Currently we enter __dentry_kill() with parent (along with the victim
dentry and victim's inode) held locked. Then we
mark dentry refcount as dead
call ->d_prune()
remove dentry from hash
remove it from the parent's list of children
unlock the parent, don't need it from that point on
detach dentry from inode, unlock dentry and drop the inode
(via ->d_iput())
call ->d_release()
regain the lock on dentry
check if it's on a shrink list (in which case freeing its empty husk
has to be left to shrink_dentry_list()) or not (in which case we can free it
ourselves). In the former case, mark it as an empty husk, so that
shrink_dentry_list() would know it can free the sucker.
drop the lock on dentry
... and usually the caller proceeds to drop a reference on the parent,
possibly retaking the lock on it.
That is painful for a bunch of reasons, starting with the need to take locks
out of order, but not limited to that - the parent of positive dentry can
change if we drop its ->d_lock, so getting these locks has to be done with
care. Moreover, as soon as dentry is out of the parent's list of children,
shrink_dcache_for_umount() won't see it anymore, making it appear as if
the parent is inexplicably busy. We do work around that by having
shrink_dentry_list() decrement the parent's refcount first and put it on
shrink list to be evicted once we are done with __dentry_kill() of child,
but that may in some cases lead to ->d_iput() on child called after the
parent got killed. That doesn't happen in cases where in-tree ->d_iput()
instances might want to look at the parent, but that's brittle as hell.
Solution: do removal from the parent's list of children in the very
end of __dentry_kill(). As the result, the callers do not need to
lock the parent and by the time we really need the parent locked,
dentry is negative and is guaranteed not to be moved around.
It does mean that ->d_prune() will be called with parent not locked.
It also means that we might see dentries in process of being torn
down while going through the parent's list of children; those dentries
will be unhashed, negative and with refcount marked dead. In practice,
that's enough for in-tree code that looks through the list of children
to do the right thing as-is. Out-of-tree code might need to be adjusted.
Calling conventions: __dentry_kill(dentry) is called with dentry->d_lock
held, along with ->i_lock of its inode (if any). It either returns
the parent (locked, with refcount decremented to 0) or NULL (if there'd
been no parent or if refcount decrement for parent hadn't reached 0).
lock_for_kill() is adjusted for new requirements - it doesn't touch
the parent's ->d_lock at all.
Callers adjusted. Note that for dput() we don't need to bother with
fast_dput() for the parent - we just need to check retain_dentry()
for it, since its ->d_lock is still held since the moment when
__dentry_kill() had taken it to remove the victim from the list of
children.
The kludge with early decrement of parent's refcount in
shrink_dentry_list() is no longer needed - shrink_dcache_for_umount()
sees the half-killed dentries in the list of children for as long
as they are pinning the parent. They are easily recognized and
accounted for by select_collect(), so we know we are not done yet.
As the result, we always have the expected ordering for ->d_iput()/->d_release()
vs. __dentry_kill() of the parent, no exceptions. Moreover, the current
rules for shrink lists (one must make sure that shrink_dcache_for_umount()
won't happen while any dentries from the superblock in question are on
any shrink lists) are gone - shrink_dcache_for_umount() will do the
right thing in all cases, taking such dentries out. Their empty
husks (memory occupied by struct dentry itself + its external name,
if any) will remain on the shrink lists, but they are no obstacles
to filesystem shutdown. And such husks will get freed as soon as
shrink_dentry_list() of the list they are on gets to them.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Instead of dropping aliases one by one, restarting, etc., just
collect them into a shrink list and kill them off in one pass.
We don't really need the restarts - one alias can't pin another
(directory has only one alias, and couldn't be its own ancestor
anyway), so collecting everything that is not busy and taking it
out would take care of everything evictable that had been there
as we entered the function. And new aliases added while we'd
been dropping old ones could just as easily have appeared right
as we return to caller...
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The only thing it does if refcount is not zero is d_lru_del(); no
point, IMO, seeing that plain dput() does nothing of that sort...
