virtio_console: fix order of fields cols and rows

According to section 5.3.6.2 (Multiport Device Operation) of the virtio
spec(version 1.2) a control buffer with the event VIRTIO_CONSOLE_RESIZE
is f

virtio_console: fix order of fields cols and rows

According to section 5.3.6.2 (Multiport Device Operation) of the virtio
spec(version 1.2) a control buffer with the event VIRTIO_CONSOLE_RESIZE
is followed by a virtio_console_resize struct containing cols then rows.
The kernel implements this the wrong way around (rows then cols) resulting
in the two values being swapped.

Signed-off-by: Maximilian Immanuel Brandtner <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio_console: fix missing byte order handling for cols and rows

As per virtio spec the fields cols and rows are specified as little
endian. Although there is no legacy interface requirement that w

virtio_console: fix missing byte order handling for cols and rows

As per virtio spec the fields cols and rows are specified as little
endian. Although there is no legacy interface requirement that would
state that cols and rows need to be handled as native endian when legacy
interface is used, unlike for the fields of the adjacent struct
virtio_console_control, I decided to err on the side of caution based
on some non-conclusive virtio spec repo archaeology and opt for using
virtio16_to_cpu() much like for virtio_console_control.event. Strictly
by the letter of the spec virtio_le_to_cpu() would have been sufficient.
But when the legacy interface is not used, it boils down to the same.

And when using the legacy interface, the device formatting these as
little endian when the guest is big endian would surprise me more than
it using guest native byte order (which would make it compatible with
the current implementation). Nevertheless somebody trying to implement
the spec following it to the letter could end up forcing little endian
byte order when the legacy interface is in use. So IMHO this ultimately
needs a judgement call by the maintainers.

Fixes: 8345adbf96fc1 ("virtio: console: Accept console size along with resize control message")
Signed-off-by: Halil Pasic <[email protected]>
Cc: [email protected] # v2.6.35+
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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fs/pipe: add simpler helpers for common cases

The fix to atomically read the pipe head and tail state when not holding
the pipe mutex has caused a number of headaches due to the size change
of the i

fs/pipe: add simpler helpers for common cases

The fix to atomically read the pipe head and tail state when not holding
the pipe mutex has caused a number of headaches due to the size change
of the involved types.

It turns out that we don't have _that_ many places that access these
fields directly and were affected, but we have more than we strictly
should have, because our low-level helper functions have been designed
to have intimate knowledge of how the pipes work.

And as a result, that random noise of direct 'pipe->head' and
'pipe->tail' accesses makes it harder to pinpoint any actual potential
problem spots remaining.

For example, we didn't have a "is the pipe full" helper function, but
instead had a "given these pipe buffer indexes and this pipe size, is
the pipe full". That's because some low-level pipe code does actually
want that much more complicated interface.

But most other places literally just want a "is the pipe full" helper,
and not having it meant that those places ended up being unnecessarily
much too aware of this all.

It would have been much better if only the very core pipe code that
cared had been the one aware of this all.

So let's fix it - better late than never. This just introduces the
trivial wrappers for "is this pipe full or empty" and to get how many
pipe buffers are used, so that instead of writing

if (pipe_full(pipe->head, pipe->tail, pipe->max_usage))

the places that literally just want to know if a pipe is full can just
say

if (pipe_is_full(pipe))

instead. The existing trivial cases were converted with a 'sed' script.

This cuts down on the places that access pipe->head and pipe->tail
directly outside of the pipe code (and core splice code) quite a lot.

The splice code in particular still revels in doing the direct low-level
accesses, and the fuse fuse_dev_splice_write() code also seems a bit
unnecessarily eager to go very low-level, but it's at least a bit better
than it used to be.

