If the circular buffer is empty, it just means we fit all characters to
send into the HW fifo, but not that the hardware finished transmitting
them.
So if we immediately call stop_tx() after that, this may abort any
pending characters in the HW fifo, and cause dropped characters on the
console.
Fix this by only stopping tx when the tx HW fifo is actually empty.
Fixes: 8275b48b27 ("tty: serial: introduce transmit helpers")
Cc: stable@vger.kernel.org
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Link: https://lore.kernel.org/r/20240303150807.68117-1-jonas.gorski@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
The driver splits the locking function into two parts: local_irq_save() and
uart_port_lock() and this breaks PREEMPT_RT.
Delay handling sysrq until port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-19-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The struct eg20t_port has a spinlock_t which is used for locking while
access I/O of the device. Then there is the uart_portlock which is
sometimes and nests within eg20t_port's lock.
The uart_port lock is not used while using the struct in
pch_uart_hal_read() which might be okay. Then both locks are used in
pch_console_write() which looks odd especially the double try_lock part.
All in all it looks like the uart_port's lock could replace eg20t_port's
lock and simplify the code.
Remove eg20t_port::lock and use uart_port's lock for the lock scope.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-18-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
The driver splits the locking function into two parts: local_irq_save() and
uart_port_lock() and this breaks PREEMPT_RT.
Delay handling sysrq until port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.
Cc: Hammer Hsieh <hammerh0314@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-9-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
The driver splits the locking function into two parts: local_irq_save() and
uart_port_lock() and this breaks PREEMPT_RT.
Delay handling sysrq until port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-8-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
The driver splits the locking function into two parts: local_irq_save() and
uart_port_lock() and this breaks PREEMPT_RT.
Delay handling sysrq until port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-7-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
The driver splits the locking function into two parts: local_irq_save() and
uart_port_lock() and this breaks PREEMPT_RT.
Delay handling sysrq until port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-4-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
The driver splits the locking function into two parts: local_irq_save() and
uart_port_lock() and this breaks PREEMPT_RT.
Delay handling sysrq until port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-3-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
The driver splits the locking function into two parts: local_irq_save() and
uart_port_lock() and this breaks PREEMPT_RT.
Delay handling sysrq until port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-2-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Compiling a kernel for the ColdFire causes a compiler warning:
drivers/tty/serial/mcf.c:473:12: warning: no previous prototype for
‘early_mcf_setup’ [-Wmissing-prototypes]
473 | int __init early_mcf_setup(struct mcf_platform_uart *platp)
| ^~~~~~~~~~~~~~~
This function seems to be completely unused, so let's remove it
to silence the warning.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20240219164002.520342-1-thuth@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We are not supposed to spread quirks in 8250_port module especially
when we have a separate driver for the hardware in question.
Move quirk from generic module to the driver that uses it.
While at it, move IO to ->set_divisor() callback as it has to be from
day 1. ->get_divisor() is not supposed to perform any IO as UART port:
- might not be powered on
- is not locked by a spin lock
Fixes: 1ed67ecd13 ("8250: microchip: Add 4 Mbps support in PCI1XXXX UART")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rengarajan S <rengarajan.s@microchip.com>
Link: https://lore.kernel.org/r/20240219162917.2159736-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull bcachefs fixes from Kent Overstreet:
"Some more mostly boring fixes, but some not
User reported ones:
- the BTREE_ITER_FILTER_SNAPSHOTS one fixes a really nasty
performance bug; user reported an untar initially taking two
seconds and then ~2 minutes
- kill a __GFP_NOFAIL in the buffered read path; this was a leftover
from the trickier fix to kill __GFP_NOFAIL in readahead, where we
can't return errors (and have to silently truncate the read
ourselves).
bcachefs can't use GFP_NOFAIL for folio state unlike iomap based
filesystems because our folio state is just barely too big, 2MB
hugepages cause us to exceed the 2 page threshhold for GFP_NOFAIL.
additionally, the flags argument was just buggy, we weren't
supplying GFP_KERNEL previously (!)"
