summaryrefslogtreecommitdiff
path: root/lib
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2020-11-18 20:48:40 +0100
committerThomas Gleixner <tglx@linutronix.de>2020-11-24 14:42:08 +0100
commit0e91a0c6984c837a7c6760e3f28e8e1c532abf87 (patch)
treeca90a3abad7717fa27186c38c2ed0c02f93ab7de /lib
parent6e799cb69a70eedbb41561b750f7180c12cff280 (diff)
mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
CONFIG_DEBUG_KMAP_LOCAL, which is selected by CONFIG_DEBUG_HIGHMEM is only providing guard pages, but does not provide a mechanism to enforce the usage of the kmap_local() infrastructure. Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP which forces the temporary mapping even for lowmem pages. This needs to be a seperate config switch because this only works on architectures which do not have cache aliasing problems. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20201118204007.028261233@linutronix.de
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug14
1 files changed, 14 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index f24fa158f9db..e952f892f047 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -856,9 +856,23 @@ config DEBUG_KMAP_LOCAL
This option enables additional error checking for the kmap_local
infrastructure. Disable for production use.
+config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
+ bool
+
+config DEBUG_KMAP_LOCAL_FORCE_MAP
+ bool "Enforce kmap_local temporary mappings"
+ depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
+ select KMAP_LOCAL
+ select DEBUG_KMAP_LOCAL
+ help
+ This option enforces temporary mappings through the kmap_local
+ mechanism for non-highmem pages and on non-highmem systems.
+ Disable this for production systems!
+
config DEBUG_HIGHMEM
bool "Highmem debugging"
depends on DEBUG_KERNEL && HIGHMEM
+ select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
select DEBUG_KMAP_LOCAL
help
This option enables additional error checking for high memory