mdadm: add map_num_s()

map_num() returns NULL if key is not defined. This patch adds
alternative, non NULL version for cases where NULL is not expected.

There are many printf() calls where map_num() is called on variable
without NULL verification. It works, even if NULL is passed because
gcc is able to ignore NULL argument quietly but the behavior is
undefined. For safety reasons such usages will use map_num_s() now.
It is a potential point of regression.

Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

13 files changed, 61 insertions, 38 deletions

diff --git a/Assemble.c b/Assemble.c
index 704b8293..9eac9ce0 100644
--- a/Assemble.c
+++ b/Assemble.c
@@ -63,7 +63,7 @@ static void set_array_assembly_status(struct context *c,
 				   struct assembly_array_info *arr)
 {
 	int raid_disks = arr->preexist_cnt + arr->new_cnt;
-	char *status_msg = map_num(assemble_statuses, status);
+	char *status_msg = map_num_s(assemble_statuses, status);
 
 	if (c->export && result)
 		*result |= status;
@@ -77,9 +77,7 @@ static void set_array_assembly_status(struct context *c,
 		fprintf(stderr, " (%d new)", arr->new_cnt);
 	if (arr->exp_cnt)
 		fprintf(stderr, " ( + %d for expansion)", arr->exp_cnt);
-	if (status_msg)
-		fprintf(stderr, " %s", status_msg);
-	fprintf(stderr, ".\n");
+	fprintf(stderr, " %s.\n", status_msg);
 }
 
 static int name_matches(char *found, char *required, char *homehost, int require_homehost)
diff --git a/Create.c b/Create.c
index 9ea19de0..c84c1ac8 100644
--- a/Create.c
+++ b/Create.c
@@ -83,7 +83,7 @@ int default_layout(struct supertype *st, int level, int verbose)
 
 	if (layout_map) {
 		layout = map_name(layout_map, "default");
-		layout_name = map_num(layout_map, layout);
+		layout_name = map_num_s(layout_map, layout);
 	}
 	if (layout_name && verbose > 0)
 		pr_err("layout defaults to %s\n", layout_name);
diff --git a/Detail.c b/Detail.c
index 95d4cc70..ce7a8445 100644
--- a/Detail.c
+++ b/Detail.c
@@ -495,8 +495,8 @@ int Detail(char *dev, struct context *c)
 			if (array.state & (1 << MD_SB_CLEAN)) {
 				if ((array.level == 0) ||
 				    (array.level == LEVEL_LINEAR))
-					arrayst = map_num(sysfs_array_states,
-							  sra->array_state);
+					arrayst = map_num_s(sysfs_array_states,
+							       sra->array_state);
 				else
 					arrayst = "clean";
 			} else {
diff --git a/Grow.c b/Grow.c
index 18c5719b..8a242b0f 100644
--- a/Grow.c
+++ b/Grow.c
@@ -547,7 +547,7 @@ int Grow_consistency_policy(char *devname, int fd, struct context *c, struct sha
 	if (s->consistency_policy != CONSISTENCY_POLICY_RESYNC &&
 	    s->consistency_policy != CONSISTENCY_POLICY_PPL) {
 		pr_err("Operation not supported for consistency policy %s\n",
-		       map_num(consistency_policies, s->consistency_policy));
+		       map_num_s(consistency_policies, s->consistency_policy));
 		return 1;
 	}
 
@@ -578,14 +578,14 @@ int Grow_consistency_policy(char *devname, int fd, struct context *c, struct sha
 
 	if (sra->consistency_policy == (unsigned)s->consistency_policy) {
 		pr_err("Consistency policy is already %s\n",
-		       map_num(consistency_policies, s->consistency_policy));
+		       map_num_s(consistency_policies, s->consistency_policy));
 		ret = 1;
 		goto free_info;
 	} else if (sra->consistency_policy != CONSISTENCY_POLICY_RESYNC &&
 		   sra->consistency_policy != CONSISTENCY_POLICY_PPL) {
 		pr_err("Current consistency policy is %s, cannot change to %s\n",
-		       map_num(consistency_policies, sra->consistency_policy),
-		       map_num(consistency_policies, s->consistency_policy));
+		       map_num_s(consistency_policies, sra->consistency_policy),
+		       map_num_s(consistency_policies, s->consistency_policy));
 		ret = 1;
 		goto free_info;
 	}
@@ -704,8 +704,8 @@ int Grow_consistency_policy(char *devname, int fd, struct context *c, struct sha
 	}
 
