diff --git a/src/shared/binfmt-util.c b/src/shared/binfmt-util.c new file mode 100644 index 0000000000..0229726b42 --- /dev/null +++ b/src/shared/binfmt-util.c @@ -0,0 +1,33 @@ +#include +#include +#include + +#include "binfmt-util.h" +#include "fileio.h" +#include "missing_magic.h" +#include "stat-util.h" + +int disable_binfmt(void) { + int r; + + /* Flush out all rules. This is important during shutdown to cover for rules using "F", since those + * might pin a file and thus block us from unmounting stuff cleanly. + * + * We are a bit careful here, since binfmt_misc might still be an autofs which we don't want to + * trigger. */ + + r = path_is_fs_type("/proc/sys/fs/binfmt_misc", BINFMTFS_MAGIC); + if (r == 0 || r == -ENOENT) { + log_debug("binfmt_misc is not mounted, not detaching entries."); + return 0; + } + if (r < 0) + return log_warning_errno(r, "Failed to determine whether binfmt_misc is mounted: %m"); + + r = write_string_file("/proc/sys/fs/binfmt_misc/status", "-1", WRITE_STRING_FILE_DISABLE_BUFFER); + if (r < 0) + return log_warning_errno(r, "Failed to unregister binfmt_misc entries: %m"); + + log_debug("Unregistered all remaining binfmt_misc entries."); + return 0; +} diff --git a/src/shared/binfmt-util.h b/src/shared/binfmt-util.h new file mode 100644 index 0000000000..70feaad314 --- /dev/null +++ b/src/shared/binfmt-util.h @@ -0,0 +1,4 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ +#pragma once + +int disable_binfmt(void); diff --git a/src/shared/meson.build b/src/shared/meson.build index 483148492c..e608ea8a1d 100644 --- a/src/shared/meson.build +++ b/src/shared/meson.build @@ -12,6 +12,8 @@ shared_sources = files(''' barrier.h base-filesystem.c base-filesystem.h + binfmt-util.c + binfmt-util.h bitmap.c bitmap.h blkid-util.h