+++ /dev/null
-From 39a193250eef2ead8b1eff317ba76941c2188c82 Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Wed, 2 Feb 2022 09:18:18 -0800
-Subject: printk: Add panic_in_progress helper
-
-From: Stephen Brennan <stephen.s.brennan@oracle.com>
-
-[ Upstream commit 77498617857f68496b360081dde1a492d40c28b2 ]
-
-This will be used help avoid deadlocks during panics. Although it would
-be better to include this in linux/panic.h, it would require that header
-to include linux/atomic.h as well. On some architectures, this results
-in a circular dependency as well. So instead add the helper directly to
-printk.c.
-
-Suggested-by: Petr Mladek <pmladek@suse.com>
-Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
-Reviewed-by: Petr Mladek <pmladek@suse.com>
-Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
-Signed-off-by: Petr Mladek <pmladek@suse.com>
-Link: https://lore.kernel.org/r/20220202171821.179394-2-stephen.s.brennan@oracle.com
-Stable-dep-of: d04d5882cd67 ("printk: Disable passing console lock owner completely during panic()")
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- kernel/printk/printk.c | 5 +++++
- 1 file changed, 5 insertions(+)
-
-diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
-index 17a310dcb6d96..94af80b7fa9b5 100644
---- a/kernel/printk/printk.c
-+++ b/kernel/printk/printk.c
-@@ -258,6 +258,11 @@ static void __up_console_sem(unsigned long ip)
- }
- #define up_console_sem() __up_console_sem(_RET_IP_)
-
-+static bool panic_in_progress(void)
-+{
-+ return unlikely(atomic_read(&panic_cpu) != PANIC_CPU_INVALID);
-+}
-+
- /*
- * This is used for debugging the mess that is the VT code by
- * keeping track if we have the console semaphore held. It's
---
-2.43.0
-
+++ /dev/null
-From b8b3bf167cb2439f091179cd6054ab6927273a56 Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Wed, 7 Feb 2024 14:47:00 +0106
-Subject: printk: Disable passing console lock owner completely during panic()
-
-From: Petr Mladek <pmladek@suse.com>
-
-[ Upstream commit d04d5882cd678b898a9d7c5aee6afbe9e6e77fcd ]
-
-The commit d51507098ff91 ("printk: disable optimistic spin
-during panic") added checks to avoid becoming a console waiter
-if a panic is in progress.
-
-However, the transition to panic can occur while there is
-already a waiter. The current owner should not pass the lock to
-the waiter because it might get stopped or blocked anytime.
-
-Also the panic context might pass the console lock owner to an
-already stopped waiter by mistake. It might happen when
-console_flush_on_panic() ignores the current lock owner, for
-example:
-
-CPU0 CPU1
----- ----
-console_lock_spinning_enable()
- console_trylock_spinning()
- [CPU1 now console waiter]
-NMI: panic()
- panic_other_cpus_shutdown()
- [stopped as console waiter]
- console_flush_on_panic()
- console_lock_spinning_enable()
- [print 1 record]
- console_lock_spinning_disable_and_check()
- [handover to stopped CPU1]
-
-This results in panic() not flushing the panic messages.
-
-Fix these problems by disabling all spinning operations
-completely during panic().
-
-Another advantage is that it prevents possible deadlocks caused
-by "console_owner_lock". The panic() context does not need to
-take it any longer. The lockless checks are safe because the
-functions become NOPs when they see the panic in progress. All
-operations manipulating the state are still synchronized by the
-lock even when non-panic CPUs would notice the panic
-synchronously.
-
-The current owner might stay spinning. But non-panic() CPUs
-would get stopped anyway and the panic context will never start
-spinning.
-
-Fixes: dbdda842fe96 ("printk: Add console owner and waiter logic to load balance console writes")
-Signed-off-by: John Ogness <john.ogness@linutronix.de>
-Link: https://lore.kernel.org/r/20240207134103.1357162-12-john.ogness@linutronix.de
-Signed-off-by: Petr Mladek <pmladek@suse.com>
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- kernel/printk/printk.c | 29 +++++++++++++++++++++++++++++
- 1 file changed, 29 insertions(+)
-
-diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
-index 94af80b7fa9b5..d109411f108f9 100644
---- a/kernel/printk/printk.c
-+++ b/kernel/printk/printk.c
-@@ -1760,10 +1760,23 @@ static bool console_waiter;
- */
- static void console_lock_spinning_enable(void)
- {
-+ /*
-+ * Do not use spinning in panic(). The panic CPU wants to keep the lock.