 	ret = sysfs_set_str(sra, NULL, "consistency_policy",
-			    map_num(consistency_policies,
-				    s->consistency_policy));
+			    map_num_s(consistency_policies,
+					 s->consistency_policy));
 	if (ret)
 		pr_err("Failed to change array consistency policy\n");
 
@@ -2241,7 +2241,7 @@ size_change_error:
 		info.new_layout = UnSet;
 		if (info.array.level == 6 && info.new_level == UnSet) {
 			char l[40], *h;
-			strcpy(l, map_num(r6layout, info.array.layout));
+			strcpy(l, map_num_s(r6layout, info.array.layout));
 			h = strrchr(l, '-');
 			if (h && strcmp(h, "-6") == 0) {
 				*h = 0;
@@ -2266,7 +2266,7 @@ size_change_error:
 			info.new_layout = info.array.layout;
 		else if (info.array.level == 5 && info.new_level == 6) {
 			char l[40];
-			strcpy(l, map_num(r5layout, info.array.layout));
+			strcpy(l, map_num_s(r5layout, info.array.layout));
 			strcat(l, "-6");
 			info.new_layout = map_name(r6layout, l);
 		} else {
diff --git a/Query.c b/Query.c
index 23fbf8aa..adcd231e 100644
--- a/Query.c
+++ b/Query.c
@@ -93,7 +93,7 @@ int Query(char *dev)
 	else {
 		printf("%s: %s %s %d devices, %d spare%s. Use mdadm --detail for more detail.\n",
 		       dev, human_size_brief(larray_size,IEC),
-		       map_num(pers, level), raid_disks,
+		       map_num_s(pers, level), raid_disks,
 		       spare_disks, spare_disks == 1 ? "" : "s");
 	}
 	st = guess_super(fd);
@@ -131,7 +131,7 @@ int Query(char *dev)
 		       dev,
 		       info.disk.number, info.array.raid_disks,
 		       activity,
-		       map_num(pers, info.array.level),
+		       map_num_s(pers, info.array.level),
 		       mddev);
 		if (st->ss == &super0)
 			put_md_name(mddev);
diff --git a/maps.c b/maps.c
index a4fd2797..20fcf719 100644
--- a/maps.c
+++ b/maps.c
@@ -166,6 +166,30 @@ mapping_t sysfs_array_states[] = {
 	{ NULL, ARRAY_UNKNOWN_STATE }
 };
 
+/**
+ * map_num_s() - Safer alternative of map_num() function.
+ * @map: map to search.
+ * @num: key to match.
+ *
+ * Shall be used only if key existence is quaranted.
+ *
+ * Return: Pointer to name of the element.
+ */
+char *map_num_s(mapping_t *map, int num)
+{
+	char *ret = map_num(map, num);
+
+	assert(ret);
+	return ret;
+}
+
+/**
+ * map_num() - get element name by key.
+ * @map: map to search.
+ * @num: key to match.
+ *
+ * Return: Pointer to name of the element or NULL.
+ */
 char *map_num(mapping_t *map, int num)
 {
 	while (map->name) {
diff --git a/mdadm.c b/mdadm.c
index 26299b2e..be40686c 100644
--- a/mdadm.c
+++ b/mdadm.c
@@ -280,8 +280,8 @@ int main(int argc, char *argv[])
 			else
 				fprintf(stderr, "-%c", opt);
 			fprintf(stderr, " would set mdadm mode to \"%s\", but it is already set to \"%s\".\n",
-				map_num(modes, newmode),
-				map_num(modes, mode));
+				map_num_s(modes, newmode),
+				map_num_s(modes, mode));
 			exit(2);
 		} else if (!mode && newmode) {
 			mode = newmode;
@@ -544,7 +544,7 @@ int main(int argc, char *argv[])
 			switch(s.level) {
 			default:
 				pr_err("layout not meaningful for %s arrays.\n",
-					map_num(pers, s.level));
+					map_num_s(pers, s.level));
 				exit(2);
 			case UnSet:
 				pr_err("raid level must be given before layout.\n");
@@ -1248,10 +1248,10 @@ int main(int argc, char *argv[])
 		if (option_index > 0)
 			pr_err(":option --%s not valid in %s mode\n",
 				long_options[option_index].name,
-				map_num(modes, mode));
+				map_num_s(modes, mode));
 		else
 			pr_err("option -%c not valid in %s mode\n",
-				opt, map_num(modes, mode));
+				opt, map_num_s(modes, mode));
 		exit(2);
 
