Commit 20a6e35a authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Thomas Gleixner
Browse files

x86/debug: Move kprobe_debug_handler() into exc_debug_kernel() 



Kprobes are on kernel text, and thus only matter for #DB-from-kernel.
Kprobes are ordered before the generic notifier, preserve that order.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Acked-by: default avatarAndy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200902133200.847465360@infradead.org
parent c182487d

arch/x86/include/asm/kprobes.h

+4 −0
Original line number Diff line number Diff line
@@ -106,5 +106,9 @@ extern int kprobe_exceptions_notify(struct notifier_block *self, 
extern int kprobe_int3_handler(struct pt_regs *regs);

extern int kprobe_debug_handler(struct pt_regs *regs);



#else



static inline int kprobe_debug_handler(struct pt_regs *regs) { return 0; }



#endif /* CONFIG_KPROBES */

#endif /* _ASM_X86_KPROBES_H */

arch/x86/kernel/traps.c

+4 −6
Original line number Diff line number Diff line
@@ -806,12 +806,6 @@ static void handle_debug(struct pt_regs *regs, unsigned long dr6, bool user) 
	/* Store the virtualized DR6 value */

	tsk->thread.debugreg6 = dr6;



#ifdef CONFIG_KPROBES

	if (kprobe_debug_handler(regs)) {

		return;

	}

#endif



	if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, 0,

		       SIGTRAP) == NOTIFY_STOP) {

		return;
@@ -877,8 +871,12 @@ static __always_inline void exc_debug_kernel(struct pt_regs *regs, 
	if ((dr6 & DR_STEP) && is_sysenter_singlestep(regs))

		dr6 &= ~DR_STEP;



	if (kprobe_debug_handler(regs))

		goto out;



	handle_debug(regs, dr6, false);



out:

	instrumentation_end();

	idtentry_exit_nmi(regs, irq_state);

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