forked from rpms/glibc
355 lines
12 KiB
Diff
355 lines
12 KiB
Diff
commit 2fe64148a81f0d78050c302f34a6853d21f7cae4
|
||
Author: DJ Delorie <dj@redhat.com>
|
||
Date: Mon Mar 28 23:53:33 2022 -0400
|
||
|
||
Allow for unpriviledged nested containers
|
||
|
||
If the build itself is run in a container, we may not be able to
|
||
fully set up a nested container for test-container testing.
|
||
Notably is the mounting of /proc, since it's critical that it
|
||
be mounted from within the same PID namespace as its users, and
|
||
thus cannot be bind mounted from outside the container like other
|
||
mounts.
|
||
|
||
This patch defaults to using the parent's PID namespace instead of
|
||
creating a new one, as this is more likely to be allowed.
|
||
|
||
If the test needs an isolated PID namespace, it should add the "pidns"
|
||
command to its init script.
|
||
|
||
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
|
||
|
||
Conflicts:
|
||
nss/tst-reload2.c
|
||
(not in RHEL-8)
|
||
support/Makefile
|
||
(RHEL-8 missing some routines in libsupport-routines)
|
||
|
||
diff --git a/elf/tst-pldd.c b/elf/tst-pldd.c
|
||
index f381cb0fa7e6b93d..45ac033a0f897088 100644
|
||
--- a/elf/tst-pldd.c
|
||
+++ b/elf/tst-pldd.c
|
||
@@ -85,6 +85,8 @@ in_str_list (const char *libname, const char *const strlist[])
|
||
static int
|
||
do_test (void)
|
||
{
|
||
+ support_need_proc ("needs /proc/sys/kernel/yama/ptrace_scope and /proc/$child");
|
||
+
|
||
/* Check if our subprocess can be debugged with ptrace. */
|
||
{
|
||
int ptrace_scope = support_ptrace_scope ();
|
||
diff --git a/nptl/tst-pthread-getattr.c b/nptl/tst-pthread-getattr.c
|
||
index 273b6073abe9cb60..f1c0b39f3a27724c 100644
|
||
--- a/nptl/tst-pthread-getattr.c
|
||
+++ b/nptl/tst-pthread-getattr.c
|
||
@@ -28,6 +28,8 @@
|
||
#include <unistd.h>
|
||
#include <inttypes.h>
|
||
|
||
+#include <support/support.h>
|
||
+
|
||
/* There is an obscure bug in the kernel due to which RLIMIT_STACK is sometimes
|
||
returned as unlimited when it is not, which may cause this test to fail.
|
||
There is also the other case where RLIMIT_STACK is intentionally set as
|
||
@@ -152,6 +154,8 @@ check_stack_top (void)
|
||
static int
|
||
do_test (void)
|
||
{
|
||
+ support_need_proc ("Reads /proc/self/maps to get stack size.");
|
||
+
|
||
pagesize = sysconf (_SC_PAGESIZE);
|
||
return check_stack_top ();
|
||
}
|
||
diff --git a/support/Makefile b/support/Makefile
|
||
index 636d69c4f8e7e139..e184fccbe7d2310c 100644
|
||
--- a/support/Makefile
|
||
+++ b/support/Makefile
|
||
@@ -59,6 +59,7 @@ libsupport-routines = \
|
||
support_format_hostent \
|
||
support_format_netent \
|
||
support_isolate_in_subprocess \
|
||
+ support_need_proc \
|
||
support_process_state \
|
||
support_ptrace \
|
||
support_openpty \
|
||
diff --git a/support/support.h b/support/support.h
|
||
index 96833bd4e992e6d3..1466eb29f840fa59 100644
|
||
--- a/support/support.h
|
||
+++ b/support/support.h
|
||
@@ -81,6 +81,11 @@ char *support_quote_string (const char *);
|
||
regular file open for writing, and initially empty. */
|
||
int support_descriptor_supports_holes (int fd);
|
||
|
||
+/* Predicates that a test requires a working /proc filesystem. This
|
||
+ call will exit with UNSUPPORTED if /proc is not available, printing
|
||
+ WHY_MSG as part of the diagnostic. */
|
||
+void support_need_proc (const char *why_msg);
|
||
+
|
||
/* Error-checking wrapper functions which terminate the process on
|
||
error. */
|
||
|
||
diff --git a/support/support_need_proc.c b/support/support_need_proc.c
|
||
new file mode 100644
|
||
index 0000000000000000..9b4eab7539b2d6c3
|
||
--- /dev/null
|
||
+++ b/support/support_need_proc.c
|
||
@@ -0,0 +1,35 @@
|
||
+/* Indicate that a test requires a working /proc.