-+ * Non-panic CPUs abandon the flush anyway.
-+ *
-+ * Just keep the lockdep annotation. The panic-CPU should avoid
-+ * taking console_owner_lock because it might cause a deadlock.
-+ * This looks like the easiest way how to prevent false lockdep
-+ * reports without handling races a lockless way.
-+ */
-+ if (panic_in_progress())
-+ goto lockdep;
-+
- raw_spin_lock(&console_owner_lock);
- console_owner = current;
- raw_spin_unlock(&console_owner_lock);
-
-+lockdep:
- /* The waiter may spin on us after setting console_owner */
- spin_acquire(&console_owner_dep_map, 0, 0, _THIS_IP_);
- }
-@@ -1787,6 +1800,22 @@ static int console_lock_spinning_disable_and_check(void)
- {
- int waiter;
-
-+ /*
-+ * Ignore spinning waiters during panic() because they might get stopped
-+ * or blocked at any time,
-+ *
-+ * It is safe because nobody is allowed to start spinning during panic
-+ * in the first place. If there has been a waiter then non panic CPUs
-+ * might stay spinning. They would get stopped anyway. The panic context
-+ * will never start spinning and an interrupted spin on panic CPU will
-+ * never continue.
-+ */
-+ if (panic_in_progress()) {
-+ /* Keep lockdep happy. */
-+ spin_release(&console_owner_dep_map, _THIS_IP_);
-+ return 0;
-+ }
-+
- raw_spin_lock(&console_owner_lock);
- waiter = READ_ONCE(console_waiter);
- console_owner = NULL;
---
-2.43.0
-
wifi-iwlwifi-fix-ewrd-table-validity-check.patch
net-blackhole_dev-fix-build-warning-for-ethh-set-but.patch
wifi-libertas-fix-some-memleaks-in-lbs_allocate_cmd_.patch
-printk-add-panic_in_progress-helper.patch
-printk-disable-passing-console-lock-owner-completely.patch
arm64-dts-mediatek-mt7622-add-missing-device_type-to.patch
bpf-factor-out-bpf_spin_lock-into-helpers.patch
bpf-mark-bpf_spin_-lock-unlock-helpers-with-notrace-.patch
+++ /dev/null
-From 638bff97b02854768b03c7de106b677613c51560 Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Wed, 2 Feb 2022 09:18:18 -0800
-Subject: printk: Add panic_in_progress helper
-
-From: Stephen Brennan <stephen.s.brennan@oracle.com>
-
-[ Upstream commit 77498617857f68496b360081dde1a492d40c28b2 ]
-
-This will be used help avoid deadlocks during panics. Although it would
-be better to include this in linux/panic.h, it would require that header
-to include linux/atomic.h as well. On some architectures, this results
-in a circular dependency as well. So instead add the helper directly to
-printk.c.
-
-Suggested-by: Petr Mladek <pmladek@suse.com>
-Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
-Reviewed-by: Petr Mladek <pmladek@suse.com>
-Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
-Signed-off-by: Petr Mladek <pmladek@suse.com>
-Link: https://lore.kernel.org/r/20220202171821.179394-2-stephen.s.brennan@oracle.com
-Stable-dep-of: d04d5882cd67 ("printk: Disable passing console lock owner completely during panic()")
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- kernel/printk/printk.c | 5 +++++
- 1 file changed, 5 insertions(+)
-
-diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
-index 8b110b245d92c..de44ccf9743c1 100644
---- a/kernel/printk/printk.c
-+++ b/kernel/printk/printk.c
-@@ -258,6 +258,11 @@ static void __up_console_sem(unsigned long ip)
- }
- #define up_console_sem() __up_console_sem(_RET_IP_)
-
-+static bool panic_in_progress(void)
-+{
-+ return unlikely(atomic_read(&panic_cpu) != PANIC_CPU_INVALID);
-+}
-+
- /*
- * This is used for debugging the mess that is the VT code by
- * keeping track if we have the console semaphore held. It's
---
-2.43.0
-
+++ /dev/null
-From edf4e1e6001bf8bc53c4ed01fc18f8ea53e06e64 Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Wed, 7 Feb 2024 14:47:00 +0106
-Subject: printk: Disable passing console lock owner completely during panic()
-
-From: Petr Mladek <pmladek@suse.com>
-
-[ Upstream commit d04d5882cd678b898a9d7c5aee6afbe9e6e77fcd ]
-
-The commit d51507098ff91 ("printk: disable optimistic spin
-during panic") added checks to avoid becoming a console waiter
-if a panic is in progress.
