attach: use __do_free

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

src/lxc/attach.c

@@ -59,6 +59,7 @@
 #include "lxcseccomp.h"
 #include "macro.h"
 #include "mainloop.h"
+#include "memory_utils.h"
 #include "namespace.h"
 #include "raw_syscalls.h"
 #include "syscall_wrappers.h"
@@ -76,31 +77,28 @@ static lxc_attach_options_t attach_static_default_options = LXC_ATTACH_OPTIONS_D
 
 static struct lxc_proc_context_info *lxc_proc_get_context_info(pid_t pid)
 {
+	__do_free char *line = NULL;
+	__do_fclose FILE *proc_file = NULL;
 	int ret;
 	bool found;
-	FILE *proc_file;
 	char proc_fn[LXC_PROC_STATUS_LEN];
+	struct lxc_proc_context_info *info;
 	size_t line_bufsz = 0;
-	char *line = NULL;
-	struct lxc_proc_context_info *info = NULL;
 
 	/* Read capabilities. */
 	ret = snprintf(proc_fn, LXC_PROC_STATUS_LEN, "/proc/%d/status", pid);
 	if (ret < 0 || ret >= LXC_PROC_STATUS_LEN)
-		goto on_error;
+		return NULL;
 
 	proc_file = fopen(proc_fn, "r");
 	if (!proc_file) {
-		SYSERROR("Could not open %s", proc_fn);
-		goto on_error;
+		SYSERROR("Failed to open %s", proc_fn);
+		return NULL;
 	}
 
 	info = calloc(1, sizeof(*info));
-	if (!info) {
-		SYSERROR("Could not allocate memory");
-		fclose(proc_file);
+	if (!info)
 		return NULL;
-	}
 
 	found = false;
 
@@ -112,24 +110,17 @@ static struct lxc_proc_context_info *lxc_proc_get_context_info(pid_t pid)
 		}
 	}
 
-	free(line);
-	fclose(proc_file);
-
 	if (!found) {
-		ERROR("Could not read capability bounding set from %s",
-		      proc_fn);
-		goto on_error;
+		ERROR("Could not read capability bounding set from %s", proc_fn);
+		free(info);
+		return NULL;
 	}
 
 	info->lsm_label = lsm_process_label_get(pid);
 	info->ns_inherited = 0;
 	memset(info->ns_fd, -1, sizeof(int) * LXC_NS_MAX);
 
 	return info;
-
-on_error:
-	free(info);
-	return NULL;
 }
 
 static inline void lxc_proc_close_ns_fd(struct lxc_proc_context_info *ctx)
@@ -440,13 +431,14 @@ static int lxc_attach_set_environment(struct lxc_proc_context_info *init_ctx,
 
 static char *lxc_attach_getpwshell(uid_t uid)
 {
+	__do_free char *line = NULL;
+	__do_fclose FILE *pipe_f = NULL;
 	int fd, ret;
 	pid_t pid;
 	int pipes[2];
-	FILE *pipe_f;
 	bool found = false;
 	size_t line_bufsz = 0;
-	char *line = NULL, *result = NULL;
+	char *result = NULL;
 
 	/* We need to fork off a process that runs the getent program, and we
 	 * need to capture its output, so we use a pipe for that purpose.
@@ -567,9 +559,6 @@ static char *lxc_attach_getpwshell(uid_t uid)
 		found = true;
 	}
 
-	free(line);
-	fclose(pipe_f);
-
 	ret = wait_for_pid(pid);
 	if (ret < 0) {
 		free(result);
@@ -586,10 +575,10 @@ static char *lxc_attach_getpwshell(uid_t uid)
 
 static void lxc_attach_get_init_uidgid(uid_t *init_uid, gid_t *init_gid)
 {
-	FILE *proc_file;
+	__do_free char *line = NULL;
+	__do_fclose FILE *proc_file = NULL;
 	char proc_fn[LXC_PROC_STATUS_LEN];
 	int ret;
-	char *line = NULL;
 	size_t line_bufsz = 0;
 	long value = -1;
 	uid_t uid = (uid_t)-1;
@@ -620,9 +609,6 @@ static void lxc_attach_get_init_uidgid(uid_t *init_uid, gid_t *init_gid)
 			break;
 	}
 
-	fclose(proc_file);
-	free(line);
-
 	/* Only override arguments if we found something. */
 	if (uid != (uid_t)-1)
 		*init_uid = uid;
@@ -637,9 +623,9 @@ static void lxc_attach_get_init_uidgid(uid_t *init_uid, gid_t *init_gid)
 
 static bool fetch_seccomp(struct lxc_container *c, lxc_attach_options_t *options)
 {
+	__do_free char *path = NULL;
 	int ret;
 	bool bret;
-	char *path;
 
 	if (!(options->namespaces & CLONE_NEWNS) ||
 	    !(options->attach_flags & LXC_ATTACH_LSM)) {
@@ -667,7 +653,6 @@ static bool fetch_seccomp(struct lxc_container *c, lxc_attach_options_t *options
 
 	/* Copy the value into the new lxc_conf. */
 	bret = c->set_config_item(c, "lxc.seccomp.profile", path);
-	free(path);
 	if (!bret)
 		return false;
 
@@ -684,8 +669,7 @@ static bool fetch_seccomp(struct lxc_container *c, lxc_attach_options_t *options
 
 static bool no_new_privs(struct lxc_container *c, lxc_attach_options_t *options)
 {
-	bool bret;
-	char *val;
+	__do_free char *val = NULL;
 
 	/* Remove current setting. */
 	if (!c->set_config_item(c, "lxc.no_new_privs", "")) {
@@ -701,24 +685,18 @@ static bool no_new_privs(struct lxc_container *c, lxc_attach_options_t *options)
 	}
 
 	/* Set currently active setting. */
-	bret = c->set_config_item(c, "lxc.no_new_privs", val);
-	free(val);
-	return bret;
+	return c->set_config_item(c, "lxc.no_new_privs", val);
 }
 
 static signed long get_personality(const char *name, const char *lxcpath)
 {
-	char *p;
-	signed long ret;
+	__do_free char *p;
 
 	p = lxc_cmd_get_config_item(name, "lxc.arch", lxcpath);
 	if (!p)
 		return -1;
 
-	ret = lxc_config_parse_arch(p);
-	free(p);
-
-	return ret;
+	return lxc_config_parse_arch(p);
 }
 
 struct attach_clone_payload {
@@ -1547,11 +1525,11 @@ int lxc_attach_run_command(void *payload)
 
 int lxc_attach_run_shell(void* payload)
 {
+	__do_free char *buf = NULL;
 	uid_t uid;
 	struct passwd pwent;
 	struct passwd *pwentp = NULL;
 	char *user_shell;
-	char *buf;
 	size_t bufsize;
 	int ret;
 
@@ -1598,6 +1576,5 @@ int lxc_attach_run_shell(void* payload)
 	if (!pwentp)
 		free(user_shell);
 
-	free(buf);
 	return -1;
 }