build: Add option KERNEL_KASAN

[openwrt/staging/chunkeey.git] / config / Config-kernel.in

diff --git a/config/Config-kernel.in b/config/Config-kernel.in
index e8bcf1970fd31cb375f370651918acaca66bc30d..ed75dd585355abfb07da5970ef7aeda2fa764265 100644 (file)
--- a/config/Config-kernel.in
+++ b/config/Config-kernel.in
@@ -120,6 +120,58 @@ config KERNEL_UBSAN_NULL
          This option enables detection of memory accesses via a
          null pointer.
 
+config KERNEL_KASAN
+       bool "Compile the kernel with KASan: runtime memory debugger"
+       select KERNEL_SLUB_DEBUG
+       depends on (x86_64 || aarch64)
+       help
+         Enables kernel address sanitizer - runtime memory debugger,
+         designed to find out-of-bounds accesses and use-after-free bugs.
+         This is strictly a debugging feature and it requires a gcc version
+         of 4.9.2 or later. Detection of out of bounds accesses to stack or
+         global variables requires gcc 5.0 or later.
+         This feature consumes about 1/8 of available memory and brings about
+         ~x3 performance slowdown.
+         For better error detection enable CONFIG_STACKTRACE.
+         Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB
+         (the resulting kernel does not boot).
+
+config KERNEL_KASAN_EXTRA
+       bool "KAsan: extra checks"
+       depends on KERNEL_KASAN && KERNEL_DEBUG_KERNEL
+       help
+         This enables further checks in the kernel address sanitizer, for now
+         it only includes the address-use-after-scope check that can lead
+         to excessive kernel stack usage, frame size warnings and longer
+         compile time.
+         https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 has more
+
+
+choice
+       prompt "Instrumentation type"
+       depends on KERNEL_KASAN
+       default KERNEL_KASAN_OUTLINE
+
+config KERNEL_KASAN_OUTLINE
+       bool "Outline instrumentation"
+       help
+         Before every memory access compiler insert function call
+         __asan_load*/__asan_store*. These functions performs check
+         of shadow memory. This is slower than inline instrumentation,
+         however it doesn't bloat size of kernel's .text section so
+         much as inline does.
+
+config KERNEL_KASAN_INLINE
+       bool "Inline instrumentation"
+       help
+         Compiler directly inserts code checking shadow memory before
+         memory accesses. This is faster than outline (in some workloads
+         it gives about x2 boost over outline instrumentation), but
+         make kernel's .text size much bigger.
+         This requires a gcc version of 5.0 or later.
+
+endchoice
+
 config KERNEL_TASKSTATS
        bool "Compile the kernel with task resource/io statistics and accounting"
        default n