[dpdk-dev] [PATCH v5] eal: do not panic on shared memory init

[Arnon Warshavsky <arnon@qwilt.com>]

This patch changes some void functions to return a value,
so that the init sequence may tear down orderly
instead of calling panic.

Signed-off-by: Arnon Warshavsky <arnon@qwilt.com>
---

The calls for launching core messaging threads were left in tact
in all 3 eal implementations.
This should be addressed in a different patchset.
There are still cases where the PMDs or message threads
may call panic with no context for the user.
For these I will submit a patch suggesting a callback registration,
allowing the user to register a context to be called
in case of a panic that takes place outside the init sequence.

-v2 fix freebsd compilation
-v3 fix freebsd compilation, haste from the devil
-v4 fix comments by David
-v5 fix more comments by david. rename patch

 lib/librte_eal/freebsd/eal/eal.c |  69 ++++++++++++++++++--------
 lib/librte_eal/linux/eal/eal.c   | 101 +++++++++++++++++++++++++++------------
 2 files changed, 120 insertions(+), 50 deletions(-)

diff --git a/lib/librte_eal/freebsd/eal/eal.c b/lib/librte_eal/freebsd/eal/eal.c
index c6ac902..f18f08e 100644
--- a/lib/librte_eal/freebsd/eal/eal.c
+++ b/lib/librte_eal/freebsd/eal/eal.c
@@ -215,7 +215,7 @@ enum rte_iova_mode
  * We also don't lock the whole file, so that in future we can use read-locks
  * on other parts, e.g. memzones, to detect if there are running secondary
  * processes. */
-static void
+static int
 rte_eal_config_create(void)
 {
 	void *rte_mem_cfg_addr;
@@ -224,60 +224,82 @@ enum rte_iova_mode
 	const char *pathname = eal_runtime_config_path();
 
 	if (internal_config.no_shconf)
-		return;
+		return 0;
 
 	if (mem_cfg_fd < 0){
 		mem_cfg_fd = open(pathname, O_RDWR | O_CREAT, 0600);
-		if (mem_cfg_fd < 0)
-			rte_panic("Cannot open '%s' for rte_mem_config\n", pathname);
+		if (mem_cfg_fd < 0) {
+			RTE_LOG(ERR, EAL, "Cannot open '%s' for rte_mem_config\n",
+				pathname);
+			return -1;
+		}
 	}
 
 	retval = ftruncate(mem_cfg_fd, sizeof(*rte_config.mem_config));
 	if (retval < 0){
 		close(mem_cfg_fd);
-		rte_panic("Cannot resize '%s' for rte_mem_config\n", pathname);
+		mem_cfg_fd = -1;
+		RTE_LOG(ERR, EAL, "Cannot resize '%s' for rte_mem_config\n",
+			pathname);
+		return -1;
 	}
 
 	retval = fcntl(mem_cfg_fd, F_SETLK, &wr_lock);
 	if (retval < 0){
 		close(mem_cfg_fd);
-		rte_exit(EXIT_FAILURE, "Cannot create lock on '%s'. Is another primary "
-				"process running?\n", pathname);
+		mem_cfg_fd = -1;
+		RTE_LOG(ERR, EAL, "Cannot create lock on '%s'. Is another primary "
+			"process running?\n", pathname);
+		return -1;
 	}
 
 	rte_mem_cfg_addr = mmap(NULL, sizeof(*rte_config.mem_config),
 				PROT_READ | PROT_WRITE, MAP_SHARED, mem_cfg_fd, 0);
 
 	if (rte_mem_cfg_addr == MAP_FAILED){
-		rte_panic("Cannot mmap memory for rte_config\n");
+		RTE_LOG(ERR, EAL, "Cannot mmap memory for rte_config\n");
+		close(mem_cfg_fd);
+		mem_cfg_fd = -1;
+		return -1;
 	}
 	memcpy(rte_mem_cfg_addr, &early_mem_config, sizeof(early_mem_config));
 	rte_config.mem_config = rte_mem_cfg_addr;
+
+	return 0;
 }
 