Note that 2 of 3 current callers are guaranteed that refcount is 0.
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
That is to say, do *not* treat the ->d_inode or ->d_parent changes
as "it's hard, return false; somebody must have grabbed it, so
even if has zero refcount, we don't need to bother killing it -
final dput() from whoever grabbed it would've done everything".
First of all, that is not guaranteed. It might have been dropped
by shrink_kill() handling of victim's parent, which would've found
it already on a shrink list (ours) and decided that they don't need
to put it on their shrink list.
What's more, dentry_kill() is doing pretty much the same thing,
cutting its own set of corners (it assumes that dentry can't
go from positive to negative, so its inode can change but only once
and only in one direction).
Doing that right allows to get rid of that not-quite-duplication
and removes the only reason for re-incrementing refcount before
the call of dentry_kill().
Replacement is called lock_for_kill(); called under rcu_read_lock
and with ->d_lock held. If it returns false, dentry has non-zero
refcount and the same locks are held. If it returns true,
dentry has zero refcount and all locks required by __dentry_kill()
are taken.
Part of __lock_parent() had been lifted into lock_parent() to
allow its reuse. Now it's called with rcu_read_lock already
held and dentry already unlocked.
Note that this is not the final change - locking requirements for
__dentry_kill() are going to change later in the series and the
set of locks taken by lock_for_kill() will be adjusted. Both
lock_parent() and __lock_parent() will be gone once that happens.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Calls of retain_dentry() happen immediately after getting false
from fast_dput() and getting true from retain_dentry() is
treated the same way as non-zero refcount would be treated by
fast_dput() - unlock dentry and bugger off.
Doing that in fast_dput() itself is simpler.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Instead of bumping it from 0 to 1, calling retain_dentry(), then
decrementing it back to 0 (with ->d_lock held all the way through),
just leave refcount at 0 through all of that.
It will have a visible effect for ->d_delete() - now it can be
called with refcount 0 instead of 1 and it can no longer play
silly buggers with dropping/regaining ->d_lock. Not that any
in-tree instances tried to (it's pretty hard to get right).
Any out-of-tree ones will have to adjust (assuming they need any
changes).
Note that we do not need to extend rcu-critical area here - we have
verified that refcount is non-negative after having grabbed ->d_lock,
so nobody will be able to free dentry until they get into __dentry_kill(),
which won't happen until they manage to grab ->d_lock.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We have already checked it and dentry used to look not worthy
of keeping. The only hard obstacle to evicting dentry is
non-zero refcount; everything else is advisory - e.g. memory
pressure could evict any dentry found with refcount zero.
On the slow path in dentry_kill() we had dropped and regained
->d_lock; we must recheck the refcount, but everything else
is not worth bothering with.
Note that filesystem can not count upon ->d_delete() being
called for dentry - not even once. Again, memory pressure
(as well as d_prune_aliases(), or attempted rmdir() of ancestor,
or...) will not call ->d_delete() at all.
So from the correctness point of view we are fine doing the
check only once. And it makes things simpler down the road.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently we call it with refcount equal to 1 when called from
dentry_kill(); all other callers have it equal to 0.
Make it always be called with zero refcount; on this step we
just decrement it before the calls in dentry_kill(). That is
safe, since all places that care about the value of refcount
either do that under ->d_lock or hold a reference to dentry
in question. Either is sufficient to prevent observing a
dentry immediately prior to __dentry_kill() getting called
from dentry_kill().
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
retain_dentry() used to decrement refcount if and only if it returned
true. Lift those decrements into the callers.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and rename it to to_shrink_list(), seeing that it no longer
does dropping any references
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
By now there is only one place in entire fast_dput() where we return
false; that happens after refcount had been decremented and found (under
->d_lock) to be zero. In that case, just prior to returning false to
caller, fast_dput() forcibly changes the refcount from 0 to 1.
