Use absolute path for image files

Now I try to restore CWD and a relative path will be invalid.

Add new options -D to set image files directory.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

cr-restore.c

@@ -295,7 +295,7 @@ static int prepare_shmem_pid(int pid)
 	int sh_fd;
 	u32 type = 0;
 
-	sh_fd = open_fmt_ro(FMT_FNAME_SHMEM, pid);
+	sh_fd = open_image_ro(FMT_FNAME_SHMEM, pid);
 	if (sh_fd < 0) {
 		pr_perror("%d: Can't open shmem info\n", pid);
 		return 1;
@@ -333,7 +333,7 @@ static int prepare_pipes_pid(int pid)
 	int p_fd;
 	u32 type = 0;
 
-	p_fd = open_fmt_ro(FMT_FNAME_PIPES, pid);
+	p_fd = open_image_ro(FMT_FNAME_PIPES, pid);
 	if (p_fd < 0) {
 		pr_perror("%d: Can't open pipes image\n", pid);
 		return 1;
@@ -514,7 +514,7 @@ static int prepare_fds(int pid)
 
 	pr_info("%d: Opening files img\n", pid);
 
-	fdinfo_fd = open_fmt_ro(FMT_FNAME_FDINFO, pid);
+	fdinfo_fd = open_image_ro(FMT_FNAME_FDINFO, pid);
 	if (fdinfo_fd < 0) {
 		pr_perror("Can't open %d fdinfo", pid);
 		return 1;
@@ -593,7 +593,7 @@ static int prepare_shmem(int pid)
 	int sh_fd;
 	u32 type = 0;
 
-	sh_fd = open_fmt_ro(FMT_FNAME_SHMEM, pid);
+	sh_fd = open_image_ro(FMT_FNAME_SHMEM, pid);
 	if (sh_fd < 0) {
 		pr_perror("%d: Can't open shmem info\n", pid);
 		return 1;
@@ -754,7 +754,7 @@ static int fixup_pages_data(int pid, int fd)
 
 	pr_info("%d: Reading shmem pages img\n", pid);
 
-	shfd = open_fmt_ro(FMT_FNAME_PAGES_SHMEM, pid);
+	shfd = open_image_ro(FMT_FNAME_PAGES_SHMEM, pid);
 	if (shfd < 0) {
 		pr_perror("Can't open %d shmem image %s\n", pid);
 		return 1;
@@ -836,7 +836,7 @@ static int prepare_and_sigreturn(int pid)
 	int fd, fd_new;
 	struct stat buf;
 
-	fd = open_fmt_ro(FMT_FNAME_CORE, pid);
+	fd = open_image_ro(FMT_FNAME_CORE, pid);
 	if (fd < 0) {
 		pr_perror("%d: Can't open exec image\n", pid);
 		return 1;
@@ -846,7 +846,7 @@ static int prepare_and_sigreturn(int pid)
 		return 1;
 	}
 
-	sprintf(path, FMT_FNAME_CORE_OUT, pid);
+	IMAGE_PATH(path, FMT_FNAME_CORE_OUT, pid);
 	unlink(path);
 
 	fd_new = open(path, O_RDWR | O_CREAT | O_EXCL, CR_FD_PERM);
@@ -1058,7 +1058,7 @@ static int prepare_sigactions(int pid)
 	u32 type = 0;
 	int sig, i;
 
-	fd_sigact = open_fmt_ro(FMT_FNAME_SIGACTS, pid);
+	fd_sigact = open_image_ro(FMT_FNAME_SIGACTS, pid);
 	if (fd_sigact < 0) {
 		pr_perror("%d: Can't open sigactions img\n", pid);
 		return 1;
@@ -1111,7 +1111,7 @@ static int prepare_pipes(int pid)
 
 	pr_info("%d: Opening pipes\n", pid);
 
