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: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200902133200.847465360@infradead.org
This commit is contained in:
Peter Zijlstra 2020-09-02 15:25:53 +02:00 committed by Thomas Gleixner
parent c182487da1
commit 20a6e35a94
2 changed files with 8 additions and 6 deletions

View file

@ -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 */

View file

@ -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);