[CRIU] [PATCH] rework criu check logic

Saied Kazemi saied at google.com
Tue Mar 1 07:48:21 PST 2016


Thank you both for your feedback.  I agree that testing the minimal
requirements (category 1) would be a better default action.  I was trying
to maintain some sort of compatibility with how it worked before.  But if
that's not an issue, how about the following?

1. criu check   // category 1 only
2. criu check --extra   // category 2 only
3. criu check --experimental   // category 3 only
4. criu check --all   // all categories
5. criu check --feature FEAT   // specific feature

--Saied


On Tue, Mar 1, 2016 at 2:58 AM, Adrian Reber <adrian at lisas.de> wrote:

> On Tue, Mar 01, 2016 at 12:59:03PM +0300, Pavel Emelyanov wrote:
> > On 03/01/2016 01:58 AM, Saied Kazemi wrote:
> > > Pavel and Adrian,
> > >
> > > 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.
> > >
> > > With this patch, "criu check --abs" passes on 3.19 but fails on 3.13
> due to PR_SET_MM_MAP.
> >
> > I like the patch and have only two suggestions:
> >
> > 1. Isn't it better to make 'criu check' w/o any option to check for
> minimally
> >    required set of features? And, the --full (or smth like this) to
> check for
> >    all the possible functionality.
>
> This is also what I would expect. For a new criu user the check command
> is a good start to see if criu is usable on his platform. Only checking
> for the minimum which is required to run criu would make sense and if
> advanced features are needed/desired a more detailed or better check can
> be run.
>
> > 2. The PR_SET_MM_MAP is really optional. The criu/pie/restorer.c has
> proper
> >    fall-back in case this API is not supported and there are cases when
> restore
> >    w/o this kernel API work. So I suggest to fix the check_prctl to be
> optional.
> >
> > What do you think?
> >
> > -- Pavel
> >
> > > Look forward to your review and feedback.
> > >
> > > --Saied
> > >
> > >
> > > On Mon, Feb 29, 2016 at 2:52 PM, Saied Kazemi <saied at google.com
> <mailto:saied at google.com>> wrote:
> > >
> > >     The "criu check" command to check if the kernel is properly
> configured
> > >     to run criu is broken.
> > >
> > >     The "criu check --ms" command used to be the way to tell criu to
> check
> > >     only for features that have been merged upstream.  But recent
> kernels
> > >     have a set of features whose presence doesn't necessarily mean
> dump will
> > >     fail but rather *may* fail to dump or restore (e.g., soft dirty
> tracker,
> > >     tun support, seccomp).
> > >
> > >     This patch deprecates --ms and introduces --abs for absolutely
> needed
> > >     features.
> > >
> > >     Typical use cases are:
> > >
> > >             $ sudo criu check --abs
> > >             Looks good.
> > >             $ sudo criu check
> > >             <zero or more errors...>
> > >             Looks good but some kernel features are missing.
> > >             $ sudo criu check --feature mnt_id
> > >             Looks good.
> > >             $ sudo criu check --feature seccomp_suspend
> > >             Error (cr-check.c:604): Kernel doesn't support
> PTRACE_O_SUSPEND_SECCOMP
> > >             $ sudo criu check --feature list
> > >             mnt_id aio_remap timerfd tun userns fdinfo_lock
> seccomp_suspend \
> > >                     seccomp_filters loginuid cgroupns
> > >
> > >     Signed-off-by: Saied Kazemi <saied at google.com <mailto:
> saied at google.com>>
> > >     ---
> > >      criu/cr-check.c           | 178
> +++++++++++++++++++++++-----------------------
> > >      criu/cr-service.c         |   4 +-
> > >      criu/crtools.c            |  28 ++++++--
> > >      criu/include/cr_options.h |   2 +-
> > >      4 files changed, 112 insertions(+), 100 deletions(-)
> > >
> > >     diff --git a/criu/cr-check.c b/criu/cr-check.c
> > >     index a67ee2d..d08e085 100644
> > >     --- a/criu/cr-check.c
> > >     +++ b/criu/cr-check.c
> > >     @@ -171,7 +171,6 @@ static int check_kcmp(void)
> > >
> > >      static int check_prctl(void)
> > >      {
> > >     -       unsigned long user_auxv = 0;
> > >             unsigned int *tid_addr;
> > >             unsigned int size = 0;
> > >             int ret;
> > >     @@ -183,37 +182,13 @@ static int check_prctl(void)
> > >             }
> > >
> > >             /*
> > >     -        * Either new or old interface must be supported in the
> kernel.
