As recently pointed out: https://lists.gnu.org/archive/html/qemu-devel/2020-04/msg03133.html code that blindly calls fcntl(fd, F_SETFD, 1) rather than performing a read-modify-write when it intends to add FD_CLOEXEC is broken, in that it can inadvertently clear other bits.
Thankfully, the culprits fixed in this series are unlikely to be clearing either FD_CLOFORK (if Linux ever follows Solaris' lead in adding that), or the new FD_32BIT_MODE being proposed (as the fds in question are unlikely to have that set) - but it is still better to write proper code than to set up a bad example prone to copy-and-paste propagation. And as these usages are not new to 5.0, I don't see any reason against waiting until 5.1 to apply them. Eric Blake (2): hax: Fix setting of FD_CLOEXEC tools: Fix use of fcntl(F_SETFD) during socket activation target/i386/hax-posix.c | 6 +++--- util/systemd.c | 4 +++- 2 files changed, 6 insertions(+), 4 deletions(-) -- 2.26.1
