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| author | Yu Watanabe <watanabe.yu+github@gmail.com> | 2022-01-13 00:09:38 +0900 |
|---|---|---|
| committer | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2022-04-28 18:02:59 +0200 |
| commit | 9029ab8ae01f315cc9ce795ad52e09013e10d893 (patch) | |
| tree | 77cfd45ac2d2cb7f6f69a7770fa7cab067a0c1e4 | |
| parent | 0a54e62e46fa256c31e01cd5f191b1035a449f60 (diff) | |
| download | systemd-9029ab8ae01f315cc9ce795ad52e09013e10d893.tar.gz | |
pid1,cgroup-show: ignore -EOPNOTSUPP in cg_read_pid()
The function is called in recursion, and cgroup.procs in some subcgroups
may not be read.
Fixes #22089.
(cherry picked from commit 1fb50408ce23e67e0be94ead69c891d26b4823e2)
(cherry picked from commit 1b003bbc806198dbdd57b405d968f30565495e70)
| -rw-r--r-- | src/core/dbus-unit.c | 8 | ||||
| -rw-r--r-- | src/shared/cgroup-show.c | 17 |
2 files changed, 18 insertions, 7 deletions
diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c index fe320f1b05..0419f6205e 100644 --- a/src/core/dbus-unit.c +++ b/src/core/dbus-unit.c @@ -1295,11 +1295,15 @@ static int append_cgroup(sd_bus_message *reply, const char *p, Set *pids) { for (;;) { pid_t pid; + /* libvirt / qemu uses threaded mode and cgroup.procs cannot be read at the lower levels. + * From https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#threads, + * “cgroup.procs” in a threaded domain cgroup contains the PIDs of all processes in + * the subtree and is not readable in the subtree proper. */ r = cg_read_pid(f, &pid); + if (IN_SET(r, 0, -EOPNOTSUPP)) + break; if (r < 0) return r; - if (r == 0) - break; if (is_kernel_thread(pid) > 0) continue; diff --git a/src/shared/cgroup-show.c b/src/shared/cgroup-show.c index c7e63be508..c324652552 100644 --- a/src/shared/cgroup-show.c +++ b/src/shared/cgroup-show.c @@ -86,7 +86,6 @@ static int show_cgroup_one_by_path( _cleanup_fclose_ FILE *f = NULL; _cleanup_free_ char *p = NULL; size_t n = 0; - pid_t pid; char *fn; int r; @@ -99,7 +98,18 @@ static int show_cgroup_one_by_path( if (!f) return -errno; - while ((r = cg_read_pid(f, &pid)) > 0) { + for (;;) { + pid_t pid; + + /* libvirt / qemu uses threaded mode and cgroup.procs cannot be read at the lower levels. + * From https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#threads, + * “cgroup.procs” in a threaded domain cgroup contains the PIDs of all processes in + * the subtree and is not readable in the subtree proper. */ + r = cg_read_pid(f, &pid); + if (IN_SET(r, 0, -EOPNOTSUPP)) + break; + if (r < 0) + return r; if (!(flags & OUTPUT_KERNEL_THREADS) && is_kernel_thread(pid) > 0) continue; @@ -110,9 +120,6 @@ static int show_cgroup_one_by_path( pids[n++] = pid; } - if (r < 0) - return r; - show_pid_array(pids, n, prefix, n_columns, false, more, flags); return 0; |