Use qemu_dup() to ensure the cloexec flag is set on dup'd fds.
The following dup() instances were left unchanged:
FILE REASON
util/osdep.c implementation of qemu_dup
migration/cpr-exec.c fd is intentionally kept across exec
{linux,bsd}-user/* guest syscalls
tests/* left for future work
Signed-off-by: Filip Hejsek <[email protected]>
---
For each call I replaced, I checked how the resulting fd is used
afterwards. In summary:
hw/virtio/virtio.c:
the fd is passed to memory_region_init_ram_from_fd, used for mmaping
io/channel-file.c:
the fd is passed to qio_channel_file_new_fd, used for reading/writing
qemu-nbd.c:
the fd is stored into old_stderr, then dup2'd back to STDERR_FILENO
system/vl.c:
no change in behavior, the code was already setting the cloexec flag
ui/dmabuf.c:
the function is called by qemu_spice_gl_update, which passes the fds
to SPICE server
These uses shouldn't require keeping the fd open across exec.
Changes in v2:
- Replace the use in qemu-nbd.c too
- Changed commit message
- Link to v1:
https://lore.kernel.org/qemu-devel/[email protected]
---
hw/virtio/virtio.c | 2 +-
io/channel-file.c | 2 +-
qemu-nbd.c | 2 +-
system/vl.c | 9 +--------
ui/dmabuf.c | 2 +-
5 files changed, 5 insertions(+), 12 deletions(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index c9f9e5b511..70779fbd56 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -3204,7 +3204,7 @@ VirtioSharedMemoryMapping
*virtio_shared_memory_mapping_new(uint8_t shmid,
return NULL;
}
- fd = dup(fd);
+ fd = qemu_dup(fd);
if (fd < 0) {
error_report("Failed to duplicate fd: %s", strerror(errno));
return NULL;
diff --git a/io/channel-file.c b/io/channel-file.c
index 5cef75a67c..3f707e80c9 100644
--- a/io/channel-file.c
+++ b/io/channel-file.c
@@ -48,7 +48,7 @@ qio_channel_file_new_fd(int fd)
QIOChannelFile *
qio_channel_file_new_dupfd(int fd, Error **errp)
{
- int newfd = dup(fd);
+ int newfd = qemu_dup(fd);
if (newfd < 0) {
error_setg_errno(errp, errno, "Could not dup FD %d", fd);
diff --git a/qemu-nbd.c b/qemu-nbd.c
index ed5895861b..db1a70b008 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -975,7 +975,7 @@ int main(int argc, char **argv)
/* Remember parent's stderr if we will be restoring it. */
if (opts.verbose /* fork_process is set */) {
- opts.old_stderr = dup(STDERR_FILENO);
+ opts.old_stderr = qemu_dup(STDERR_FILENO);
if (opts.old_stderr < 0) {
error_report("Could not dup original stderr: %s",
strerror(errno));
diff --git a/system/vl.c b/system/vl.c
index 468a9fc247..9381e3d7f7 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -614,14 +614,7 @@ static int parse_add_fd(void *opaque, QemuOpts *opts,
Error **errp)
return -1;
}
-#ifdef F_DUPFD_CLOEXEC
- dupfd = fcntl(fd, F_DUPFD_CLOEXEC, 0);
-#else
- dupfd = dup(fd);
- if (dupfd != -1) {
- qemu_set_cloexec(dupfd);
- }
-#endif
+ dupfd = qemu_dup(fd);
if (dupfd == -1) {
error_setg_errno(errp, errno, "error duplicating fd");
return -1;
diff --git a/ui/dmabuf.c b/ui/dmabuf.c
index 497f82cc61..6d5dffdf84 100644
--- a/ui/dmabuf.c
+++ b/ui/dmabuf.c
@@ -95,7 +95,7 @@ void qemu_dmabuf_dup_fds(QemuDmaBuf *dmabuf, int *fds, int
nfds)
assert(nfds >= dmabuf->num_planes);
for (i = 0; i < dmabuf->num_planes; i++) {
- fds[i] = dmabuf->fd[i] >= 0 ? dup(dmabuf->fd[i]) : -1;
+ fds[i] = dmabuf->fd[i] >= 0 ? qemu_dup(dmabuf->fd[i]) : -1;
}
}
---
base-commit: 615ece3c406b262996e569f29ea6eed0d81c4d8d
change-id: 20261012-use-qemu-dup-38628dbac3ee
Best regards,
--
Filip Hejsek <[email protected]>