-	pipes_fd = open_fmt_ro(FMT_FNAME_PIPES, pid);
+	pipes_fd = open_image_ro(FMT_FNAME_PIPES, pid);
 	if (pipes_fd < 0) {
 		pr_perror("%d: Can't open pipes img\n", pid);
 		return 1;
@@ -1310,7 +1310,7 @@ static int restore_all_tasks(pid_t pid)
 	int pstree_fd;
 	u32 type = 0;
 
-	sprintf(path, FMT_FNAME_PSTREE, pid);
+	IMAGE_PATH(path, FMT_FNAME_PSTREE, pid);
 	pstree_fd = open(path, O_RDONLY);
 	if (pstree_fd < 0) {
 		pr_perror("%d: Can't open pstree image\n", pid);
@@ -1349,7 +1349,7 @@ static long restorer_get_vma_hint(pid_t pid, struct list_head *self_vma_list, lo
 	 * better to stick with it.
 	 */
 
-	snprintf(path, sizeof(path), FMT_FNAME_CORE, pid);
+	IMAGE_PATH(path, FMT_FNAME_CORE, pid);
 	fd = open(path, O_RDONLY, CR_FD_PERM);
 	if (fd < 0) {
 		pr_perror("Can't open %s\n", path);
@@ -1431,21 +1431,21 @@ static void sigreturn_restore(pid_t pstree_pid, pid_t pid)
 	BUILD_BUG_ON(sizeof(struct task_restore_core_args) & 1);
 	BUILD_BUG_ON(sizeof(struct thread_restore_args) & 1);
 
-	snprintf(path, sizeof(path), FMT_FNAME_PSTREE, pstree_pid);
+	IMAGE_PATH(path, FMT_FNAME_PSTREE, pstree_pid);
 	fd_pstree = open(path, O_RDONLY, CR_FD_PERM);
 	if (fd_pstree < 0) {
 		pr_perror("Can't open %s\n", path);
 		goto err;
 	}
 
-	snprintf(path, sizeof(path), FMT_FNAME_CORE_OUT, pid);
+	IMAGE_PATH(path, FMT_FNAME_CORE_OUT, pid);
 	fd_core = open(path, O_RDONLY, CR_FD_PERM);
 	if (fd_core < 0) {
 		pr_perror("Can't open %s\n", path);
 		goto err;
 	}
 
-	snprintf(self_vmas_path, sizeof(self_vmas_path), FMT_FNAME_VMAS, getpid());
+	IMAGE_PATH(self_vmas_path, FMT_FNAME_VMAS, getpid());
 	unlink(self_vmas_path);
 	fd_self_vmas = open(self_vmas_path, O_CREAT | O_RDWR, CR_FD_PERM);
 	if (fd_self_vmas < 0) {
@@ -1593,7 +1593,7 @@ static void sigreturn_restore(pid_t pstree_pid, pid_t pid)
 			read_ptr_safe(fd_pstree, &thread_args[i].pid, err);
 
 			/* Core files are to be opened */
-			snprintf(path, sizeof(path), FMT_FNAME_CORE, thread_args[i].pid);
+			IMAGE_PATH(path, FMT_FNAME_CORE, thread_args[i].pid);
 			thread_args[i].fd_core = open(path, O_RDONLY, CR_FD_PERM);
 			if (thread_args[i].fd_core < 0) {
 				pr_perror("Can't open %s\n", path);

crtools.c

@@ -91,6 +91,7 @@ struct cr_fdset *alloc_cr_fdset(pid_t pid)
 {
 	struct cr_fdset *cr_fdset;
 	unsigned int i;
+	int ret;
 
 	cr_fdset = xzalloc(sizeof(*cr_fdset));
 	if (!cr_fdset)
@@ -98,10 +99,14 @@ struct cr_fdset *alloc_cr_fdset(pid_t pid)
 
 	for (i = 0; i < CR_FD_MAX; i++) {
 		cr_fdset->desc[i].tmpl = &fdset_template[i];
-		snprintf(cr_fdset->desc[i].name,
-			 sizeof(cr_fdset->desc[i].name),
-			 cr_fdset->desc[i].tmpl->fmt,
-			 pid);
+		ret = get_image_path(cr_fdset->desc[i].name,
+				sizeof(cr_fdset->desc[i].name),
+				cr_fdset->desc[i].tmpl->fmt,
+				pid);
+		if (ret) {
+			xfree(cr_fdset);
+			return NULL;
+		}
 		cr_fdset->desc[i].fd = -1;
 	}
 