* tag 'bcachefs-2024-02-25' of https://evilpiepirate.org/git/bcachefs:
bcachefs: fix bch2_save_backtrace()
bcachefs: Fix check_snapshot() memcpy
bcachefs: Fix bch2_journal_flush_device_pins()
bcachefs: fix iov_iter count underflow on sub-block dio read
bcachefs: Fix BTREE_ITER_FILTER_SNAPSHOTS on inodes btree
bcachefs: Kill __GFP_NOFAIL in buffered read path
bcachefs: fix backpointer_to_text() when dev does not exist
Pull two documentation build fixes from Jonathan Corbet:
- The XFS online fsck documentation uses incredibly deeply nested
subsection and list nesting; that broke the PDF docs build. Tweak a
parameter to tell LaTeX to allow the deeper nesting.
- Fix a 6.8 PDF-build regression
* tag 'docs-6.8-fixes3' of git://git.lwn.net/linux:
docs: translations: use attribute to store current language
docs: Instruct LaTeX to cope with deeper nesting
Pull USB fixes from Greg KH:
"Here are some small USB fixes for 6.8-rc6 to resolve some reported
problems. These include:
- regression fixes with typec tpcm code as reported by many
- cdnsp and cdns3 driver fixes
- usb role setting code bugfixes
- build fix for uhci driver
- ncm gadget driver bugfix
- MAINTAINERS entry update
All of these have been in linux-next all week with no reported issues
and there is at least one fix in here that is in Thorsten's regression
list that is being tracked"
* tag 'usb-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: typec: tpcm: Fix issues with power being removed during reset
MAINTAINERS: Drop myself as maintainer of TYPEC port controller drivers
usb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs
Revert "usb: typec: tcpm: reset counter when enter into unattached state after try role"
usb: gadget: omap_udc: fix USB gadget regression on Palm TE
usb: dwc3: gadget: Don't disconnect if not started
usb: cdns3: fix memory double free when handle zero packet
usb: cdns3: fixed memory use after free at cdns3_gadget_ep_disable()
usb: roles: don't get/set_role() when usb_role_switch is unregistered
usb: roles: fix NULL pointer issue when put module's reference
usb: cdnsp: fixed issue with incorrect detecting CDNSP family controllers
usb: cdnsp: blocked some cdns3 specific code
usb: uhci-grlib: Explicitly include linux/platform_device.h
Pull tty/serial driver fixes from Greg KH:
"Here are three small serial/tty driver fixes for 6.8-rc6 that resolve
the following reported errors:
- riscv hvc console driver fix that was reported by many
- amba-pl011 serial driver fix for RS485 mode
- stm32 serial driver fix for RS485 mode
All of these have been in linux-next all week with no reported
problems"
* tag 'tty-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: amba-pl011: Fix DMA transmission in RS485 mode
serial: stm32: do not always set SER_RS485_RX_DURING_TX if RS485 is enabled
tty: hvc: Don't enable the RISC-V SBI console by default
Pull x86 fixes from Borislav Petkov:
- Make sure clearing CPU buffers using VERW happens at the latest
possible point in the return-to-userspace path, otherwise memory
accesses after the VERW execution could cause data to land in CPU
buffers again
* tag 'x86_urgent_for_v6.8_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
KVM/VMX: Move VERW closer to VMentry for MDS mitigation
KVM/VMX: Use BT+JNC, i.e. EFLAGS.CF to select VMRESUME vs. VMLAUNCH
x86/bugs: Use ALTERNATIVE() instead of mds_user_clear static key
x86/entry_32: Add VERW just before userspace transition
x86/entry_64: Add VERW just before userspace transition
x86/bugs: Add asm helpers for executing VERW
Pull irq fixes from Borislav Petkov:
- Make sure GICv4 always gets initialized to prevent a kexec-ed kernel
from silently failing to set it up
- Do not call bus_get_dev_root() for the mbigen irqchip as it always
returns NULL - use NULL directly
- Fix hardware interrupt number truncation when assigning MSI
interrupts
- Correct sending end-of-interrupt messages to disabled interrupts
lines on RISC-V PLIC
* tag 'irq_urgent_for_v6.8_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic-v3-its: Do not assume vPE tables are preallocated
irqchip/mbigen: Don't use bus_get_dev_root() to find the parent
PCI/MSI: Prevent MSI hardware interrupt number truncation
irqchip/sifive-plic: Enable interrupt if needed before EOI
Pull erofs fix from Gao Xiang:
- Fix page refcount leak when looking up specific inodes
introduced by metabuf reworking
* tag 'erofs-for-6.8-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
erofs: fix refcount on the metabuf used for inode lookup
Pull RCU pathwalk fixes from Al Viro:
"We still have some races in filesystem methods when exposed to RCU
pathwalk. This series is a result of code audit (the second round of
it) and it should deal with most of that stuff.
