The following commit has been merged into the x86/entry branch of tip: Commit-ID: 20a6e35a948284b8ab246ed35eefc56d674ad076 Gitweb: https://git.kernel.org/tip/20a6e35a948284b8ab246ed35eefc56d674ad076 Author: Peter Zijlstra <[email protected]> AuthorDate: Wed, 02 Sep 2020 15:25:53 +02:00 Committer: Thomas Gleixner <[email protected]> CommitterDate: Fri, 04 Sep 2020 15:12:52 +02:00
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) <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Daniel Thompson <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lore.kernel.org/r/[email protected] --- arch/x86/include/asm/kprobes.h | 4 ++++ arch/x86/kernel/traps.c | 10 ++++------ 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/kprobes.h b/arch/x86/include/asm/kprobes.h index 143bc9a..991a7ad 100644 --- a/arch/x86/include/asm/kprobes.h +++ b/arch/x86/include/asm/kprobes.h @@ -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 */ diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 9945642..9cb39d3 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -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);
