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Diffstat (limited to 'support/test-container.c')
| -rw-r--r-- | support/test-container.c | 988 |
1 files changed, 988 insertions, 0 deletions
diff --git a/support/test-container.c b/support/test-container.c new file mode 100644 index 0000000000..ce16e061e7 --- /dev/null +++ b/support/test-container.c @@ -0,0 +1,988 @@ +/* Run a test case in an isolated namespace. + Copyright (C) 2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#define _FILE_OFFSET_BITS 64 + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sched.h> +#include <sys/syscall.h> +#include <unistd.h> +#include <sys/types.h> +#include <dirent.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/fcntl.h> +#include <sys/file.h> +#include <sys/wait.h> +#include <stdarg.h> +#include <sys/sysmacros.h> +#include <ctype.h> +#include <utime.h> +#include <errno.h> +#include <error.h> + +#ifdef __linux__ +#include <sys/mount.h> +#endif + +#include <support/support.h> +#include <support/xunistd.h> +#include "check.h" +#include "test-driver.h" + +#ifndef __linux__ +#define mount(s,t,fs,f,d) no_mount() +int no_mount (void) +{ + FAIL_UNSUPPORTED("mount not supported; port needed"); +} +#endif + +int verbose = 0; + +/* Running a test in a container is tricky. There are two main + categories of things to do: + + 1. "Once" actions, like setting up the container and doing an + install into it. + + 2. "Per-test" actions, like copying in support files and + configuring the container. + + + "Once" actions: + + * mkdir $buildroot/testroot.pristine/ + * install into it + * rsync to $buildroot/testroot.root/ + + "Per-test" actions: + * maybe rsync to $buildroot/testroot.root/ + * copy support files and test binary + * chroot/unshare + * set up any mounts (like /proc) + + Magic files: + + For test $srcdir/foo/mytest.c we look for $srcdir/foo/mytest.root + and, if found... + + * mytest.root/ is rsync'd into container + * mytest.root/preclean.req causes fresh rsync (with delete) before + test if present + * mytest.root/mytset.script has a list of "commands" to run: + syntax: + # comment + mv FILE FILE + cp FILE FILE + rm FILE + FILE must start with $B/, $S/, $I/, $L/, or / + (expands to build dir, source dir, install dir, library dir + (in container), or container's root) + * mytest.root/postclean.req causes fresh rsync (with delete) after + test if present + + Note that $srcdir/foo/mytest.script may be used instead of a + $srcdir/foo/mytest.root/mytest.script in the sysroot template, if + there is no other reason for a sysroot. + + Design goals: + + * independent of other packages which may not be installed (like + rsync or Docker, or even "cp") + + * Simple, easy to review code (i.e. prefer simple naive code over + complex efficient code) + + * The current implementation ist parallel-make-safe, but only in + that it uses a lock to prevent parallel access to the testroot. */ + + +/* Utility Functions */ + +/* Like xunlink, but it's OK if the file already doesn't exist. */ +void +maybe_xunlink (const char *path) +{ + int rv = unlink (path); + if (rv < 0 && errno != ENOENT) + FAIL_EXIT1 ("unlink (\"%s\"): %m", path); +} + +/* Like xmkdir, but it's OK if the directory already exists. */ +void +maybe_xmkdir (const char *path, mode_t mode) +{ + struct stat st; + + if (stat (path, &st) == 0 + && S_ISDIR (st.st_mode)) + return; + xmkdir (path, mode); +} + +/* Temporarily concatenate multiple strings into one. Allows up to 10 + temporary results; use strdup () if you need them to be + permanent. */ +static char * +concat (const char *str, ...) +{ + /* Assume initialized to NULL/zero. */ + static char *bufs[10]; + static size_t buflens[10]; + static int bufn = 0; + int n; + size_t len; + va_list ap, ap2; + char *cp; + char *next; + + va_start (ap, str); + va_copy (ap2, ap); + + n = bufn; + bufn = (bufn + 1) % 10; + len = strlen (str); + + while ((next = va_arg (ap, char *)) != NULL) + len = len + strlen (next); + + va_end (ap); + + if (bufs[n] == NULL) + { + bufs[n] = xmalloc (len + 1); /* NUL */ + buflens[n] = len + 1; + } + else if (buflens[n] < len + 1) + { + bufs[n] = xrealloc (bufs[n], len + 1); /* NUL */ + buflens[n] = len + 1; + } + + strcpy (bufs[n], str); + cp = strchr (bufs[n], '\0'); + while ((next = va_arg (ap2, char *)) != NULL) + { + strcpy (cp, next); + cp = strchr (cp, '\0'); + } + *cp = 0; + va_end (ap2); + + return bufs[n]; +} + +/* Try to mount SRC onto DEST. */ +static void +trymount (const char *src, const char *dest) +{ + if (mount (src, dest, "", MS_BIND, NULL) < 0) + FAIL_EXIT1 ("can't mount %s onto %s\n", src, dest); +} + +/* Special case of above for devices like /dev/zero where we have to + mount a device over a device, not a directory over a directory. */ +static void +devmount (const char *new_root_path, const char *which) +{ + int fd; + fd = open (concat (new_root_path, "/dev/", which, NULL), + O_CREAT | O_TRUNC | O_RDWR, 0777); + xclose (fd); + + trymount (concat ("/dev/", which, NULL), + concat (new_root_path, "/dev/", which, NULL)); +} + +/* Returns true if the string "looks like" an environement variable + being set. */ +static int +is_env_setting (const char *a) +{ + int count_name = 0; + + while (*a) + { + if (isalnum (*a) || *a == '_') + ++count_name; + else if (*a == '=' && count_name > 0) + return 1; + else + return 0; + ++a; + } + return 0; +} + +/* Break the_line into words and store in the_words. Max nwords, + returns actual count. */ +static int +tokenize (char *the_line, char **the_words, int nwords) +{ + int rv = 0; + + while (nwords > 0) + { + /* Skip leading whitespace, if any. */ + while (*the_line && isspace (*the_line)) + ++the_line; + + /* End of line? */ + if (*the_line == 0) + return rv; + + /* THE_LINE points to a non-whitespace character, so we have a + word. */ + *the_words = the_line; + ++the_words; + nwords--; + ++rv; + + /* Skip leading whitespace, if any. */ + while (*the_line && ! isspace (*the_line)) + ++the_line; + + /* We now point at the trailing NUL *or* some whitespace. */ + if (*the_line == 0) + return rv; + + /* It was whitespace, skip and keep tokenizing. */ + *the_line++ = 0; + } + + /* We get here if we filled the words buffer. */ + return rv; +} + + +/* Mini-RSYNC implementation. Optimize later. */ + +/* A few routines for an "rsync buffer" which stores the paths we're + working on. We continuously grow and shrink the paths in each + buffer so there's lot of re-use. */ + +/* We rely on "initialized to zero" to set these up. */ +typedef struct +{ + char *buf; + size_t len; + size_t size; +} path_buf; + +static path_buf spath, dpath; + +static void +r_setup (char *path, path_buf * pb) +{ + size_t len = strlen (path); + if (pb->buf == NULL || pb->size < len + 1) + { + /* Round up. This is an arbitrary number, just to keep from + reallocing too often. */ + size_t sz = ALIGN_UP (len + 1, 512); + if (pb->buf == NULL) + pb->buf = (char *) xmalloc (sz); + else + pb->buf = (char *) xrealloc (pb->buf, sz); + if (pb->buf == NULL) + FAIL_EXIT1 ("Out of memory while rsyncing\n"); + + pb->size = sz; + } + strcpy (pb->buf, path); + pb->len = len; +} + +static void +r_append (const char *path, path_buf * pb) +{ + size_t len = strlen (path) + pb->len; + if (pb->size < len + 1) + { + /* Round up */ + size_t sz = ALIGN_UP (len + 1, 512); + pb->buf = (char *) xrealloc (pb->buf, sz); + if (pb->buf == NULL) + FAIL_EXIT1 ("Out of memory while rsyncing\n"); + + pb->size = sz; + } + strcpy (pb->buf + pb->len, path); + pb->len = len; +} + +static int +file_exists (char *path) +{ + struct stat st; + if (lstat (path, &st) == 0) + return 1; + return 0; +} + +static void +recursive_remove (char *path) +{ + pid_t child; + int status; + + child = fork (); + + switch (child) { + case -1: + FAIL_EXIT1 ("Unable to fork"); + case 0: + /* Child. */ + execlp ("rm", "rm", "-rf", path, NULL); + default: + /* Parent. */ + waitpid (child, &status, 0); + /* "rm" would have already printed a suitable error message. */ + if (! WIFEXITED (status) + || WEXITSTATUS (status) != 0) + exit (1); + + break; + } +} + +/* Used for both rsync and the mytest.script "cp" command. */ +static void +copy_one_file (const char *sname, const char *dname) +{ + int sfd, dfd; + struct stat st; + struct utimbuf times; + + sfd = open (sname, O_RDONLY); + if (sfd < 0) + FAIL_EXIT1 ("unable to open %s for reading\n", sname); + + if (fstat (sfd, &st) < 0) + FAIL_EXIT1 ("unable to fstat %s\n", sname); + + dfd = open (dname, O_WRONLY | O_TRUNC | O_CREAT, 0600); + if (dfd < 0) + FAIL_EXIT1 ("unable to open %s for writing\n", dname); + + if (copy_file_range (sfd, 0, dfd, 0, st.st_size, 0) != st.st_size) + FAIL_EXIT1 ("cannot copy file %s to %s\n", sname, dname); + + xclose (sfd); + xclose (dfd); + + if (chmod (dname, st.st_mode & 0777) < 0) + FAIL_EXIT1 ("chmod %s: %s\n", dname, strerror (errno)); + + times.actime = st.st_atime; + times.modtime = st.st_mtime; + if (utime (dname, ×) < 0) + FAIL_EXIT1 ("utime %s: %s\n", dname, strerror (errno)); +} + +/* We don't check *everything* about the two files to see if a copy is + needed, just the minimum to make sure we get the latest copy. */ +static int +need_sync (char *ap, char *bp, struct stat *a, struct stat *b) +{ + if ((a->st_mode & S_IFMT) != (b->st_mode & S_IFMT)) + return 1; + + if (S_ISLNK (a->st_mode)) + { + int rv; + char *al, *bl; + + if (a->st_size != b->st_size) + return 1; + + al = xreadlink (ap); + bl = xreadlink (bp); + rv = strcmp (al, bl); + free (al); + free (bl); + if (rv == 0) + return 0; /* links are same */ + return 1; /* links differ */ + } + + if (verbose) + { + if (a->st_size != b->st_size) + printf ("SIZE\n"); + if ((a->st_mode & 0777) != (b->st_mode & 0777)) + printf ("MODE\n"); + if (a->st_mtime != b->st_mtime) + printf ("TIME\n"); + } + + if (a->st_size == b->st_size + && ((a->st_mode & 0777) == (b->st_mode & 0777)) + && a->st_mtime == b->st_mtime) + return 0; + + return 1; +} + +static void +rsync_1 (path_buf * src, path_buf * dest, int and_delete) +{ + DIR *dir; + struct dirent *de; + struct stat s, d; + + r_append ("/", src); + r_append ("/", dest); + + if (verbose) + printf ("sync %s to %s %s\n", src->buf, dest->buf, + and_delete ? "and delete" : ""); + + size_t staillen = src->len; + + size_t dtaillen = dest->len; + + dir = opendir (src->buf); + + while ((de = readdir (dir)) != NULL) + { + if (strcmp (de->d_name, ".") == 0 + || strcmp (de->d_name, "..") == 0) + continue; + + src->len = staillen; + r_append (de->d_name, src); + dest->len = dtaillen; + r_append (de->d_name, dest); + + s.st_mode = ~0; + d.st_mode = ~0; + + if (lstat (src->buf, &s) != 0) + FAIL_EXIT1 ("%s obtained by readdir, but stat failed.\n", src->buf); + + /* It's OK if this one fails, since we know the file might be + missing. */ + lstat (dest->buf, &d); + + if (! need_sync (src->buf, dest->buf, &s, &d)) + { + if (S_ISDIR (s.st_mode)) + rsync_1 (src, dest, and_delete); + continue; + } + + if (d.st_mode != ~0) + switch (d.st_mode & S_IFMT) + { + case S_IFDIR: + if (!S_ISDIR (s.st_mode)) + { + if (verbose) + printf ("-D %s\n", dest->buf); + recursive_remove (dest->buf); + } + break; + + default: + if (verbose) + printf ("-F %s\n", dest->buf); + maybe_xunlink (dest->buf); + break; + } + + switch (s.st_mode & S_IFMT) + { + case S_IFREG: + if (verbose) + printf ("+F %s\n", dest->buf); + copy_one_file (src->buf, dest->buf); + break; + + case S_IFDIR: + if (verbose) + printf ("+D %s\n", dest->buf); + maybe_xmkdir (dest->buf, (s.st_mode & 0777) | 0700); + rsync_1 (src, dest, and_delete); + break; + + case S_IFLNK: + { + char *lp; + if (verbose) + printf ("+L %s\n", dest->buf); + lp = xreadlink (src->buf); + xsymlink (lp, dest->buf); + free (lp); + break; + } + + default: + break; + } + } + + closedir (dir); + src->len = staillen; + src->buf[staillen] = 0; + dest->len = dtaillen; + dest->buf[dtaillen] = 0; + + if (!and_delete) + return; + + /* The rest of this function removes any files/directories in DEST + that do not exist in SRC. This is triggered as part of a + preclean or postsclean step. */ + + dir = opendir (dest->buf); + + while ((de = readdir (dir)) != NULL) + { + if (strcmp (de->d_name, ".") == 0 + || strcmp (de->d_name, "..") == 0) + continue; + + src->len = staillen; + r_append (de->d_name, src); + dest->len = dtaillen; + r_append (de->d_name, dest); + + s.st_mode = ~0; + d.st_mode = ~0; + + lstat (src->buf, &s); + + if (lstat (dest->buf, &d) != 0) + FAIL_EXIT1 ("%s obtained by readdir, but stat failed.\n", dest->buf); + + if (s.st_mode == ~0) + { + /* dest exists and src doesn't, clean it. */ + switch (d.st_mode & S_IFMT) + { + case S_IFDIR: + if (!S_ISDIR (s.st_mode)) + { + if (verbose) + printf ("-D %s\n", dest->buf); + recursive_remove (dest->buf); + } + break; + + default: + if (verbose) + printf ("-F %s\n", dest->buf); + maybe_xunlink (dest->buf); + break; + } + } + } + + closedir (dir); +} + +static void +rsync (char *src, char *dest, int and_delete) +{ + r_setup (src, &spath); + r_setup (dest, &dpath); + + rsync_1 (&spath, &dpath, and_delete); +} + + +int +main (int argc, char **argv) +{ + pid_t child; + char *pristine_root_path; + char *new_root_path; + char *new_cwd_path; + char *new_objdir_path; + char *new_srcdir_path; + char **new_child_proc; + char *command_root; + char *command_base; + char *command_basename; + char *so_base; + int do_postclean = 0; + + uid_t original_uid; + gid_t original_gid; + int UMAP; + int GMAP; + /* Used for "%lld %lld 1" so need not be large. */ + char tmp[100]; + struct stat st; + int lock_fd; + + setbuf (stdout, NULL); + + /* The command line we're expecting looks like this: + env <set some vars> ld.so <library path> test-binary + + We need to peel off any "env" or "ld.so" portion of the command + line, and keep track of which env vars we should preserve and + which we drop. */ + + if (argc < 2) + { + fprintf (stderr, "Usage: containerize <program to run> <args...