x86: add debug of invalid per_cpu map accesses
Provide a means to trap usages of per_cpu map variables before
they are setup. Define CONFIG_DEBUG_PER_CPU_MAPS to activate.
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 88420af..0a82b88 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -47,6 +47,18 @@
This results in a large slowdown, but helps to find certain types
of memory corruptions.
+config DEBUG_PER_CPU_MAPS
+ bool "Debug access to per_cpu maps"
+ depends on DEBUG_KERNEL
+ depends on X86_64_SMP
+ default n
+ help
+ Say Y to verify that the per_cpu map being accessed has
+ been setup. Adds a fair amount of code to kernel memory
+ and decreases performance.
+
+ Say N if unsure.
+
config DEBUG_RODATA
bool "Write protect kernel read-only data structures"
depends on DEBUG_KERNEL