Author: kib
Date: Sun Jan 6 00:52:53 2019
New Revision: 342801
URL: https://svnweb.freebsd.org/changeset/base/342801
Log:
MFC r342628, r342670 (by cem):
Fix linux_destroy_dev() behaviour when there are still files open from
the destroying cdev.
Also bump __FreeBSD_version since struct linux_cdev size on i386 increased
(this is unmergeable r342629 on HEAD).
Modified:
stable/12/sys/compat/linuxkpi/common/include/linux/cdev.h
stable/12/sys/compat/linuxkpi/common/src/linux_compat.c
stable/12/sys/sys/param.h
Directory Properties:
stable/12/ (props changed)
Modified: stable/12/sys/compat/linuxkpi/common/include/linux/cdev.h
==============================================================================
--- stable/12/sys/compat/linuxkpi/common/include/linux/cdev.h Sun Jan 6
00:45:41 2019 (r342800)
+++ stable/12/sys/compat/linuxkpi/common/include/linux/cdev.h Sun Jan 6
00:52:53 2019 (r342801)
@@ -52,7 +52,8 @@ struct linux_cdev {
struct cdev *cdev;
dev_t dev;
const struct file_operations *ops;
- atomic_long_t refs;
+ u_int refs;
+ u_int siref;
};
static inline void
@@ -61,7 +62,7 @@ cdev_init(struct linux_cdev *cdev, const struct file_o
kobject_init(&cdev->kobj, &linux_cdev_static_ktype);
cdev->ops = ops;
- atomic_long_set(&cdev->refs, 0);
+ cdev->refs = 1;
}
static inline struct linux_cdev *
@@ -70,8 +71,8 @@ cdev_alloc(void)
struct linux_cdev *cdev;
cdev = kzalloc(sizeof(struct linux_cdev), M_WAITOK);
- if (cdev)
- kobject_init(&cdev->kobj, &linux_cdev_ktype);
+ kobject_init(&cdev->kobj, &linux_cdev_ktype);
+ cdev->refs = 1;
return (cdev);
}
Modified: stable/12/sys/compat/linuxkpi/common/src/linux_compat.c
==============================================================================
--- stable/12/sys/compat/linuxkpi/common/src/linux_compat.c Sun Jan 6
00:45:41 2019 (r342800)
+++ stable/12/sys/compat/linuxkpi/common/src/linux_compat.c Sun Jan 6
00:52:53 2019 (r342801)
@@ -40,6 +40,7 @@ __FBSDID("$FreeBSD$");
#include <sys/proc.h>
#include <sys/sglist.h>
#include <sys/sleepqueue.h>
+#include <sys/refcount.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/bus.h>
@@ -100,6 +101,7 @@ MALLOC_DEFINE(M_KMALLOC, "linux", "Linux kmalloc compa
#undef cdev
#define RB_ROOT(head) (head)->rbh_root
+static void linux_cdev_deref(struct linux_cdev *ldev);
static struct vm_area_struct *linux_cdev_handle_find(void *handle);
struct kobject linux_class_root;
@@ -691,6 +693,52 @@ zap_vma_ptes(struct vm_area_struct *vma, unsigned long
return (0);
}
+static struct file_operations dummy_ldev_ops = {
+ /* XXXKIB */
+};
+
+static struct linux_cdev dummy_ldev = {
+ .ops = &dummy_ldev_ops,
+};
+
+#define LDEV_SI_DTR 0x0001
+#define LDEV_SI_REF 0x0002
+
+static void
+linux_get_fop(struct linux_file *filp, const struct file_operations **fop,
+ struct linux_cdev **dev)
+{
+ struct linux_cdev *ldev;
+ u_int siref;
+
+ ldev = filp->f_cdev;
+ *fop = filp->f_op;
+ if (ldev != NULL) {
+ for (siref = ldev->siref;;) {
+ if ((siref & LDEV_SI_DTR) != 0) {
+ ldev = &dummy_ldev;
+ siref = ldev->siref;
+ *fop = ldev->ops;
+ MPASS((ldev->siref & LDEV_SI_DTR) == 0);
+ } else if (atomic_fcmpset_int(&ldev->siref, &siref,
+ siref + LDEV_SI_REF)) {
+ break;
+ }
+ }
+ }
+ *dev = ldev;
+}
+
+static void
+linux_drop_fop(struct linux_cdev *ldev)
+{
+
+ if (ldev == NULL)
+ return;
+ MPASS((ldev->siref & ~LDEV_SI_DTR) != 0);
+ atomic_subtract_int(&ldev->siref, LDEV_SI_REF);
+}
+
#define OPW(fp,td,code) ({ \
