git: ba0d9b43e940 - main - kern_descrip.c: provide helpers to translate between fd flags namespace
Date: Tue, 08 Jul 2025 21:49:16 UTC
The branch main has been updated by kib:
URL: https://cgit.FreeBSD.org/src/commit/?id=ba0d9b43e940077f4025e7e4e85d16c8d525db79
commit ba0d9b43e940077f4025e7e4e85d16c8d525db79
Author: Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2025-07-08 16:30:29 +0000
Commit: Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2025-07-08 21:48:59 +0000
kern_descrip.c: provide helpers to translate between fd flags namespace
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D51206
---
sys/kern/kern_descrip.c | 110 +++++++++++++++++++++++++++++++++++++++---------
1 file changed, 90 insertions(+), 20 deletions(-)
diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index 406236fc2723..2e1da2fdee29 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -480,6 +480,90 @@ kern_fcntl_freebsd(struct thread *td, int fd, int cmd, intptr_t arg)
return (error);
}
+struct flags_trans_elem {
+ u_int f;
+ u_int t;
+};
+
+static u_int
+flags_trans(const struct flags_trans_elem *ftes, int nitems, u_int from_flags)
+{
+ u_int res;
+ int i;
+
+ res = 0;
+ for (i = 0; i < nitems; i++) {
+ if ((from_flags & ftes[i].f) != 0)
+ res |= ftes[i].t;
+ }
+ return (res);
+}
+
+static uint8_t
+fd_to_fde_flags(int fd_flags)
+{
+ static const struct flags_trans_elem fd_to_fde_flags_s[] = {
+ { .f = FD_CLOEXEC, .t = UF_EXCLOSE },
+ { .f = FD_CLOFORK, .t = UF_FOCLOSE },
+ { .f = FD_RESOLVE_BENEATH, .t = UF_RESOLVE_BENEATH },
+ };
+
+ return (flags_trans(fd_to_fde_flags_s, nitems(fd_to_fde_flags_s),
+ fd_flags));
+}
+
+static int
+fde_to_fd_flags(uint8_t fde_flags)
+{
+ static const struct flags_trans_elem fde_to_fd_flags_s[] = {
+ { .f = UF_EXCLOSE, .t = FD_CLOEXEC },
+ { .f = UF_FOCLOSE, .t = FD_CLOFORK },
+ { .f = UF_RESOLVE_BENEATH, .t = FD_RESOLVE_BENEATH },
+ };
+
+ return (flags_trans(fde_to_fd_flags_s, nitems(fde_to_fd_flags_s),
+ fde_flags));
+}
+
+static uint8_t
+fddup_to_fde_flags(int fddup_flags)
+{
+ static const struct flags_trans_elem fddup_to_fde_flags_s[] = {
+ { .f = FDDUP_FLAG_CLOEXEC, .t = UF_EXCLOSE },
+ { .f = FDDUP_FLAG_CLOFORK, .t = UF_FOCLOSE },
+ };
+
+ return (flags_trans(fddup_to_fde_flags_s, nitems(fddup_to_fde_flags_s),
+ fddup_flags));
+}
+
+static uint8_t
+close_range_to_fde_flags(int close_range_flags)
+{
+ static const struct flags_trans_elem close_range_to_fde_flags_s[] = {
+ { .f = CLOSE_RANGE_CLOEXEC, .t = UF_EXCLOSE },
+ { .f = CLOSE_RANGE_CLOFORK, .t = UF_FOCLOSE },
+ };
+
+ return (flags_trans(close_range_to_fde_flags_s,
+ nitems(close_range_to_fde_flags_s), close_range_flags));
+}
+
+static uint8_t
+open_to_fde_flags(int open_flags, bool sticky_orb)
+{
+ static const struct flags_trans_elem open_to_fde_flags_s[] = {
+ { .f = O_CLOEXEC, .t = UF_EXCLOSE },
+ { .f = O_CLOFORK, .t = UF_FOCLOSE },
+ { .f = O_RESOLVE_BENEATH, .t = UF_RESOLVE_BENEATH },
+ };
+ _Static_assert(open_to_fde_flags_s[nitems(open_to_fde_flags_s) - 1].f ==
+ O_RESOLVE_BENEATH, "O_RESOLVE_BENEATH must be last, for sticky_orb");
+
+ return (flags_trans(open_to_fde_flags_s, nitems(open_to_fde_flags_s) -
+ (sticky_orb ? 0 : 1), open_flags));
+}
+
int
kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
{
@@ -534,11 +618,7 @@ kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
FILEDESC_SLOCK(fdp);
fde = fdeget_noref(fdp, fd);
if (fde != NULL) {
- td->td_retval[0] =
- ((fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0) |
- ((fde->fde_flags & UF_FOCLOSE) ? FD_CLOFORK : 0) |
- ((fde->fde_flags & UF_RESOLVE_BENEATH) ?
