<div dir="ltr">Pavel and Adrian,<div><br></div><div>Had some time this morning and did a quick rework of criu check hopefully without having broken anything. Haven't had time for thorough testing but in the interest of time wanted to send the patch for everyone's comments.</div><div><br></div><div>With this patch, "criu check --abs" passes on 3.19 but fails on 3.13 due to PR_SET_MM_MAP.</div><div><br></div><div>Look forward to your review and feedback.</div><div><br></div><div>--Saied</div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Feb 29, 2016 at 2:52 PM, Saied Kazemi <span dir="ltr"><<a href="mailto:saied@google.com" target="_blank">saied@google.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">The "criu check" command to check if the kernel is properly configured<br>
to run criu is broken.<br>
<br>
The "criu check --ms" command used to be the way to tell criu to check<br>
only for features that have been merged upstream. But recent kernels<br>
have a set of features whose presence doesn't necessarily mean dump will<br>
fail but rather *may* fail to dump or restore (e.g., soft dirty tracker,<br>
tun support, seccomp).<br>
<br>
This patch deprecates --ms and introduces --abs for absolutely needed<br>
features.<br>
<br>
Typical use cases are:<br>
<br>
$ sudo criu check --abs<br>
Looks good.<br>
$ sudo criu check<br>
<zero or more errors...><br>
Looks good but some kernel features are missing.<br>
$ sudo criu check --feature mnt_id<br>
Looks good.<br>
$ sudo criu check --feature seccomp_suspend<br>
Error (cr-check.c:604): Kernel doesn't support PTRACE_O_SUSPEND_SECCOMP<br>
$ sudo criu check --feature list<br>
mnt_id aio_remap timerfd tun userns fdinfo_lock seccomp_suspend \<br>
seccomp_filters loginuid cgroupns<br>
<br>
Signed-off-by: Saied Kazemi <<a href="mailto:saied@google.com">saied@google.com</a>><br>
---<br>
criu/cr-check.c | 178 +++++++++++++++++++++++-----------------------<br>
criu/cr-service.c | 4 +-<br>
criu/crtools.c | 28 ++++++--<br>
criu/include/cr_options.h | 2 +-<br>
4 files changed, 112 insertions(+), 100 deletions(-)<br>
<br>
diff --git a/criu/cr-check.c b/criu/cr-check.c<br>
index a67ee2d..d08e085 100644<br>
--- a/criu/cr-check.c<br>
+++ b/criu/cr-check.c<br>
@@ -171,7 +171,6 @@ static int check_kcmp(void)<br>
<br>
static int check_prctl(void)<br>
{<br>
- unsigned long user_auxv = 0;<br>
unsigned int *tid_addr;<br>
unsigned int size = 0;<br>
int ret;<br>
@@ -183,37 +182,13 @@ static int check_prctl(void)<br>
}<br>
<br>
/*<br>
- * Either new or old interface must be supported in the kernel.<br>
+ * The new interface must be supported in the kernel.<br>
*/<br>
ret = prctl(PR_SET_MM, PR_SET_MM_MAP_SIZE, (unsigned long)&size, 0, 0);<br>
if (ret) {<br>
- if (!opts.check_ms_kernel) {<br>
- pr_msg("prctl: PR_SET_MM_MAP is not supported, which "<br>
- "is required for restoring user namespaces\n");<br>
- return -1;<br>
- } else<br>
- pr_warn("Skipping unssuported PR_SET_MM_MAP\n");<br>
-<br>
- ret = prctl(PR_SET_MM, PR_SET_MM_BRK, brk(0), 0, 0);<br>
- if (ret) {<br>
- if (ret == -EPERM)<br>
- pr_msg("prctl: One needs CAP_SYS_RESOURCE capability to perform testing\n");<br>
- else<br>
- pr_msg("prctl: PR_SET_MM is not supported\n");<br>
- return -1;<br>
- }<br>
-<br>
- ret = prctl(PR_SET_MM, PR_SET_MM_EXE_FILE, -1, 0, 0);<br>
- if (ret != -EBADF) {<br>
