https://github.com/torvalds/linux
Revision 04e36857d6747e4525e68c4292c081b795b48366 authored by Linus Torvalds on 19 November 2016, 00:45:21 UTC, committed by Linus Torvalds on 19 November 2016, 00:45:21 UTC
Pull kbuild fixes from Michal Marek:
 "Here are some regression fixes for kbuild:

   - modversion support for exported asm symbols (Nick Piggin). The
     affected architectures need separate patches adding
     asm-prototypes.h.

   - fix rebuilds of lib-ksyms.o (Nick Piggin)

   - -fno-PIE builds (Sebastian Siewior and Borislav Petkov). This is
     not a kernel regression, but one of the Debian gcc package.
     Nevertheless, it's quite annoying, so I think it should go into
     mainline and stable now"

* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: Steal gcc's pie from the very beginning
  kbuild: be more careful about matching preprocessed asm ___EXPORT_SYMBOL
  x86/kexec: add -fno-PIE
  scripts/has-stack-protector: add -fno-PIE
  kbuild: add -fno-PIE
  kbuild: modversions for EXPORT_SYMBOL() for asm
  kbuild: prevent lib-ksyms.o rebuilds
2 parent s aad931a + c6a3855
Raw File
Tip revision: 04e36857d6747e4525e68c4292c081b795b48366 authored by Linus Torvalds on 19 November 2016, 00:45:21 UTC
Merge branch 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Tip revision: 04e3685
Kconfig.kasan
config HAVE_ARCH_KASAN
	bool

if HAVE_ARCH_KASAN

config KASAN
	bool "KASan: runtime memory debugger"
	depends on SLUB || (SLAB && !DEBUG_SLAB)
	select CONSTRUCTORS
	select STACKDEPOT
	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).

choice
	prompt "Instrumentation type"
	depends on KASAN
	default KASAN_OUTLINE

config 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 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 TEST_KASAN
	tristate "Module for testing kasan for bug detection"
	depends on m && KASAN
	help
	  This is a test module doing various nasty things like
	  out of bounds accesses, use after free. It is useful for testing
	  kernel debugging features like kernel address sanitizer.

endif
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