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Commit 3383642c authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar
Browse files

x86/traps: Use a new on_thread_stack() helper to clean up an assertion 



Let's keep the stack-related logic together rather than open-coding
a comparison in an assertion in the traps code.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/856b15bee1f55017b8f79d3758b0d51c48a08cf8.1509609304.git.luto@kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent d375cf15

arch/x86/include/asm/processor.h

+6 −0
Original line number Diff line number Diff line
@@ -541,6 +541,12 @@ static inline unsigned long current_top_of_stack(void) 
#endif

}



static inline bool on_thread_stack(void)

{

	return (unsigned long)(current_top_of_stack() -

			       current_stack_pointer) < THREAD_SIZE;

}



#ifdef CONFIG_PARAVIRT

#include <asm/paravirt.h>

#else

arch/x86/kernel/traps.c

+1 −2
Original line number Diff line number Diff line
@@ -141,8 +141,7 @@ void ist_begin_non_atomic(struct pt_regs *regs) 
	 * will catch asm bugs and any attempt to use ist_preempt_enable

	 * from double_fault.

	 */

	BUG_ON((unsigned long)(current_top_of_stack() -

			       current_stack_pointer) >= THREAD_SIZE);

	BUG_ON(!on_thread_stack());



	preempt_enable_no_resched();

}