[dpdk-stable] please check if patch 'eal: fix strdup usages in internal config' is applicable to LTS release 17.11.6

[Yongseok Koh <yskoh@mellanox.com>]

Hi,

Even though the patch doesn't have "Cc: stable@dpdk.org" tag or "Fixes:" tag,
the commit log says it fixes some issue. Tags might be mistakenly missed. We
don't want to miss any fixes for stable releases. That's why I'm sending this
email.

Please send backports if you think the patch should be merged to LTS release 17.11.6
Or, let me know if you have any comments, say, need more time, or it's worthless
to backport it. And please send it to "stable@dpdk.org", but not "dev@dpdk.org".

FYI, branch 17.11 is located at tree:
   git://dpdk.org/dpdk-stable

It'd be great if you could do that in one or two weeks. Also, please add a
heading line like below before the commit log body:
    [ backported from upstream commit xxx ]

Example: http://dpdk.org/browse/dpdk-stable/commit/?h=16.07&id=c4831394c7d1944d8ec27d52c22997f20d19718e

Also please mention the target LTS in the subject line, as we have
more than one at the same time, for example:

    [PATCH 17.11] foo/bar: fix baz

With git send-email, this can be achieved by appending the parameter:

    --subject-prefix='17.11'


Thanks.

Yongseok

---
>From 66d9f61de0885bd07662a016542600fe139d4eed Mon Sep 17 00:00:00 2001
From: Anatoly Burakov <anatoly.burakov@intel.com>
Date: Thu, 10 Jan 2019 13:38:59 +0000
Subject: [PATCH] eal: fix strdup usages in internal config

Currently, we use strdup in a few places to store command-line
parameter values for certain internal config values. There are
several issues with that.

First of all, they're never freed, so memory ends up leaking
either after EAL exit, or when these command-line options are
supplied multiple times.

Second of all, they're defined as `const char *`, so they
*cannot* be freed even if we wanted to.

Finally, strdup may return NULL, which will be stored in the
config. For most fields, NULL is a valid value, but for the
default prefix, the value is always expected to be valid.

To fix all of this, three things are done. First, we change
the definitions of these values to `char *` as opposed to
`const char *`. This does not break the ABI, and previous
code assumes constness (which is more restrictive), so it's
safe to do so.

Then, fix all usages of strdup to check return value, and add
a cleanup function that will free the memory occupied by
these strings, as well as freeing them before assigning a new
value to prevent leaks when parameter is specified multiple
times.

And finally, add an internal API to query hugefile prefix, so
that, absent of a valid value, a default value will be
returned, and also fix up all usages of hugefile prefix to
use this API instead of accessing hugefile prefix directly.

Bugzilla ID: 108

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 lib/librte_eal/bsdapp/eal/eal.c            | 19 ++++++++++--
 lib/librte_eal/common/eal_common_options.c | 25 ++++++++++++++--
 lib/librte_eal/common/eal_filesystem.h     |  6 +++-
 lib/librte_eal/common/eal_internal_cfg.h   |  6 ++--
 lib/librte_eal/common/eal_options.h        |  1 +
 lib/librte_eal/linuxapp/eal/eal.c          | 46 ++++++++++++++++++++++++------
 lib/librte_eal/linuxapp/eal/eal_memory.c   |  2 +-
 7 files changed, 87 insertions(+), 18 deletions(-)

diff --git a/lib/librte_eal/bsdapp/eal/eal.c b/lib/librte_eal/bsdapp/eal/eal.c
index c8e0da097..1ba9bd7cf 100644
--- a/lib/librte_eal/bsdapp/eal/eal.c
+++ b/lib/librte_eal/bsdapp/eal/eal.c
@@ -117,7 +117,7 @@ eal_create_runtime_dir(void)
 
 	/* create prefix-specific subdirectory under DPDK runtime dir */
 	ret = snprintf(runtime_dir, sizeof(runtime_dir), "%s/%s",
-			tmp, internal_config.hugefile_prefix);
+			tmp, eal_get_hugefile_prefix());
 	if (ret < 0 || ret == sizeof(runtime_dir)) {
 		RTE_LOG(ERR, EAL, "Error creating prefix-specific runtime path name\n");
 		return -1;
@@ -535,9 +535,21 @@ eal_parse_args(int argc, char **argv)
 
