5.10-stable patches

added patches:
	genirq-cpuhotplug-x86-vector-prevent-vector-leak-during-cpu-offline.patch

diff --git a/queue-5.10/genirq-cpuhotplug-x86-vector-prevent-vector-leak-during-cpu-offline.patch b/queue-5.10/genirq-cpuhotplug-x86-vector-prevent-vector-leak-during-cpu-offline.patch
new file mode 100644 (file)
index 0000000..fbe1f54
--- /dev/null
+++ b/queue-5.10/genirq-cpuhotplug-x86-vector-prevent-vector-leak-during-cpu-offline.patch
@@ -0,0 +1,123 @@
+From a6c11c0a5235fb144a65e0cb2ffd360ddc1f6c32 Mon Sep 17 00:00:00 2001
+From: Dongli Zhang <dongli.zhang@oracle.com>
+Date: Wed, 22 May 2024 15:02:18 -0700
+Subject: genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offline
+
+From: Dongli Zhang <dongli.zhang@oracle.com>
+
+commit a6c11c0a5235fb144a65e0cb2ffd360ddc1f6c32 upstream.
+
+The absence of IRQD_MOVE_PCNTXT prevents immediate effectiveness of
+interrupt affinity reconfiguration via procfs. Instead, the change is
+deferred until the next instance of the interrupt being triggered on the
+original CPU.
+
+When the interrupt next triggers on the original CPU, the new affinity is
+enforced within __irq_move_irq(). A vector is allocated from the new CPU,
+but the old vector on the original CPU remains and is not immediately
+reclaimed. Instead, apicd->move_in_progress is flagged, and the reclaiming
+process is delayed until the next trigger of the interrupt on the new CPU.
+
+Upon the subsequent triggering of the interrupt on the new CPU,
+irq_complete_move() adds a task to the old CPU's vector_cleanup list if it
+remains online. Subsequently, the timer on the old CPU iterates over its
+vector_cleanup list, reclaiming old vectors.
+
+However, a rare scenario arises if the old CPU is outgoing before the
+interrupt triggers again on the new CPU.
+
+In that case irq_force_complete_move() is not invoked on the outgoing CPU
+to reclaim the old apicd->prev_vector because the interrupt isn't currently
+affine to the outgoing CPU, and irq_needs_fixup() returns false. Even
+though __vector_schedule_cleanup() is later called on the new CPU, it
+doesn't reclaim apicd->prev_vector; instead, it simply resets both
+apicd->move_in_progress and apicd->prev_vector to 0.
+
+As a result, the vector remains unreclaimed in vector_matrix, leading to a
+CPU vector leak.
+
+To address this issue, move the invocation of irq_force_complete_move()
+before the irq_needs_fixup() call to reclaim apicd->prev_vector, if the
+interrupt is currently or used to be affine to the outgoing CPU.
+
+Additionally, reclaim the vector in __vector_schedule_cleanup() as well,
+following a warning message, although theoretically it should never see
+apicd->move_in_progress with apicd->prev_cpu pointing to an offline CPU.
+
+Fixes: f0383c24b485 ("genirq/cpuhotplug: Add support for cleaning up move in progress")
+Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Cc: stable@vger.kernel.org
+Link: https://lore.kernel.org/r/20240522220218.162423-1-dongli.zhang@oracle.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/kernel/apic/vector.c |    9 ++++++---
+ kernel/irq/cpuhotplug.c       |   16 ++++++++--------
+ 2 files changed, 14 insertions(+), 11 deletions(-)
+
+--- a/arch/x86/kernel/apic/vector.c
++++ b/arch/x86/kernel/apic/vector.c
+@@ -920,7 +920,8 @@ static void __send_cleanup_vector(struct
+               hlist_add_head(&apicd->clist, per_cpu_ptr(&cleanup_list, cpu));
+               apic->send_IPI(cpu, IRQ_MOVE_CLEANUP_VECTOR);
+       } else {
+-              apicd->prev_vector = 0;
++              pr_warn("IRQ %u schedule cleanup for offline CPU %u\n", apicd->irq, cpu);
++              free_moved_vector(apicd);
+       }
+       raw_spin_unlock(&vector_lock);
+ }
+@@ -957,6 +958,7 @@ void irq_complete_move(struct irq_cfg *c
+  */
+ void irq_force_complete_move(struct irq_desc *desc)
+ {
++      unsigned int cpu = smp_processor_id();
+       struct apic_chip_data *apicd;
+       struct irq_data *irqd;
+       unsigned int vector;
+@@ -981,10 +983,11 @@ void irq_force_complete_move(struct irq_
+               goto unlock;
+ 
+       /*
+-       * If prev_vector is empty, no action required.
++       * If prev_vector is empty or the descriptor is neither currently
++       * nor previously on the outgoing CPU no action required.
+        */
+       vector = apicd->prev_vector;
+-      if (!vector)
++      if (!vector || (apicd->cpu != cpu && apicd->prev_cpu != cpu))
+               goto unlock;
+ 
+       /*
+--- a/kernel/irq/cpuhotplug.c
++++ b/kernel/irq/cpuhotplug.c
+@@ -70,6 +70,14 @@ static bool migrate_one_irq(struct irq_d
+       }
+ 
+       /*
++       * Complete an eventually pending irq move cleanup. If this
++       * interrupt was moved in hard irq context, then the vectors need
++       * to be cleaned up. It can't wait until this interrupt actually
++       * happens and this CPU was involved.
++       */
++      irq_force_complete_move(desc);
++
++      /*
+        * No move required, if:
+        * - Interrupt is per cpu
+        * - Interrupt is not started
+@@ -88,14 +96,6 @@ static bool migrate_one_irq(struct irq_d
+       }
+ 
+       /*
+-       * Complete an eventually pending irq move cleanup. If this
+-       * interrupt was moved in hard irq context, then the vectors need
+-       * to be cleaned up. It can't wait until this interrupt actually
+-       * happens and this CPU was involved.
+-       */
+-      irq_force_complete_move(desc);
+-
+-      /*
+        * If there is a setaffinity pending, then try to reuse the pending
+        * mask, so the last change of the affinity does not get lost. If
+        * there is no move pending or the pending mask does not contain

diff --git a/queue-5.10/series b/queue-5.10/series
index 5bb63ec0c9e300565c0d1a0d2b44996b5c04fd42..eeb333c01420b1b8175e3e6e0fd97e32ca938019 100644 (file)
--- a/queue-5.10/series
+++ b/queue-5.10/series
@@ -263,3 +263,4 @@ powerpc-uaccess-use-asm-goto-for-get_user-when-compi.patch
 powerpc-uaccess-use-yz-asm-constraint-for-ld.patch
 hwmon-shtc1-fix-property-misspelling.patch
 alsa-timer-set-lower-bound-of-start-tick-time.patch
+genirq-cpuhotplug-x86-vector-prevent-vector-leak-during-cpu-offline.patch