Signed-off-by: Linus Torvalds <[email protected]>

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virtio_console: Get rid of unneeded temporary variable

When compiling a kernel with GCC using `make W=1` with CONFIG_WERROR=y
(which is default nowadays), the build fails:

drivers/char/virtio_conso

virtio_console: Get rid of unneeded temporary variable

When compiling a kernel with GCC using `make W=1` with CONFIG_WERROR=y
(which is default nowadays), the build fails:

drivers/char/virtio_console.c:1427:9: note: ‘snprintf’ output between 9 and 27 bytes into a destination of size 16

Indeed, GCC can't see the limits of the variables that are in use.
Fix this by using dev_name() of the newly created device that is
luckily the same as the string used for the DebugFS node name.

Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Amit Shah <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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virtio: console: Use str_yes_no() helper in port_debugfs_show()

Remove hard-coded strings by using the str_yes_no() helper function.

Signed-off-by: Thorsten Blum <[email protected]>
Reviewed-

virtio: console: Use str_yes_no() helper in port_debugfs_show()

Remove hard-coded strings by using the str_yes_no() helper function.

Signed-off-by: Thorsten Blum <[email protected]>
Reviewed-by: Amit Shah <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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virtio: console: Replace deprecated kmap_atomic with kmap_local_page

kmap_atomic() is deprecated and should be replaced with kmap_local_page()
[1][2]. kmap_local_page() is faster in kernels with HIG

virtio: console: Replace deprecated kmap_atomic with kmap_local_page

kmap_atomic() is deprecated and should be replaced with kmap_local_page()
[1][2]. kmap_local_page() is faster in kernels with HIGHMEM enabled, can
take page faults, and allows preemption.

According to [2], this replacement is safe as long as the code between
kmap_atomic() and kunmap_atomic() does not implicitly depend on disabling
page faults or preemption. In this patch, the only thing happening between
mapping and unmapping the page is a memcpy, and I don't suspect it depends
on disabling page faults or preemption.

[1] https://lwn.net/Articles/836144/
[2] https://docs.kernel.org/mm/highmem.html#temporary-virtual-mappings

Signed-off-by: David Reaver <[email protected]>
Reviewed-by: Amit Shah <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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[tree-wide] finally take no_llseek out

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

[tree-wide] finally take no_llseek out

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 '/\<no_llseek\>/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 <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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virtio_console: fix misc probe bugs

This fixes the following issue discovered by code review:

after vqs have been created, a buggy device can send an interrupt.

A control vq callback will then try

virtio_console: fix misc probe bugs

This fixes the following issue discovered by code review:

after vqs have been created, a buggy device can send an interrupt.

A control vq callback will then try to schedule control_work which has
not been initialized yet. Similarly for config interrupt. Further, in
and out vq callbacks invoke find_port_by_vq which attempts to take
ports_lock which also has not been initialized.

To fix, init all locks and work before creating vqs.

Message-ID: <ad982e975a6160ad110c623c016041311ca15b4f.1726511547.git.mst@redhat.com>
Fixes: 17634ba25544 ("virtio: console: Add a new MULTIPORT feature, support for generic ports")
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: rename virtio_find_vqs_info() to virtio_find_vqs()

Since the original virtio_find_vqs() is no longer present, rename
virtio_find_vqs_info() back to virtio_find_vqs().

Signed-off-by: Jiri Pi

virtio: rename virtio_find_vqs_info() to virtio_find_vqs()

Since the original virtio_find_vqs() is no longer present, rename
virtio_find_vqs_info() back to virtio_find_vqs().

Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio_console: convert to use virtio_find_vqs_info()

Instead of passing separate names and callbacks arrays
to virtio_find_vqs(), allocate one of virtual_queue_info structs and
pass it to virtio_fi

virtio_console: convert to use virtio_find_vqs_info()

Instead of passing separate names and callbacks arrays
to virtio_find_vqs(), allocate one of virtual_queue_info structs and
pass it to virtio_find_vqs_info().

Suggested-by: Xuan Zhuo <[email protected]>
Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio_console: drop owner assignment

virtio core already sets the .owner, so driver does not need to.

Signed-off-by: Krzysztof Kozlowski <[email protected]>

Message-Id: <20240331-mod

virtio_console: drop owner assignment

virtio core already sets the .owner, so driver does not need to.

