Commit 2bc2f688 authored by Kees Cook's avatar Kees Cook Committed by Linus Torvalds
Browse files

Makefile: move stack-protector availability out of Kconfig 

Various portions of the kernel, especially per-architecture pieces,
need to know if the compiler is building with the stack protector.
This was done in the arch/Kconfig with 'select', but this doesn't
allow a way to do auto-detected compiler support. In preparation for
creating an on-if-available default, move the logic for the definition of
CONFIG_CC_STACKPROTECTOR into the Makefile.

Link: http://lkml.kernel.org/r/1510076320-69931-3-git-send-email-keescook@chromium.org


Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Tested-by: default avatarLaura Abbott <labbott@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2b838392

Makefile

+5 −1
Original line number Diff line number Diff line
@@ -693,7 +693,7 @@ else 
endif

endif

# Find arch-specific stack protector compiler sanity-checking script.

ifdef CONFIG_CC_STACKPROTECTOR

ifdef stackp-name

  stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh

  stackp-check := $(wildcard $(stackp-path))

  # If the wildcard test matches a test script, run it to check functionality.
@@ -702,6 +702,10 @@ ifdef CONFIG_CC_STACKPROTECTOR 
      stackp-broken := y

    endif

  endif

  ifndef stackp-broken

    # If the stack protector is functional, enable code that depends on it.

    KBUILD_CPPFLAGS += -DCONFIG_CC_STACKPROTECTOR

  endif

endif

KBUILD_CFLAGS += $(stackp-flag)

arch/Kconfig

+0 −8
Original line number Diff line number Diff line
@@ -538,12 +538,6 @@ config HAVE_CC_STACKPROTECTOR 
	  - its compiler supports the -fstack-protector option

	  - it has implemented a stack canary (e.g. __stack_chk_guard)



config CC_STACKPROTECTOR

	def_bool n

	help

	  Set when a stack-protector mode is enabled, so that the build

	  can enable kernel-side support for the GCC feature.



choice

	prompt "Stack Protector buffer overflow detection"

	depends on HAVE_CC_STACKPROTECTOR
@@ -564,7 +558,6 @@ config CC_STACKPROTECTOR_NONE 


config CC_STACKPROTECTOR_REGULAR

	bool "Regular"

	select CC_STACKPROTECTOR

	help

	  Functions will have the stack-protector canary logic added if they

	  have an 8-byte or larger character array on the stack.
@@ -578,7 +571,6 @@ config CC_STACKPROTECTOR_REGULAR 


config CC_STACKPROTECTOR_STRONG

	bool "Strong"

	select CC_STACKPROTECTOR

	help

	  Functions will have the stack-protector canary logic added in any

	  of the following conditions:

arch/x86/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -322,7 +322,7 @@ config X86_64_SMP 


config X86_32_LAZY_GS

	def_bool y

	depends on X86_32 && !CC_STACKPROTECTOR

	depends on X86_32 && CC_STACKPROTECTOR_NONE



config ARCH_SUPPORTS_UPROBES

	def_bool y

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