|
||
+ Copyright (C) 2022 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
|
||
+ <https://www.gnu.org/licenses/>. */
|
||
+
|
||
+#include <unistd.h>
|
||
+#include <support/check.h>
|
||
+#include <support/support.h>
|
||
+
|
||
+/* We test for /proc/self/maps since that's one of the files that one
|
||
+ of our tests actually uses, but the general idea is if Linux's
|
||
+ /proc/ (procfs) filesystem is mounted. If not, the process exits
|
||
+ with an UNSUPPORTED result code. */
|
||
+
|
||
+void
|
||
+support_need_proc (const char *why_msg)
|
||
+{
|
||
+#ifdef __linux__
|
||
+ if (access ("/proc/self/maps", R_OK))
|
||
+ FAIL_UNSUPPORTED ("/proc is not available, %s", why_msg);
|
||
+#endif
|
||
+}
|
||
diff --git a/support/test-container.c b/support/test-container.c
|
||
index 9975c8cb7bc9a955..2bce4db841ff7668 100644
|
||
--- a/support/test-container.c
|
||
+++ b/support/test-container.c
|
||
@@ -95,6 +95,7 @@ int verbose = 0;
|
||
* mytest.root/mytest.script has a list of "commands" to run:
|
||
syntax:
|
||
# comment
|
||
+ pidns <comment>
|
||
su
|
||
mv FILE FILE
|
||
cp FILE FILE
|
||
@@ -120,6 +121,8 @@ int verbose = 0;
|
||
|
||
details:
|
||
- '#': A comment.
|
||
+ - 'pidns': Require a separate PID namespace, prints comment if it can't
|
||
+ (default is a shared pid namespace)
|
||
- 'su': Enables running test as root in the container.
|
||
- 'mv': A minimal move files command.
|
||
- 'cp': A minimal copy files command.
|
||
@@ -143,7 +146,7 @@ int verbose = 0;
|
||
* 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
|
||
+ * The current implementation is parallel-make-safe, but only in
|
||
that it uses a lock to prevent parallel access to the testroot. */
|
||
|
||
|
||
@@ -222,11 +225,37 @@ concat (const char *str, ...)
|
||
return bufs[n];
|
||
}
|
||
|
||
+/* Like the above, but put spaces between words. Caller frees. */
|
||
+static char *
|
||
+concat_words (char **words, int num_words)
|
||
+{
|
||
+ int len = 0;
|
||
+ int i;
|
||
+ char *rv, *p;
|
||
+
|
||
+ for (i = 0; i < num_words; i ++)
|
||
+ {
|
||
+ len += strlen (words[i]);
|
||
+ len ++;
|
||
+ }
|
||
+
|
||
+ p = rv = (char *) xmalloc (len);
|
||
+
|
||
+ for (i = 0; i < num_words; i ++)
|
||
+ {
|
||
+ if (i > 0)
|
||
+ p = stpcpy (p, " ");
|
||
+ p = stpcpy (p, words[i]);
|
||
+ }
|
||
+
|
||
+ return rv;
|
||
+}
|
||
+
|
||
/* Try to mount SRC onto DEST. */
|
||
static void
|
||
trymount (const char *src, const char *dest)
|
||
{
|
||
- if (mount (src, dest, "", MS_BIND, NULL) < 0)
|
||
+ if (mount (src, dest, "", MS_BIND | MS_REC, NULL) < 0)
|
||
FAIL_EXIT1 ("can't mount %s onto %s\n", src, dest);
|
||
}
|
||
|
||
@@ -709,6 +738,9 @@ main (int argc, char **argv)
|
||
gid_t original_gid;
|
||
/* If set, the test runs as root instead of the user running the testsuite. */
|
||
int be_su = 0;
|
||
+ int require_pidns = 0;
|
||
+ const char *pidns_comment = NULL;
|
||
+ int do_proc_mounts = 0;
|
||
int UMAP;
|
||
int GMAP;
|
||
/* Used for "%lld %lld 1" so need not be large. */
|
||
@@ -991,6 +1023,12 @@ main (int argc, char **argv)
|
||
{
|
||
be_su = 1;
|
||
}
|
||
+ else if (nt >= 1 && strcmp (the_words[0], "pidns") == 0)
|
||
+ {
|
||
+ require_pidns = 1;
|
||
+ if (nt > 1)
|
||
+ pidns_comment = concat_words (the_words + 1, nt - 1);
|
||
+ }
