When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-21-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-20-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-19-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-18-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-17-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-16-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-15-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-14-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-13-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-12-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-11-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-10-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-9-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-8-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-7-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-6-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-5-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-4-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-3-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
Provide wrapper functions for spin_[un]lock*(port->lock) invocations so
that the console mechanics can be applied later on at a single place and
does not require to copy the same logic all over the drivers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-2-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a pid leakage:
------------------------------
unreferenced object 0xffff88810c181940 (size 224):
comm "sshd", pid 8191, jiffies 4294946950 (age 524.570s)
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 00 00 00 00 ad 4e ad de .............N..
ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........
backtrace:
[<ffffffff814774e6>] kmem_cache_alloc+0x5c6/0x9b0
[<ffffffff81177342>] alloc_pid+0x72/0x570
[<ffffffff81140ac4>] copy_process+0x1374/0x2470
[<ffffffff81141d77>] kernel_clone+0xb7/0x900
[<ffffffff81142645>] __se_sys_clone+0x85/0xb0
[<ffffffff8114269b>] __x64_sys_clone+0x2b/0x30
[<ffffffff83965a72>] do_syscall_64+0x32/0x80
[<ffffffff83a00085>] entry_SYSCALL_64_after_hwframe+0x61/0xc6
It turns out that there is a race condition between disassociate_ctty() and
tty_signal_session_leader(), which caused this leakage.
The pid memleak is triggered by the following race:
task[sshd] task[bash]
----------------------- -----------------------
disassociate_ctty();
spin_lock_irq(¤t->sighand->siglock);
put_pid(current->signal->tty_old_pgrp);
current->signal->tty_old_pgrp = NULL;
tty = tty_kref_get(current->signal->tty);
spin_unlock_irq(¤t->sighand->siglock);
tty_vhangup();
tty_lock(tty);
...
tty_signal_session_leader();
spin_lock_irq(&p->sighand->siglock);
...
if (tty->ctrl.pgrp) //tty->ctrl.pgrp is not NULL
p->signal->tty_old_pgrp = get_pid(tty->ctrl.pgrp); //An extra get
spin_unlock_irq(&p->sighand->siglock);
...
tty_unlock(tty);
if (tty) {
tty_lock(tty);
...
put_pid(tty->ctrl.pgrp);
tty->ctrl.pgrp = NULL; //It's too late
...
tty_unlock(tty);
}
The issue is believed to be introduced by commit c8bcd9c5be ("tty:
Fix ->session locking") who moves the unlock of siglock in
disassociate_ctty() above "if (tty)", making a small window allowing
tty_signal_session_leader() to kick in. It can be easily reproduced by
adding a delay before "if (tty)" and at the entrance of
tty_signal_session_leader().
To fix this issue, we move "put_pid(current->signal->tty_old_pgrp)" after
"tty->ctrl.pgrp = NULL".
Fixes: c8bcd9c5be ("tty: Fix ->session locking")
Signed-off-by: Yi Yang <yiyang13@huawei.com>
Co-developed-by: GUO Zihua <guozihua@huawei.com>
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Link: https://lore.kernel.org/r/20230831023329.165737-1-yiyang13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Three of the four entries of imx_uart_devdata[] use .uts_reg =
IMX21_UTS. The difference in the .devtype member isn't relevant, the
only thing that matters is if is equal to IMX1_UART.
So use an entry with .devtype = IMX21_UART on all platforms but i.MX1.
There is no need to have the dev types in an array, so split them up in
two separate variables.
The fsl,imx53-uart devinfo can go away because in the binding and also
the dts files all fsl,imx53-uart devices also are compatible to
fsl,imx21-uart. That's not the case for fsl,imx6q-uart (which is a bit
strange IMHO), so the fsl,imx6q-uart must stay around.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230911085451.628798-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- Fix an UV boot crash
- Skip spurious ENDBR generation on _THIS_IP_
- Fix ENDBR use in putuser() asm methods
- Fix corner case boot crashes on 5-level paging
- and fix a false positive WARNING on LTO kernels"
* tag 'x86-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/purgatory: Remove LTO flags
x86/boot/compressed: Reserve more memory for page tables
x86/ibt: Avoid duplicate ENDBR in __put_user_nocheck*()
x86/ibt: Suppress spurious ENDBR
x86/platform/uv: Use alternate source for socket to node data
Pull scheduler fixes from Ingo Molnar:
"Fix a performance regression on large SMT systems, an Intel SMT4
balancing bug, and a topology setup bug on (Intel) hybrid processors"
* tag 'sched-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sched: Restore the SD_ASYM_PACKING flag in the DIE domain
sched/fair: Fix SMT4 group_smt_balance handling
sched/fair: Optimize should_we_balance() for large SMT systems
Pull objtool fix from Ingo Molnar:
"Fix a cold functions related false-positive objtool warning that
triggers on Clang"
* tag 'objtool-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Fix _THIS_IP_ detection for cold functions
Pull WARN fix from Ingo Molnar:
"Fix a missing preempt-enable in the WARN() slowpath"
* tag 'core-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
panic: Reenable preemption in WARN slowpath
The choose_32_64() macros were added to deal with an odd inconsistency
between the 32-bit and 64-bit layout of 'struct stat' way back when in
commit a52dd971f9 ("vfs: de-crapify "cp_new_stat()" function").