 /* attach to an existing shared memory config */
-static void
+static int
 rte_eal_config_attach(void)
 {
 	void *rte_mem_cfg_addr;
 	const char *pathname = eal_runtime_config_path();
 
 	if (internal_config.no_shconf)
-		return;
+		return 0;
 
 	if (mem_cfg_fd < 0){
 		mem_cfg_fd = open(pathname, O_RDWR);
-		if (mem_cfg_fd < 0)
-			rte_panic("Cannot open '%s' for rte_mem_config\n", pathname);
+		if (mem_cfg_fd < 0) {
+			RTE_LOG(ERR, EAL, "Cannot open '%s' for rte_mem_config\n",
+				pathname);
+			return -1;
+		}
 	}
 
 	rte_mem_cfg_addr = mmap(NULL, sizeof(*rte_config.mem_config),
 				PROT_READ | PROT_WRITE, MAP_SHARED, mem_cfg_fd, 0);
 	close(mem_cfg_fd);
-	if (rte_mem_cfg_addr == MAP_FAILED)
-		rte_panic("Cannot mmap memory for rte_config\n");
+	mem_cfg_fd = -1;
+	if (rte_mem_cfg_addr == MAP_FAILED) {
+		RTE_LOG(ERR, EAL, "Cannot mmap memory for rte_config! error %i (%s)\n",
+			errno, strerror(errno));
+		return -1;
+	}
 
 	rte_config.mem_config = rte_mem_cfg_addr;
+
+	return 0;
 }
 
 /* Detect if we are a primary or a secondary process */
@@ -306,23 +328,29 @@ enum rte_proc_type_t
 }
 
 /* Sets up rte_config structure with the pointer to shared memory config.*/
-static void
+static int
 rte_config_init(void)
 {
 	rte_config.process_type = internal_config.process_type;
 
 	switch (rte_config.process_type){
 	case RTE_PROC_PRIMARY:
-		rte_eal_config_create();
+		if (rte_eal_config_create() < 0)
+			return -1;
 		break;
 	case RTE_PROC_SECONDARY:
-		rte_eal_config_attach();
+		if (rte_eal_config_attach() < 0)
+			return -1;
 		rte_eal_mcfg_wait_complete(rte_config.mem_config);
 		break;
 	case RTE_PROC_AUTO:
 	case RTE_PROC_INVALID:
-		rte_panic("Invalid process type\n");
+		RTE_LOG(ERR, EAL, "Invalid process type %d\n",
+			rte_config.process_type);
+		return -1;
 	}
+
+	return 0;
 }
 
 /* display usage */
@@ -655,7 +683,10 @@ static void rte_eal_init_alert(const char *msg)
 		return -1;
 	}
 
-	rte_config_init();
+	if (rte_config_init() < 0) {
+		rte_eal_init_alert("Cannot init config");
+		return -1;
+	}
 
 	if (rte_eal_intr_init() < 0) {
 		rte_eal_init_alert("Cannot init interrupt-handling thread");
diff --git a/lib/librte_eal/linux/eal/eal.c b/lib/librte_eal/linux/eal/eal.c
index 1613996..224ba90 100644
--- a/lib/librte_eal/linux/eal/eal.c
+++ b/lib/librte_eal/linux/eal/eal.c
@@ -300,7 +300,7 @@ enum rte_iova_mode
  * We also don't lock the whole file, so that in future we can use read-locks
  * on other parts, e.g. memzones, to detect if there are running secondary
  * processes. */
-static void
+static int
 rte_eal_config_create(void)
 {
 	void *rte_mem_cfg_addr;
@@ -309,7 +309,7 @@ enum rte_iova_mode
 	const char *pathname = eal_runtime_config_path();
 
 	if (internal_config.no_shconf)
-		return;
+		return 0;
 