 		switch (opt) {
 		case OPT_MBUF_POOL_OPS_NAME_NUM:
-			internal_config.user_mbuf_pool_ops_name =
-			    strdup(optarg);
+		{
+			char *ops_name = strdup(optarg);
+			if (ops_name == NULL)
+				RTE_LOG(ERR, EAL, "Could not store mbuf pool ops name\n");
+			else {
+				/* free old ops name */
+				if (internal_config.user_mbuf_pool_ops_name !=
+						NULL)
+					free(internal_config.user_mbuf_pool_ops_name);
+
+				internal_config.user_mbuf_pool_ops_name =
+						ops_name;
+			}
 			break;
+		}
 		case 'h':
 			eal_usage(prgname);
 			exit(EXIT_SUCCESS);
@@ -923,6 +935,7 @@ rte_eal_cleanup(void)
 {
 	rte_service_finalize();
 	rte_mp_channel_cleanup();
+	eal_cleanup_config(&internal_config);
 	return 0;
 }
 
diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c
index 6e3a83b98..a2d862b5f 100644
--- a/lib/librte_eal/common/eal_common_options.c
+++ b/lib/librte_eal/common/eal_common_options.c
@@ -169,6 +169,14 @@ eal_option_device_parse(void)
 	return ret;
 }
 
+const char *
+eal_get_hugefile_prefix(void)
+{
+	if (internal_config.hugefile_prefix != NULL)
+		return internal_config.hugefile_prefix;
+	return HUGEFILE_PREFIX_DEFAULT;
+}
+
 void
 eal_reset_internal_config(struct internal_config *internal_cfg)
 {
@@ -177,7 +185,7 @@ eal_reset_internal_config(struct internal_config *internal_cfg)
 	internal_cfg->memory = 0;
 	internal_cfg->force_nrank = 0;
 	internal_cfg->force_nchannel = 0;
-	internal_cfg->hugefile_prefix = HUGEFILE_PREFIX_DEFAULT;
+	internal_cfg->hugefile_prefix = NULL;
 	internal_cfg->hugepage_dir = NULL;
 	internal_cfg->force_sockets = 0;
 	/* zero out the NUMA config */
@@ -1348,6 +1356,19 @@ eal_auto_detect_cores(struct rte_config *cfg)
 }
 
 int
+eal_cleanup_config(struct internal_config *internal_cfg)
+{
+	if (internal_cfg->hugefile_prefix != NULL)
+		free(internal_cfg->hugefile_prefix);
+	if (internal_cfg->hugepage_dir != NULL)
+		free(internal_cfg->hugepage_dir);
+	if (internal_cfg->user_mbuf_pool_ops_name != NULL)
+		free(internal_cfg->user_mbuf_pool_ops_name);
+
+	return 0;
+}
+
+int
 eal_adjust_config(struct internal_config *internal_cfg)
 {
 	int i;
@@ -1387,7 +1408,7 @@ eal_check_common_options(struct internal_config *internal_cfg)
 		RTE_LOG(ERR, EAL, "Invalid process type specified\n");
 		return -1;
 	}
-	if (index(internal_cfg->hugefile_prefix, '%') != NULL) {
+	if (index(eal_get_hugefile_prefix(), '%') != NULL) {
 		RTE_LOG(ERR, EAL, "Invalid char, '%%', in --"OPT_FILE_PREFIX" "
 			"option\n");
 		return -1;
diff --git a/lib/librte_eal/common/eal_filesystem.h b/lib/librte_eal/common/eal_filesystem.h
index 64a028db7..89a3added 100644
--- a/lib/librte_eal/common/eal_filesystem.h
+++ b/lib/librte_eal/common/eal_filesystem.h
@@ -28,6 +28,10 @@ eal_create_runtime_dir(void);
 int
 eal_clean_runtime_dir(void);
 
+/** Function to return hugefile prefix that's currently set up */
+const char *
+eal_get_hugefile_prefix(void);
+
 #define RUNTIME_CONFIG_FNAME "config"
 static inline const char *
 eal_runtime_config_path(void)
@@ -89,7 +93,7 @@ static inline const char *
 eal_get_hugefile_path(char *buffer, size_t buflen, const char *hugedir, int f_id)
 {
 	snprintf(buffer, buflen, HUGEFILE_FMT, hugedir,
-			internal_config.hugefile_prefix, f_id);
+			eal_get_hugefile_prefix(), f_id);
 	buffer[buflen - 1] = '\0';
 	return buffer;
 }
diff --git a/lib/librte_eal/common/eal_internal_cfg.h b/lib/librte_eal/common/eal_internal_cfg.h
index 98e314fef..60eaead8f 100644
--- a/lib/librte_eal/common/eal_internal_cfg.h
+++ b/lib/librte_eal/common/eal_internal_cfg.h
@@ -66,9 +66,9 @@ struct internal_config {
 	volatile int syslog_facility;	  /**< facility passed to openlog() */
 	/** default interrupt mode for VFIO */
 	volatile enum rte_intr_mode vfio_intr_mode;
-	const char *hugefile_prefix;      /**< the base filename of hugetlbfs files */
-	const char *hugepage_dir;         /**< specific hugetlbfs directory to use */
-	const char *user_mbuf_pool_ops_name;
+	char *hugefile_prefix;      /**< the base filename of hugetlbfs files */
+	char *hugepage_dir;         /**< specific hugetlbfs directory to use */
+	char *user_mbuf_pool_ops_name;
 			/**< user defined mbuf pool ops name */
 	unsigned num_hugepage_sizes;      /**< how many sizes on this system */
 	struct hugepage_info hugepage_info[MAX_HUGEPAGE_SIZES];
diff --git a/lib/librte_eal/common/eal_options.h b/lib/librte_eal/common/eal_options.h
index 1480c5d77..58ee9ae33 100644
--- a/lib/librte_eal/common/eal_options.h
+++ b/lib/librte_eal/common/eal_options.h
@@ -77,6 +77,7 @@ int eal_parse_common_option(int opt, const char *argv,
 			    struct internal_config *conf);
 int eal_option_device_parse(void);
 int eal_adjust_config(struct internal_config *internal_cfg);
+int eal_cleanup_config(struct internal_config *internal_cfg);
 int eal_check_common_options(struct internal_config *internal_cfg);
 void eal_common_usage(void);
 enum rte_proc_type_t eal_proc_type_detect(void);
diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
index 2d8d470b8..a386829f3 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -125,7 +125,7 @@ eal_create_runtime_dir(void)
 