 	}
@@ -1276,7 +1276,7 @@ int main(int argc, char *argv[])
 		if (s.consistency_policy != CONSISTENCY_POLICY_UNKNOWN &&
 		    s.consistency_policy != CONSISTENCY_POLICY_JOURNAL) {
 			pr_err("--write-journal is not supported with consistency policy: %s\n",
-			       map_num(consistency_policies, s.consistency_policy));
+			       map_num_s(consistency_policies, s.consistency_policy));
 			exit(2);
 		}
 	}
@@ -1285,12 +1285,12 @@ int main(int argc, char *argv[])
 	    s.consistency_policy != CONSISTENCY_POLICY_UNKNOWN) {
 		if (s.level <= 0) {
 			pr_err("--consistency-policy not meaningful with level %s.\n",
-			       map_num(pers, s.level));
+			       map_num_s(pers, s.level));
 			exit(2);
 		} else if (s.consistency_policy == CONSISTENCY_POLICY_JOURNAL &&
 			   !s.journaldisks) {
 			pr_err("--write-journal is required for consistency policy: %s\n",
-			       map_num(consistency_policies, s.consistency_policy));
+			       map_num_s(consistency_policies, s.consistency_policy));
 			exit(2);
 		} else if (s.consistency_policy == CONSISTENCY_POLICY_PPL &&
 			   s.level != 5) {
@@ -1300,14 +1300,14 @@ int main(int argc, char *argv[])
 			   (!s.bitmap_file ||
 			    strcmp(s.bitmap_file, "none") == 0)) {
 			pr_err("--bitmap is required for consistency policy: %s\n",
-			       map_num(consistency_policies, s.consistency_policy));
+			       map_num_s(consistency_policies, s.consistency_policy));
 			exit(2);
 		} else if (s.bitmap_file &&
 			   strcmp(s.bitmap_file, "none") != 0 &&
 			   s.consistency_policy != CONSISTENCY_POLICY_BITMAP &&
 			   s.consistency_policy != CONSISTENCY_POLICY_JOURNAL) {
 			pr_err("--bitmap is not compatible with consistency policy: %s\n",
-			       map_num(consistency_policies, s.consistency_policy));
+			       map_num_s(consistency_policies, s.consistency_policy));
 			exit(2);
 		}
 	}
diff --git a/mdadm.h b/mdadm.h
index cd72e711..09915a00 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -770,7 +770,7 @@ extern int restore_stripes(int *dest, unsigned long long *offsets,
 #endif
 