- pr_msg("prctl: PR_SET_MM_EXE_FILE is not supported (%d)\n", ret);<br>
- return -1;<br>
- }<br>
-<br>
- ret = prctl(PR_SET_MM, PR_SET_MM_AUXV, (long)&user_auxv, sizeof(user_auxv), 0);<br>
- if (ret) {<br>
- pr_msg("prctl: PR_SET_MM_AUXV is not supported\n");<br>
- return -1;<br>
- }<br>
+ pr_msg("prctl: PR_SET_MM_MAP is not supported, which "<br>
+ "is required for restoring user namespaces\n");<br>
+ return -1;<br>
}<br>
<br>
return 0;<br>
@@ -766,11 +741,8 @@ static int check_aio_remap(void)<br>
ctx = (aio_context_t)naddr;<br>
r = syscall(SYS_io_getevents, ctx, 0, 1, NULL, NULL);<br>
if (r < 0) {<br>
- if (!opts.check_ms_kernel) {<br>
- pr_err("AIO remap doesn't work properly\n");<br>
- return -1;<br>
- } else<br>
- pr_warn("Skipping unsupported AIO remap\n");<br>
+ pr_err("AIO remap doesn't work properly\n");<br>
+ return -1;<br>
}<br>
<br>
return 0;<br>
@@ -782,12 +754,8 @@ static int check_fdinfo_lock(void)<br>
return -1;<br>
<br>
if (!kdat.has_fdinfo_lock) {<br>
- if (!opts.check_ms_kernel) {<br>
- pr_err("fdinfo doesn't contain the lock field\n");<br>
- return -1;<br>
- } else {<br>
- pr_warn("fdinfo doesn't contain the lock field\n");<br>
- }<br>
+ pr_err("fdinfo doesn't contain the lock field\n");<br>
+ return -1;<br>
}<br>
<br>
return 0;<br>
@@ -823,14 +791,10 @@ static int check_clone_parent_vs_pid()<br>
static int check_cgroupns(void)<br>
{<br>
int ret;<br>
- if (opts.check_ms_kernel) {<br>
- pr_warn("Skipping cgroup namespaces check\n");<br>
- return 0;<br>
- }<br>
<br>
ret = access("/proc/self/ns/cgroup", F_OK);<br>
if (ret < 0) {<br>
- pr_err("cgroupns not supported. This is not fatal.");<br>
+ pr_err("cgroupns not supported. This is not fatal.\n");<br>
return -1;<br>
}<br>
<br>
@@ -839,9 +803,22 @@ static int check_cgroupns(void)<br>
<br>
static int (*chk_feature)(void);<br>
<br>
+/*<br>
+ * There are three categories of kernel features:<br>
+ *<br>
+ * 1. Absolutely required (/proc/pid/map_files, ptrace PEEKSIGINFO, etc.)<br>
+ * 2. Required only for specific cases (aio remap, tun, etc.)<br>
+ * 3. Experimental (task-diag)<br>
+ *<br>
+ * We fail if any feature in category 1 is missing but tolerate failures<br>
+ * in the other categories. Currently, there is nothing in category 3.<br>
+ */<br>
+#define GOOD "Looks good."<br>
+#define GOOD_BUT "Looks good but some kernel features are missing."<br>
int cr_check(void)<br>
{<br>
struct ns_id ns = { .type = NS_CRIU, .ns_pid = PROC_SELF, .nd = &mnt_ns_desc };<br>
+ int absret = 0;<br>
int ret = 0;<br>
<br>
if (!is_root_user())<br>
@@ -863,26 +840,39 @@ int cr_check(void)<br>
return -1;<br>
<br>
if (chk_feature) {<br>
- ret = chk_feature();<br>
+ if (chk_feature())<br>
+ return -1;<br>
goto out;<br>
}<br>
<br>
- ret |= check_map_files();<br>
- ret |= check_sock_diag();<br>
- ret |= check_ns_last_pid();<br>
- ret |= check_sock_peek_off();<br>
- ret |= check_kcmp();<br>
- ret |= check_prctl();<br>
- ret |= check_fcntl();<br>
- ret |= check_proc_stat();<br>
- ret |= check_tcp();<br>
- ret |= check_fdinfo_ext();<br>
- ret |= check_unaligned_vmsplice();<br>
- ret |= check_tty();<br>
- ret |= check_so_gets();<br>
- ret |= check_ipc();<br>
- ret |= check_sigqueuinfo();<br>
- ret |= check_ptrace_peeksiginfo();<br>
+ /*<br>
+ * Category 1 - absolutely required.<br>
+ */<br>
+ absret |= check_map_files();<br>
+ absret |= check_sock_diag();<br>
+ absret |= check_ns_last_pid();<br>
