fd: split kern_dup flags argument into actual flags and a mode

Tidy up the code inside to switch on the mode.
This commit is contained in:
Mateusz Guzik 2015-07-10 11:01:30 +00:00
parent 85237e335d
commit 5fe97c20dc
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=285356
4 changed files with 42 additions and 28 deletions

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@ -97,7 +97,7 @@ cloudabi_sys_fd_replace(struct thread *td,
* clear the return value, as this system call yields no return
* value.
*/
error = kern_dup(td, FDDUP_MUSTREPLACE, uap->from, uap->to);
error = kern_dup(td, FDDUP_MUSTREPLACE, 0, uap->from, uap->to);
td->td_retval[0] = 0;
return (error);
}

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@ -355,7 +355,7 @@ int
sys_dup2(struct thread *td, struct dup2_args *uap)
{
return (kern_dup(td, FDDUP_FIXED, (int)uap->from, (int)uap->to));
return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to));
}
/*
@ -371,7 +371,7 @@ int
sys_dup(struct thread *td, struct dup_args *uap)
{
return (kern_dup(td, 0, (int)uap->fd, 0));
return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0));
}
/*
@ -481,22 +481,22 @@ kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
switch (cmd) {
case F_DUPFD:
tmp = arg;
error = kern_dup(td, FDDUP_FCNTL, fd, tmp);
error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp);
break;
case F_DUPFD_CLOEXEC:
tmp = arg;
error = kern_dup(td, FDDUP_FCNTL | FDDUP_CLOEXEC, fd, tmp);
error = kern_dup(td, FDDUP_FCNTL, FDDUP_CLOEXEC, fd, tmp);
break;
case F_DUP2FD:
tmp = arg;
error = kern_dup(td, FDDUP_FIXED, fd, tmp);
error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp);
break;
case F_DUP2FD_CLOEXEC:
tmp = arg;
error = kern_dup(td, FDDUP_FIXED | FDDUP_CLOEXEC, fd, tmp);
error = kern_dup(td, FDDUP_FIXED, FDDUP_CLOEXEC, fd, tmp);
break;
case F_GETFD:
@ -789,7 +789,7 @@ getmaxfd(struct thread *td)
* Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD).
*/
int
kern_dup(struct thread *td, int flags, int old, int new)
kern_dup(struct thread *td, u_int mode, int flags, int old, int new)
{
struct filedesc *fdp;
struct filedescent *oldfde, *newfde;
@ -801,10 +801,8 @@ kern_dup(struct thread *td, int flags, int old, int new)
p = td->td_proc;
fdp = p->p_fd;
MPASS((flags & ~(FDDUP_FIXED | FDDUP_FCNTL | FDDUP_CLOEXEC |
FDDUP_MUSTREPLACE)) == 0);
MPASS((flags & (FDDUP_FIXED | FDDUP_MUSTREPLACE)) !=
(FDDUP_FIXED | FDDUP_MUSTREPLACE));
MPASS((flags & ~(FDDUP_CLOEXEC)) == 0);
MPASS(mode < FDDUP_LASTMODE);
/*
* Verify we have a valid descriptor to dup from and possibly to
@ -825,7 +823,7 @@ kern_dup(struct thread *td, int flags, int old, int new)
return (EBADF);
}
oldfde = &fdp->fd_ofiles[old];
if (flags & (FDDUP_FIXED | FDDUP_MUSTREPLACE) && old == new) {
if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) {
td->td_retval[0] = new;
if (flags & FDDUP_CLOEXEC)
fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE;
@ -840,7 +838,17 @@ kern_dup(struct thread *td, int flags, int old, int new)
* table is large enough to hold it, and grab it. Otherwise, just
* allocate a new descriptor the usual way.
*/
if (flags & FDDUP_MUSTREPLACE) {
switch (mode) {
case FDDUP_NORMAL:
case FDDUP_FCNTL:
if ((error = fdalloc(td, new, &new)) != 0) {
FILEDESC_XUNLOCK(fdp);
fdrop(fp, td);
return (error);
}
newfde = &fdp->fd_ofiles[new];
break;
case FDDUP_MUSTREPLACE:
/* Target file descriptor must exist. */
if (new >= fdp->fd_nfiles ||
fdp->fd_ofiles[new].fde_file == NULL) {
@ -849,7 +857,8 @@ kern_dup(struct thread *td, int flags, int old, int new)
return (EBADF);
}
newfde = &fdp->fd_ofiles[new];
} else if (flags & FDDUP_FIXED) {
break;
case FDDUP_FIXED:
if (new >= fdp->fd_nfiles) {
/*
* The resource limits are here instead of e.g.
@ -877,13 +886,12 @@ kern_dup(struct thread *td, int flags, int old, int new)
newfde = &fdp->fd_ofiles[new];
if (newfde->fde_file == NULL)
fdused(fdp, new);
} else {
if ((error = fdalloc(td, new, &new)) != 0) {
FILEDESC_XUNLOCK(fdp);
fdrop(fp, td);
return (error);
}
newfde = &fdp->fd_ofiles[new];
break;
#ifdef INVARIANTS
default:
newfde = NULL; /* silence the compiler */
KASSERT(0, ("%s unsupported mode %d", __func__, mode));
#endif
}
KASSERT(fp == oldfde->fde_file, ("old fd has been modified"));
@ -2223,7 +2231,7 @@ fdcheckstd(struct thread *td)
save = td->td_retval[0];
if (devnull != -1) {
error = kern_dup(td, FDDUP_FIXED, devnull, i);
error = kern_dup(td, FDDUP_FIXED, 0, devnull, i);
} else {
error = kern_openat(td, AT_FDCWD, "/dev/null",
UIO_SYSSPACE, O_RDWR, 0);

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@ -134,11 +134,17 @@ struct filedesc_to_leader {
SX_NOTRECURSED)
#define FILEDESC_UNLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_UNLOCKED)
/* Operation types for kern_dup(). */
enum {
FDDUP_NORMAL = 0x01, /* dup() behavior. */
FDDUP_FCNTL, /* fcntl()-style errors. */
FDDUP_FIXED, /* Force fixed allocation. */
FDDUP_MUSTREPLACE, /* Target must exist. */
FDDUP_LASTMODE,
};
/* Flags for kern_dup(). */
#define FDDUP_FIXED 0x1 /* Force fixed allocation. */
#define FDDUP_FCNTL 0x2 /* fcntl()-style errors. */
#define FDDUP_CLOEXEC 0x4 /* Atomically set FD_CLOEXEC. */
#define FDDUP_MUSTREPLACE 0x8 /* Target must exist. */
#define FDDUP_CLOEXEC 0x1 /* Atomically set FD_CLOEXEC. */
struct thread;

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@ -85,7 +85,7 @@ int kern_clock_settime(struct thread *td, clockid_t clock_id,
int kern_close(struct thread *td, int fd);
int kern_connectat(struct thread *td, int dirfd, int fd,
struct sockaddr *sa);
int kern_dup(struct thread *td, int flags, int old, int new);
int kern_dup(struct thread *td, u_int mode, int flags, int old, int new);
int kern_execve(struct thread *td, struct image_args *args,
struct mac *mac_p);
int kern_fchmodat(struct thread *td, int fd, char *path,