>\n"); + exit (1); + } + + if (strcmp (argv[1], "-v") == 0) + { + verbose = 1; + ++argv; + --argc; + } + + if (strcmp (argv[1], "env") == 0) + { + ++argv; + --argc; + while (is_env_setting (argv[1])) + { + /* If there are variables we do NOT want to propogate, this + is where the test for them goes. */ + { + /* Need to keep these. Note that putenv stores a + pointer to our argv. */ + putenv (argv[1]); + } + ++argv; + --argc; + } + } + + if (strncmp (argv[1], concat (support_objdir_root, "/elf/ld-linux-", NULL), + strlen (support_objdir_root) + 14) == 0) + { + ++argv; + --argc; + while (argv[1][0] == '-') + { + if (strcmp (argv[1], "--library-path") == 0) + { + ++argv; + --argc; + } + ++argv; + --argc; + } + } + + pristine_root_path = strdup (concat (support_objdir_root, + "/testroot.pristine", NULL)); + new_root_path = strdup (concat (support_objdir_root, + "/testroot.root", NULL)); + new_cwd_path = get_current_dir_name (); + new_child_proc = argv + 1; + + lock_fd = open (concat (pristine_root_path, "/lock.fd", NULL), + O_CREAT | O_TRUNC | O_RDWR, 0666); + if (lock_fd < 0) + FAIL_EXIT1 ("Cannot create testroot lock.\n"); + + while (flock (lock_fd, LOCK_EX) != 0) + { + if (errno != EINTR) + FAIL_EXIT1 ("Cannot lock testroot.\n"); + } + + xmkdirp (new_root_path, 0755); + + /* We look for extra setup info in a subdir in the same spot as the + test, with the same name but a ".root" extension. This is that + directory. We try to look in the source tree if the path we're + given refers to the build tree, but we rely on the path to be + absolute. This is what the glibc makefiles do. */ + command_root = concat (argv[1], ".root", NULL); + if (strncmp (command_root, support_objdir_root, + strlen (support_objdir_root)) == 0 + && command_root[strlen (support_objdir_root)] == '/') + command_root = concat (support_srcdir_root, + argv[1] + strlen (support_objdir_root), + ".root", NULL); + command_root = strdup (command_root); + + /* This cuts off the ".root" we appended above. */ + command_base = strdup (command_root); + command_base[strlen (command_base) - 5] = 0; + + /* This is the basename of the test we're running. */ + command_basename = strrchr (command_base, '/'); + if (command_basename == NULL) + command_basename = command_base; + else + ++command_basename; + + /* Shared object base directory. */ + so_base = strdup (argv[1]); + if (strrchr (so_base, '/') != NULL) + strrchr (so_base, '/')[1] = 0; + + if (file_exists (concat (command_root, "/postclean.req", NULL))) + do_postclean = 1; + + rsync (pristine_root_path, new_root_path, + file_exists (concat (command_root, "/preclean.req", NULL))); + + if (stat (command_root, &st) >= 0 + && S_ISDIR (st.st_mode)) + rsync (command_root, new_root_path, 0); + + new_objdir_path = strdup (concat (new_root_path, + support_objdir_root, NULL)); + new_srcdir_path = strdup (concat (new_root_path, + support_srcdir_root, NULL)); + + /* new_cwd_path