Still pending: ntfs3 ->d_hash()/->d_compare() and ceph_d_revalidate().
Up to maintainers (a note for NTFS folks - when documentation says
that a method may not block, it *does* imply that blocking allocations
are to be avoided. Really)"
[ More explanations for people who aren't familiar with the vagaries of
RCU path walking: most of it is hidden from filesystems, but if a
filesystem actively participates in the low-level path walking it
needs to make sure the fields involved in that walk are RCU-safe.
That "actively participate in low-level path walking" includes things
like having its own ->d_hash()/->d_compare() routines, or by having
its own directory permission function that doesn't just use the common
helpers. Having a ->d_revalidate() function will also have this issue.
Note that instead of making everything RCU safe you can also choose to
abort the RCU pathwalk if your operation cannot be done safely under
RCU, but that obviously comes with a performance penalty. One common
pattern is to allow the simple cases under RCU, and abort only if you
need to do something more complicated.
So not everything needs to be RCU-safe, and things like the inode etc
that the VFS itself maintains obviously already are. But these fixes
tend to be about properly RCU-delaying things like ->s_fs_info that
are maintained by the filesystem and that got potentially released too
early. - Linus ]
* tag 'pull-fixes.pathwalk-rcu-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ext4_get_link(): fix breakage in RCU mode
cifs_get_link(): bail out in unsafe case
fuse: fix UAF in rcu pathwalks
procfs: make freeing proc_fs_info rcu-delayed
procfs: move dropping pde and pid from ->evict_inode() to ->free_inode()
nfs: fix UAF on pathwalk running into umount
nfs: make nfs_set_verifier() safe for use in RCU pathwalk
afs: fix __afs_break_callback() / afs_drop_open_mmap() race
hfsplus: switch to rcu-delayed unloading of nls and freeing ->s_fs_info
exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helper
affs: free affs_sb_info with kfree_rcu()
rcu pathwalk: prevent bogus hard errors from may_lookup()
fs/super.c: don't drop ->s_user_ns until we free struct super_block itself
Pull vfs fixes from Al Viro:
"A couple of fixes - revert of regression from this cycle and a fix for
erofs failure exit breakage (had been there since way back)"
* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
erofs: fix handling kern_mount() failure
Revert "get rid of DCACHE_GENOCIDE"
1) errors from ext4_getblk() should not be propagated to caller
unless we are really sure that we would've gotten the same error
in non-RCU pathwalk.
2) we leak buffer_heads if ext4_getblk() is successful, but bh is
not uptodate.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
->d_revalidate() bails out there, anyway. It's not enough
to prevent getting into ->get_link() in RCU mode, but that
could happen only in a very contrieved setup. Not worth
trying to do anything fancy here unless ->d_revalidate()
stops kicking out of RCU mode at least in some cases.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
->permission(), ->get_link() and ->inode_get_acl() might dereference
->s_fs_info (and, in case of ->permission(), ->s_fs_info->fc->user_ns
as well) when called from rcu pathwalk.
Freeing ->s_fs_info->fc is rcu-delayed; we need to make freeing ->s_fs_info
and dropping ->user_ns rcu-delayed too.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
makes proc_pid_ns() safe from rcu pathwalk (put_pid_ns()
is still synchronous, but that's not a problem - it does
rcu-delay everything that needs to be)
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