Signed-off-by: Krzysztof Kozlowski <[email protected]>

Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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tty: hvc: convert to u8 and size_t

Switch character types to u8 and sizes to size_t. To conform to
characters/sizes in the rest of the tty layer.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kerne

tty: hvc: convert to u8 and size_t

Switch character types to u8 and sizes to size_t. To conform to
characters/sizes in the rest of the tty layer.

Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Amit Shah <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: virtio: drop virtio_cons_early_init()

The last user of virtio_cons_early_init() was dropped in commit
7fb2b2d51244 ("s390/virtio: remove the old KVM virtio transport").

So now, drop virtio_con

tty: virtio: drop virtio_cons_early_init()

The last user of virtio_cons_early_init() was dropped in commit
7fb2b2d51244 ("s390/virtio: remove the old KVM virtio transport").

So now, drop virtio_cons_early_init() and the logic and headers behind
too.

Signed-off-by: Jiri Slaby (SUSE) <[email protected]>
Acked-by: Jason Wang <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Amit Shah <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Xuan Zhuo <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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virtio_console: Annotate struct port_buffer with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by

virtio_console: Annotate struct port_buffer with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct port_buffer.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Amit Shah <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: [email protected]
Reviewed-by: "Gustavo A. R. Silva" <[email protected]>
Reviewed-by: Amit Shah <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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virtio-console: call scheduler when we free unused buffs

For virtio-net we were getting CPU stall warnings, and fixed it by
calling the scheduler: see f8bb51043945 ("virtio_net: suppress cpu stall
w

virtio-console: call scheduler when we free unused buffs

For virtio-net we were getting CPU stall warnings, and fixed it by
calling the scheduler: see f8bb51043945 ("virtio_net: suppress cpu stall
when free_unused_bufs").

This driver is similar so theoretically the same logic applies.

Signed-off-by: Xianting Tian <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio_console: make port class a static const structure

Now that the driver core allows for struct class to be in read-only
memory, remove the class field of the ports_driver_data structure and
cre

virtio_console: make port class a static const structure

Now that the driver core allows for struct class to be in read-only
memory, remove the class field of the ports_driver_data structure and
create the port_class static class structure declared at build time
which places it into read-only memory, instead of having it to be
dynamically allocated at load time.

Cc: Amit Shah <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: [email protected]
Suggested-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Ivan Orlov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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driver core: class: remove module * from class_create()

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
s

driver core: class: remove module * from class_create()

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something. So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <[email protected]>
Acked-by: Benjamin Tissoires <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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virtio_console: Use strscpy() to instead of strncpy()

The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL-terminated strings.

Signed-off-by: Bo Liu

virtio_console: Use strscpy() to instead of strncpy()

The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL-terminated strings.

Signed-off-by: Bo Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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virtio_console: Introduce an ID allocator for virtual console numbers

When a virtio console port is initialized, it is registered as an hvc
console using a virtual console number. If a KVM guest is

virtio_console: Introduce an ID allocator for virtual console numbers

When a virtio console port is initialized, it is registered as an hvc
console using a virtual console number. If a KVM guest is started with
multiple virtio console devices, the same vtermno (or virtual console
number) can be used to allocate different hvc consoles, which leads to
various communication problems later on.

This is also reported in debugfs :

# grep vtermno /sys/kernel/debug/virtio-ports/*
/sys/kernel/debug/virtio-ports/vport1p1:console_vtermno: 1
/sys/kernel/debug/virtio-ports/vport2p1:console_vtermno: 1
/sys/kernel/debug/virtio-ports/vport3p1:console_vtermno: 2
/sys/kernel/debug/virtio-ports/vport4p1:console_vtermno: 3

Replace the next_vtermno global with an ID allocator and start the
allocation at 1 as it is today. Also recycle IDs when a console port
is removed.