 	/* create prefix-specific subdirectory under DPDK runtime dir */
 	ret = snprintf(runtime_dir, sizeof(runtime_dir), "%s/%s",
-			tmp, internal_config.hugefile_prefix);
+			tmp, eal_get_hugefile_prefix());
 	if (ret < 0 || ret == sizeof(runtime_dir)) {
 		RTE_LOG(ERR, EAL, "Error creating prefix-specific runtime path name\n");
 		return -1;
@@ -727,13 +727,31 @@ eal_parse_args(int argc, char **argv)
 			exit(EXIT_SUCCESS);
 
 		case OPT_HUGE_DIR_NUM:
-			internal_config.hugepage_dir = strdup(optarg);
+		{
+			char *hdir = strdup(optarg);
+			if (hdir == NULL)
+				RTE_LOG(ERR, EAL, "Could not store hugepage directory\n");
+			else {
+				/* free old hugepage dir */
+				if (internal_config.hugepage_dir != NULL)
+					free(internal_config.hugepage_dir);
+				internal_config.hugepage_dir = hdir;
+			}
 			break;
-
+		}
 		case OPT_FILE_PREFIX_NUM:
-			internal_config.hugefile_prefix = strdup(optarg);
+		{
+			char *prefix = strdup(optarg);
+			if (prefix == NULL)
+				RTE_LOG(ERR, EAL, "Could not store file prefix\n");
+			else {
+				/* free old prefix */
+				if (internal_config.hugefile_prefix != NULL)
+					free(internal_config.hugefile_prefix);
+				internal_config.hugefile_prefix = prefix;
+			}
 			break;
-
+		}
 		case OPT_SOCKET_MEM_NUM:
 			if (eal_parse_socket_arg(optarg,
 					internal_config.socket_mem) < 0) {
@@ -783,10 +801,21 @@ eal_parse_args(int argc, char **argv)
 			break;
 
 		case OPT_MBUF_POOL_OPS_NAME_NUM:
-			internal_config.user_mbuf_pool_ops_name =
-			    strdup(optarg);
+		{
+			char *ops_name = strdup(optarg);
+			if (ops_name == NULL)
+				RTE_LOG(ERR, EAL, "Could not store mbuf pool ops name\n");
+			else {
+				/* free old ops name */
+				if (internal_config.user_mbuf_pool_ops_name !=
+						NULL)
+					free(internal_config.user_mbuf_pool_ops_name);
+
+				internal_config.user_mbuf_pool_ops_name =
+						ops_name;
+			}
 			break;
-
+		}
 		case OPT_MATCH_ALLOCATIONS_NUM:
 			internal_config.match_allocations = 1;
 			break;
@@ -1238,6 +1267,7 @@ rte_eal_cleanup(void)
 		rte_memseg_walk(mark_freeable, NULL);
 	rte_service_finalize();
 	rte_mp_channel_cleanup();
+	eal_cleanup_config(&internal_config);
 	return 0;
 }
 
diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
index 7d922a965..1b96b576e 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -438,7 +438,7 @@ find_numasocket(struct hugepage_file *hugepg_tbl, struct hugepage_info *hpi)
 	}
 
 	snprintf(hugedir_str, sizeof(hugedir_str),
-			"%s/%s", hpi->hugedir, internal_config.hugefile_prefix);
+			"%s/%s", hpi->hugedir, eal_get_hugefile_prefix());
 
 	/* parse numa map */
 	while (fgets(buf, sizeof(buf), f) != NULL) {
-- 
2.11.0