77 lines
2.5 KiB
Text
77 lines
2.5 KiB
Text
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config HAVE_ARCH_KASAN
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bool
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if HAVE_ARCH_KASAN
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config KASAN
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bool "KASan: runtime memory debugger"
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depends on SLUB_DEBUG
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select CONSTRUCTORS
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help
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Enables kernel address sanitizer - runtime memory debugger,
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designed to find out-of-bounds accesses and use-after-free bugs.
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This is strictly a debugging feature and it requires a gcc version
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of 4.9.2 or later. Detection of out of bounds accesses to stack or
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global variables requires gcc 5.0 or later.
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This feature consumes about 1/8 of available memory and brings about
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~x3 performance slowdown.
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For better error detection enable CONFIG_STACKTRACE,
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and add slub_debug=U to boot cmdline.
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See KASAN_SANITIZE_ALL for selectively compiling files and directories
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with this compiler feature enabled.
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config KASAN_SHADOW_OFFSET
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hex
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default 0xdffffc0000000000 if X86_64
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choice
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prompt "Instrumentation type"
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depends on KASAN
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default KASAN_OUTLINE
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config KASAN_OUTLINE
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bool "Outline instrumentation"
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help
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Before every memory access compiler insert function call
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__asan_load*/__asan_store*. These functions performs check
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of shadow memory. This is slower than inline instrumentation,
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however it doesn't bloat size of kernel's .text section so
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much as inline does.
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config KASAN_INLINE
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bool "Inline instrumentation"
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help
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Compiler directly inserts code checking shadow memory before
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memory accesses. This is faster than outline (in some workloads
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it gives about x2 boost over outline instrumentation), but
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make kernel's .text size much bigger.
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This requires a gcc version of 5.0 or later.
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endchoice
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config KASAN_SANITIZE_ALL
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bool "KASan: Enable Instrumentation for entire kernel"
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depends on KASAN
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default y
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help
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Enable compilation with $(CFLAGS_KASAN) by default.
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KASAN_SANITIZE := n - exclude all files in a directory
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KASAN_SANITIZE_file_name.o := n - exclude a single file
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Setting KASAN_SANITIZE_ALL to 'n' allows enabling kasan in
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only certain files or directories.
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KASAN_SANITIZE := y - include all files in a directory
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KASAN_SANITIZE_file_name.o := y - include single file
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KASAN_SANITIZE does not affect subdirectories.
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KASAN_SANITIZE_file_name.o has priority over KASAN_SANITIZE.
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config TEST_KASAN
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tristate "Module for testing kasan for bug detection"
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depends on m && KASAN
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help
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This is a test module doing various nasty things like
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out of bounds accesses, use after free. It is useful for testing
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kernel debugging features like kernel address sanitizer.
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endif
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