Signed-off-by: Cédric Le Goater <[email protected]>
Reviewed-by: Thomas Huth <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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virtio_console: eliminate anonymous module_init & module_exit

Eliminate anonymous module_init() and module_exit(), which can lead to
confusion or ambiguity when reading System.map, crashes/oops/bugs

virtio_console: eliminate anonymous module_init & module_exit

Eliminate anonymous module_init() and module_exit(), which can lead to
confusion or ambiguity when reading System.map, crashes/oops/bugs,
or an initcall_debug log.

Give each of these init and exit functions unique driver-specific
names to eliminate the anonymous names.

Example 1: (System.map)
ffffffff832fc78c t init
ffffffff832fc79e t init
ffffffff832fc8f8 t init

Example 2: (initcall_debug log)
calling init+0x0/0x12 @ 1
initcall init+0x0/0x12 returned 0 after 15 usecs
calling init+0x0/0x60 @ 1
initcall init+0x0/0x60 returned 0 after 2 usecs
calling init+0x0/0x9a @ 1
initcall init+0x0/0x9a returned 0 after 74 usecs

Signed-off-by: Randy Dunlap <[email protected]>
Reviewed-by: Amit Shah <[email protected]>
Cc: [email protected]
Cc: Arnd Bergmann <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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virtio_console: break out of buf poll on remove

A common pattern for device reset is currently:
vdev->config->reset(vdev);
.. cleanup ..

reset prevents new interrupts from arriving and waits for in

virtio_console: break out of buf poll on remove

A common pattern for device reset is currently:
vdev->config->reset(vdev);
.. cleanup ..

reset prevents new interrupts from arriving and waits for interrupt
handlers to finish.

However if - as is common - the handler queues a work request which is
flushed during the cleanup stage, we have code adding buffers / trying
to get buffers while device is reset. Not good.

This was reproduced by running
modprobe virtio_console
modprobe -r virtio_console
in a loop.

Fix this up by calling virtio_break_device + flush before reset.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1786239
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: wrap config->reset calls

This will enable cleanups down the road.
The idea is to disable cbs, then add "flush_queued_cbs" callback
as a parameter, this way drivers can flush any work
queued

virtio: wrap config->reset calls

This will enable cleanups down the road.
The idea is to disable cbs, then add "flush_queued_cbs" callback
as a parameter, this way drivers can flush any work
queued after callbacks have been disabled.

Signed-off-by: Michael S. Tsirkin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio_console: validate max_nr_ports before trying to use it

We calculate nr_ports based on the max_nr_ports:

nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;

If the device advertises

virtio_console: validate max_nr_ports before trying to use it

We calculate nr_ports based on the max_nr_ports:

nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;

If the device advertises a large max_nr_ports, we will end up with a
integer overflow. Fixing this by validating the max_nr_ports and fail
the probe for invalid max_nr_ports in this case.

Cc: Amit Shah <[email protected]>
Signed-off-by: Jason Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>

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Revert "virtio-console: remove unnecessary kmemdup()"

This reverts commit 9db81eca10ba2d84177fa076704db3a5d76863c3.

A dependant patch on this one needs to be reverted, so this one also
needs to be

Revert "virtio-console: remove unnecessary kmemdup()"

This reverts commit 9db81eca10ba2d84177fa076704db3a5d76863c3.

A dependant patch on this one needs to be reverted, so this one also
needs to be reverted at this point in time.

Link: https://lore.kernel.org/r/[email protected]
Reported-by: Jiri Slaby <[email protected]>
Cc: Xianting Tian <[email protected]>
Cc: Shile Zhang <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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virtio-console: remove unnecessary kmemdup()

This revert commit c4baad5029 ("virtio-console: avoid DMA from stack")

hvc framework will never pass stack memory to the put_chars() function,
So the ca

virtio-console: remove unnecessary kmemdup()

This revert commit c4baad5029 ("virtio-console: avoid DMA from stack")

hvc framework will never pass stack memory to the put_chars() function,
So the calling of kmemdup() is unnecessary, we can remove it.

Signed-off-by: Xianting Tian <[email protected]>
Reviewed-by: Shile Zhang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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