@@ -226,6 +231,22 @@ void free_cr_fdset(struct cr_fdset **cr_fdset)
 	}
 }
 
+char image_dir[PATH_MAX];
+int get_image_path(char *path, int size, const char *fmt, int pid)
+{
+	int image_dir_size = strlen(image_dir);
+	int ret;
+
+	strcpy(path, image_dir);
+	path[image_dir_size] = '/';
+	ret = snprintf(path + image_dir_size + 1, size, fmt, pid);
+	if (ret == -1 || ret > size) {
+		pr_err("can't get image path");
+		return -1;
+	}
+	return 0;
+}
+
 int main(int argc, char *argv[])
 {
 	pid_t pid;
@@ -233,7 +254,7 @@ int main(int argc, char *argv[])
 	int opt, idx;
 	int action = -1;
 
-	static const char short_opts[] = "drskf:p:t:hc";
+	static const char short_opts[] = "drskf:p:t:hcD:";
 	static const struct option long_opts[] = {
 		{ "dump",	no_argument, NULL, 'd' },
 		{ "restore",	no_argument, NULL, 'r' },
@@ -284,12 +305,23 @@ int main(int argc, char *argv[])
 		case 'k':
 			opts.final_state = CR_TASK_KILL;
 			break;
+		case 'D':
+			if (chdir(optarg)) {
+				pr_perror("can't change working directory");
+				return 1;
+			}
+			break;
 		case 'h':
 		default:
 			goto usage;
 		}
 	}
 
+	if (getcwd(image_dir, sizeof(image_dir)) < 0) {
+		pr_perror("can't get currect directory\n");
+		return 1;
+	}
+
 	switch (action) {
 	case 'd':
 		ret = cr_dump_tasks(pid, &opts);

include/crtools.h

@@ -58,6 +58,12 @@ struct cr_fd_desc_tmpl {
 #define FMT_FNAME_VMAS		"vmas-%d.img"
 #define FMT_FNAME_SIGACTS	"sigacts-%d.img"
 
+extern int get_image_path(char *path, int size, const char *fmt, int pid);
+#define IMAGE_PATH(path, fmt, pid) get_image_path(path, sizeof(path), fmt, pid);
+
+extern char image_dir[];
+#define open_image_ro(fmt, ...)	open_fmt("%s/" fmt, O_RDONLY, image_dir, __VA_ARGS__)
+
 #define LAST_PID_PATH		"/proc/sys/kernel/ns_last_pid"
 #define LAST_PID_PERM		0666
 

include/util.h

@@ -174,8 +174,6 @@ DIR *opendir_proc(char *fmt, ...);
 FILE *fopen_proc(char *fmt, char *mode, ...);
 int open_fmt(char *fmt, int mode, ...);
 
-#define open_fmt_ro(fmt, ...)		open_fmt(fmt, O_RDONLY, __VA_ARGS__)
-
 #define __xalloc(op, size, ...)						\
 	({								\
 		void *___p = op( __VA_ARGS__ );				\

parasite-syscall.c

@@ -345,20 +345,12 @@ int parasite_dump_sigacts_seized(struct parasite_ctl *ctl, struct cr_fdset *cr_f
 	parasite_args_cmd_dumpsigacts_t parasite_sigacts	= { };
 
 	int status, path_len, ret = -1;
-	char *cwd = NULL;
 
 	pr_info("\n");
 	pr_info("Dumping sigactions (pid: %d)\n", ctl->pid);
 	pr_info("----------------------------------------\n");
 
