From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Mon, 8 May 2023 08:10:12 +0000 (+0200)
Subject: 4.19-stable patches
X-Git-Tag: v5.15.111~35
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a39ed93cec0ca3bb1b0a5af3efb5bd2b3256e6b6;p=thirdparty%2Fkernel%2Fstable-queue.git

4.19-stable patches

added patches:
	debugobject-ensure-pool-refill-again.patch
---

diff --git a/queue-4.19/debugobject-ensure-pool-refill-again.patch b/queue-4.19/debugobject-ensure-pool-refill-again.patch
new file mode 100644
index 00000000000..866e2dd710b
--- /dev/null
+++ b/queue-4.19/debugobject-ensure-pool-refill-again.patch
@@ -0,0 +1,80 @@
+From 0af462f19e635ad522f28981238334620881badc Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Mon, 1 May 2023 17:42:06 +0200
+Subject: debugobject: Ensure pool refill (again)
+
+From: Thomas Gleixner <tglx@linutronix.de>
+
+commit 0af462f19e635ad522f28981238334620881badc upstream.
+
+The recent fix to ensure atomicity of lookup and allocation inadvertently
+broke the pool refill mechanism.
+
+Prior to that change debug_objects_activate() and debug_objecs_assert_init()
+invoked debug_objecs_init() to set up the tracking object for statically
+initialized objects. That's not longer the case and debug_objecs_init() is
+now the only place which does pool refills.
+
+Depending on the number of statically initialized objects this can be
+enough to actually deplete the pool, which was observed by Ido via a
+debugobjects OOM warning.
+
+Restore the old behaviour by adding explicit refill opportunities to
+debug_objects_activate() and debug_objecs_assert_init().
+
+Fixes: 63a759694eed ("debugobject: Prevent init race with static objects")
+Reported-by: Ido Schimmel <idosch@nvidia.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Tested-by: Ido Schimmel <idosch@nvidia.com>
+Link: https://lore.kernel.org/r/871qk05a9d.ffs@tglx
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ lib/debugobjects.c |   16 +++++++++++++++-
+ 1 file changed, 15 insertions(+), 1 deletion(-)
+
+--- a/lib/debugobjects.c
++++ b/lib/debugobjects.c
+@@ -460,6 +460,16 @@ static struct debug_obj *lookup_object_o
+ 	return NULL;
+ }
+ 
++static void debug_objects_fill_pool(void)
++{
++	/*
++	 * On RT enabled kernels the pool refill must happen in preemptible
++	 * context:
++	 */
++	if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible())
++		fill_pool();
++}
++
+ static void
+ __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
+ {
+@@ -468,7 +478,7 @@ __debug_object_init(void *addr, struct d
+ 	struct debug_obj *obj;
+ 	unsigned long flags;
+ 
+-	fill_pool();
++	debug_objects_fill_pool();
+ 
+ 	db = get_bucket((unsigned long) addr);
+ 
+@@ -553,6 +563,8 @@ int debug_object_activate(void *addr, st
+ 	if (!debug_objects_enabled)
+ 		return 0;
+ 
++	debug_objects_fill_pool();
++
+ 	db = get_bucket((unsigned long) addr);
+ 
+ 	raw_spin_lock_irqsave(&db->lock, flags);
+@@ -762,6 +774,8 @@ void debug_object_assert_init(void *addr
+ 	if (!debug_objects_enabled)
+ 		return;
+ 
++	debug_objects_fill_pool();
++
+ 	db = get_bucket((unsigned long) addr);
+ 
+ 	raw_spin_lock_irqsave(&db->lock, flags);
diff --git a/queue-4.19/series b/queue-4.19/series
index c20426392df..7fc16360b13 100644
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -135,3 +135,4 @@ dm-integrity-call-kmem_cache_destroy-in-dm_integrity_init-error-path.patch
 dm-flakey-fix-a-crash-with-invalid-table-line.patch
 dm-ioctl-fix-nested-locking-in-table_clear-to-remove-deadlock-concern.patch
 perf-auxtrace-fix-address-filter-entire-kernel-size.patch
+debugobject-ensure-pool-refill-again.patch