- FD_RESOLVE_BENEATH : 0);
+ td->td_retval[0] = fde_to_fd_flags(fde->fde_flags);
error = 0;
}
FILEDESC_SUNLOCK(fdp);
@@ -553,10 +633,7 @@ kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
* UF_RESOLVE_BENEATH is sticky and cannot be cleared.
*/
fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) |
- ((arg & FD_CLOEXEC) != 0 ? UF_EXCLOSE : 0) |
- ((arg & FD_CLOFORK) != 0 ? UF_FOCLOSE : 0) |
- ((arg & FD_RESOLVE_BENEATH) != 0 ?
- UF_RESOLVE_BENEATH : 0);
+ fd_to_fde_flags(arg);
error = 0;
}
FILEDESC_XUNLOCK(fdp);
@@ -991,10 +1068,7 @@ kern_dup(struct thread *td, u_int mode, int flags, int old, int new)
goto unlock;
if (mode == FDDUP_FIXED && old == new) {
td->td_retval[0] = new;
- if ((flags & FDDUP_FLAG_CLOEXEC) != 0)
- fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE;
- if ((flags & FDDUP_FLAG_CLOFORK) != 0)
- fdp->fd_ofiles[new].fde_flags |= UF_FOCLOSE;
+ fdp->fd_ofiles[new].fde_flags |= fddup_to_fde_flags(flags);
error = 0;
goto unlock;
}
@@ -1070,8 +1144,7 @@ kern_dup(struct thread *td, u_int mode, int flags, int old, int new)
filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps,
nioctls);
newfde->fde_flags = (oldfde->fde_flags & ~(UF_EXCLOSE | UF_FOCLOSE)) |
- ((flags & FDDUP_FLAG_CLOEXEC) != 0 ? UF_EXCLOSE : 0) |
- ((flags & FDDUP_FLAG_CLOFORK) != 0 ? UF_FOCLOSE : 0);
+ fddup_to_fde_flags(flags);
#ifdef CAPABILITIES
seqc_write_end(&newfde->fde_seqc);
#endif
@@ -1444,8 +1517,7 @@ close_range_flags(struct thread *td, u_int lowfd, u_int highfd, int flags)
struct filedescent *fde;
int fd, fde_flags;
- fde_flags = ((flags & CLOSE_RANGE_CLOEXEC) != 0 ? UF_EXCLOSE : 0) |
- ((flags & CLOSE_RANGE_CLOFORK) != 0 ? UF_FOCLOSE : 0);
+ fde_flags = close_range_to_fde_flags(flags);
fdp = td->td_proc->p_fd;
FILEDESC_XLOCK(fdp);
fdt = atomic_load_ptr(&fdp->fd_files);
@@ -2194,9 +2266,7 @@ _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags,
seqc_write_begin(&fde->fde_seqc);
#endif
fde->fde_file = fp;
- fde->fde_flags = ((flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0) |
- ((flags & O_CLOFORK) != 0 ? UF_FOCLOSE : 0) |
- ((flags & O_RESOLVE_BENEATH) != 0 ? UF_RESOLVE_BENEATH : 0);
+ fde->fde_flags = open_to_fde_flags(flags, true);
if (fcaps != NULL)
filecaps_move(fcaps, &fde->fde_caps);
else