struct file *__fpop; \
__typeof(code) __retval; \
@@ -703,10 +751,12 @@ zap_vma_ptes(struct vm_area_struct *vma, unsigned long
})
static int
-linux_dev_fdopen(struct cdev *dev, int fflags, struct thread *td, struct file
*file)
+linux_dev_fdopen(struct cdev *dev, int fflags, struct thread *td,
+ struct file *file)
{
struct linux_cdev *ldev;
struct linux_file *filp;
+ const struct file_operations *fop;
int error;
ldev = dev->si_drv1;
@@ -718,20 +768,17 @@ linux_dev_fdopen(struct cdev *dev, int fflags, struct
filp->f_flags = file->f_flag;
filp->f_vnode = file->f_vnode;
filp->_file = file;
+ refcount_acquire(&ldev->refs);
filp->f_cdev = ldev;
linux_set_current(td);
+ linux_get_fop(filp, &fop, &ldev);
- /* get a reference on the Linux character device */
- if (atomic_long_add_unless(&ldev->refs, 1, -1L) == 0) {
- kfree(filp);
- return (EINVAL);
- }
-
- if (filp->f_op->open) {
- error = -filp->f_op->open(file->f_vnode, filp);
- if (error) {
- atomic_long_dec(&ldev->refs);
+ if (fop->open != NULL) {
+ error = -fop->open(file->f_vnode, filp);
+ if (error != 0) {
+ linux_drop_fop(ldev);
+ linux_cdev_deref(filp->f_cdev);
kfree(filp);
return (error);
}
@@ -742,6 +789,7 @@ linux_dev_fdopen(struct cdev *dev, int fflags, struct
/* release the file from devfs */
finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
+ linux_drop_fop(ldev);
return (ENXIO);
}
@@ -877,7 +925,8 @@ linux_get_error(struct task_struct *task, int error)
static int
linux_file_ioctl_sub(struct file *fp, struct linux_file *filp,
- u_long cmd, caddr_t data, struct thread *td)
+ const struct file_operations *fop, u_long cmd, caddr_t data,
+ struct thread *td)
{
struct task_struct *task = current;
unsigned size;
@@ -902,20 +951,28 @@ linux_file_ioctl_sub(struct file *fp, struct linux_fil
#if defined(__amd64__)
if (td->td_proc->p_elf_machine == EM_386) {
/* try the compat IOCTL handler first */
- if (filp->f_op->compat_ioctl != NULL)
- error = -OPW(fp, td, filp->f_op->compat_ioctl(filp,
cmd, (u_long)data));
- else
+ if (fop->compat_ioctl != NULL) {
+ error = -OPW(fp, td, fop->compat_ioctl(filp,
+ cmd, (u_long)data));
+ } else {
error = ENOTTY;
+ }
/* fallback to the regular IOCTL handler, if any */
- if (error == ENOTTY && filp->f_op->unlocked_ioctl != NULL)
- error = -OPW(fp, td, filp->f_op->unlocked_ioctl(filp,
cmd, (u_long)data));
+ if (error == ENOTTY && fop->unlocked_ioctl != NULL) {
+ error = -OPW(fp, td, fop->unlocked_ioctl(filp,
+ cmd, (u_long)data));
+ }
} else
#endif
- if (filp->f_op->unlocked_ioctl != NULL)
- error = -OPW(fp, td, filp->f_op->unlocked_ioctl(filp, cmd,
(u_long)data));
- else
- error = ENOTTY;
+ {
+ if (fop->unlocked_ioctl != NULL) {
+ error = -OPW(fp, td, fop->unlocked_ioctl(filp,
+ cmd, (u_long)data));
+ } else {
+ error = ENOTTY;
+ }
+ }
if (size > 0) {
task->bsd_ioctl_data = NULL;
task->bsd_ioctl_len = 0;
@@ -1084,30 +1141,36 @@ static struct filterops linux_dev_kqfiltops_write = {
static void
linux_file_kqfilter_poll(struct linux_file *filp, int kqflags)
{
+ struct thread *td;
+ const struct file_operations *fop;
+ struct linux_cdev *ldev;
int temp;
- if (filp->f_kqflags & kqflags) {
- struct thread *td = curthread;
+ if ((filp->f_kqflags & kqflags) == 0)
+ return;
- /* get the latest polling state */
- temp = OPW(filp->_file, td, filp->f_op->poll(filp, NULL));
+ td = curthread;
- spin_lock(&filp->f_kqlock);
- /* clear kqflags */
