diff options
Diffstat (limited to 'debian/patches-rt/0012-printk-nbcon-Use-driver-synchronization-while-regist.patch')
| -rw-r--r-- | debian/patches-rt/0012-printk-nbcon-Use-driver-synchronization-while-regist.patch | 68 |
1 files changed, 0 insertions, 68 deletions
diff --git a/debian/patches-rt/0012-printk-nbcon-Use-driver-synchronization-while-regist.patch b/debian/patches-rt/0012-printk-nbcon-Use-driver-synchronization-while-regist.patch deleted file mode 100644 index 71afdf6e29..0000000000 --- a/debian/patches-rt/0012-printk-nbcon-Use-driver-synchronization-while-regist.patch +++ /dev/null @@ -1,68 +0,0 @@ -From: John Ogness <john.ogness@linutronix.de> -Date: Fri, 15 Mar 2024 15:38:22 +0000 -Subject: [PATCH 12/48] printk: nbcon: Use driver synchronization while - registering -Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.8/older/patches-6.8.2-rt11.tar.xz - -Depending on if an nbcon console is registered, a driver may -handle its internal locking differently. If a driver is holding -its internal lock while the nbcon console is registered, there -may be a risk that two different contexts access the hardware -simultaneously without synchronization. (For example, if the -printk subsystem invokes atomic printing while another driver -context acquired the internal lock without considering the -atomic console.) - -Use the driver synchronization while a registering nbcon console -transitions to being registered. This guarantees that if the -driver acquires its internal lock when the nbcon console was not -registered, it will remain unregistered until that context -releases the lock. - -Signed-off-by: John Ogness <john.ogness@linutronix.de> -Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> ---- - kernel/printk/printk.c | 18 ++++++++++++++++++ - 1 file changed, 18 insertions(+) - ---- a/kernel/printk/printk.c -+++ b/kernel/printk/printk.c -@@ -3453,6 +3453,7 @@ void register_console(struct console *ne - struct console *con; - bool bootcon_registered = false; - bool realcon_registered = false; -+ unsigned long flags; - int err; - - console_list_lock(); -@@ -3545,6 +3546,19 @@ void register_console(struct console *ne - } - - /* -+ * If another context is actively using the hardware of this new -+ * console, it will not be aware of the nbcon synchronization. This -+ * is a risk that two contexts could access the hardware -+ * simultaneously if this new console is used for atomic printing -+ * and the other context is still using the hardware. -+ * -+ * Use the driver synchronization to ensure that the hardware is not -+ * in use while this new console transitions to being registered. -+ */ -+ if ((newcon->flags & CON_NBCON) && newcon->write_atomic) -+ newcon->device_lock(newcon, &flags); -+ -+ /* - * Put this console in the list - keep the - * preferred driver at the head of the list. - */ -@@ -3568,6 +3582,10 @@ void register_console(struct console *ne - * register_console() completes. - */ - -+ /* This new console is now registered. */ -+ if ((newcon->flags & CON_NBCON) && newcon->write_atomic) -+ newcon->device_unlock(newcon, flags); -+ - console_sysfs_notify(); - - /* |