Lift that resetting refcount to 1 into the callers; later in the series
it will be massaged out of existence.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If refcount is less than 1, we should just warn, unlock dentry and
return true, so that the caller doesn't try to do anything else.
Taking care of that leaves the rest of "lockref_put_return() has
failed" case equivalent to "decrement refcount and rejoin the
normal slow path after the point where we grab ->d_lock".
NOTE: lockref_put_return() is strictly a fastpath thing - unlike
the rest of lockref primitives, it does not contain a fallback.
Caller (and it looks like fast_dput() is the only legitimate one
in the entire kernel) has to do that itself. Reasons for
lockref_put_return() failures:
* ->d_lock held by somebody
* refcount <= 0
* ... or an architecture not supporting lockref use of
cmpxchg - sparc, anything non-SMP, config with spinlock debugging...
We could add a fallback, but it would be a clumsy API - we'd have
to distinguish between:
(1) refcount > 1 - decremented, lock not held on return
(2) refcount < 1 - left alone, probably no sense to hold the lock
(3) refcount is 1, no cmphxcg - decremented, lock held on return
(4) refcount is 1, cmphxcg supported - decremented, lock *NOT* held
on return.
We want to return with no lock held in case (4); that's the whole point of that
thing. We very much do not want to have the fallback in case (3) return without
a lock, since the caller might have to retake it in that case.
So it wouldn't be more convenient than doing the fallback in the caller and
it would be very easy to screw up, especially since the test coverage would
suck - no way to test (3) and (4) on the same kernel build.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
->d_delete() is a way for filesystem to tell that dentry is not worth
keeping cached. It is not guaranteed to be called every time a dentry
has refcount drop down to zero; it is not guaranteed to be called before
dentry gets evicted. In other words, it is not suitable for any kind
of keeping track of dentry state.
None of the in-tree filesystems attempt to use it that way, fortunately.
So the contortions done by fast_dput() (as well as dentry_kill()) are
not warranted. fast_dput() certainly should treat having ->d_delete()
instance as "can't assume we'll be keeping it", but that's not different
from the way we treat e.g. DCACHE_DONTCACHE (which is rather similar
to making ->d_delete() returns true when called).
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... we won't see DCACHE_MAY_FREE on anything that is *not* dead
and checking d_flags is just as cheap as checking refcount.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
new helper unifying identical bits of shrink_dentry_list() and
shring_dcache_for_umount()
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Saves a pointer per struct dentry and actually makes the things less
clumsy. Cleaned the d_walk() and dcache_readdir() a bit by use
of hlist_for_... iterators.
A couple of new helpers - d_first_child() and d_next_sibling(),
to make the expressions less awful.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
->d_lock on parent does not stabilize ->d_inode of child.
We don't do much with that inode in there, but we need
at least to avoid struct inode getting freed under us...
[rcu_read_lock() is not needed here, since parent's ->d_lock
provides an rcu-critical area]
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
There is no need to have a separate iterator ('cur') through 'buf' in
srmcons_do_write(). 'buf' can be used directly which simplifies the code
a bit.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: linux-alpha@vger.kernel.org
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Link: https://lore.kernel.org/r/20231121092258.9334-14-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
DUMP()'s only use is commented out. Remove the macro completely along
with this unused use.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231121092258.9334-13-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This means:
* move outbuf to the end of struct hvc_struct and convert from pointer
to flexible array (the structure is smaller now)
* use struct_size() at the allocation site
* align outbuf in the struct instead of ALIGN() at kzalloc()
And apart from the above, use u8 instead of char (which are the same
thanks to -funsigned-char). The former is now preferred over the latter.
