Jan Beulich
2012-Sep-24 15:54 UTC
[PATCH 2/3] linux-2.6.18/pciback: properly clean up after calling pcistub_device_find()
As the function calls pcistub_device_get() before returning non-NULL,
its callers need to take care of calling pcistub_device_put() on
(mostly, but not exclusively) error paths.
Otoh, the function already guarantees that the ''dev'' member is
non-NULL
upon successful return, so callers do not need to check for this a
second time.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/drivers/xen/pciback/pci_stub.c
+++ b/drivers/xen/pciback/pci_stub.c
@@ -642,14 +642,14 @@ static pci_ers_result_t pciback_slot_res
dev_err(&dev->dev, "pciback device is not connected or
owned"
" by HVM, kill it\n");
kill_domain_by_device(psdev);
- goto release;
+ goto end;
}
if ( !test_bit(_XEN_PCIB_AERHANDLER,
(unsigned long *)&psdev->pdev->sh_info->flags) ) {
dev_err(&dev->dev,
"guest with no AER driver should have been killed\n");
- goto release;
+ goto end;
}
result = common_process(psdev, 1, XEN_PCI_OP_aer_slotreset, result);
@@ -659,9 +659,9 @@ static pci_ers_result_t pciback_slot_res
"No AER slot_reset service or disconnected!\n");
kill_domain_by_device(psdev);
}
-release:
- pcistub_device_put(psdev);
end:
+ if (psdev)
+ pcistub_device_put(psdev);
up_write(&pcistub_sem);
return result;
@@ -702,14 +702,14 @@ static pci_ers_result_t pciback_mmio_ena
dev_err(&dev->dev, "pciback device is not connected or
owned"
" by HVM, kill it\n");
kill_domain_by_device(psdev);
- goto release;
+ goto end;
}
if ( !test_bit(_XEN_PCIB_AERHANDLER,
(unsigned long *)&psdev->pdev->sh_info->flags) ) {
dev_err(&dev->dev,
"guest with no AER driver should have been killed\n");
- goto release;
+ goto end;
}
result = common_process(psdev, 1, XEN_PCI_OP_aer_mmio, result);
@@ -719,9 +719,9 @@ static pci_ers_result_t pciback_mmio_ena
"No AER mmio_enabled service or disconnected!\n");
kill_domain_by_device(psdev);
}
-release:
- pcistub_device_put(psdev);
end:
+ if (psdev)
+ pcistub_device_put(psdev);
up_write(&pcistub_sem);
return result;
}
@@ -762,7 +762,7 @@ static pci_ers_result_t pciback_error_de
dev_err(&dev->dev, "pciback device is not connected or
owned"
" by HVM, kill it\n");
kill_domain_by_device(psdev);
- goto release;
+ goto end;
}
/*Guest owns the device yet no aer handler regiested, kill guest*/
@@ -770,7 +770,7 @@ static pci_ers_result_t pciback_error_de
(unsigned long *)&psdev->pdev->sh_info->flags) ) {
dev_dbg(&dev->dev, "guest may have no aer driver, kill
it\n");
kill_domain_by_device(psdev);
- goto release;
+ goto end;
}
result = common_process(psdev, error, XEN_PCI_OP_aer_detected, result);
@@ -780,9 +780,9 @@ static pci_ers_result_t pciback_error_de
"No AER error_detected service or disconnected!\n");
kill_domain_by_device(psdev);
}
-release:
- pcistub_device_put(psdev);
end:
+ if (psdev)
+ pcistub_device_put(psdev);
up_write(&pcistub_sem);
return result;
}
@@ -818,7 +818,7 @@ static void pciback_error_resume(struct
dev_err(&dev->dev, "pciback device is not connected or
owned"
" by HVM, kill it\n");
kill_domain_by_device(psdev);
- goto release;
+ goto end;
}
if ( !test_bit(_XEN_PCIB_AERHANDLER,
@@ -826,12 +826,12 @@ static void pciback_error_resume(struct
dev_err(&dev->dev,
"guest with no AER driver should have been killed\n");
kill_domain_by_device(psdev);
- goto release;
+ goto end;
}
common_process(psdev, 1, XEN_PCI_OP_aer_resume, PCI_ERS_RESULT_RECOVERED);
-release:
- pcistub_device_put(psdev);
end:
+ if (psdev)
+ pcistub_device_put(psdev);
up_write(&pcistub_sem);
return;
}
@@ -988,7 +988,7 @@ static int pcistub_reg_add(int domain, i
struct config_field *field;
psdev = pcistub_device_find(domain, bus, slot, func);
- if (!psdev || !psdev->dev) {
+ if (!psdev) {
err = -ENODEV;
goto out;
}
@@ -1012,6 +1012,8 @@ static int pcistub_reg_add(int domain, i
if (err)
kfree(field);
out:
+ if (psdev)
+ pcistub_device_put(psdev);
return err;
}
@@ -1163,10 +1165,7 @@ static ssize_t permissive_add(struct dev
err = -ENODEV;
goto out;
}
- if (!psdev->dev) {
- err = -ENODEV;
- goto release;
- }
+
dev_data = pci_get_drvdata(psdev->dev);
/* the driver data for a device should never be null at this point */
if (!dev_data) {
@@ -1219,14 +1218,18 @@ DRIVER_ATTR(permissive, S_IRUSR | S_IWUS
int pciback_get_owner(struct pci_dev *dev)
{
struct pcistub_device *psdev;
+ int rc;
psdev = pcistub_device_find(pci_domain_nr(dev->bus),
dev->bus->number,
PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
- if (!psdev || !psdev->pdev)
- return -1;
+ if (!psdev)
+ return -ESRCH;
+
+ rc = psdev->pdev ? psdev->pdev->xdev->otherend_id : -EINVAL;
- return psdev->pdev->xdev->otherend_id;
+ pcistub_device_put(psdev);
+ return rc;
}
#endif
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