linux-stable.git/drivers/xen, branch v6.12.2

xen: Fix the issue of resource not being properly released in xenbus_dev_probe()

2024-12-05T13:02:40+00:00

commit afc545da381ba0c651b2658966ac737032676f01 upstream.

This patch fixes an issue in the function xenbus_dev_probe(). In the
xenbus_dev_probe() function, within the if (err) branch at line 313, the
program incorrectly returns err directly without releasing the resources
allocated by err = drv->probe(dev, id). As the return value is non-zero,
the upper layers assume the processing logic has failed. However, the probe
operation was performed earlier without a corresponding remove operation.
Since the probe actually allocates resources, failing to perform the remove
operation could lead to problems.

To fix this issue, we followed the resource release logic of the
xenbus_dev_remove() function by adding a new block fail_remove before the
fail_put block. After entering the branch if (err) at line 313, the
function will use a goto statement to jump to the fail_remove block,
ensuring that the previously acquired resources are correctly released,
thus preventing the reference count leak.

This bug was identified by an experimental static analysis tool developed
by our team. The tool specializes in analyzing reference count operations
and detecting potential issues where resources are not properly managed.
In this case, the tool flagged the missing release operation as a
potential problem, which led to the development of this patch.

Fixes: 4bac07c993d0 ("xen: add the Xenbus sysfs and virtual device hotplug driver")
Cc: stable@vger.kernel.org
Signed-off-by: Qiu-ji Chen 
Reviewed-by: Juergen Gross 
Message-ID: <20241105130919.4621-1-chenqiuji666@gmail.com>
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen: Remove dependency between pciback and privcmd

2024-10-18T09:59:04+00:00

Commit 2fae6bb7be32 ("xen/privcmd: Add new syscall to get gsi from dev")
adds a weak reverse dependency to the config XEN_PRIVCMD definition, that
dependency causes xen-privcmd can't be loaded on domU, because dependent
xen-pciback isn't always be loaded successfully on domU.

To solve above problem, remove that dependency, and do not call
pcistub_get_gsi_from_sbdf() directly, instead add a hook in
drivers/xen/apci.c, xen-pciback register the real call function, then in
privcmd_ioctl_pcidev_get_gsi call that hook.

Fixes: 2fae6bb7be32 ("xen/privcmd: Add new syscall to get gsi from dev")
Reported-by: Marek Marczykowski-Górecki 
Signed-off-by: Jiqian Chen 
Reviewed-by: Juergen Gross 
Message-ID: <20241012084537.1543059-1-Jiqian.Chen@amd.com>
Signed-off-by: Juergen Gross

xen: Fix config option reference in XEN_PRIVCMD definition

2024-10-02T14:14:30+00:00

Commit 2fae6bb7be32 ("xen/privcmd: Add new syscall to get gsi from dev")
adds a weak reverse dependency to the config XEN_PRIVCMD definition,
referring to CONFIG_XEN_PCIDEV_BACKEND. In Kconfig files, one refers to
config options without the CONFIG prefix, though. So in its current form,
this does not create the reverse dependency as intended, but is an
attribute with no effect.

Refer to the intended config option XEN_PCIDEV_BACKEND in the XEN_PRIVCMD
definition.

Fixes: 2fae6bb7be32 ("xen/privcmd: Add new syscall to get gsi from dev")
Signed-off-by: Lukas Bulwahn 
Reviewed-by: Juergen Gross 
Message-ID: <20240930090650.429813-1-lukas.bulwahn@redhat.com>
Signed-off-by: Juergen Gross

Merge tag 'for-linus-6.12-rc1a-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2024-09-27T16:55:30+00:00

Pull more xen updates from Juergen Gross:
 "A second round of Xen related changes and features:

   - a small fix of the xen-pciback driver for a warning issued by
     sparse

   - support PCI passthrough when using a PVH dom0

   - enable loading the kernel in PVH mode at arbitrary addresses,
     avoiding conflicts with the memory map when running as a Xen dom0
     using the host memory layout"

