Commit 92652cf9 authored by Kees Cook's avatar Kees Cook
Browse files

xtensa: Implement "current_stack_pointer" 



To follow the existing per-arch conventions replace open-coded uses
of asm "sp" as "current_stack_pointer". This will let it be used in
non-arch places (like HARDENED_USERCOPY).

Cc: Chris Zankel <chris@zankel.net>
Cc: Marc Zyngier <maz@kernel.org>
Cc: linux-xtensa@linux-xtensa.org
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
Link: https://lore.kernel.org/lkml/CAMo8BfJFJE-n3=AF+pb9_6oF3gzxX7a+7aBrASHjjNX5byqDqw@mail.gmail.com
parent 2792d84e

arch/xtensa/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ config XTENSA 
	def_bool y

	select ARCH_32BIT_OFF_T

	select ARCH_HAS_BINFMT_FLAT if !MMU

	select ARCH_HAS_CURRENT_STACK_POINTER

	select ARCH_HAS_DMA_PREP_COHERENT if MMU

	select ARCH_HAS_SYNC_DMA_FOR_CPU if MMU

	select ARCH_HAS_SYNC_DMA_FOR_DEVICE if MMU

arch/xtensa/include/asm/current.h

+2 −0
Original line number Diff line number Diff line
@@ -26,6 +26,8 @@ static inline struct task_struct *get_current(void) 


#define current get_current()



register unsigned long current_stack_pointer __asm__("a1");



#else



#define GET_CURRENT(reg,sp)		\

arch/xtensa/include/asm/stacktrace.h

+4 −4
Original line number Diff line number Diff line
@@ -19,14 +19,14 @@ struct stackframe { 


static __always_inline unsigned long *stack_pointer(struct task_struct *task)

{

	unsigned long *sp;

	unsigned long sp;



	if (!task || task == current)

		__asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp));

		sp = current_stack_pointer;

	else

		sp = (unsigned long *)task->thread.sp;

		sp = task->thread.sp;



	return sp;

	return (unsigned long *)sp;

}



void walk_stackframe(unsigned long *sp,

arch/xtensa/kernel/irq.c

+1 −2
Original line number Diff line number Diff line
@@ -36,9 +36,8 @@ asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs) 
#ifdef CONFIG_DEBUG_STACKOVERFLOW

	/* Debugging check for stack overflow: is there less than 1KB free? */

	{

		unsigned long sp;

		unsigned long sp = current_stack_pointer;



		__asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp));

		sp &= THREAD_SIZE - 1;



		if (unlikely(sp < (sizeof(thread_info) + 1024)))