Adding debian version 5.10.209-2.debian/5.10.209-2debian

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 61 insertions, 0 deletions

diff --git a/debian/patches-rt/0030-highmem-Make-DEBUG_HIGHMEM-functional.patch b/debian/patches-rt/0030-highmem-Make-DEBUG_HIGHMEM-functional.patch
new file mode 100644
index 000000000..139157832
--- /dev/null
+++ b/debian/patches-rt/0030-highmem-Make-DEBUG_HIGHMEM-functional.patch
@@ -0,0 +1,61 @@
+From 4c9348bc5b225c2de1552b059787335345d30d2c Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Tue, 3 Nov 2020 10:27:19 +0100
+Subject: [PATCH 030/323] highmem: Make DEBUG_HIGHMEM functional
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz
+
+For some obscure reason when CONFIG_DEBUG_HIGHMEM is enabled the stack
+depth is increased from 20 to 41. But the only thing DEBUG_HIGHMEM does is
+to enable a few BUG_ON()'s in the mapping code.
+
+That's a leftover from the historical mapping code which had fixed entries
+for various purposes. DEBUG_HIGHMEM inserted guard mappings between the map
+types. But that got all ditched when kmap_atomic() switched to a stack
+based map management. Though the WITH_KM_FENCE magic survived without being
+functional. All the thing does today is to increase the stack depth.
+
+Add a working implementation to the generic kmap_local* implementation.
+
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ mm/highmem.c | 14 ++++++++++++--
+ 1 file changed, 12 insertions(+), 2 deletions(-)
+
+diff --git a/mm/highmem.c b/mm/highmem.c
+index bb4ce13ee7e7..67d2d5983cb0 100644
+--- a/mm/highmem.c
++++ b/mm/highmem.c
+@@ -376,9 +376,19 @@ EXPORT_SYMBOL(kunmap_high);
+ 
+ static DEFINE_PER_CPU(int, __kmap_local_idx);
+ 
++/*
++ * With DEBUG_HIGHMEM the stack depth is doubled and every second
++ * slot is unused which acts as a guard page
++ */
++#ifdef CONFIG_DEBUG_HIGHMEM
++# define KM_INCR	2
++#else
++# define KM_INCR	1
++#endif
++
+ static inline int kmap_local_idx_push(void)
+ {
+-	int idx = __this_cpu_inc_return(__kmap_local_idx) - 1;
++	int idx = __this_cpu_add_return(__kmap_local_idx, KM_INCR) - 1;
+ 
+ 	WARN_ON_ONCE(in_irq() && !irqs_disabled());
+ 	BUG_ON(idx >= KM_MAX_IDX);
+@@ -392,7 +402,7 @@ static inline int kmap_local_idx(void)
+ 
+ static inline void kmap_local_idx_pop(void)
+ {
+-	int idx = __this_cpu_dec_return(__kmap_local_idx);
++	int idx = __this_cpu_sub_return(__kmap_local_idx, KM_INCR);
+ 
+ 	BUG_ON(idx < 0);
+ }
+-- 
+2.43.0
+