It makes the code easier to understand.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20231121092258.9334-12-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'serial_table' is global, so there is no need to initialize it to NULLs
at the module load. Drop this unneeded for loop.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-usb@vger.kernel.org
Cc: netdev@vger.kernel.org
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20231121092258.9334-11-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's preferred NOT to emit anything during the module load and unload
(in case the un/load was successful). So drop these prints from hso
along with global 'version'. It even contains no version after all.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-usb@vger.kernel.org
Cc: netdev@vger.kernel.org
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20231121092258.9334-10-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We can pass 'buf' directly to goldfish_tty_rw() using simple (unsigned
long) cast. There is no need to obfuscate the code by another variable
with double casts.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231121092258.9334-9-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a helper for memcpy(buffer)+memset(the_rest). Use it for
simplicity.
And add a comment why we are doing the copy in the first place.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20231121092258.9334-8-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'oe' is a yes-no flag, switch it to boolean. And rename to overrun. All
for the code to be more obvious.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231121092258.9334-7-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'out' label is just before 'return'. So return immediately and drop
both the label and the return. This makes the code more straightforward.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231121092258.9334-6-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Both tty_kref_get() and tty_get_baud_rate() note about locking in their
Return kernel-doc clause. Extract this info into a separate "Locking"
paragraph -- the same as we do for other tty functions.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231121092258.9334-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'mbz' in tiocsti() is used only to pass TTY_NORMAL to
tty_ldisc_ops::receive_buf(). But that can be achieved easier by simply
passing NULL to ::receive_buf().
So drop this 'mbz'.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231121092258.9334-3-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty_write_message() has only one user: quotas. In particular, there the
use depends on CONFIG_PRINT_QUOTA_WARNING. And that is deprecated and
marked as BROKEN already too.
So make tty_write_message() dependent on that very config option. This
action in fact drops tty_write_message() from the vmlinux binary. Good
riddance.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Jan Kara <jack@suse.com>
Acked-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20231121092258.9334-2-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commits 95713967ba ("tty: make tty_operations::write()'s count
size_t") and dcaafbe6ee ("tty: propagate u8 data to
tty_operations::put_char()") changed types of characters to u8, but
omitted to fix the documentation.
Fix the latter now.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231121092258.9334-4-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The comment wording can be confusing, as txlen will return the number of
bytes available in the FIFO, which can be less than the maximum theoretical
Tx FIFO size.
Change the comment so that it is unambiguous.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231122175957.3875102-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The comment wording can be confusing, as txlen will return the number of
bytes available in the FIFO, which can be less than the maximum theoretical
Tx FIFO size.
Change the comment so that it is unambiguous.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231122175859.3874753-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 81a61051e0.
With tty and serdev controller moved to be children of the serial core
port device, runtime PM usage count of the serdev controller now
propagates to the serial hardware controller parent device as expected.
Cc: Maximilian Luz <luzmaximilian@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20231113080758.30346-2-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Let's move tty and serdev controller to be children of the serial core port
device. This way the runtime PM usage count of a child device propagates
to the serial hardware device.
The tty and serdev devices are associated with a specific serial port of
a serial hardware controller device, and we now have serial core hierarchy
of controllers and ports.
The tty device moves happily with just a change of the parent device and
update of device_find_child() handling. The serdev device init needs some
changes to separate the serial hardware controller device from the parent
device.
With this change the tty devices move under sysfs similar to this x86_64
qemu example of a diff of "find /sys -name ttyS*":
/sys/class/tty/ttyS0
/sys/class/tty/ttyS3
/sys/class/tty/ttyS1
-/sys/devices/pnp0/00:04/tty/ttyS0
-/sys/devices/platform/serial8250/tty/ttyS2
-/sys/devices/platform/serial8250/tty/ttyS3
-/sys/devices/platform/serial8250/tty/ttyS1
+/sys/devices/pnp0/00:04/00:04:0/00:04:0.0/tty/ttyS0
+/sys/devices/platform/serial8250/serial8250:0/serial8250:0.3/tty/ttyS3
+/sys/devices/platform/serial8250/serial8250:0/serial8250:0.1/tty/ttyS1
+/sys/devices/platform/serial8250/serial8250:0/serial8250:0.2/tty/ttyS2
If a serdev device is used instead of a tty, it moves in a similar way.
