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Hoist locking giant back up into the ioctl handler

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Move the locking back into the ioctl handler. This "fixes" the race where we hve
a hot plug event just after the dropping of Giant in pci_find_dbsf, assuming the
driver doesn't then call anything that drops and picks up Giant again... It's a
little safer since don't think it doesn't, but we lack the tools to know for
sure.
This commit is contained in:
Warner Losh 2019-11-24 15:37:14 +00:00
parent 57aa9163fd
commit 96b506a57c
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=355057
2 changed files with 9 additions and 5 deletions
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3
sys/dev/pci/pci.c
View File

@ -447,8 +447,6 @@ pci_find_dbsf(uint32_t domain, uint8_t bus, uint8_t slot, uint8_t func)
{
struct pci_devinfo *dinfo = NULL;
/* Giant because newbus is Giant locked revisit with newbus locking */
mtx_lock(&Giant);
STAILQ_FOREACH(dinfo, &pci_devq, pci_links) {
if ((dinfo->cfg.domain == domain) &&
(dinfo->cfg.bus == bus) &&
@ -457,7 +455,6 @@ pci_find_dbsf(uint32_t domain, uint8_t bus, uint8_t slot, uint8_t func)
break;
}
}
mtx_unlock(&Giant);
return (dinfo != NULL ? dinfo->cfg.dev : NULL);
}

11
sys/dev/pci/pci_user.c
View File

@ -965,6 +965,9 @@ pci_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *t
}
/* Giant because newbus is Giant locked revisit with newbus locking */
mtx_lock(&Giant);
switch (cmd) {
case PCIOCGETCONF:
#ifdef COMPAT_FREEBSD32
@ -1288,8 +1291,10 @@ pci_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *t
case PCIOCBARMMAP:
pbm = (struct pci_bar_mmap *)data;
if ((flag & FWRITE) == 0 &&
(pbm->pbm_flags & PCIIO_BAR_MMAP_RW) != 0)
return (EPERM);
(pbm->pbm_flags & PCIIO_BAR_MMAP_RW) != 0) {
error = EPERM;
break;
}
pcidev = pci_find_dbsf(pbm->pbm_sel.pc_domain,
pbm->pbm_sel.pc_bus, pbm->pbm_sel.pc_dev,
pbm->pbm_sel.pc_func);
@ -1301,5 +1306,7 @@ pci_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *t
break;
}
mtx_unlock(&Giant);
return (error);
}