[squash] livepatch/klp-convert: fix remaining memory leaks

Note: squash with ("livepatch: Add klp-convert tool")

As discovered by running valgrind --leak-check=full --track-origins=yes
against the livepatch sample and selftest modules.

I didn't capture all of the valgrind output to correlate to specific
fixes, but suffice to say that valgrind output is now happy reporting
"0 bytes in 0 blocks in use at exit" in its HEAP SUMMARY.

[joe: fix remaining valgrind leak complaints (non-error paths only)]

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>

scripts/livepatch/elf.c

@@ -351,7 +351,18 @@ static int update_shstrtab(struct elf *elf)
 	shstrtab->elf_data->d_size = shstrtab->size = new_size;
 	shstrtab->sh.sh_size = new_size;
 
-	return 0;
+	return 1;
+}
+
+static void free_shstrtab(struct elf *elf)
+{
+	struct section *shstrtab;
+
+	shstrtab = find_section_by_name(elf, ".shstrtab");
+	if (!shstrtab)
+		return;
+
+	free(shstrtab->elf_data->d_buf);
 }
 
 static int update_strtab(struct elf *elf)
@@ -399,7 +410,19 @@ static int update_strtab(struct elf *elf)
 	strtab->elf_data->d_size = strtab->size = new_size;
 	strtab->sh.sh_size = new_size;
 
-	return 0;
+	return 1;
+}
+
+static void free_strtab(struct elf *elf)
+{
+	struct section *strtab;
+
+	strtab = find_section_by_name(elf, ".strtab");
+	if (!strtab)
+		return;
+
+	if (strtab->elf_data)
+		free(strtab->elf_data->d_buf);
 }
 
 static int update_symtab(struct elf *elf)
@@ -455,7 +478,18 @@ static int update_symtab(struct elf *elf)
 	/* update symtab section header */
 	symtab->sh.sh_info = nr_locals;
 
-	return 0;
+	return 1;
+}
+
+static void free_symtab(struct elf *elf)
+{
+	struct section *symtab;
+
+	symtab = find_section_by_name(elf, ".symtab");
+	if (!symtab)
+		return;
+
+	free(symtab->elf_data->d_buf);
 }
 
 static int update_relas(struct elf *elf)
@@ -500,7 +534,23 @@ static int update_relas(struct elf *elf)
 		}
 	}
 
-	return 0;
+	return 1;
+}
+
+static void free_relas(struct elf *elf)
+{
+	struct section *sec, *symtab;
+
+	symtab = find_section_by_name(elf, ".symtab");
+	if (!symtab)
+		return;
+
+	list_for_each_entry(sec, &elf->sections, list) {
+		if (!is_rela_section(sec))
+			continue;
+
+		free(sec->elf_data->d_buf);
+	}
 }
 
 static int write_file(struct elf *elf, const char *file)
@@ -595,30 +645,49 @@ static int write_file(struct elf *elf, const char *file)
 		return -1;
 	}
 
+	elf_end(e);
+
 	return 0;
 }
 
 int elf_write_file(struct elf *elf, const char *file)
 {
+	int ret_shstrtab;
+	int ret_strtab;
+	int ret_symtab;
+	int ret_relas;
 	int ret;
 
-	ret = update_shstrtab(elf);
-	if (ret)
-		return ret;
+	ret_shstrtab = update_shstrtab(elf);
+	if (ret_shstrtab < 0)
+		return ret_shstrtab;
 
-	ret = update_strtab(elf);
-	if (ret)
-		return ret;
+	ret_strtab = update_strtab(elf);
+	if (ret_strtab < 0)
+		return ret_strtab;
 
-	ret = update_symtab(elf);
-	if (ret)
-		return ret;
+	ret_symtab = update_symtab(elf);
+	if (ret_symtab < 0)
+		return ret_symtab;
+
+	ret_relas = update_relas(elf);
+	if (ret_relas < 0)
+		return ret_relas;
 
-	ret = update_relas(elf);
+	ret = write_file(elf, file);
 	if (ret)
 		return ret;
 
-	return write_file(elf, file);
+	if (ret_relas > 0)
+		free_relas(elf);
+	if (ret_symtab > 0)
+		free_symtab(elf);
+	if (ret_strtab > 0)
+		free_strtab(elf);
+	if (ret_shstrtab > 0)
+		free_shstrtab(elf);
+
+	return 0;
 }
 
 struct elf *elf_open(const char *name)

scripts/livepatch/klp-convert.c

@@ -89,6 +89,7 @@ static bool load_syms_lists(const char *symbols_list)
 	}
 
 	len = 0;
+	free(sym);
 	sym = NULL;
 
 	/* read file */
@@ -192,6 +193,12 @@ static void clear_sympos_annontations(struct elf *klp_elf)
 			continue;
 		}
 		if (strncmp(sec->name, ".rela.klp.module_relocs.", 24) == 0) {
+
+			struct rela *rela, *tmprela;
+			list_for_each_entry_safe(rela, tmprela, &sec->relas, list) {
+				list_del(&rela->list);
+				free(rela);
+			}
 			list_del(&sec->list);
 			free(sec);
 			continue;
@@ -565,6 +572,38 @@ static bool must_convert(struct symbol *sym)
 	return (!(is_converted(sym->name) || is_exported(sym->name)));
 }
 
+/* Checks if a section is a klp rela section */
+static bool is_klp_rela_section(char *sname)
+{
+	int len = strlen(KLP_RELA_PREFIX);
+
+	if (strncmp(sname, KLP_RELA_PREFIX, len) == 0)
+		return true;
+	return false;
+}
+
+/*
+ * Frees the new names and rela sections as created by convert_rela()
+ */
+static void free_converted_resources(struct elf *klp_elf)
+{
+	struct symbol *sym;
+	struct section *sec;
+
+	list_for_each_entry(sym, &klp_elf->symbols, list) {
+		if (sym->name && is_converted(sym->name)) {
+			free(sym->name);
+		}
+	}
+
+	list_for_each_entry(sec, &klp_elf->sections, list) {
+		if (is_klp_rela_section(sec->name)) {
+			free(sec->elf_data);
+			free(sec->name);
+		}
+	}
+}
+
 int main(int argc, const char **argv)
 {
 	const char *klp_in_module, *klp_out_module, *symbols_list;
@@ -619,6 +658,9 @@ int main(int argc, const char **argv)
 	if (elf_write_file(klp_elf, klp_out_module))
 		return -1;
 
+	free_converted_resources(klp_elf);
+	elf_close(klp_elf);
+
 	return 0;
 }