Remove criu exec code

It's now obsoleted by compel library.
Maybe-TODO: Add compel tool exec action?
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

compel/include/infect-priv.h

@@ -53,14 +53,6 @@ struct parasite_thread_ctl {
 struct ctl_msg;
 int parasite_wait_ack(int sockfd, unsigned int cmd, struct ctl_msg *m);
 
-/* XXX -- remove with cr-exec.c */
-extern int compel_map_exchange(struct parasite_ctl *ctl, unsigned long size);
-extern int compel_syscall(struct parasite_ctl *ctl, int nr, long *ret,
-			  unsigned long arg1, unsigned long arg2,
-			  unsigned long arg3, unsigned long arg4,
-			  unsigned long arg5, unsigned long arg6);
-
-
 extern void parasite_setup_regs(unsigned long new_ip, void *stack, user_regs_struct_t *regs);
 extern void *remote_mmap(struct parasite_ctl *ctl,
 		void *addr, size_t length, int prot,

compel/src/lib/infect.c

@@ -817,7 +817,7 @@ void compel_relocs_apply(void *mem, void *vbase, size_t size, compel_reloc_t *el
 	}
 }
 
-int compel_map_exchange(struct parasite_ctl *ctl, unsigned long size)
+static int compel_map_exchange(struct parasite_ctl *ctl, unsigned long size)
 {
 	int ret;
 

criu/Makefile.crtools

@@ -14,7 +14,6 @@ obj-y			+= cr-check.o
 obj-y			+= cr-dedup.o
 obj-y			+= cr-dump.o
 obj-y			+= cr-errno.o
-#obj-y			+= cr-exec.o
 obj-y			+= cr-restore.o
 obj-y			+= cr-service.o
 obj-y			+= crtools.o

criu/cr-exec.c

-#include <unistd.h>
-#include <string.h>
-#include <stdlib.h>
-#include "int.h"
-#include "types.h"
-#include "crtools.h"
-#include "parasite-syscall.h"
-#include "proc_parse.h"
-#include "ptrace.h"
-#include "pstree.h"
-#include "vma.h"
-#include "log.h"
-#include "util.h"
-#include "kerndat.h"
-#include <compel/compel.h>
-
-struct syscall_exec_desc {
-	char *name;
-	unsigned nr;
-};
-
-#define SYSCALL(__name, __nr) { .name = #__name, .nr = __nr, },
-#include "sys-exec-tbl.c"
-#undef SYSCALL
-
-#ifndef ARCH_HAS_FIND_SYSCALL
-struct syscall_exec_desc *
-find_syscall(char *name, struct parasite_ctl __always_unused *ctl)
-{
-	int i;
-
-	for (i = 0; sc_exec_table[i].name != NULL; i++)
-		if (!strcmp(sc_exec_table[i].name, name))
-			return &sc_exec_table[i];
-
-	return NULL;
-}
-#endif
-
-#define MAX_ARGS	6
-
-static int execute_syscall(struct parasite_ctl *ctl,
-		struct syscall_exec_desc *scd, char **opt)
-{
-	int i, err;
-	unsigned long args[MAX_ARGS] = {}, ret, r_mem_size = 0;
-	unsigned int ret_args[MAX_ARGS] = {};
-	void *r_mem = NULL;
-
-	for (i = 0; i < MAX_ARGS; i++) {
-		if (opt[i] == NULL)
-			break;
-
-		/*
-		 * &foo -- argument string "foo"
-		 * @<size> -- ret-arg of size <size>
-		 */
-
-		if ((opt[i][0] == '&') || (opt[i][0] == '@')) {
-			int len;
-
-			if (!r_mem) {
-				err = compel_map_exchange(ctl, PAGE_SIZE);
-				if (err)
-					return err;
-
-				r_mem_size = PAGE_SIZE;
-				r_mem = ctl->local_map;
-			}
-
-			if (opt[i][0] == '&') {
-				len = strlen(opt[i]);
-				if (r_mem_size < len) {
-					pr_err("Arg size overflow\n");
-					return -1;
-				}
-
-				memcpy(r_mem, opt[i] + 1, len);
-			} else {
-				len = strtol(opt[i] + 1, NULL, 0);
-				if (!len || (r_mem_size < len)) {
-					pr_err("Bad argument size %d\n", len);
-					return -1;
-				}
-
-				ret_args[i] = len;
-			}
-
-			args[i] = (unsigned long)ctl->remote_map + (r_mem - ctl->local_map);
-			pr_info("Pushing %c mem arg [%s]\n", opt[i][0], (char *)r_mem);
-			r_mem_size -= len;
-			r_mem += len;
-		} else
-			args[i] = strtol(opt[i], NULL, 0);
-	}
-
-	pr_info("Calling %d with %lu %lu %lu %lu %lu %lu\n", scd->nr,
-			args[0], args[1], args[2], args[3], args[4], args[5]);
-
-	err = compel_syscall(ctl, scd->nr, &ret,
-			args[0], args[1], args[2], args[3], args[4], args[5]);
-	if (err)
-		return err;
-
-	pr_msg("Syscall returned %lx(%d)\n", ret, (int)ret);
-	for (i = 0; i < MAX_ARGS; i++) {
-		unsigned long addr;
-
-		if (!ret_args[i])
-			continue;
-
-		pr_msg("Argument %d returns:\n", i);
-		addr = (unsigned long)ctl->local_map + (args[i] - (unsigned long)ctl->remote_map);
-		print_data(0, (unsigned char *)addr, ret_args[i]);
-	}
-
-	return 0;
-}
-
-int cr_exec(int pid, char **opt)
-{
-	char *sys_name = opt[0];
-	struct syscall_exec_desc *si;
-	struct parasite_ctl *ctl;
-	struct vm_area_list vmas;
-	int ret, prev_state, exit_code = -1;
-	struct proc_status_creds creds;
-	unsigned long p_start;
-
-	if (!sys_name) {
-		pr_err("Syscall name required\n");
-		goto out;
-	}
-
-	if (kerndat_init_cr_exec()) {
-		pr_err("Failed to init kerndat\n");
-		goto out;
-	}
-
-	if (compel_interrupt_task(pid))
-		goto out;
-
-	/*
-	 * We don't seize a task's threads here, so there is no reason to
-	 * mess with creds in this use case anyway.
-	 */
-
-	prev_state = ret = compel_wait_task(pid, -1, parse_pid_status, &creds.s);
-	if (ret < 0) {
-		pr_err("Can't seize task %d\n", pid);
-		goto out;
-	}
-
-	if (!is_alive_state(prev_state)) {
-		pr_err("Only can exec on running/stopped tasks\n");
-		goto out;
-	}
-
-	ret = collect_mappings(pid, &vmas, NULL);
-	if (ret) {
-		pr_err("Can't collect vmas for %d\n", pid);
-		goto out_unseize;
-	}
-
-	p_start = get_exec_start(&vmas);
-	if (!p_start) {
-		pr_err("No suitable VM are found\n");
-		goto out_unseize;
-	}
-
-	ctl = compel_prepare(pid);
-	if (!ctl) {
-		pr_err("Can't prep ctl %d\n", pid);
-		goto out_unseize;
-	}
-
-	ctl->ictx.syscall_ip = p_start;
-
-	si = find_syscall(sys_name, ctl);
-	if (!si) {
-		pr_err("Unknown syscall [%s]\n", sys_name);
-		goto out_cure;
-	}
-
-	ret = execute_syscall(ctl, si, opt + 1);
-	if (ret < 0) {
-		pr_err("Can't execute syscall remotely\n");
-		goto out_cure;
-	}
-
-	exit_code = 0;
-out_cure:
-	compel_cure(ctl);
-out_unseize:
-	compel_resume_task(pid, prev_state, prev_state);
-out:
-	return exit_code;
-}