> > >     +        * The new interface must be supported in the kernel.
> > >              */
> > >             ret = prctl(PR_SET_MM, PR_SET_MM_MAP_SIZE, (unsigned
> long)&size, 0, 0);
> > >             if (ret) {
> > >     -               if (!opts.check_ms_kernel) {
> > >     -                       pr_msg("prctl: PR_SET_MM_MAP is not
> supported, which "
> > >     -                              "is required for restoring user
> namespaces\n");
> > >     -                       return -1;
> > >     -               } else
> > >     -                       pr_warn("Skipping unssuported
> PR_SET_MM_MAP\n");
> > >     -
> > >     -               ret = prctl(PR_SET_MM, PR_SET_MM_BRK, brk(0), 0,
> 0);
> > >     -               if (ret) {
> > >     -                       if (ret == -EPERM)
> > >     -                               pr_msg("prctl: One needs
> CAP_SYS_RESOURCE capability to perform testing\n");
> > >     -                       else
> > >     -                               pr_msg("prctl: PR_SET_MM is not
> supported\n");
> > >     -                       return -1;
> > >     -               }
> > >     -
> > >     -               ret = prctl(PR_SET_MM, PR_SET_MM_EXE_FILE, -1, 0,
> 0);
> > >     -               if (ret != -EBADF) {
> > >     -                       pr_msg("prctl: PR_SET_MM_EXE_FILE is not
> supported (%d)\n", ret);
> > >     -                       return -1;
> > >     -               }
> > >     -
> > >     -               ret = prctl(PR_SET_MM, PR_SET_MM_AUXV,
> (long)&user_auxv, sizeof(user_auxv), 0);
> > >     -               if (ret) {
> > >     -                       pr_msg("prctl: PR_SET_MM_AUXV is not
> supported\n");
> > >     -                       return -1;
> > >     -               }
> > >     +               pr_msg("prctl: PR_SET_MM_MAP is not supported,
> which "
> > >     +                      "is required for restoring user
> namespaces\n");
> > >     +               return -1;
> > >             }
> > >
> > >             return 0;
> > >     @@ -766,11 +741,8 @@ static int check_aio_remap(void)
> > >             ctx = (aio_context_t)naddr;
> > >             r = syscall(SYS_io_getevents, ctx, 0, 1, NULL, NULL);
> > >             if (r < 0) {
> > >     -               if (!opts.check_ms_kernel) {
> > >     -                       pr_err("AIO remap doesn't work
> properly\n");
> > >     -                       return -1;
> > >     -               } else
> > >     -                       pr_warn("Skipping unsupported AIO
> remap\n");
> > >     +               pr_err("AIO remap doesn't work properly\n");
> > >     +               return -1;
> > >             }
> > >
> > >             return 0;
> > >     @@ -782,12 +754,8 @@ static int check_fdinfo_lock(void)
> > >                     return -1;
> > >
> > >             if (!kdat.has_fdinfo_lock) {
> > >     -               if (!opts.check_ms_kernel) {
> > >     -                       pr_err("fdinfo doesn't contain the lock
> field\n");
> > >     -                       return -1;
> > >     -               } else {
> > >     -                       pr_warn("fdinfo doesn't contain the lock
> field\n");
> > >     -               }
> > >     +               pr_err("fdinfo doesn't contain the lock field\n");
> > >     +               return -1;
> > >             }
> > >
> > >             return 0;
> > >     @@ -823,14 +791,10 @@ static int check_clone_parent_vs_pid()
> > >      static int check_cgroupns(void)
> > >      {
> > >             int ret;
> > >     -       if (opts.check_ms_kernel) {
> > >     -               pr_warn("Skipping cgroup namespaces check\n");
> > >     -               return 0;
> > >     -       }
> > >
> > >             ret = access("/proc/self/ns/cgroup", F_OK);
> > >             if (ret < 0) {
> > >     -               pr_err("cgroupns not supported. This is not
> fatal.");
> > >     +               pr_err("cgroupns not supported. This is not
> fatal.\n");
> > >                     return -1;
> > >             }
> > >
> > >     @@ -839,9 +803,22 @@ static int check_cgroupns(void)
> > >
> > >      static int (*chk_feature)(void);
> > >
> > >     +/*
> > >     + * There are three categories of kernel features:
> > >     + *
> > >     + *     1. Absolutely required (/proc/pid/map_files, ptrace
> PEEKSIGINFO, etc.)