+ absret |= check_sock_peek_off();<br>
+ absret |= check_kcmp();<br>
+ absret |= check_prctl();<br>
+ absret |= check_fcntl();<br>
+ absret |= check_proc_stat();<br>
+ absret |= check_tcp();<br>
+ absret |= check_fdinfo_ext();<br>
+ absret |= check_unaligned_vmsplice();<br>
+ absret |= check_tty();<br>
+ absret |= check_so_gets();<br>
+ absret |= check_ipc();<br>
+ absret |= check_sigqueuinfo();<br>
+ absret |= check_ptrace_peeksiginfo();<br>
+ if (absret || opts.check_abs_features) {<br>
+ if (!absret)<br>
+ print_on_level(DEFAULT_LOGLEVEL, "%s\n", GOOD);<br>
+ return absret;<br>
+ }<br>
+<br>
+ /*<br>
+ * Category 2 - required for specific cases.<br>
+ */<br>
ret |= check_ptrace_suspend_seccomp();<br>
ret |= check_ptrace_dump_seccomp_filters();<br>
ret |= check_mem_dirty_track();<br>
@@ -896,10 +886,8 @@ int cr_check(void)<br>
ret |= check_cgroupns();<br>
<br>
out:<br>
- if (!ret)<br>
- print_on_level(DEFAULT_LOGLEVEL, "Looks good.\n");<br>
-<br>
- return ret;<br>
+ print_on_level(DEFAULT_LOGLEVEL, "%s\n", ret ? GOOD_BUT : GOOD);<br>
+ return 0;<br>
}<br>
<br>
static int check_tun(void)<br>
@@ -947,32 +935,42 @@ static int check_loginuid(void)<br>
return 0;<br>
}<br>
<br>
+struct feature_list {<br>
+ char *name;<br>
+ int (*func)();<br>
+};<br>
+<br>
+static struct feature_list feature_list[] = {<br>
+ { "mnt_id", check_mnt_id },<br>
+ { "aio_remap", check_aio_remap },<br>
+ { "timerfd", check_timerfd },<br>
+ { "tun", check_tun },<br>
+ { "userns", check_userns },<br>
+ { "fdinfo_lock", check_fdinfo_lock },<br>
+ { "seccomp_suspend", check_ptrace_suspend_seccomp },<br>
+ { "seccomp_filters", check_ptrace_dump_seccomp_filters },<br>
+ { "loginuid", check_loginuid },<br>
+ { "cgroupns", check_cgroupns },<br>
+ { NULL, NULL },<br>
+};<br>
+<br>
int check_add_feature(char *feat)<br>
{<br>
- if (!strcmp(feat, "mnt_id"))<br>
- chk_feature = check_mnt_id;<br>
- else if (!strcmp(feat, "aio_remap"))<br>
- chk_feature = check_aio_remap;<br>
- else if (!strcmp(feat, "timerfd"))<br>
- chk_feature = check_timerfd;<br>
- else if (!strcmp(feat, "tun"))<br>
- chk_feature = check_tun;<br>
- else if (!strcmp(feat, "userns"))<br>
- chk_feature = check_userns;<br>
- else if (!strcmp(feat, "fdinfo_lock"))<br>
- chk_feature = check_fdinfo_lock;<br>
- else if (!strcmp(feat, "seccomp_suspend"))<br>
- chk_feature = check_ptrace_suspend_seccomp;<br>
- else if (!strcmp(feat, "seccomp_filters"))<br>
- chk_feature = check_ptrace_dump_seccomp_filters;<br>
- else if (!strcmp(feat, "loginuid"))<br>
- chk_feature = check_loginuid;<br>
- else if (!strcmp(feat, "cgroupns"))<br>
- chk_feature = check_cgroupns;<br>
- else {<br>
- pr_err("Unknown feature %s\n", feat);<br>
- return -1;<br>
+ struct feature_list *fl;<br>
+<br>
+ if (!strcmp(feat, "list")) {<br>
+ for (fl = feature_list; fl->name; fl++)<br>
+ pr_msg("%s ", fl->name);<br>
+ pr_msg("\n");<br>
+ return 1;<br>
}<br>
<br>
- return 0;<br>
+ for (fl = feature_list; fl->name; fl++) {<br>
+ if (!strcmp(feat, fl->name)) {<br>
+ chk_feature = fl->func;<br>
+ return 0;<br>
+ }<br>
+ }<br>
+ pr_err("Unknown feature %s\n", feat);<br>
+ return -1;<br>
}<br>
diff --git a/criu/cr-service.c b/criu/cr-service.c<br>
index 88d4af7..a1d843d 100644<br>
--- a/criu/cr-service.c<br>
+++ b/criu/cr-service.c<br>
@@ -567,8 +567,8 @@ static int check(int sk)<br>
<br>
setproctitle("check --rpc");<br>
<br>