Then a decade later Mikulas noticed that said inconsistency had been a
mistake in the early x86-64 port, and shouldn't have existed in the
first place. So commit 932aba1e16 ("stat: fix inconsistency between
struct stat and struct compat_stat") removed the uses of the helpers.
But the helpers remained around, unused.
Get rid of them.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull smb client fixes from Steve French:
"Three small SMB3 client fixes, one to improve a null check and two
minor cleanups"
* tag '6.6-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
smb3: fix some minor typos and repeated words
smb3: correct places where ENOTSUPP is used instead of preferred EOPNOTSUPP
smb3: move server check earlier when setting channel sequence number
Pull smb server fixes from Steve French:
"Two ksmbd server fixes"
* tag '6.6-rc1-ksmbd' of git://git.samba.org/ksmbd:
ksmbd: fix passing freed memory 'aux_payload_buf'
ksmbd: remove unneeded mark_inode_dirty in set_info_sec()
Pull ext4 fixes from Ted Ts'o:
"Regression and bug fixes for ext4"
* tag 'ext4_for_linus-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix rec_len verify error
ext4: do not let fstrim block system suspend
ext4: move setting of trimmed bit into ext4_try_to_trim_range()
jbd2: Fix memory leak in journal_init_common()
jbd2: Remove page size assumptions
buffer: Make bh_offset() work for compound pages
-flto* implies -ffunction-sections. With LTO enabled, ld.lld generates
multiple .text sections for purgatory.ro:
$ readelf -S purgatory.ro | grep " .text"
[ 1] .text PROGBITS 0000000000000000 00000040
[ 7] .text.purgatory PROGBITS 0000000000000000 000020e0
[ 9] .text.warn PROGBITS 0000000000000000 000021c0
[13] .text.sha256_upda PROGBITS 0000000000000000 000022f0
[15] .text.sha224_upda PROGBITS 0000000000000000 00002be0
[17] .text.sha256_fina PROGBITS 0000000000000000 00002bf0
[19] .text.sha224_fina PROGBITS 0000000000000000 00002cc0
This causes WARNING from kexec_purgatory_setup_sechdrs():
WARNING: CPU: 26 PID: 110894 at kernel/kexec_file.c:919
kexec_load_purgatory+0x37f/0x390
Fix this by disabling LTO for purgatory.
[ AFAICT, x86 is the only arch that supports LTO and purgatory. ]
We could also fix this with an explicit linker script to rejoin .text.*
sections back into .text. However, given the benefit of LTOing purgatory
is small, simply disable the production of more .text.* sections for now.
Fixes: b33fff07e3 ("x86, build: allow LTO to be selected")
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20230914170138.995606-1-song@kernel.org
The decompressor has a hard limit on the number of page tables it can
allocate. This limit is defined at compile-time and will cause boot
failure if it is reached.
The kernel is very strict and calculates the limit precisely for the
worst-case scenario based on the current configuration. However, it is
easy to forget to adjust the limit when a new use-case arises. The
worst-case scenario is rarely encountered during sanity checks.
In the case of enabling 5-level paging, a use-case was overlooked. The
limit needs to be increased by one to accommodate the additional level.
This oversight went unnoticed until Aaron attempted to run the kernel
via kexec with 5-level paging and unaccepted memory enabled.
Update wost-case calculations to include 5-level paging.
To address this issue, let's allocate some extra space for page tables.
128K should be sufficient for any use-case. The logic can be simplified
by using a single value for all kernel configurations.
[ Also add a warning, should this memory run low - by Dave Hansen. ]
Fixes: 34bbb0009f ("x86/boot/compressed: Enable 5-level paging during decompression stage")
Reported-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230915070221.10266-1-kirill.shutemov@linux.intel.com
Pull Kbuild fixes from Masahiro Yamada:
- Fix kernel-devel RPM and linux-headers Deb package
- Fix too long argument list error in 'make modules_install'
* tag 'kbuild-fixes-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: avoid long argument lists in make modules_install
kbuild: fix kernel-devel RPM package and linux-headers Deb package
Commit 408579cd62 ("mm: Update do_vmi_align_munmap() return
semantics") seems to have updated one of the callers of do_vmi_munmap()
incorrectly: it used to check for the error case (which didn't
change: negative means error).
That commit changed the check to the success case (which did change:
before that commit, 0 was success, and 1 was "success and lock
downgraded". After the change, it's always 0 for success, and the lock
will have been released if requested).
This didn't change any actual VM behavior _except_ for memory accounting
when 'VM_ACCOUNT' was set on the vma. Which made the wrong return value
test fairly subtle, since everything continues to work.
Or rather - it continues to work but the "Committed memory" accounting
goes all wonky (Committed_AS value in /proc/meminfo), and depending on
settings that then causes problems much much later as the VM relies on
bogus statistics for its heuristics.
Revert that one line of the change back to the original logic.
Fixes: 408579cd62 ("mm: Update do_vmi_align_munmap() return semantics")
Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
Reported-bisected-and-tested-by: Michael Labiuk <michael.labiuk@virtuozzo.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Link: https://lore.kernel.org/all/1694366957@msgid.manchmal.in-ulm.de/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
