From 51fac37bb20c9440a9a4e0a20846c139364d6d13 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 25 Apr 2024 04:54:52 +0200 Subject: Adding upstream version 255.5. Signed-off-by: Daniel Baumann --- src/shared/serialize.c | 55 ++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 44 insertions(+), 11 deletions(-) (limited to 'src/shared/serialize.c') diff --git a/src/shared/serialize.c b/src/shared/serialize.c index 483cbc7..344b102 100644 --- a/src/shared/serialize.c +++ b/src/shared/serialize.c @@ -180,7 +180,7 @@ int serialize_strv(FILE *f, const char *key, char **l) { } int serialize_pidref(FILE *f, FDSet *fds, const char *key, PidRef *pidref) { - int copy; + int r; assert(f); assert(fds); @@ -188,17 +188,23 @@ int serialize_pidref(FILE *f, FDSet *fds, const char *key, PidRef *pidref) { if (!pidref_is_set(pidref)) return 0; - /* If we have a pidfd we serialize the fd and encode the fd number prefixed by "@" in the - * serialization. Otherwise we serialize the numeric PID as it is. */ + /* We always serialize the pid separately, to keep downgrades mostly working (older versions will + * deserialize the pid and silently fail to deserialize the pidfd). If we also have a pidfd, we + * serialize both the pid and pidfd, so that we can construct the exact same pidref after + * deserialization (this doesn't work with only the pidfd, as we can't retrieve the original pid + * from the pidfd anymore if the process is reaped). */ - if (pidref->fd < 0) - return serialize_item_format(f, key, PID_FMT, pidref->pid); + if (pidref->fd >= 0) { + int copy = fdset_put_dup(fds, pidref->fd); + if (copy < 0) + return log_error_errno(copy, "Failed to add file descriptor to serialization set: %m"); - copy = fdset_put_dup(fds, pidref->fd); - if (copy < 0) - return log_error_errno(copy, "Failed to add file descriptor to serialization set: %m"); + r = serialize_item_format(f, key, "@%i:" PID_FMT, copy, pidref->pid); + if (r < 0) + return r; + } - return serialize_item_format(f, key, "@%i", copy); + return serialize_item_format(f, key, PID_FMT, pidref->pid); } int serialize_ratelimit(FILE *f, const char *key, const RateLimit *rl) { @@ -476,12 +482,39 @@ int deserialize_pidref(FDSet *fds, const char *value, PidRef *ret) { e = startswith(value, "@"); if (e) { - int fd = deserialize_fd(fds, e); + _cleanup_free_ char *fdstr = NULL, *pidstr = NULL; + _cleanup_close_ int fd = -EBADF; + + r = extract_many_words(&e, ":", /* flags = */ 0, &fdstr, &pidstr, NULL); + if (r < 0) + return log_debug_errno(r, "Failed to deserialize pidref '%s': %m", e); + if (r == 0) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot deserialize pidref from empty string."); + + assert(r <= 2); + fd = deserialize_fd(fds, fdstr); if (fd < 0) return fd; - r = pidref_set_pidfd_consume(ret, fd); + /* The serialization format changed after 255.4. In systemd <= 255.4 only pidfd is + * serialized, but that causes problems when reconstructing pidref (see serialize_pidref for + * details). After 255.4 the pid is serialized as well even if we have a pidfd, but we still + * need to support older format as we might be upgrading from a version that still uses the + * old format. */ + if (pidstr) { + pid_t pid; + + r = parse_pid(pidstr, &pid); + if (r < 0) + return log_debug_errno(r, "Failed to parse PID: %s", pidstr); + + *ret = (PidRef) { + .pid = pid, + .fd = TAKE_FD(fd), + }; + } else + r = pidref_set_pidfd_consume(ret, TAKE_FD(fd)); } else { pid_t pid; -- cgit v1.2.3