* tag 'for-linus-6.12-rc1a-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/pvh: Add 64bit relocation page tables
  x86/kernel: Move page table macros to header
  x86/pvh: Set phys_base when calling xen_prepare_pvh()
  x86/pvh: Make PVH entrypoint PIC for x86-64
  xen: sync elfnote.h from xen tree
  xen/pciback: fix cast to restricted pci_ers_result_t and pci_power_t
  xen/privcmd: Add new syscall to get gsi from dev
  xen/pvh: Setup gsi for passthrough device
  xen/pci: Add a function to reset device for xen

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43+00:00

no_llseek had been defined to NULL two years ago, in commit 868941b14441
("fs: remove no_llseek")

To quote that commit,

  At -rc1 we'll need do a mechanical removal of no_llseek -

  git grep -l -w no_llseek | grep -v porting.rst | while read i; do
	sed -i '/\/d' $i
  done

  would do it.

Unfortunately, that hadn't been done.  Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
	.llseek = no_llseek,
so it's obviously safe.

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

xen/pciback: fix cast to restricted pci_ers_result_t and pci_power_t

2024-09-25T09:31:09+00:00

This patch fix the following sparse warning by applying
__force cast to pci_ers_result_t and pci_power_t.

drivers/xen/xen-pciback/pci_stub.c:760:16: sparse: warning: cast to restricted pci_ers_result_t
drivers/xen/xen-pciback/conf_space_capability.c:125:22: sparse: warning: cast to restricted pci_power_t

No functional changes intended.

Signed-off-by: Min-Hua Chen 
Reviewed-by: Juergen Gross 
Message-ID: <20240917233653.61630-1-minhuadotchen@gmail.com>
Signed-off-by: Juergen Gross

xen/privcmd: Add new syscall to get gsi from dev

2024-09-25T07:54:55+00:00

On PVH dom0, when passthrough a device to domU, QEMU and xl tools
want to use gsi number to do pirq mapping, see QEMU code
xen_pt_realize->xc_physdev_map_pirq, and xl code
pci_add_dm_done->xc_physdev_map_pirq, but in current codes, the gsi
number is got from file /sys/bus/pci/devices//irq, that is
wrong, because irq is not equal with gsi, they are in different
spaces, so pirq mapping fails.
And in current linux codes, there is no method to get gsi
for userspace.

For above purpose, record gsi of pcistub devices when init
pcistub and add a new syscall into privcmd to let userspace
can get gsi when they have a need.

Signed-off-by: Jiqian Chen 
Signed-off-by: Huang Rui 
Signed-off-by: Jiqian Chen 
Reviewed-by: Stefano Stabellini 
Message-ID: <20240924061437.2636766-4-Jiqian.Chen@amd.com>
Signed-off-by: Juergen Gross

xen/pvh: Setup gsi for passthrough device

2024-09-25T07:54:52+00:00

In PVH dom0, the gsis don't get registered, but the gsi of
a passthrough device must be configured for it to be able to be
mapped into a domU.

When assigning a device to passthrough, proactively setup the gsi
of the device during that process.

Signed-off-by: Jiqian Chen 
Signed-off-by: Huang Rui 
Signed-off-by: Jiqian Chen 
Reviewed-by: Stefano Stabellini 
Message-ID: <20240924061437.2636766-3-Jiqian.Chen@amd.com>
Signed-off-by: Juergen Gross

xen/pci: Add a function to reset device for xen

2024-09-25T07:54:40+00:00

When device on dom0 side has been reset, the vpci on Xen side
won't get notification, so that the cached state in vpci is
all out of date with the real device state.
To solve that problem, add a new function to clear all vpci
device state when device is reset on dom0 side.

And call that function in pcistub_init_device. Because when
using "pci-assignable-add" to assign a passthrough device in
Xen, it will reset passthrough device and the vpci state will
out of date, and then device will fail to restore bar state.

Signed-off-by: Jiqian Chen 
Signed-off-by: Huang Rui 
Signed-off-by: Jiqian Chen 
Reviewed-by: Stefano Stabellini 
Message-ID: <20240924061437.2636766-2-Jiqian.Chen@amd.com>
Signed-off-by: Juergen Gross

Merge tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2024-09-23T16:35:36+00:00

Pull 'struct fd' updates from Al Viro:
 "Just the 'struct fd' layout change, with conversion to accessor
  helpers"

* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  add struct fd constructors, get rid of __to_fd()
  struct fd: representation change
  introduce fd_file(), convert all accessors to it.