- filp->f_kqflags &= ~(LINUX_KQ_FLAG_NEED_READ |
- LINUX_KQ_FLAG_NEED_WRITE);
- /* update kqflags */
- if (temp & (POLLIN | POLLOUT)) {
- if (temp & POLLIN)
- filp->f_kqflags |= LINUX_KQ_FLAG_NEED_READ;
- if (temp & POLLOUT)
- filp->f_kqflags |= LINUX_KQ_FLAG_NEED_WRITE;
+ linux_get_fop(filp, &fop, &ldev);
+ /* get the latest polling state */
+ temp = OPW(filp->_file, td, fop->poll(filp, NULL));
+ linux_drop_fop(ldev);
- /* make sure the "knote" gets woken up */
- KNOTE_LOCKED(&filp->f_selinfo.si_note, 0);
- }
- spin_unlock(&filp->f_kqlock);
+ spin_lock(&filp->f_kqlock);
+ /* clear kqflags */
+ filp->f_kqflags &= ~(LINUX_KQ_FLAG_NEED_READ |
+ LINUX_KQ_FLAG_NEED_WRITE);
+ /* update kqflags */
+ if ((temp & (POLLIN | POLLOUT)) != 0) {
+ if ((temp & POLLIN) != 0)
+ filp->f_kqflags |= LINUX_KQ_FLAG_NEED_READ;
+ if ((temp & POLLOUT) != 0)
+ filp->f_kqflags |= LINUX_KQ_FLAG_NEED_WRITE;
+
+ /* make sure the "knote" gets woken up */
+ KNOTE_LOCKED(&filp->f_selinfo.si_note, 0);
}
+ spin_unlock(&filp->f_kqlock);
}
static int
@@ -1156,9 +1219,9 @@ linux_file_kqfilter(struct file *file, struct knote *k
}
static int
-linux_file_mmap_single(struct file *fp, vm_ooffset_t *offset,
- vm_size_t size, struct vm_object **object, int nprot,
- struct thread *td)
+linux_file_mmap_single(struct file *fp, const struct file_operations *fop,
+ vm_ooffset_t *offset, vm_size_t size, struct vm_object **object,
+ int nprot, struct thread *td)
{
struct task_struct *task;
struct vm_area_struct *vmap;
@@ -1170,7 +1233,7 @@ linux_file_mmap_single(struct file *fp, vm_ooffset_t *
filp = (struct linux_file *)fp->f_data;
filp->f_flags = fp->f_flag;
- if (filp->f_op->mmap == NULL)
+ if (fop->mmap == NULL)
return (EOPNOTSUPP);
linux_set_current(td);
@@ -1200,7 +1263,7 @@ linux_file_mmap_single(struct file *fp, vm_ooffset_t *
if (unlikely(down_write_killable(&vmap->vm_mm->mmap_sem))) {
error = linux_get_error(task, EINTR);
} else {
- error = -OPW(fp, td, filp->f_op->mmap(filp, vmap));
+ error = -OPW(fp, td, fop->mmap(filp, vmap));
error = linux_get_error(task, error);
up_write(&vmap->vm_mm->mmap_sem);
}
@@ -1319,6 +1382,8 @@ linux_file_read(struct file *file, struct uio *uio, st
int flags, struct thread *td)
{
struct linux_file *filp;
+ const struct file_operations *fop;
+ struct linux_cdev *ldev;
ssize_t bytes;
int error;
@@ -1331,8 +1396,10 @@ linux_file_read(struct file *file, struct uio *uio, st
if (uio->uio_resid > DEVFS_IOSIZE_MAX)
return (EINVAL);
linux_set_current(td);
- if (filp->f_op->read) {
- bytes = OPW(file, td, filp->f_op->read(filp,
uio->uio_iov->iov_base,
+ linux_get_fop(filp, &fop, &ldev);
+ if (fop->read != NULL) {
+ bytes = OPW(file, td, fop->read(filp,
+ uio->uio_iov->iov_base,
uio->uio_iov->iov_len, &uio->uio_offset));
if (bytes >= 0) {
uio->uio_iov->iov_base =
@@ -1347,6 +1414,7 @@ linux_file_read(struct file *file, struct uio *uio, st
/* update kqfilter status, if any */
linux_file_kqfilter_poll(filp, LINUX_KQ_FLAG_HAS_READ);
+ linux_drop_fop(ldev);
return (error);
}
@@ -1356,10 +1424,11 @@ linux_file_write(struct file *file, struct uio *uio, s
int flags, struct thread *td)
{
struct linux_file *filp;
+ const struct file_operations *fop;
+ struct linux_cdev *ldev;
ssize_t bytes;
int error;
- error = 0;
filp = (struct linux_file *)file->f_data;
filp->f_flags = file->f_flag;
/* XXX no support for I/O vectors currently */
@@ -1368,14 +1437,17 @@ linux_file_write(struct file *file, struct uio *uio, s
