On Mon, May 11 2026, Vipin Sharma wrote: > Add helper functions to preserve and retrieve file descriptors from an > LUO session. This allows library users to work with FD preservation. > > No functional change intended. > > Signed-off-by: Vipin Sharma <[email protected]> > Co-developed-by: David Matlack <[email protected]> > Signed-off-by: David Matlack <[email protected]> > Signed-off-by: Vipin Sharma <[email protected]> > --- > .../liveupdate/lib/include/libliveupdate.h | 3 ++ > .../selftests/liveupdate/lib/liveupdate.c | 41 +++++++++++++++---- > 2 files changed, 35 insertions(+), 9 deletions(-) > > diff --git a/tools/testing/selftests/liveupdate/lib/include/libliveupdate.h > b/tools/testing/selftests/liveupdate/lib/include/libliveupdate.h > index 4390a2737930..2b04b3256382 100644 > --- a/tools/testing/selftests/liveupdate/lib/include/libliveupdate.h > +++ b/tools/testing/selftests/liveupdate/lib/include/libliveupdate.h > @@ -26,6 +26,9 @@ int luo_create_session(int luo_fd, const char *name); > int luo_retrieve_session(int luo_fd, const char *name); > int luo_session_finish(int session_fd); > > +int luo_session_preserve_fd(int session_fd, int fd, __u64 token); > +int luo_session_retrieve_fd(int session_fd, __u64 token); > + > int create_and_preserve_memfd(int session_fd, int token, const char *data); > int restore_and_verify_memfd(int session_fd, int token, const char > *expected_data); > > diff --git a/tools/testing/selftests/liveupdate/lib/liveupdate.c > b/tools/testing/selftests/liveupdate/lib/liveupdate.c > index 60121873f685..7bc6707d8bb7 100644 > --- a/tools/testing/selftests/liveupdate/lib/liveupdate.c > +++ b/tools/testing/selftests/liveupdate/lib/liveupdate.c > @@ -54,9 +54,35 @@ int luo_retrieve_session(int luo_fd, const char *name) > return arg.fd; > } > > +int luo_session_preserve_fd(int session_fd, int fd, __u64 token) > +{ > + struct liveupdate_session_preserve_fd arg = { > + .size = sizeof(arg), > + .fd = fd, > + .token = token, > + }; > + > + if (ioctl(session_fd, LIVEUPDATE_SESSION_PRESERVE_FD, &arg) < 0) > + return -errno; > + > + return 0; > +} > + > +int luo_session_retrieve_fd(int session_fd, __u64 token) > +{ > + struct liveupdate_session_retrieve_fd arg = { > + .size = sizeof(arg), > + .token = token, > + }; > + > + if (ioctl(session_fd, LIVEUPDATE_SESSION_RETRIEVE_FD, &arg) < 0) > + return -errno; > + > + return arg.fd; > +} > + > int create_and_preserve_memfd(int session_fd, int token, const char *data) > { > - struct liveupdate_session_preserve_fd arg = { .size = sizeof(arg) }; > long page_size = sysconf(_SC_PAGE_SIZE); > void *map = MAP_FAILED; > int mfd = -1, ret = -1; > @@ -75,9 +101,8 @@ int create_and_preserve_memfd(int session_fd, int token, > const char *data) > snprintf(map, page_size, "%s", data); > munmap(map, page_size); > > - arg.fd = mfd; > - arg.token = token; > - if (ioctl(session_fd, LIVEUPDATE_SESSION_PRESERVE_FD, &arg) < 0) > + ret = luo_session_preserve_fd(session_fd, mfd, token); > + if (ret) > goto out; > > ret = 0; > @@ -92,15 +117,13 @@ int create_and_preserve_memfd(int session_fd, int token, > const char *data) > int restore_and_verify_memfd(int session_fd, int token, > const char *expected_data) > { > - struct liveupdate_session_retrieve_fd arg = { .size = sizeof(arg) }; > long page_size = sysconf(_SC_PAGE_SIZE); > void *map = MAP_FAILED; > int mfd = -1, ret = -1; > > - arg.token = token; > - if (ioctl(session_fd, LIVEUPDATE_SESSION_RETRIEVE_FD, &arg) < 0) > - return -errno; > - mfd = arg.fd; > + mfd = luo_session_retrieve_fd(session_fd, token); > + if (mfd < 0) > + return mfd;
There is also preserve_fd() in selftests/liveupdate/liveupdate.c which pretty much does what your luo_session_preserve_fd() does. I think you should remove it and make its callers use the new library. LGTM otherwise. > > map = mmap(NULL, page_size, PROT_READ, MAP_SHARED, mfd, 0); > if (map == MAP_FAILED) -- Regards, Pratyush Yadav