-	cwd = get_current_dir_name();
-	if (!cwd) {
-		pr_err("No memory to obtain cwd\n");
-		goto out;
-	}
-
-	path_len = strlen(cr_fdset->desc[CR_FD_SIGACT].name) +
-			strlen(cwd) + 2;
+	path_len = strlen(cr_fdset->desc[CR_FD_SIGACT].name);
 
 	if (path_len > sizeof(parasite_sigacts.open_path)) {
 		pr_panic("Dumping sigactions path is too long (%d while %d allowed)\n",
@@ -371,9 +363,9 @@ int parasite_dump_sigacts_seized(struct parasite_ctl *ctl, struct cr_fdset *cr_f
 		goto out;
 	}
 
-	snprintf(parasite_sigacts.open_path,
-		 sizeof(parasite_sigacts.open_path),
-		"%s/%s", cwd, cr_fdset->desc[CR_FD_SIGACT].name);
+	strncpy(parasite_sigacts.open_path,
+		 cr_fdset->desc[CR_FD_SIGACT].name,
+		 sizeof(parasite_sigacts.open_path));
 
 	parasite_sigacts.open_flags	= O_WRONLY;
 	parasite_sigacts.open_mode	= CR_FD_PERM_DUMP;
@@ -385,7 +377,6 @@ int parasite_dump_sigacts_seized(struct parasite_ctl *ctl, struct cr_fdset *cr_f
 err:
 	jerr(fchmod(cr_fdset->desc[CR_FD_SIGACT].fd, CR_FD_PERM), out);
 out:
-	xfree(cwd);
 	pr_info("----------------------------------------\n");
 
 	return ret;
@@ -406,20 +397,13 @@ int parasite_dump_pages_seized(struct parasite_ctl *ctl, struct list_head *vma_a
 	struct vma_area *vma_area;
 	siginfo_t siginfo;
 	int status, path_len, ret = -1;
-	char *cwd = NULL;
 
 	pr_info("\n");
 	pr_info("Dumping pages (type: %d pid: %d)\n", fd_type, ctl->pid);
 	pr_info("----------------------------------------\n");
 
-	cwd = get_current_dir_name();
-	if (!cwd) {
-		pr_err("No memory to obtain cwd\n");
-		goto out;
-	}
-
-	path_len = strlen(cr_fdset->desc[fd_type].name) +
-			strlen(cwd) + 2;
+	path_len = strlen(cr_fdset->desc[fd_type].name);
+	pr_info("Dumping pages %s\n", cr_fdset->desc[fd_type].name);
 
 	if (path_len > sizeof(parasite_dumppages.open_path)) {
 		pr_panic("Dumping pages path is too long (%d while %d allowed)\n",
@@ -438,9 +422,9 @@ int parasite_dump_pages_seized(struct parasite_ctl *ctl, struct list_head *vma_a
 	 */
 	fsync(cr_fdset->desc[fd_type].fd);
 
-	snprintf(parasite_dumppages.open_path,
-		 sizeof(parasite_dumppages.open_path),
-		"%s/%s", cwd, cr_fdset->desc[fd_type].name);
+	strncpy(parasite_dumppages.open_path,
+		 cr_fdset->desc[fd_type].name,
+		 sizeof(parasite_dumppages.open_path));
 
 	parasite_dumppages.open_flags	= O_WRONLY;
 	parasite_dumppages.open_mode	= CR_FD_PERM_DUMP;
@@ -511,7 +495,6 @@ err_restore:
 	jerr(fchmod(cr_fdset->desc[fd_type].fd, CR_FD_PERM), out);
 
 out:
-	xfree(cwd);
 	pr_info("----------------------------------------\n");
 
 	return ret;