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Do not dereference cdev->si_cdevsw, use the dev_refthread() to properly

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obtain the reference. In particular, this fixes the panic reported in
the PR. Remove the comments stating that this needs to be done.

PR:	kern/119422
MFC after:	1 week
This commit is contained in:
Konstantin Belousov 2008-03-20 16:08:42 +00:00
parent 4b539f02f5
commit 91a35e7870
2 changed files with 28 additions and 9 deletions
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17
sys/fs/devfs/devfs_rule.c
View File

@ -527,6 +527,7 @@ devfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de)
{
struct devfs_rule *dr = &dk->dk_rule;
struct cdev *dev;
struct cdevsw *dsw;
dev = devfs_rule_getdev(de);
/*
@ -540,13 +541,19 @@ devfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de)
* They're actually testing to see whether the condition does
* *not* match, since the default is to assume the rule should
* be run (such as if there are no conditions).
*
* XXX: lacks threadref on dev
*/
if (dr->dr_icond & DRC_DSWFLAGS)
if (dev == NULL ||
(dev->si_devsw->d_flags & dr->dr_dswflags) == 0)
if (dr->dr_icond & DRC_DSWFLAGS) {
if (dev == NULL)
return (0);
dsw = dev_refthread(dev);
if (dsw == NULL)
return (0);
if ((dsw->d_flags & dr->dr_dswflags) == 0) {
dev_relthread(dev);
return (0);
}
dev_relthread(dev);
}
if (dr->dr_icond & DRC_PATHPTRN)
if (!devfs_rule_matchpath(dk, de))
return (0);

20
sys/vm/vm_mmap.c
View File

@ -1160,6 +1160,7 @@ vm_mmap_vnode(struct thread *td, vm_size_t objsize,
void *handle;
vm_object_t obj;
struct mount *mp;
struct cdevsw *dsw;
int error, flags, type;
int vfslocked;
@ -1190,13 +1191,19 @@ vm_mmap_vnode(struct thread *td, vm_size_t objsize,
type = OBJT_DEVICE;
handle = vp->v_rdev;
/* XXX: lack thredref on device */
if(vp->v_rdev->si_devsw->d_flags & D_MMAP_ANON) {
dsw = dev_refthread(handle);
if (dsw == NULL) {
error = ENXIO;
goto done;
}
if (dsw->d_flags & D_MMAP_ANON) {
dev_relthread(handle);
*maxprotp = VM_PROT_ALL;
*flagsp |= MAP_ANON;
error = 0;
goto done;
}
dev_relthread(handle);
/*
* cdevs does not provide private mappings of any kind.
*/
@ -1273,16 +1280,21 @@ vm_mmap_cdev(struct thread *td, vm_size_t objsize,
struct cdev *cdev, vm_ooffset_t foff, vm_object_t *objp)
{
vm_object_t obj;
struct cdevsw *dsw;
int flags;
flags = *flagsp;
/* XXX: lack thredref on device */
if (cdev->si_devsw->d_flags & D_MMAP_ANON) {
dsw = dev_refthread(cdev);
if (dsw == NULL)
return (ENXIO);
if (dsw->d_flags & D_MMAP_ANON) {
dev_relthread(cdev);
*maxprotp = VM_PROT_ALL;
*flagsp |= MAP_ANON;
return (0);
}
dev_relthread(cdev);
/*
* cdevs does not provide private mappings of any kind.
*/