|
||
else if (nt == 3 && strcmp (the_words[0], "mkdirp") == 0)
|
||
{
|
||
long int m;
|
||
@@ -1048,7 +1086,8 @@ main (int argc, char **argv)
|
||
|
||
#ifdef CLONE_NEWNS
|
||
/* The unshare here gives us our own spaces and capabilities. */
|
||
- if (unshare (CLONE_NEWUSER | CLONE_NEWPID | CLONE_NEWNS) < 0)
|
||
+ if (unshare (CLONE_NEWUSER | CLONE_NEWNS
|
||
+ | (require_pidns ? CLONE_NEWPID : 0)) < 0)
|
||
{
|
||
/* Older kernels may not support all the options, or security
|
||
policy may block this call. */
|
||
@@ -1059,6 +1098,11 @@ main (int argc, char **argv)
|
||
check_for_unshare_hints ();
|
||
FAIL_UNSUPPORTED ("unable to unshare user/fs: %s", strerror (saved_errno));
|
||
}
|
||
+ /* We're about to exit anyway, it's "safe" to call unshare again
|
||
+ just to see if the CLONE_NEWPID caused the error. */
|
||
+ else if (require_pidns && unshare (CLONE_NEWUSER | CLONE_NEWNS) >= 0)
|
||
+ FAIL_EXIT1 ("unable to unshare pid ns: %s : %s", strerror (errno),
|
||
+ pidns_comment ? pidns_comment : "required by test");
|
||
else
|
||
FAIL_EXIT1 ("unable to unshare user/fs: %s", strerror (errno));
|
||
}
|
||
@@ -1074,6 +1118,15 @@ main (int argc, char **argv)
|
||
trymount (support_srcdir_root, new_srcdir_path);
|
||
trymount (support_objdir_root, new_objdir_path);
|
||
|
||
+ /* It may not be possible to mount /proc directly. */
|
||
+ if (! require_pidns)
|
||
+ {
|
||
+ char *new_proc = concat (new_root_path, "/proc", NULL);
|
||
+ xmkdirp (new_proc, 0755);
|
||
+ trymount ("/proc", new_proc);
|
||
+ do_proc_mounts = 1;
|
||
+ }
|
||
+
|
||
xmkdirp (concat (new_root_path, "/dev", NULL), 0755);
|
||
devmount (new_root_path, "null");
|
||
devmount (new_root_path, "zero");
|
||
@@ -1136,42 +1189,60 @@ main (int argc, char **argv)
|
||
|
||
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) (be_su ? 0 : 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)
|
||
+ if (require_pidns)
|
||
{
|
||
- /* We support kernels old enough to not have this. */
|
||
- write (GMAP, "deny\n", 5);
|
||
- xclose (GMAP);
|
||
+ /* Now that we're pid 1 (effectively "root") we can mount /proc */
|
||
+ maybe_xmkdir ("/proc", 0777);
|
||
+ if (mount ("proc", "/proc", "proc", 0, NULL) != 0)
|
||
+ {
|
||
+ /* This happens if we're trying to create a nested container,
|
||
+ like if the build is running under podman, and we lack
|
||
+ priviledges.
|
||
+
|
||
+ Ideally we would WARN here, but that would just add noise to
|
||
+ *every* test-container test, and the ones that care should
|
||
+ have their own relevent diagnostics.
|
||
+
|
||
+ FAIL_EXIT1 ("Unable to mount /proc: "); */
|
||
+ }
|
||
+ else
|
||
+ do_proc_mounts = 1;
|
||
}
|
||
|
||
- /* 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");
|
||
+ if (do_proc_mounts)
|
||
+ {
|
||
+ /* 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) (be_su ? 0 : 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);
|
||
+ }
|
||
|
||
- sprintf (tmp, "%lld %lld 1\n",
|
||
- (long long) (be_su ? 0 : original_gid), (long long) original_gid);
|
||
- write (GMAP, tmp, strlen (tmp));
|
||
- 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) (be_su ? 0 : original_gid), (long long) original_gid);
|
||
+ write (GMAP, tmp, strlen (tmp));
|
||
+ xclose (GMAP);
|
||
+ }
|
||
|
||
if (change_cwd)
|
||
{
|