kyber: Replace strlcpy with strscpy

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if

kyber: Replace strlcpy with strscpy

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230703172159.3668349-2-azeemshaikh38@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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kyber: avoid q->disk dereferences in trace points

q->disk becomes invalid after the gendisk is removed. Work around this
by caching the dev_t for the tracepoints. The real fix would be to
properly

kyber: avoid q->disk dereferences in trace points

q->disk becomes invalid after the gendisk is removed. Work around this
by caching the dev_t for the tracepoints. The real fix would be to
properly tear down the I/O schedulers with the gendisk, but that is
a much more invasive change.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211012093301.GA27795@lst.de
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: add an explicit ->disk backpointer to the request_queue

Replace the magic lookup through the kobject tree with an explicit
backpointer, given that the device model links are set up and torn
d

block: add an explicit ->disk backpointer to the request_queue

Replace the magic lookup through the kobject tree with an explicit
backpointer, given that the device model links are set up and torn
down at times when I/O is still possible, leading to potential
NULL or invalid pointer dereferences.

Fixes: edb0872f44ec ("block: move the bdi from the request_queue to the gendisk")
Reported-by: syzbot <syzbot+aa0801b6b32dca9dda82@syzkaller.appspotmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Link: https://lore.kernel.org/r/20210816134624.GA24234@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: add queue_to_disk() to get gendisk from request_queue

Sometimes we need to get the corresponding gendisk from request_queue.

It is preferred that block drivers store private data in
gendisk-

block: add queue_to_disk() to get gendisk from request_queue

Sometimes we need to get the corresponding gendisk from request_queue.

It is preferred that block drivers store private data in
gendisk->private_data rather than request_queue->queuedata, e.g. see:
commit c4a59c4e5db3 ("dm: stop using ->queuedata").

So if only request_queue is given, we need to get its corresponding
gendisk to get the private data stored in that gendisk.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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kyber: fix wrong strlcpy() size in trace_kyber_latency()

When copying to the latency type, we should be passing LATENCY_TYPE_LEN,
not DOMAIN_LEN (this isn't a problem in practice because we only pas

kyber: fix wrong strlcpy() size in trace_kyber_latency()

When copying to the latency type, we should be passing LATENCY_TYPE_LEN,
not DOMAIN_LEN (this isn't a problem in practice because we only pass
"total" or "I/O"). Fix it by changing all of the strlcpy() calls to use
sizeof().

Fixes: 6c3b7af1c975 ("kyber: add tracepoints")
Reported-by: Jordan Glover <Golden_Miller83@protonmail.ch>
Tested-by: Jordan Glover <Golden_Miller83@protonmail.ch>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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kyber: add tracepoints

When debugging Kyber, it's really useful to know what latencies we've
been having, how the domain depths have been adjusted, and if we've
actually been throttling. Add three t

kyber: add tracepoints

When debugging Kyber, it's really useful to know what latencies we've
been having, how the domain depths have been adjusted, and if we've
actually been throttling. Add three tracepoints, kyber_latency,
kyber_adjust, and kyber_throttled, to record that.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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