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Commit d1185a8c authored by Kees Cook's avatar Kees Cook
Browse files

Merge branch 'merge/randstruct' into for-next/gcc-plugins

parents 6f7da290 03232e0d

Documentation/dontdiff

+2 −0
Original line number Diff line number Diff line
@@ -207,6 +207,8 @@ r200_reg_safe.h 
r300_reg_safe.h

r420_reg_safe.h

r600_reg_safe.h

randomize_layout_hash.h

randomize_layout_seed.h

recordmcount

relocs

rlim_names.h

arch/Kconfig

+40 −1
Original line number Diff line number Diff line
@@ -425,7 +425,7 @@ config GCC_PLUGIN_STRUCTLEAK 
	bool "Force initialization of variables containing userspace addresses"

	depends on GCC_PLUGINS

	help

	  This plugin zero-initializes any structures that containing a

	  This plugin zero-initializes any structures containing a

	  __user attribute. This can prevent some classes of information

	  exposures.
@@ -443,6 +443,45 @@ config GCC_PLUGIN_STRUCTLEAK_VERBOSE 
	  initialized. Since not all existing initializers are detected

	  by the plugin, this can produce false positive warnings.



config GCC_PLUGIN_RANDSTRUCT

	bool "Randomize layout of sensitive kernel structures"

	depends on GCC_PLUGINS

	select MODVERSIONS if MODULES

	help

	  If you say Y here, the layouts of structures explicitly

	  marked by __randomize_layout will be randomized at

	  compile-time.  This can introduce the requirement of an

	  additional information exposure vulnerability for exploits

	  targeting these structure types.



	  Enabling this feature will introduce some performance impact,

	  slightly increase memory usage, and prevent the use of forensic

	  tools like Volatility against the system (unless the kernel

	  source tree isn't cleaned after kernel installation).



	  The seed used for compilation is located at

	  scripts/gcc-plgins/randomize_layout_seed.h.  It remains after

	  a make clean to allow for external modules to be compiled with

	  the existing seed and will be removed by a make mrproper or

	  make distclean.



	  Note that the implementation requires gcc 4.7 or newer.



	  This plugin was ported from grsecurity/PaX. More information at:

	   * https://grsecurity.net/

	   * https://pax.grsecurity.net/



config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE

	bool "Use cacheline-aware structure randomization"

	depends on GCC_PLUGIN_RANDSTRUCT

	depends on !COMPILE_TEST

	help

	  If you say Y here, the RANDSTRUCT randomization will make a

	  best effort at restricting randomization to cacheline-sized

	  groups of elements.  It will further not randomize bitfields

	  in structures.  This reduces the performance hit of RANDSTRUCT

	  at the cost of weakened randomization.



config HAVE_CC_STACKPROTECTOR

	bool

	help

arch/arm/include/asm/assembler.h

+2 −0
Original line number Diff line number Diff line
@@ -87,6 +87,8 @@ 
#define CALGN(code...)

#endif



#define IMM12_MASK 0xfff



/*

 * Enable and disable interrupts

 */

arch/arm/kernel/entry-armv.S

+4 −1
Original line number Diff line number Diff line
@@ -797,7 +797,10 @@ ENTRY(__switch_to) 
#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)

	ldr	r7, [r2, #TI_TASK]

	ldr	r8, =__stack_chk_guard

	ldr	r7, [r7, #TSK_STACK_CANARY]

	.if (TSK_STACK_CANARY > IMM12_MASK)

	add	r7, r7, #TSK_STACK_CANARY & ~IMM12_MASK

	.endif

	ldr	r7, [r7, #TSK_STACK_CANARY & IMM12_MASK]

#endif

#ifdef CONFIG_CPU_USE_DOMAINS

	mcr	p15, 0, r6, c3, c0, 0		@ Set domain register

arch/arm/mm/proc-macros.S

+4 −6
Original line number Diff line number Diff line
@@ -25,11 +25,6 @@ 
	ldr	\rd, [\rn, #VMA_VM_FLAGS]

	.endm



	.macro	tsk_mm, rd, rn

	ldr	\rd, [\rn, #TI_TASK]

	ldr	\rd, [\rd, #TSK_ACTIVE_MM]

	.endm



/*

 * act_mm - get current->active_mm

 */
@@ -37,7 +32,10 @@ 
	bic	\rd, sp, #8128

	bic	\rd, \rd, #63

	ldr	\rd, [\rd, #TI_TASK]

	ldr	\rd, [\rd, #TSK_ACTIVE_MM]

	.if (TSK_ACTIVE_MM > IMM12_MASK)

	add	\rd, \rd, #TSK_ACTIVE_MM & ~IMM12_MASK

	.endif

	ldr	\rd, [\rd, #TSK_ACTIVE_MM & IMM12_MASK]

	.endm



/*