From 052839dc77fe6edfe29682625c568465791c9f8f Mon Sep 17 00:00:00 2001 From: jhb Date: Fri, 30 Sep 2016 01:13:57 +0000 Subject: MFC 303881: Reliably return PCI_GETCONF_LAST_DEVICE from PCIOCGETCONF. Previously the loop in PCIIOCGETCONF would terminate as soon as it found enough matches. Now it will continue iterating through the PCI device list and only terminate if it finds another matching device for which it has no room to store a conf structure. This means that PCI_GETCONF_LAST_DEVICE is reliably returned when the number of matching devices is equal to the number of slots in the matches buffer. For example, if a program requests the conf structure for a single PCI function with a specified domain/bus/slot/function it will now get PCI_GETCONF_LAST_DEVICE instead of PCI_GETCONF_MORE_DEVS. While here, simplify the loop conditional a bit more by explicitly breaking out of the loop if copyout() fails and removing a redundant i < pci_numdevs check. Sponsored by: Chelsio Communications --- share/man/man4/pci.4 | 7 +++---- sys/dev/pci/pci_user.c | 14 +++++++------- 2 files changed, 10 insertions(+), 11 deletions(-) diff --git a/share/man/man4/pci.4 b/share/man/man4/pci.4 index 2cdc71b..7623a9a 100644 --- a/share/man/man4/pci.4 +++ b/share/man/man4/pci.4 @@ -254,7 +254,8 @@ The status tells the user the disposition of his request for a device list. The possible status values are: .Bl -ohang .It PCI_GETCONF_LAST_DEVICE -This means that there are no more devices in the PCI device list after the +This means that there are no more devices in the PCI device list matching +the specified criteria after the ones returned in the .Va matches buffer. @@ -270,9 +271,7 @@ and to zero to start over at the beginning of the list. .It PCI_GETCONF_MORE_DEVS This tells the user that his buffer was not large enough to hold all of the -remaining devices in the device list that possibly match his criteria. -It is possible for this status to be returned, even when none of the remaining -devices in the list would match the user's criteria. +remaining devices in the device list that match his criteria. .It PCI_GETCONF_ERROR This indicates a general error while servicing the user's request. If the diff --git a/sys/dev/pci/pci_user.c b/sys/dev/pci/pci_user.c index f5a921a..dba76d1 100644 --- a/sys/dev/pci/pci_user.c +++ b/sys/dev/pci/pci_user.c @@ -708,10 +708,9 @@ pci_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *t * Go through the list of devices and copy out the devices * that match the user's criteria. */ - for (cio->num_matches = 0, error = 0, i = 0, + for (cio->num_matches = 0, i = 0, dinfo = STAILQ_FIRST(devlist_head); - (dinfo != NULL) && (cio->num_matches < ionum) && - (error == 0) && (i < pci_numdevs); + dinfo != NULL; dinfo = STAILQ_NEXT(dinfo, pci_links), i++) { if (i < cio->offset) @@ -833,11 +832,12 @@ pci_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *t } else #endif /* PRE7_COMPAT */ confdata = &dinfo->conf; - /* Only if we can copy it out do we count it. */ - if (!(error = copyout(confdata, + error = copyout(confdata, (caddr_t)cio->matches + - confsz * cio->num_matches, confsz))) - cio->num_matches++; + confsz * cio->num_matches, confsz); + if (error) + break; + cio->num_matches++; } } -- cgit v1.1