if (uio->uio_resid > DEVFS_IOSIZE_MAX)
return (EINVAL);
linux_set_current(td);
- if (filp->f_op->write) {
- bytes = OPW(file, td, filp->f_op->write(filp,
uio->uio_iov->iov_base,
+ linux_get_fop(filp, &fop, &ldev);
+ if (fop->write != NULL) {
+ bytes = OPW(file, td, fop->write(filp,
+ uio->uio_iov->iov_base,
uio->uio_iov->iov_len, &uio->uio_offset));
if (bytes >= 0) {
uio->uio_iov->iov_base =
((uint8_t *)uio->uio_iov->iov_base) + bytes;
uio->uio_iov->iov_len -= bytes;
uio->uio_resid -= bytes;
+ error = 0;
} else {
error = linux_get_error(current, -bytes);
}
@@ -1385,6 +1457,8 @@ linux_file_write(struct file *file, struct uio *uio, s
/* update kqfilter status, if any */
linux_file_kqfilter_poll(filp, LINUX_KQ_FLAG_HAS_WRITE);
+ linux_drop_fop(ldev);
+
return (error);
}
@@ -1393,16 +1467,21 @@ linux_file_poll(struct file *file, int events, struct
struct thread *td)
{
struct linux_file *filp;
+ const struct file_operations *fop;
+ struct linux_cdev *ldev;
int revents;
filp = (struct linux_file *)file->f_data;
filp->f_flags = file->f_flag;
linux_set_current(td);
- if (filp->f_op->poll != NULL)
- revents = OPW(file, td, filp->f_op->poll(filp,
LINUX_POLL_TABLE_NORMAL)) & events;
- else
+ linux_get_fop(filp, &fop, &ldev);
+ if (fop->poll != NULL) {
+ revents = OPW(file, td, fop->poll(filp,
+ LINUX_POLL_TABLE_NORMAL)) & events;
+ } else {
revents = 0;
-
+ }
+ linux_drop_fop(ldev);
return (revents);
}
@@ -1410,23 +1489,28 @@ static int
linux_file_close(struct file *file, struct thread *td)
{
struct linux_file *filp;
+ const struct file_operations *fop;
+ struct linux_cdev *ldev;
int error;
filp = (struct linux_file *)file->f_data;
- KASSERT(file_count(filp) == 0, ("File refcount(%d) is not zero",
file_count(filp)));
+ KASSERT(file_count(filp) == 0,
+ ("File refcount(%d) is not zero", file_count(filp)));
+ error = 0;
filp->f_flags = file->f_flag;
linux_set_current(td);
linux_poll_wait_dequeue(filp);
- error = -OPW(file, td, filp->f_op->release(filp->f_vnode, filp));
+ linux_get_fop(filp, &fop, &ldev);
+ if (fop->release != NULL)
+ error = -OPW(file, td, fop->release(filp->f_vnode, filp));
funsetown(&filp->f_sigio);
if (filp->f_vnode != NULL)
vdrop(filp->f_vnode);
- if (filp->f_cdev != NULL) {
- /* put a reference on the Linux character device */
- atomic_long_dec(&filp->f_cdev->refs);
- }
+ linux_drop_fop(ldev);
+ if (filp->f_cdev != NULL)
+ linux_cdev_deref(filp->f_cdev);
kfree(filp);
return (error);
@@ -1437,27 +1521,30 @@ linux_file_ioctl(struct file *fp, u_long cmd, void *da
struct thread *td)
{
struct linux_file *filp;
+ const struct file_operations *fop;
+ struct linux_cdev *ldev;
int error;
+ error = 0;
filp = (struct linux_file *)fp->f_data;
filp->f_flags = fp->f_flag;
- error = 0;
+ linux_get_fop(filp, &fop, &ldev);
linux_set_current(td);
switch (cmd) {
case FIONBIO:
break;
case FIOASYNC:
- if (filp->f_op->fasync == NULL)
+ if (fop->fasync == NULL)
break;
- error = -OPW(fp, td, filp->f_op->fasync(0, filp, fp->f_flag &
FASYNC));
+ error = -OPW(fp, td, fop->fasync(0, filp, fp->f_flag & FASYNC));
break;
case FIOSETOWN:
error = fsetown(*(int *)data, &filp->f_sigio);
if (error == 0) {
- if (filp->f_op->fasync == NULL)
+ if (fop->fasync == NULL)
break;
- error = -OPW(fp, td, filp->f_op->fasync(0, filp,
+ error = -OPW(fp, td, fop->fasync(0, filp,
fp->f_flag & FASYNC));
}
break;
@@ -1465,16 +1552,17 @@ linux_file_ioctl(struct file *fp, u_long cmd, void *da