criu/crtools.c

@@ -646,6 +646,11 @@ int main(int argc, char *argv[], char *envp[])
 		goto usage;
 	}
 
+	if (!strcmp(argv[optind], "exec")) {
+		pr_msg("The \"exec\" action is deprecated by the Compel library.\n");
+		return -1;
+	}
+
 	has_sub_command = (argc - optind) > 1;
 
 	if (has_exec_cmd) {
@@ -671,8 +676,7 @@ int main(int argc, char *argv[], char *envp[])
 		opts.exec_cmd[argc - optind - 1] = NULL;
 	} else {
 		/* No subcommands except for cpuinfo and restore --exec-cmd */
-		if ((strcmp(argv[optind], "cpuinfo") && strcmp(argv[optind], "exec"))
-				&& has_sub_command) {
+		if (strcmp(argv[optind], "cpuinfo") && has_sub_command) {
 			pr_msg("Error: excessive parameter%s for command %s\n",
 				(argc - optind) > 2 ? "s" : "", argv[optind]);
 			goto usage;
@@ -765,16 +769,6 @@ int main(int argc, char *argv[], char *envp[])
 	if (!strcmp(argv[optind], "check"))
 		return cr_check() != 0;
 
-#if 0
-	if (!strcmp(argv[optind], "exec")) {
-		if (!pid)
-			pid = tree_id; /* old usage */
-		if (!pid)
-			goto opt_pid_missing;
-		return cr_exec(pid, argv + optind + 1) != 0;
-	}
-#endif
-
 	if (!strcmp(argv[optind], "page-server"))
 		return cr_page_server(opts.daemon_mode, -1) != 0;
 
@@ -802,7 +796,6 @@ usage:
 "  criu dump|pre-dump -t PID [<options>]\n"
 "  criu restore [<options>]\n"
 "  criu check [--feature FEAT]\n"
-"  criu exec -p PID <syscall-string>\n"
 "  criu page-server\n"
 "  criu service [<options>]\n"
 "  criu dedup\n"
@@ -812,7 +805,6 @@ usage:
 "  pre-dump       pre-dump task(s) minimizing their frozen time\n"
 "  restore        restore a process/tree\n"
 "  check          checks whether the kernel support is up-to-date\n"
-"  exec           execute a system call by other task\n"
 "  page-server    launch page server\n"
 "  service        launch service\n"
 "  dedup          remove duplicates in memory dump\n"