- /* Check only minimal kernel support */<br>
- opts.check_ms_kernel = true;<br>
+ /* Check only abolutely needed kernel features */<br>
+ opts.check_abs_features = true;<br>
<br>
if (!cr_check())<br>
resp.success = true;<br>
diff --git a/criu/crtools.c b/criu/crtools.c<br>
index a8ddb82..2120082 100644<br>
--- a/criu/crtools.c<br>
+++ b/criu/crtools.c<br>
@@ -275,6 +275,7 @@ int main(int argc, char *argv[], char *envp[])<br>
{ "timeout", required_argument, 0, 1072 },<br>
{ "external", required_argument, 0, 1073 },<br>
{ "empty-ns", required_argument, 0, 1074 },<br>
+ { "abs", no_argument, 0, 1075 },<br>
{ },<br>
};<br>
<br>
@@ -455,8 +456,8 @@ int main(int argc, char *argv[], char *envp[])<br>
opts.force_irmap = true;<br>
break;<br>
case 1054:<br>
- opts.check_ms_kernel = true;<br>
- break;<br>
+ pr_err("--ms is deprecated, use --abs instead\n");<br>
+ return 1;<br>
case 'L':<br>
opts.libdir = optarg;<br>
break;<br>
@@ -490,8 +491,11 @@ int main(int argc, char *argv[], char *envp[])<br>
return 1;<br>
break;<br>
case 1063:<br>
- if (check_add_feature(optarg) < 0)<br>
+ ret = check_add_feature(optarg);<br>
+ if (ret < 0) /* invalid kernel feature name */<br>
return 1;<br>
+ if (ret > 0) /* list kernel features and exit */<br>
+ return 0;<br>
break;<br>
case 1064:<br>
if (!add_skip_mount(optarg))<br>
@@ -554,6 +558,9 @@ int main(int argc, char *argv[], char *envp[])<br>
return 1;<br>
}<br>
break;<br>
+ case 1075:<br>
+ opts.check_abs_features = true;<br>
+ break;<br>
case 'V':<br>
pr_msg("Version: %s\n", CRIU_VERSION);<br>
if (strcmp(CRIU_GITID, "0"))<br>
@@ -714,7 +721,7 @@ usage:<br>
"Usage:\n"<br>
" criu dump|pre-dump -t PID [<options>]\n"<br>
" criu restore [<options>]\n"<br>
-" criu check [--ms]\n"<br>
+" criu check [--feature FEAT]\n"<br>
" criu exec -p PID <syscall-string>\n"<br>
" criu page-server\n"<br>
" criu service [<options>]\n"<br>
@@ -807,8 +814,16 @@ usage:<br>
" socket[inode]\n"<br>
" file[mnt_id:inode]\n"<br>
" --empty-ns {net}\n"<br>
-" Create a namespace, but don't restore its properies.\n"<br>
-" An user will retore them from action scripts.\n"<br>
+" Create a namespace, but don't restore its properies.\n"<br>
+" An user will retore them from action scripts.\n"<br>
+"Check options:\n"<br>
+" --abs check availability of absolutely needed kernel features\n"<br>
+" --ms deprecated, use --abs (don't check not yet merged kernel features)\n"<br>
+" --feature FEAT check availability of one of the following kernel features\n"<br>
+" "<br>
+ );<br>
+ check_add_feature("list");<br>
+ pr_msg(<br>
"\n"<br>
"* Logging:\n"<br>
" -o|--log-file FILE log file name\n"<br>
@@ -836,7 +851,6 @@ usage:<br>
"Other options:\n"<br>
" -h|--help show this text\n"<br>
" -V|--version show version\n"<br>
-" --ms don't check not yet merged kernel features\n"<br>
);<br>
<br>
return 0;<br>
diff --git a/criu/include/cr_options.h b/criu/include/cr_options.h<br>
index a6f0b3e..ba2633a 100644<br>
--- a/criu/include/cr_options.h<br>
+++ b/criu/include/cr_options.h<br>
@@ -56,7 +56,7 @@ struct cr_options {<br>
int final_state;<br>
char *show_dump_file;<br>
char *show_fmt;<br>
- bool check_ms_kernel;<br>
+ bool check_abs_features;<br>
bool show_pages_content;<br>
union {<br>
bool restore_detach;<br>
<span class="HOEnZb"><font color="#888888">--<br>
2.7.0.rc3.207.g0ac5344<br>
<br>
</font></span></blockquote></div><br></div>