_eal/freebsd/eal/eal.c b/lib/librte_eal/freebsd/eal/eal.c
index 6bfe203fd..e2039927c 100644
--- a/lib/librte_eal/freebsd/eal/eal.c
+++ b/lib/librte_eal/freebsd/eal/eal.c
@@ -385,6 +385,10 @@ rte_config_init(void)
 		if (rte_eal_config_attach() < 0)
 			return -1;
 		eal_mcfg_wait_complete();
+		if (eal_mcfg_check_version() < 0) {
+			RTE_LOG(ERR, EAL, "Primary and secondary process DPDK version mismatch\n");
+			return -1;
+		}
 		if (rte_eal_config_reattach() < 0)
 			return -1;
 		eal_mcfg_update_from_internal();
@@ -395,7 +399,6 @@ rte_config_init(void)
 			rte_config.process_type);
 		return -1;
 	}
-
 	return 0;
 }
 
diff --git a/lib/librte_eal/linux/eal/eal.c b/lib/librte_eal/linux/eal/eal.c
index fa205fd29..5421e934e 100644
--- a/lib/librte_eal/linux/eal/eal.c
+++ b/lib/librte_eal/linux/eal/eal.c
@@ -488,6 +488,10 @@ rte_config_init(void)
 		if (rte_eal_config_attach() < 0)
 			return -1;
 		eal_mcfg_wait_complete();
+		if (eal_mcfg_check_version() < 0) {
+			RTE_LOG(ERR, EAL, "Primary and secondary process DPDK version mismatch\n");
+			return -1;
+		}
 		if (rte_eal_config_reattach() < 0)
 			return -1;
 		eal_mcfg_update_internal();
@@ -498,7 +502,6 @@ rte_config_init(void)
 			rte_config.process_type);
 		return -1;
 	}
-
 	return 0;
 }
 
-- 
2.17.1