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Commit e704e34c authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Ingo Molnar
Browse files

kprobes/x86: Don't call the ->break_handler() in x86 kprobes 



Don't call the ->break_handler() and remove break_handler
related code from x86 since that was only used by jprobe
which got removed.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/lkml/152942465549.15209.15889693025972771135.stgit@devbox


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 059053a2

arch/x86/include/asm/kprobes.h

+1 −1
Original line number Diff line number Diff line
@@ -78,7 +78,7 @@ struct arch_specific_insn { 
	 * boostable = true: This instruction has been boosted: we have

	 * added a relative jump after the instruction copy in insn,

	 * so no single-step and fixup are needed (unless there's

	 * a post_handler or break_handler).

	 * a post_handler).

	 */

	bool boostable;

	bool if_modifier;

arch/x86/kernel/kprobes/common.h

+0 −10
Original line number Diff line number Diff line
@@ -105,14 +105,4 @@ static inline unsigned long __recover_optprobed_insn(kprobe_opcode_t *buf, unsig 
}

#endif



#ifdef CONFIG_KPROBES_ON_FTRACE

extern int skip_singlestep(struct kprobe *p, struct pt_regs *regs,

			   struct kprobe_ctlblk *kcb);

#else

static inline int skip_singlestep(struct kprobe *p, struct pt_regs *regs,

				  struct kprobe_ctlblk *kcb)

{

	return 0;

}

#endif

#endif

arch/x86/kernel/kprobes/core.c

+0 −7
Original line number Diff line number Diff line
@@ -709,13 +709,6 @@ int kprobe_int3_handler(struct pt_regs *regs) 
		regs->ip = (unsigned long)addr;

		preempt_enable_no_resched();

		return 1;

	} else if (kprobe_running()) {

		p = __this_cpu_read(current_kprobe);

		if (p->break_handler && p->break_handler(p, regs)) {

			if (!skip_singlestep(p, regs, kcb))

				setup_singlestep(p, regs, kcb, 0);

			return 1;

		}

	} /* else: not a kprobe fault; let the kernel handle it */



	preempt_enable_no_resched();

arch/x86/kernel/kprobes/ftrace.c

+11 −31
Original line number Diff line number Diff line
@@ -25,36 +25,6 @@ 


#include "common.h"



static nokprobe_inline

void __skip_singlestep(struct kprobe *p, struct pt_regs *regs,

		      struct kprobe_ctlblk *kcb, unsigned long orig_ip)

{

	/*

	 * Emulate singlestep (and also recover regs->ip)

	 * as if there is a 5byte nop

	 */

	regs->ip = (unsigned long)p->addr + MCOUNT_INSN_SIZE;

	if (unlikely(p->post_handler)) {

		kcb->kprobe_status = KPROBE_HIT_SSDONE;

		p->post_handler(p, regs, 0);

	}

	__this_cpu_write(current_kprobe, NULL);

	if (orig_ip)

		regs->ip = orig_ip;

}



int skip_singlestep(struct kprobe *p, struct pt_regs *regs,

		    struct kprobe_ctlblk *kcb)

{

	if (kprobe_ftrace(p)) {

		__skip_singlestep(p, regs, kcb, 0);

		preempt_enable_no_resched();

		return 1;

	}

	return 0;

}

NOKPROBE_SYMBOL(skip_singlestep);



/* Ftrace callback handler for kprobes -- called under preepmt disabed */

void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,

			   struct ftrace_ops *ops, struct pt_regs *regs)
@@ -80,7 +50,17 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, 
		__this_cpu_write(current_kprobe, p);

		kcb->kprobe_status = KPROBE_HIT_ACTIVE;

		if (!p->pre_handler || !p->pre_handler(p, regs)) {

			__skip_singlestep(p, regs, kcb, orig_ip);

			/*

			 * Emulate singlestep (and also recover regs->ip)

			 * as if there is a 5byte nop

			 */

			regs->ip = (unsigned long)p->addr + MCOUNT_INSN_SIZE;

			if (unlikely(p->post_handler)) {

				kcb->kprobe_status = KPROBE_HIT_SSDONE;

				p->post_handler(p, regs, 0);

			}

			regs->ip = orig_ip;

			__this_cpu_write(current_kprobe, NULL);

			preempt_enable_no_resched();

		}

		/*