 	/* map the config before hugepage address so that we don't waste a page */
 	if (internal_config.base_virtaddr != 0)
@@ -321,29 +321,41 @@ enum rte_iova_mode
 
 	if (mem_cfg_fd < 0){
 		mem_cfg_fd = open(pathname, O_RDWR | O_CREAT, 0600);
-		if (mem_cfg_fd < 0)
-			rte_panic("Cannot open '%s' for rte_mem_config\n", pathname);
+		if (mem_cfg_fd < 0) {
+			RTE_LOG(ERR, EAL, "Cannot open '%s' for rte_mem_config\n",
+				pathname);
+			return -1;
+		}
 	}
 
 	retval = ftruncate(mem_cfg_fd, sizeof(*rte_config.mem_config));
 	if (retval < 0){
 		close(mem_cfg_fd);
-		rte_panic("Cannot resize '%s' for rte_mem_config\n", pathname);
+		mem_cfg_fd = -1;
+		RTE_LOG(ERR, EAL, "Cannot resize '%s' for rte_mem_config\n",
+			pathname);
+		return -1;
 	}
 
 	retval = fcntl(mem_cfg_fd, F_SETLK, &wr_lock);
 	if (retval < 0){
 		close(mem_cfg_fd);
-		rte_exit(EXIT_FAILURE, "Cannot create lock on '%s'. Is another primary "
-				"process running?\n", pathname);
+		mem_cfg_fd = -1;
+		RTE_LOG(ERR, EAL, "Cannot create lock on '%s'. Is another primary "
+			"process running?\n", pathname);
+		return -1;
 	}
 
 	rte_mem_cfg_addr = mmap(rte_mem_cfg_addr, sizeof(*rte_config.mem_config),
 				PROT_READ | PROT_WRITE, MAP_SHARED, mem_cfg_fd, 0);
 
 	if (rte_mem_cfg_addr == MAP_FAILED){
-		rte_panic("Cannot mmap memory for rte_config\n");
+		close(mem_cfg_fd);
+		mem_cfg_fd = -1;
+		RTE_LOG(ERR, EAL, "Cannot mmap memory for rte_config\n");
+		return -1;
 	}
+
 	memcpy(rte_mem_cfg_addr, &early_mem_config, sizeof(early_mem_config));
 	rte_config.mem_config = rte_mem_cfg_addr;
 
@@ -353,10 +365,11 @@ enum rte_iova_mode
 
 	rte_config.mem_config->dma_maskbits = 0;
 
+	return 0;
 }
 
 /* attach to an existing shared memory config */
-static void
+static int
 rte_eal_config_attach(void)
 {
 	struct rte_mem_config *mem_config;
@@ -364,33 +377,42 @@ enum rte_iova_mode
 	const char *pathname = eal_runtime_config_path();
 
 	if (internal_config.no_shconf)
-		return;
+		return 0;
 
 	if (mem_cfg_fd < 0){
 		mem_cfg_fd = open(pathname, O_RDWR);
-		if (mem_cfg_fd < 0)
-			rte_panic("Cannot open '%s' for rte_mem_config\n", pathname);
+		if (mem_cfg_fd < 0) {
+			RTE_LOG(ERR, EAL, "Cannot open '%s' for rte_mem_config\n",
+				pathname);
+			return -1;
+		}
 	}
 
 	/* map it as read-only first */
 	mem_config = (struct rte_mem_config *) mmap(NULL, sizeof(*mem_config),
 			PROT_READ, MAP_SHARED, mem_cfg_fd, 0);
-	if (mem_config == MAP_FAILED)
-		rte_panic("Cannot mmap memory for rte_config! error %i (%s)\n",
-			  errno, strerror(errno));
+	if (mem_config == MAP_FAILED) {
+		close(mem_cfg_fd);
+		mem_cfg_fd = -1;
+		RTE_LOG(ERR, EAL, "Cannot mmap memory for rte_config! error %i (%s)\n",
+			errno, strerror(errno));
+		return -1;
+	}
 
 	rte_config.mem_config = mem_config;
+
+	return 0;
 }
 
 /* reattach the shared config at exact memory location primary process has it */
-static void
+static int
 rte_eal_config_reattach(void)
 {
 	struct rte_mem_config *mem_config;
 	void *rte_mem_cfg_addr;
 
 	if (internal_config.no_shconf)
-		return;
+		return 0;
 