Suggested-by: Johan Hovold <johan@kernel.org>
Cc: Maximilian Luz <luzmaximilian@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20231113080758.30346-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This way we can do:
`echo _reisub > /proc/sysrq-trigger`
Instead of:
`for i in r e i s u b; do echo "$i" > /proc/sysrq-trigger; done;`
This can be very useful when trying to execute sysrq combo remotely
or from userspace. When sending keys in multiple separate writes,
userspace (eg. bash or ssh) can be killed before whole combo is completed.
Therefore putting all keys in single write is more robust approach.
Signed-off-by: Tomas Mudrunka <tomas.mudrunka@gmail.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231120111451.527952-1-tomas.mudrunka@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Device number 204 has a range of minors on major number.
uart_register_driver is failing due to lack of minor numbers
when more number of uart ports used. So, to avoid minor number
limitation on 204 major number use dynamic major allocation
when more than 4 uart ports used otherwise use static major
allocation.
https://docs.kernel.org/arch/arm/sa1100/serial_uart.html
Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
Link: https://lore.kernel.org/r/20231116134003.3762725-3-manikanta.guntupalli@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Describe when uartlite driver uses static/dynamic allocation for major
number based on maximum number of uartlite serial ports.
Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
Link: https://lore.kernel.org/r/20231116134003.3762725-2-manikanta.guntupalli@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty/vt currently uses memdup_user() and vmemdup_array_user() to copy
userspace arrays.
Whereas there is no danger of overflowing, the call to vmemdup_user()
currently utilizes array_size() to calculate the array size
nevertheless. This is not useful because array_size() would return
SIZE_MAX and pass it to vmemdup_user() in case of (the impossible)
overflow.
string.h from the core-API now provides the wrappers memdup_array_user()
and vmemdup_array_user() to copy userspace arrays in a standardized
manner. Additionally, they also perform generic overflow-checks.
Use these wrappers to make it more obvious and readable that arrays are
being copied.
As we are at it, remove two unnecessary empty lines.
Suggested-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Link: https://lore.kernel.org/r/20231103111207.74621-2-pstanner@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since the driver was converted to use .remove_new() the return function
doesn't return a value any more. So remove the obsolete documentation
about the return value.
Reported-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/20231117101236.878008-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reverse run-queue priority enumeration such that the higest priority is now 0,
and for each consecutive integer the prioirty diminishes.
Run-queues correspond to priorities. To an external observer a scheduler
created with a single run-queue, and another created with
DRM_SCHED_PRIORITY_COUNT number of run-queues, should always schedule
sched->sched_rq[0] with the same "priority", as that index run-queue exists in
both schedulers, i.e. a scheduler with one run-queue or many. This patch makes
it so.
In other words, the "priority" of sched->sched_rq[n], n >= 0, is the same for
any scheduler created with any allowable number of run-queues (priorities), 0
to DRM_SCHED_PRIORITY_COUNT.
Cc: Rob Clark <robdclark@gmail.com>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231124052752.6915-6-ltuikov89@gmail.com
Rename DRM_SCHED_PRIORITY_MIN to DRM_SCHED_PRIORITY_LOW.
This mirrors DRM_SCHED_PRIORITY_HIGH, for a list of DRM scheduler priorities
in ascending order,
DRM_SCHED_PRIORITY_LOW,
DRM_SCHED_PRIORITY_NORMAL,
DRM_SCHED_PRIORITY_HIGH,
DRM_SCHED_PRIORITY_KERNEL.
Cc: Rob Clark <robdclark@gmail.com>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231124052752.6915-5-ltuikov89@gmail.com
No error code are available to signal an invalid firmware content.
Drivers that can check the firmware content validity can not return this
specific failure to the user-space
Expand the firmware error code with an additional code:
- "firmware invalid" code which can be used when the provided firmware
is invalid
Sync lib/test_firmware.c file accordingly.
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20231122-feature_firmware_error_code-v3-1-04ec753afb71@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