> > >     + *     2. Required only for specific cases (aio remap, tun, etc.)
> > >     + *     3. Experimental (task-diag)
> > >     + *
> > >     + * We fail if any feature in category 1 is missing but tolerate
> failures
> > >     + * in the other categories.  Currently, there is nothing in
> category 3.
> > >     + */
> > >     +#define GOOD           "Looks good."
> > >     +#define GOOD_BUT       "Looks good but some kernel features are
> missing."
> > >      int cr_check(void)
> > >      {
> > >             struct ns_id ns = { .type = NS_CRIU, .ns_pid = PROC_SELF,
> .nd = &mnt_ns_desc };
> > >     +       int absret = 0;
> > >             int ret = 0;
> > >
> > >             if (!is_root_user())
> > >     @@ -863,26 +840,39 @@ int cr_check(void)
> > >                     return -1;
> > >
> > >             if (chk_feature) {
> > >     -               ret = chk_feature();
> > >     +               if (chk_feature())
> > >     +                       return -1;
> > >                     goto out;
> > >             }
> > >
> > >     -       ret |= check_map_files();
> > >     -       ret |= check_sock_diag();
> > >     -       ret |= check_ns_last_pid();
> > >     -       ret |= check_sock_peek_off();
> > >     -       ret |= check_kcmp();
> > >     -       ret |= check_prctl();
> > >     -       ret |= check_fcntl();
> > >     -       ret |= check_proc_stat();
> > >     -       ret |= check_tcp();
> > >     -       ret |= check_fdinfo_ext();
> > >     -       ret |= check_unaligned_vmsplice();
> > >     -       ret |= check_tty();
> > >     -       ret |= check_so_gets();
> > >     -       ret |= check_ipc();
> > >     -       ret |= check_sigqueuinfo();
> > >     -       ret |= check_ptrace_peeksiginfo();
> > >     +       /*
> > >     +        * Category 1 - absolutely required.
> > >     +        */
> > >     +       absret |= check_map_files();
> > >     +       absret |= check_sock_diag();
> > >     +       absret |= check_ns_last_pid();
> > >     +       absret |= check_sock_peek_off();
> > >     +       absret |= check_kcmp();
> > >     +       absret |= check_prctl();
> > >     +       absret |= check_fcntl();
> > >     +       absret |= check_proc_stat();
> > >     +       absret |= check_tcp();
> > >     +       absret |= check_fdinfo_ext();
> > >     +       absret |= check_unaligned_vmsplice();
> > >     +       absret |= check_tty();
> > >     +       absret |= check_so_gets();
> > >     +       absret |= check_ipc();
> > >     +       absret |= check_sigqueuinfo();
> > >     +       absret |= check_ptrace_peeksiginfo();
> > >     +       if (absret || opts.check_abs_features) {
> > >     +               if (!absret)
> > >     +                       print_on_level(DEFAULT_LOGLEVEL, "%s\n",
> GOOD);
> > >     +               return absret;
> > >     +       }
> > >     +
> > >     +       /*
> > >     +        * Category 2 - required for specific cases.
