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Remove mcoverlayfs code

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mcoverlayfs code is now unused (technically should work on top of the
soft emulation but not well tested, and untested unused code is bad).
Remove it.

Left the unshare/bind_mount_recursive code in mcexec in a new
MCEXEC_BIND_MOUNT ifdef (only in config.h.in directly to discourage use.
it disables the ioctl as well, but the main code is still compiled to
keep up to date with linux api changes... although it's using kallsyms
lookup so it does not validate much more than "the symbol still exists")

I honestly think this should go as well (people who would want to use it
are root and could do it manually), but will give up for now.

Change-Id: I832b6a8ab19e24ed67a1a5044b1c6c32381ae0aa
This commit is contained in:
Dominique Martinet
2019-02-15 09:32:12 +09:00
committed by Masamichi Takagi
parent 0bb612caea
commit 791e8c2114
38 changed files with 12 additions and 20839 deletions
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146
executer/user/mcexec.c
View File

@@ -1472,45 +1472,6 @@ int init_worker_threads(int fd)
return 0;
}
#ifdef ENABLE_MCOVERLAYFS
#define READ_BUFSIZE 1024
static int find_mount_prefix(char *prefix)
{
FILE *fp;
char *line = NULL;
size_t len = 0;
ssize_t read;
char proc_path[PATH_MAX];
int ret = 0;
snprintf(proc_path, sizeof(proc_path), "/proc/%d/mounts", getpid());
fp = fopen(proc_path, "r");
if (fp == NULL) {
return -1;
}
while ((read = getline(&line, &len, fp)) != -1) {
if (strlen(line) < strlen(prefix))
continue;
if (!strncmp(line, prefix, strlen(prefix))) {
ret = 1;
break;
}
}
free(line);
return ret;
}
static int isunshare(void)
{
return find_mount_prefix("mcoverlay /proc ");
}
#endif // ENABLE_MCOVERLAYFS
#define MCK_RLIMIT_AS 0
#define MCK_RLIMIT_CORE 1
#define MCK_RLIMIT_CPU 2
@@ -1846,7 +1807,7 @@ static struct option mcexec_options[] = {
{ NULL, 0, NULL, 0, },
};
#ifdef ENABLE_MCOVERLAYFS
#ifdef MCEXEC_BIND_MOUNT
/* bind-mount files under <root>/<prefix> over <prefix> recursively */
void bind_mount_recursive(const char *root, char *prefix)
{
@@ -1922,7 +1883,7 @@ void bind_mount_recursive(const char *root, char *prefix)
closedir(dir);
}
#endif
#endif // MCEXEC_BIND_MOUNT
static void
join_all_threads()
@@ -2321,11 +2282,7 @@ int main(int argc, char **argv)
envs_len = flatten_strings(NULL, environ, &envs);
#endif /* ADD_ENVS_OPTION */
#ifdef ENABLE_MCOVERLAYFS
__dprintf("mcoverlay enable\n");
char mcos_procdir[PATH_MAX];
char mcos_sysdir[PATH_MAX];
#ifdef MCEXEC_BIND_MOUNT
error = isunshare();
if (error == 0) {
struct sys_unshare_desc unshare_desc;
@@ -2356,87 +2313,11 @@ int main(int argc, char **argv)
return 1;
}
/*
* Umount cgroup filesystems that may expose invalid NUMA
* information
*/
if (find_mount_prefix("cgroup /sys/fs/cgroup/cpu,cpuacct")) {
umount_desc.dir_name = "/sys/fs/cgroup/cpu,cpuacct";
if (ioctl(fd, MCEXEC_UP_SYS_UMOUNT,
(unsigned long)&umount_desc) != 0) {
fprintf(stderr,
"WARNING: Failed to umount cgroup/cpu,cpuacct. (%s)\n",
strerror(errno));
}
}
else if (find_mount_prefix("cgroup /sys/fs/cgroup/cpu")) {
umount_desc.dir_name = "/sys/fs/cgroup/cpu";
if (ioctl(fd, MCEXEC_UP_SYS_UMOUNT,
(unsigned long)&umount_desc) != 0) {
fprintf(stderr,
"WARNING: Failed to umount cgroup/cpu. (%s)\n",
strerror(errno));
}
}
if (find_mount_prefix("cgroup /sys/fs/cgroup/cpuset")) {
umount_desc.dir_name = "/sys/fs/cgroup/cpuset";
if (ioctl(fd, MCEXEC_UP_SYS_UMOUNT,
(unsigned long)&umount_desc) != 0) {
fprintf(stderr,
"WARNING: Failed to umount cgroup/cpuset. (%s)\n",
strerror(errno));
}
}
if (find_mount_prefix("cgroup /sys/fs/cgroup/memory")) {
umount_desc.dir_name = "/sys/fs/cgroup/memory/";
if (ioctl(fd, MCEXEC_UP_SYS_UMOUNT,
(unsigned long)&umount_desc) != 0) {
fprintf(stderr,
"WARNING: Failed to umount cgroup/memory. (%s)\n",
strerror(errno));
}
}
sprintf(mcos_procdir, "/tmp/mcos/mcos%d_proc", mcosid);
mount_desc.dev_name = mcos_procdir;
mount_desc.dir_name = "/proc";
mount_desc.type = NULL;
mount_desc.flags = MS_BIND;
mount_desc.data = NULL;
if (ioctl(fd, MCEXEC_UP_SYS_MOUNT,
(unsigned long)&mount_desc) != 0) {
fprintf(stderr, "Error: Failed to mount /proc. (%s)\n",
strerror(errno));
return 1;
}
sprintf(mcos_sysdir, "/tmp/mcos/mcos%d_sys", mcosid);
mount_desc.dev_name = mcos_sysdir;
mount_desc.dir_name = "/sys";
mount_desc.type = NULL;
mount_desc.flags = MS_BIND;
mount_desc.data = NULL;
if (ioctl(fd, MCEXEC_UP_SYS_MOUNT,
(unsigned long)&mount_desc) != 0) {
fprintf(stderr, "Error: Failed to mount /sys. (%s)\n",
strerror(errno));
return 1;
}
bind_mount_recursive(ROOTFSDIR, "");
// bind_mount_recursive(<root>, <prefix>);
} else if (error == -1) {
return 1;
}
#else
__dprintf("mcoverlay disable\n");
#endif // ENABLE_MCOVERLAYFS
#endif // MCEXEC_BIND_MOUNT
if ((ret = load_elf_desc_shebang(argv[optind], &desc,
&shebang_argv, 1 /* execvp */))) {
@@ -4144,23 +4025,6 @@ return_execve1:
ret = 0;
return_execve2:
#ifdef ENABLE_MCOVERLAYFS
{
struct sys_mount_desc mount_desc;
mount_desc.dev_name = NULL;
mount_desc.dir_name = "/proc";
mount_desc.type = NULL;
mount_desc.flags = MS_REMOUNT;
mount_desc.data = NULL;
if (ioctl(fd, MCEXEC_UP_SYS_MOUNT,
(unsigned long)&mount_desc) != 0) {
fprintf(stderr,
"WARNING: failed to remount /proc (%s)\n",
strerror(errno));
}
}
#endif
do_syscall_return(fd, cpu, ret, 0, 0, 0, 0);
break;