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authorSebastian Ott <sebott@linux.vnet.ibm.com>2017-06-10 15:10:00 +0300
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2017-06-28 08:32:09 +0300
commit725708349172f00b86e2bac5c03de360b79aaf65 (patch)
treebd2186c9804f0ee65849bc155a5ed8e1f44d5f90 /arch/s390/pci
parent4dfbd3efe3f0cf9ff1325b87491e1b1fe07afaf1 (diff)
downloadlinux-725708349172f00b86e2bac5c03de360b79aaf65.tar.xz
s390/pci: improve unreg_ioat error handling
DMA tables are freed in zpci_dma_exit_device regardless of the return code of zpci_unregister_ioat. This could lead to a use after free. On the other hand during function hot-unplug, zpci_unregister_ioat will always fail since the function is already gone. So let zpci_unregister_ioat report success when the function is gone but don't cleanup the dma table when a function could still have it in access. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/pci')
-rw-r--r--arch/s390/pci/pci.c19
-rw-r--r--arch/s390/pci/pci_dma.c4
2 files changed, 17 insertions, 6 deletions
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 82f3e788b0be..4f541f54470f 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -161,19 +161,28 @@ static int mod_pci(struct zpci_dev *zdev, int fn, u8 dmaas, struct mod_pci_args
int zpci_register_ioat(struct zpci_dev *zdev, u8 dmaas,
u64 base, u64 limit, u64 iota)
{
- struct mod_pci_args args = { base, limit, iota, 0 };
+ u64 req = ZPCI_CREATE_REQ(zdev->fh, dmaas, ZPCI_MOD_FC_REG_IOAT);
+ struct zpci_fib fib = {0};
+ u8 status;
WARN_ON_ONCE(iota & 0x3fff);
- args.iota |= ZPCI_IOTA_RTTO_FLAG;
- return mod_pci(zdev, ZPCI_MOD_FC_REG_IOAT, dmaas, &args);
+ fib.pba = base;
+ fib.pal = limit;
+ fib.iota = iota | ZPCI_IOTA_RTTO_FLAG;
+ return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
}
/* Modify PCI: Unregister I/O address translation parameters */
int zpci_unregister_ioat(struct zpci_dev *zdev, u8 dmaas)
{
- struct mod_pci_args args = { 0, 0, 0, 0 };
+ u64 req = ZPCI_CREATE_REQ(zdev->fh, dmaas, ZPCI_MOD_FC_DEREG_IOAT);
+ struct zpci_fib fib = {0};
+ u8 cc, status;
- return mod_pci(zdev, ZPCI_MOD_FC_DEREG_IOAT, dmaas, &args);
+ cc = zpci_mod_fc(req, &fib, &status);
+ if (cc == 3) /* Function already gone. */
+ cc = 0;
+ return cc ? -EIO : 0;
}
/* Modify PCI: Set PCI function measurement parameters */
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index 9081a57fa340..8eb1cc341dab 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -601,7 +601,9 @@ void zpci_dma_exit_device(struct zpci_dev *zdev)
*/
WARN_ON(zdev->s390_domain);
- zpci_unregister_ioat(zdev, 0);
+ if (zpci_unregister_ioat(zdev, 0))
+ return;
+
dma_cleanup_tables(zdev->dma_table);
zdev->dma_table = NULL;
vfree(zdev->iommu_bitmap);