-
-However, the transition to panic can occur while there is
-already a waiter. The current owner should not pass the lock to
-the waiter because it might get stopped or blocked anytime.
-
-Also the panic context might pass the console lock owner to an
-already stopped waiter by mistake. It might happen when
-console_flush_on_panic() ignores the current lock owner, for
-example:
-
-CPU0 CPU1
----- ----
-console_lock_spinning_enable()
- console_trylock_spinning()
- [CPU1 now console waiter]
-NMI: panic()
- panic_other_cpus_shutdown()
- [stopped as console waiter]
- console_flush_on_panic()
- console_lock_spinning_enable()
- [print 1 record]
- console_lock_spinning_disable_and_check()
- [handover to stopped CPU1]
-
-This results in panic() not flushing the panic messages.
-
-Fix these problems by disabling all spinning operations
-completely during panic().
-
-Another advantage is that it prevents possible deadlocks caused
-by "console_owner_lock". The panic() context does not need to
-take it any longer. The lockless checks are safe because the
-functions become NOPs when they see the panic in progress. All
-operations manipulating the state are still synchronized by the
-lock even when non-panic CPUs would notice the panic
-synchronously.
-
-The current owner might stay spinning. But non-panic() CPUs
-would get stopped anyway and the panic context will never start
-spinning.
-
-Fixes: dbdda842fe96 ("printk: Add console owner and waiter logic to load balance console writes")
-Signed-off-by: John Ogness <john.ogness@linutronix.de>
-Link: https://lore.kernel.org/r/20240207134103.1357162-12-john.ogness@linutronix.de
-Signed-off-by: Petr Mladek <pmladek@suse.com>
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- kernel/printk/printk.c | 29 +++++++++++++++++++++++++++++
- 1 file changed, 29 insertions(+)
-
-diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
-index de44ccf9743c1..5ad824b080e27 100644
---- a/kernel/printk/printk.c
-+++ b/kernel/printk/printk.c
-@@ -1802,10 +1802,23 @@ static bool console_waiter;
- */
- static void console_lock_spinning_enable(void)
- {
-+ /*
-+ * Do not use spinning in panic(). The panic CPU wants to keep the lock.
-+ * Non-panic CPUs abandon the flush anyway.
-+ *
-+ * Just keep the lockdep annotation. The panic-CPU should avoid
-+ * taking console_owner_lock because it might cause a deadlock.
-+ * This looks like the easiest way how to prevent false lockdep
-+ * reports without handling races a lockless way.
-+ */
-+ if (panic_in_progress())
-+ goto lockdep;
-+
- raw_spin_lock(&console_owner_lock);
- console_owner = current;
- raw_spin_unlock(&console_owner_lock);
-
-+lockdep:
- /* The waiter may spin on us after setting console_owner */
- spin_acquire(&console_owner_dep_map, 0, 0, _THIS_IP_);
- }
-@@ -1829,6 +1842,22 @@ static int console_lock_spinning_disable_and_check(void)
- {
- int waiter;
-
-+ /*
-+ * Ignore spinning waiters during panic() because they might get stopped
-+ * or blocked at any time,
-+ *
-+ * It is safe because nobody is allowed to start spinning during panic
-+ * in the first place. If there has been a waiter then non panic CPUs
-+ * might stay spinning. They would get stopped anyway. The panic context
-+ * will never start spinning and an interrupted spin on panic CPU will
-+ * never continue.
-+ */
-+ if (panic_in_progress()) {
-+ /* Keep lockdep happy. */
-+ spin_release(&console_owner_dep_map, _THIS_IP_);
-+ return 0;
-+ }
-+
- raw_spin_lock(&console_owner_lock);
- waiter = READ_ONCE(console_waiter);
- console_owner = NULL;
---
-2.43.0
-
pwm-atmel-hlcdc-fix-clock-imbalance-related-to-suspe.patch
net-blackhole_dev-fix-build-warning-for-ethh-set-but.patch
wifi-libertas-fix-some-memleaks-in-lbs_allocate_cmd_.patch
-printk-add-panic_in_progress-helper.patch
-printk-disable-passing-console-lock-owner-completely.patch
pwm-sti-implement-.apply-callback.patch
pwm-sti-fix-capture-for-st-pwm-num-chan-st-capture-n.patch
wifi-iwlwifi-mvm-don-t-set-replay-counters-to-0xff.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