> > >     +        */
> > >             ret |= check_ptrace_suspend_seccomp();
> > >             ret |= check_ptrace_dump_seccomp_filters();
> > >             ret |= check_mem_dirty_track();
> > >     @@ -896,10 +886,8 @@ int cr_check(void)
> > >             ret |= check_cgroupns();
> > >
> > >      out:
> > >     -       if (!ret)
> > >     -               print_on_level(DEFAULT_LOGLEVEL, "Looks good.\n");
> > >     -
> > >     -       return ret;
> > >     +       print_on_level(DEFAULT_LOGLEVEL, "%s\n", ret ? GOOD_BUT :
> GOOD);
> > >     +       return 0;
> > >      }
> > >
> > >      static int check_tun(void)
> > >     @@ -947,32 +935,42 @@ static int check_loginuid(void)
> > >             return 0;
> > >      }
> > >
> > >     +struct feature_list {
> > >     +       char *name;
> > >     +       int (*func)();
> > >     +};
> > >     +
> > >     +static struct feature_list feature_list[] = {
> > >     +       { "mnt_id", check_mnt_id },
> > >     +       { "aio_remap", check_aio_remap },
> > >     +       { "timerfd", check_timerfd },
> > >     +       { "tun", check_tun },
> > >     +       { "userns", check_userns },
> > >     +       { "fdinfo_lock", check_fdinfo_lock },
> > >     +       { "seccomp_suspend", check_ptrace_suspend_seccomp },
> > >     +       { "seccomp_filters", check_ptrace_dump_seccomp_filters },
> > >     +       { "loginuid", check_loginuid },
> > >     +       { "cgroupns", check_cgroupns },
> > >     +       { NULL, NULL },
> > >     +};
> > >     +
> > >      int check_add_feature(char *feat)
> > >      {
> > >     -       if (!strcmp(feat, "mnt_id"))
> > >     -               chk_feature = check_mnt_id;
> > >     -       else if (!strcmp(feat, "aio_remap"))
> > >     -               chk_feature = check_aio_remap;
> > >     -       else if (!strcmp(feat, "timerfd"))
> > >     -               chk_feature = check_timerfd;
> > >     -       else if (!strcmp(feat, "tun"))
> > >     -               chk_feature = check_tun;
> > >     -       else if (!strcmp(feat, "userns"))
> > >     -               chk_feature = check_userns;
> > >     -       else if (!strcmp(feat, "fdinfo_lock"))
> > >     -               chk_feature = check_fdinfo_lock;
> > >     -       else if (!strcmp(feat, "seccomp_suspend"))
> > >     -               chk_feature = check_ptrace_suspend_seccomp;
> > >     -       else if (!strcmp(feat, "seccomp_filters"))
> > >     -               chk_feature = check_ptrace_dump_seccomp_filters;
> > >     -       else if (!strcmp(feat, "loginuid"))
> > >     -               chk_feature = check_loginuid;
> > >     -       else if (!strcmp(feat, "cgroupns"))
> > >     -               chk_feature = check_cgroupns;
> > >     -       else {
> > >     -               pr_err("Unknown feature %s\n", feat);
> > >     -               return -1;
> > >     +       struct feature_list *fl;
> > >     +
> > >     +       if (!strcmp(feat, "list")) {
> > >     +               for (fl = feature_list; fl->name; fl++)
> > >     +                       pr_msg("%s ", fl->name);
> > >     +               pr_msg("\n");
> > >     +               return 1;
> > >             }
> > >
> > >     -       return 0;
> > >     +       for (fl = feature_list; fl->name; fl++) {
> > >     +               if (!strcmp(feat, fl->name)) {
> > >     +                       chk_feature = fl->func;
> > >     +                       return 0;
> > >     +               }
> > >     +       }
> > >     +       pr_err("Unknown feature %s\n", feat);
> > >     +       return -1;
> > >      }
> > >     diff --git a/criu/cr-service.c b/criu/cr-service.c
> > >     index 88d4af7..a1d843d 100644
> > >     --- a/criu/cr-service.c
> > >     +++ b/criu/cr-service.c
> > >     @@ -567,8 +567,8 @@ static int check(int sk)
> > >
> > >             setproctitle("check --rpc");
> > >
> > >     -       /* Check only minimal kernel support */
> > >     -       opts.check_ms_kernel = true;
> > >     +       /* Check only abolutely needed kernel features */
> > >     +       opts.check_abs_features = true;
> > >
> > >             if (!cr_check())
> > >                     resp.success = true;
> > >     diff --git a/criu/crtools.c b/criu/crtools.c
> > >     index a8ddb82..2120082 100644
> > >     --- a/criu/crtools.c
> > >     +++ b/criu/crtools.c
> > >     @@ -275,6 +275,7 @@ int main(int argc, char *argv[], char *envp[])
> > >                     { "timeout",
> required_argument,      0, 1072 },
> > >                     { "external",
>  required_argument,      0, 1073 },
> > >                     { "empty-ns",
>  required_argument,      0, 1074 },