*(int *)data = fgetown(&filp->f_sigio);
break;
default:
- error = linux_file_ioctl_sub(fp, filp, cmd, data, td);
+ error = linux_file_ioctl_sub(fp, filp, fop, cmd, data, td);
break;
}
+ linux_drop_fop(ldev);
return (error);
}
static int
linux_file_mmap_sub(struct thread *td, vm_size_t objsize, vm_prot_t prot,
vm_prot_t *maxprotp, int *flagsp, struct file *fp,
- vm_ooffset_t *foff, vm_object_t *objp)
+ vm_ooffset_t *foff, const struct file_operations *fop, vm_object_t *objp)
{
/*
* Character devices do not provide private mappings
@@ -1486,7 +1574,8 @@ linux_file_mmap_sub(struct thread *td, vm_size_t objsi
if ((*flagsp & (MAP_PRIVATE | MAP_COPY)) != 0)
return (EINVAL);
- return (linux_file_mmap_single(fp, foff, objsize, objp, (int)prot, td));
+ return (linux_file_mmap_single(fp, fop, foff, objsize, objp,
+ (int)prot, td));
}
static int
@@ -1495,6 +1584,8 @@ linux_file_mmap(struct file *fp, vm_map_t map, vm_offs
struct thread *td)
{
struct linux_file *filp;
+ const struct file_operations *fop;
+ struct linux_cdev *ldev;
struct mount *mp;
struct vnode *vp;
vm_object_t object;
@@ -1541,15 +1632,18 @@ linux_file_mmap(struct file *fp, vm_map_t map, vm_offs
}
maxprot &= cap_maxprot;
- error = linux_file_mmap_sub(td, size, prot, &maxprot, &flags, fp, &foff,
- &object);
+ linux_get_fop(filp, &fop, &ldev);
+ error = linux_file_mmap_sub(td, size, prot, &maxprot, &flags, fp,
+ &foff, fop, &object);
if (error != 0)
- return (error);
+ goto out;
error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
foff, FALSE, td);
if (error != 0)
vm_object_deallocate(object);
+out:
+ linux_drop_fop(ldev);
return (error);
}
@@ -1971,6 +2065,14 @@ linux_completion_done(struct completion *c)
}
static void
+linux_cdev_deref(struct linux_cdev *ldev)
+{
+
+ if (refcount_release(&ldev->refs))
+ kfree(ldev);
+}
+
+static void
linux_cdev_release(struct kobject *kobj)
{
struct linux_cdev *cdev;
@@ -1979,7 +2081,7 @@ linux_cdev_release(struct kobject *kobj)
cdev = container_of(kobj, struct linux_cdev, kobj);
parent = kobj->parent;
linux_destroy_dev(cdev);
- kfree(cdev);
+ linux_cdev_deref(cdev);
kobject_put(parent);
}
@@ -1996,20 +2098,19 @@ linux_cdev_static_release(struct kobject *kobj)
}
void
-linux_destroy_dev(struct linux_cdev *cdev)
+linux_destroy_dev(struct linux_cdev *ldev)
{
- if (cdev->cdev == NULL)
+ if (ldev->cdev == NULL)
return;
- atomic_long_dec(&cdev->refs);
+ MPASS((ldev->siref & LDEV_SI_DTR) == 0);
+ atomic_set_int(&ldev->siref, LDEV_SI_DTR);
+ while ((atomic_load_int(&ldev->siref) & ~LDEV_SI_DTR) != 0)
+ pause("ldevdtr", hz / 4);
- /* wait for all open files to be closed */
- while (atomic_long_read(&cdev->refs) != -1L)
- pause("ldevdrn", hz);
-
- destroy_dev(cdev->cdev);
- cdev->cdev = NULL;
+ destroy_dev(ldev->cdev);
+ ldev->cdev = NULL;
}
const struct kobj_type linux_cdev_ktype = {
Modified: stable/12/sys/sys/param.h
==============================================================================
--- stable/12/sys/sys/param.h Sun Jan 6 00:45:41 2019 (r342800)
+++ stable/12/sys/sys/param.h Sun Jan 6 00:52:53 2019 (r342801)
@@ -60,7 +60,7 @@
* in the range 5 to 9.
*/
#undef __FreeBSD_version
-#define __FreeBSD_version 1200500 /* Master, propagated to newvers */
+#define __FreeBSD_version 1200501 /* Master, propagated to newvers */
/*
* __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,
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