 	/* save the address primary process has mapped shared config to */
 	rte_mem_cfg_addr = (void *) (uintptr_t) rte_config.mem_config->mem_cfg_addr;
@@ -402,19 +424,26 @@ enum rte_iova_mode
 	mem_config = (struct rte_mem_config *) mmap(rte_mem_cfg_addr,
 			sizeof(*mem_config), PROT_READ | PROT_WRITE, MAP_SHARED,
 			mem_cfg_fd, 0);
+
+	close(mem_cfg_fd);
+	mem_cfg_fd = -1;
+
 	if (mem_config == MAP_FAILED || mem_config != rte_mem_cfg_addr) {
-		if (mem_config != MAP_FAILED)
+		if (mem_config != MAP_FAILED) {
 			/* errno is stale, don't use */
-			rte_panic("Cannot mmap memory for rte_config at [%p], got [%p]"
-				  " - please use '--base-virtaddr' option\n",
-				  rte_mem_cfg_addr, mem_config);
-		else
-			rte_panic("Cannot mmap memory for rte_config! error %i (%s)\n",
-				  errno, strerror(errno));
+			RTE_LOG(ERR, EAL, "Cannot mmap memory for rte_config at [%p], got [%p]"
+				" - please use '--base-virtaddr' option\n",
+				rte_mem_cfg_addr, mem_config);
+			return -1;
+		}
+		RTE_LOG(ERR, EAL, "Cannot mmap memory for rte_config! error %i (%s)\n",
+			errno, strerror(errno));
+		return -1;
 	}
-	close(mem_cfg_fd);
 
 	rte_config.mem_config = mem_config;
+
+	return 0;
 }
 
 /* Detect if we are a primary or a secondary process */
@@ -461,26 +490,33 @@ enum rte_proc_type_t
 }
 
 /* Sets up rte_config structure with the pointer to shared memory config.*/
-static void
+static int
 rte_config_init(void)
 {
 	rte_config.process_type = internal_config.process_type;
 
 	switch (rte_config.process_type){
 	case RTE_PROC_PRIMARY:
-		rte_eal_config_create();
+		if (rte_eal_config_create() < 0)
+			return -1;
 		eal_update_mem_config();
 		break;
 	case RTE_PROC_SECONDARY:
-		rte_eal_config_attach();
+		if (rte_eal_config_attach() < 0)
+			return -1;
 		rte_eal_mcfg_wait_complete(rte_config.mem_config);
-		rte_eal_config_reattach();
+		if (rte_eal_config_reattach() < 0)
+			return -1;
 		eal_update_internal_config();
 		break;
 	case RTE_PROC_AUTO:
 	case RTE_PROC_INVALID:
-		rte_panic("Invalid process type\n");
+		RTE_LOG(ERR, EAL, "Invalid process type %d\n",
+			rte_config.process_type);
+		return -1;
 	}
+
+	return 0;
 }
 
 /* Unlocks hugepage directories that were locked by eal_hugepage_info_init */
@@ -998,7 +1034,10 @@ static void rte_eal_init_alert(const char *msg)
 		return -1;
 	}
 
-	rte_config_init();
+	if (rte_config_init() < 0) {
+		rte_eal_init_alert("Cannot init config");
+		return -1;
+	}
 
 	if (rte_eal_intr_init() < 0) {
 		rte_eal_init_alert("Cannot init interrupt-handling thread");
-- 
1.8.3.1