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| author | Sebastian Ott <sebott@linux.vnet.ibm.com> | 2017-06-10 14:10:00 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2017-06-28 07:32:09 +0200 |
| commit | 725708349172f00b86e2bac5c03de360b79aaf65 (patch) | |
| tree | bd2186c9804f0ee65849bc155a5ed8e1f44d5f90 /arch/s390 | |
| parent | 4dfbd3efe3f0cf9ff1325b87491e1b1fe07afaf1 (diff) | |
| download | linux-725708349172f00b86e2bac5c03de360b79aaf65.tar.gz linux-725708349172f00b86e2bac5c03de360b79aaf65.tar.bz2 linux-725708349172f00b86e2bac5c03de360b79aaf65.zip | |
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')
| -rw-r--r-- | arch/s390/pci/pci.c | 19 | ||||
| -rw-r--r-- | arch/s390/pci/pci_dma.c | 4 |
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); |