> > >     +               { "abs",                        no_argument,
>       0, 1075 },
> > >                     { },
> > >             };
> > >
> > >     @@ -455,8 +456,8 @@ int main(int argc, char *argv[], char *envp[])
> > >                             opts.force_irmap = true;
> > >                             break;
> > >                     case 1054:
> > >     -                       opts.check_ms_kernel = true;
> > >     -                       break;
> > >     +                       pr_err("--ms is deprecated, use --abs
> instead\n");
> > >     +                       return 1;
> > >                     case 'L':
> > >                             opts.libdir = optarg;
> > >                             break;
> > >     @@ -490,8 +491,11 @@ int main(int argc, char *argv[], char *envp[])
> > >                                     return 1;
> > >                             break;
> > >                     case 1063:
> > >     -                       if (check_add_feature(optarg) < 0)
> > >     +                       ret = check_add_feature(optarg);
> > >     +                       if (ret < 0)    /* invalid kernel feature
> name */
> > >                                     return 1;
> > >     +                       if (ret > 0)    /* list kernel features
> and exit */
> > >     +                               return 0;
> > >                             break;
> > >                     case 1064:
> > >                             if (!add_skip_mount(optarg))
> > >     @@ -554,6 +558,9 @@ int main(int argc, char *argv[], char *envp[])
> > >                                     return 1;
> > >                             }
> > >                             break;
> > >     +               case 1075:
> > >     +                       opts.check_abs_features = true;
> > >     +                       break;
> > >                     case 'V':
> > >                             pr_msg("Version: %s\n", CRIU_VERSION);
> > >                             if (strcmp(CRIU_GITID, "0"))
> > >     @@ -714,7 +721,7 @@ usage:
> > >      "Usage:\n"
> > >      "  criu dump|pre-dump -t PID [<options>]\n"
> > >      "  criu restore [<options>]\n"
> > >     -"  criu check [--ms]\n"
> > >     +"  criu check [--feature FEAT]\n"
> > >      "  criu exec -p PID <syscall-string>\n"
> > >      "  criu page-server\n"
> > >      "  criu service [<options>]\n"
> > >     @@ -807,8 +814,16 @@ usage:
> > >      "                            socket[inode]\n"
> > >      "                            file[mnt_id:inode]\n"
> > >      "  --empty-ns {net}\n"
> > >     -"                      Create a namespace, but don't restore its
> properies.\n"
> > >     -"                      An user will retore them from action
> scripts.\n"
> > >     +"                        Create a namespace, but don't restore
> its properies.\n"
> > >     +"                        An user will retore them from action
> scripts.\n"
> > >     +"Check options:\n"
> > >     +"  --abs                 check availability of absolutely needed
> kernel features\n"
> > >     +"  --ms                  deprecated, use --abs (don't check not
> yet merged kernel features)\n"
> > >     +"  --feature FEAT        check availability of one of the
> following kernel features\n"
> > >     +"                        "
> > >     +       );
> > >     +       check_add_feature("list");
> > >     +       pr_msg(
> > >      "\n"
> > >      "* Logging:\n"
> > >      "  -o|--log-file FILE    log file name\n"
> > >     @@ -836,7 +851,6 @@ usage:
> > >      "Other options:\n"
> > >      "  -h|--help             show this text\n"
> > >      "  -V|--version          show version\n"
> > >     -"     --ms               don't check not yet merged kernel
> features\n"
> > >             );
> > >
> > >             return 0;
> > >     diff --git a/criu/include/cr_options.h b/criu/include/cr_options.h
> > >     index a6f0b3e..ba2633a 100644
> > >     --- a/criu/include/cr_options.h
> > >     +++ b/criu/include/cr_options.h
> > >     @@ -56,7 +56,7 @@ struct cr_options {
> > >             int                     final_state;
> > >             char                    *show_dump_file;
> > >             char                    *show_fmt;
> > >     -       bool                    check_ms_kernel;
> > >     +       bool                    check_abs_features;
> > >             bool                    show_pages_content;
> > >             union {
> > >                     bool            restore_detach;
> > >     --
> > >     2.7.0.rc3.207.g0ac5344
> > >
> > >
>
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