 #define SYSLOG_FACILITY LOG_DAEMON
-
+extern char *map_num_s(mapping_t *map, int num);
 extern char *map_num(mapping_t *map, int num);
 extern int map_name(mapping_t *map, char *name);
 extern mapping_t r0layout[], r5layout[], r6layout[],
diff --git a/super-ddf.c b/super-ddf.c
index 3f304cdc..8cda23a7 100644
--- a/super-ddf.c
+++ b/super-ddf.c
@@ -1477,13 +1477,13 @@ static void examine_vds(struct ddf_super *sb)
 		printf("\n");
 		printf("         unit[%d] : %d\n", i, be16_to_cpu(ve->unit));
 		printf("        state[%d] : %s, %s%s\n", i,
-		       map_num(ddf_state, ve->state & 7),
+		       map_num_s(ddf_state, ve->state & 7),
 		       (ve->state & DDF_state_morphing) ? "Morphing, ": "",
 		       (ve->state & DDF_state_inconsistent)? "Not Consistent" : "Consistent");
 		printf("   init state[%d] : %s\n", i,
-		       map_num(ddf_init_state, ve->init_state&DDF_initstate_mask));
+		       map_num_s(ddf_init_state, ve->init_state & DDF_initstate_mask));
 		printf("       access[%d] : %s\n", i,
-		       map_num(ddf_access, (ve->init_state & DDF_access_mask) >> 6));
+		       map_num_s(ddf_access, (ve->init_state & DDF_access_mask) >> 6));
 		printf("         Name[%d] : %.16s\n", i, ve->name);
 		examine_vd(i, sb, ve->guid);
 	}
diff --git a/super-intel.c b/super-intel.c
index 6ff336ee..ba3bd41f 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -5625,7 +5625,7 @@ static int init_super_imsm_volume(struct supertype *st, mdu_array_info_t *info,
 		free(dev);
 		free(dv);
 		pr_err("imsm does not support consistency policy %s\n",
-		       map_num(consistency_policies, s->consistency_policy));
+		       map_num_s(consistency_policies, s->consistency_policy));
 		return 0;
 	}
 
diff --git a/super0.c b/super0.c
index b79b97a9..61c9ec1d 100644
--- a/super0.c
+++ b/super0.c
@@ -288,7 +288,7 @@ static void export_examine_super0(struct supertype *st)
 {
 	mdp_super_t *sb = st->sb;
 
-	printf("MD_LEVEL=%s\n", map_num(pers, sb->level));
+	printf("MD_LEVEL=%s\n", map_num_s(pers, sb->level));
 	printf("MD_DEVICES=%d\n", sb->raid_disks);
 	if (sb->minor_version >= 90)
 		printf("MD_UUID=%08x:%08x:%08x:%08x\n",
diff --git a/super1.c b/super1.c
index a12a5bc8..e3e2f954 100644
--- a/super1.c
+++ b/super1.c
@@ -671,7 +671,7 @@ static void export_examine_super1(struct supertype *st)
 	int len = 32;
 	int layout;
 
-	printf("MD_LEVEL=%s\n", map_num(pers, __le32_to_cpu(sb->level)));
+	printf("MD_LEVEL=%s\n", map_num_s(pers, __le32_to_cpu(sb->level)));
 	printf("MD_DEVICES=%d\n", __le32_to_cpu(sb->raid_disks));
 	for (i = 0; i < 32; i++)
 		if (sb->set_name[i] == '\n' || sb->set_name[i] == '\0') {
diff --git a/sysfs.c b/sysfs.c
index 2995713d..0d98a65f 100644
--- a/sysfs.c
+++ b/sysfs.c
@@ -689,7 +689,7 @@ int sysfs_set_array(struct mdinfo *info, int vers)
 	if (info->array.level < 0)
 		return 0; /* FIXME */
 	rv |= sysfs_set_str(info, NULL, "level",
-			    map_num(pers, info->array.level));
+			    map_num_s(pers, info->array.level));
 	if (info->reshape_active && info->delta_disks != UnSet)
 		raid_disks -= info->delta_disks;
 	rv |= sysfs_set_num(info, NULL, "raid_disks", raid_disks);
@@ -724,9 +724,10 @@ int sysfs_set_array(struct mdinfo *info, int vers)
 	}
 
 	if (info->consistency_policy == CONSISTENCY_POLICY_PPL) {
-		if (sysfs_set_str(info, NULL, "consistency_policy",
-				  map_num(consistency_policies,
-					  info->consistency_policy))) {
+		char *policy = map_num_s(consistency_policies,
+					    info->consistency_policy);
+
+		if (sysfs_set_str(info, NULL, "consistency_policy", policy)) {
 			pr_err("This kernel does not support PPL. Falling back to consistency-policy=resync.\n");
 			info->consistency_policy = CONSISTENCY_POLICY_RESYNC;
 		}