starts with '/' so no "/" needed between the two. */ + xmkdirp (concat (new_root_path, new_cwd_path, NULL), 0755); + xmkdirp (new_srcdir_path, 0755); + xmkdirp (new_objdir_path, 0755); + + original_uid = getuid (); + original_gid = getgid (); + + /* Handle the cp/mv/rm "script" here. */ + { + char *the_line = NULL; + size_t line_len = 0; + char *fname = concat (command_root, "/", + command_basename, ".script", NULL); + char *the_words[3]; + FILE *f = fopen (fname, "r"); + + if (verbose && f) + fprintf (stderr, "running %s\n", fname); + + if (f == NULL) + { + /* Try foo.script instead of foo.root/foo.script, as a shortcut. */ + fname = concat (command_base, ".script", NULL); + f = fopen (fname, "r"); + if (verbose && f) + fprintf (stderr, "running %s\n", fname); + } + + /* Note that we do NOT look for a Makefile-generated foo.script in + the build directory. If that is ever needed, this is the place + to add it. */ + + /* This is where we "interpret" the mini-script which is <test>.script. */ + if (f != NULL) + { + while (getline (&the_line, &line_len, f) > 0) + { + int nt = tokenize (the_line, the_words, 3); + int i; + + for (i = 1; i < nt; ++i) + { + if (memcmp (the_words[i], "$B/", 3) == 0) + the_words[i] = concat (support_objdir_root, + the_words[i] + 2, NULL); + else if (memcmp (the_words[i], "$S/", 3) == 0) + the_words[i] = concat (support_srcdir_root, + the_words[i] + 2, NULL); + else if (memcmp (the_words[i], "$I/", 3) == 0) + the_words[i] = concat (new_root_path, + support_install_prefix, + the_words[i] + 2, NULL); + else if (memcmp (the_words[i], "$L/", 3) == 0) + the_words[i] = concat (new_root_path, + support_libdir_prefix, + the_words[i] + 2, NULL); + else if (the_words[i][0] == '/') + the_words[i] = concat (new_root_path, + the_words[i], NULL); + } + + if (nt == 3 && the_words[2][strlen (the_words[2]) - 1] == '/') + { + char *r = strrchr (the_words[1], '/'); + if (r) + the_words[2] = concat (the_words[2], r + 1, NULL); + else + the_words[2] = concat (the_words[2], the_words[1], NULL); + } + + if (nt == 2 && strcmp (the_words[0], "so") == 0) + { + the_words[2] = concat (new_root_path, support_libdir_prefix, + "/", the_words[1], NULL); + the_words[1] = concat (so_base, the_words[1], NULL); + copy_one_file (the_words[1], the_words[2]); + } + else if (nt == 3 && strcmp (the_words[0], "cp") == 0) + { + copy_one_file (the_words[1], the_words[2]); + } + else if (nt == 3 && strcmp (the_words[0], "mv") == 0) + { + if (rename (the_words[1], the_words[2]) < 0) + FAIL_EXIT1 ("rename %s -> %s: %s", the_words[1], + the_words[2], strerror (errno)); + } + else if (nt == 3 && strcmp (the_words[0], "chmod") == 0) + { + long int m; + m = strtol (the_words[1], NULL, 0); + if (chmod (the_words[2], m) < 0) + FAIL_EXIT1 ("chmod %s: %s\n", + the_words[2], strerror (errno)); + + } + else if (nt == 2 && strcmp (the_words[0], "rm") == 0) + { + maybe_xunlink (the_words[1]); + } + else if (nt > 0 && the_words[0][0] != '#') + { + printf ("\033[31minvalid [%s]\033[0m\n", the_words[0]); + } + } + fclose (f); + } + } + +#ifdef CLONE_NEWNS + /* The unshare here gives us our own spaces and capabilities. */ + if (unshare (CLONE_NEWUSER | CLONE_NEWPID | CLONE_NEWNS) < 0) + { + /* Older kernels may not support all the options. */ + if (errno == EINVAL) + FAIL_UNSUPPORTED ("unable to unshare user/fs: %s", strerror (errno)); + else + FAIL_EXIT1 ("unable to unshare user/fs: %s", strerror (errno)); + } +#else + /* Some targets may not support unshare at all. */ + FAIL_UNSUPPORTED ("unshare support missing"); +#endif + + /* Some systems, by default, all mounts leak out of the namespace. */ + if (mount ("none", "/", NULL, MS_REC | MS_PRIVATE, NULL) != 0) + FAIL_EXIT1 ("could not create a private mount namespace\n"); + + trymount (support_srcdir_root, new_srcdir_path); + trymount (support_objdir_root, new_objdir_path); + + xmkdirp (concat (new_root_path, "/dev", NULL), 0755); + devmount (new_root_path, "null"); + devmount (new_root_path, "zero"); + devmount (new_root_path, "urandom"); + + /* We're done with the "old" root, switch to the new one. */ + if (chroot (new_root_path) < 0) + FAIL_EXIT1 ("Can't chroot to %s - ", new_root_path); + + if (chdir (new_cwd_path) < 0) + FAIL_EXIT1 ("Can't cd to new %s - ", new_cwd_path); + + /* To complete the containerization, we need to fork () at least + once. We can't exec, nor can we somehow link the new child to + our parent. So we run the child and propogate it's exit status + up. */ + child = fork (); + if (child < 0) + FAIL_EXIT1 ("Unable to fork"); + else if (child > 0) + { + /* Parent. */ + int status; + waitpid (child, &status, 0); + + /* There's a bit of magic here, since the buildroot is mounted + in our space, the paths are still valid, and since the mounts + aren't recursive, it sees *only* the built root, not anything + we would normally se if we rsync'd to "/" like mounted /dev + files. */ + if (do_postclean) + rsync (pristine_root_path, new_root_path, 1); + + if (WIFEXITED (status)) + exit (WEXITSTATUS (status)); + + if (WIFSIGNALED (status)) + { + printf ("%%SIGNALLED%%\n"); + exit (77); + } + + printf ("%%EXITERROR%%\n"); + exit (78); + } + + /* The rest is the child process, which is now PID 1 and "in" the + new root. */ + + maybe_xmkdir ("/tmp", 0755); + + /* Now that we're pid 1 (effectively "root") we can mount /proc */ + maybe_xmkdir ("/proc", 0777); + if (mount ("proc", "/proc", "proc", 0, NULL) < 0) + FAIL_EXIT1 ("Unable to mount /proc: "); + + /* We map our original UID to the same UID in the container so we + can own our own files normally. */ + UMAP = open ("/proc/self/uid_map", O_WRONLY); + if (UMAP < 0) + FAIL_EXIT1 ("can't write to /proc/self/uid_map\n"); + + sprintf (tmp, "%lld %lld 1\n", + (long long) original_uid, (long long) original_uid); + write (UMAP, tmp, strlen (tmp)); + xclose (UMAP); + + /* We must disable setgroups () before we can map our groups, else we + get EPERM. */ + GMAP = open ("/proc/self/setgroups", O_WRONLY); + if (GMAP >= 0) + { + /* We support kernels old enough to not have this. */ + write (GMAP, "deny\n", 5); + xclose (GMAP); + } + + /* We map our original GID to the same GID in the container so we + can own our own files normally. */ + GMAP = open ("/proc/self/gid_map", O_WRONLY); + if (GMAP < 0) + FAIL_EXIT1 ("can't write to /proc/self/gid_map\n"); + + sprintf (tmp, "%lld %lld 1\n", + (long long) original_gid, (long long) original_gid); + write (GMAP, tmp, strlen (tmp)); + xclose (GMAP); + + /* Now run the child. */ + execvp (new_child_proc[0], new_child_proc); + + /* Or don't run the child? */ + FAIL_EXIT1 ("Unable to exec %s\n", new_child_proc[0]); + + /* Because gcc won't know error () never returns... */ + exit (EXIT_UNSUPPORTED); +} |