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Commit 2efb75cd authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Ingo Molnar
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arm64/kprobes: Remove jprobe implementation 



Remove arch dependent setjump/longjump functions
and unused fields in kprobe_ctlblk for jprobes
from arch/arm64.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
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
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/lkml/152942442318.15209.17767976282305601884.stgit@devbox


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 454f3e13

arch/arm64/include/asm/kprobes.h

+0 −1
Original line number Diff line number Diff line
@@ -48,7 +48,6 @@ struct kprobe_ctlblk { 
	unsigned long saved_irqflag;

	struct prev_kprobe prev_kprobe;

	struct kprobe_step_ctx ss_ctx;

	struct pt_regs jprobe_saved_regs;

};



void arch_remove_kprobe(struct kprobe *);

arch/arm64/kernel/probes/kprobes.c

+0 −68
Original line number Diff line number Diff line
@@ -465,74 +465,6 @@ kprobe_breakpoint_handler(struct pt_regs *regs, unsigned int esr) 
	return DBG_HOOK_HANDLED;

}



int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)

{

	struct jprobe *jp = container_of(p, struct jprobe, kp);

	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();



	kcb->jprobe_saved_regs = *regs;

	/*

	 * Since we can't be sure where in the stack frame "stacked"

	 * pass-by-value arguments are stored we just don't try to

	 * duplicate any of the stack. Do not use jprobes on functions that

	 * use more than 64 bytes (after padding each to an 8 byte boundary)

	 * of arguments, or pass individual arguments larger than 16 bytes.

	 */



	instruction_pointer_set(regs, (unsigned long) jp->entry);

	preempt_disable();

	pause_graph_tracing();

	return 1;

}



void __kprobes jprobe_return(void)

{

	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();



	/*

	 * Jprobe handler return by entering break exception,

	 * encoded same as kprobe, but with following conditions

	 * -a special PC to identify it from the other kprobes.

	 * -restore stack addr to original saved pt_regs

	 */

	asm volatile("				mov sp, %0	\n"

		     "jprobe_return_break:	brk %1		\n"

		     :

		     : "r" (kcb->jprobe_saved_regs.sp),

		       "I" (BRK64_ESR_KPROBES)

		     : "memory");



	unreachable();

}



int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)

{

	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();

	long stack_addr = kcb->jprobe_saved_regs.sp;

	long orig_sp = kernel_stack_pointer(regs);

	struct jprobe *jp = container_of(p, struct jprobe, kp);

	extern const char jprobe_return_break[];



	if (instruction_pointer(regs) != (u64) jprobe_return_break)

		return 0;



	if (orig_sp != stack_addr) {

		struct pt_regs *saved_regs =

		    (struct pt_regs *)kcb->jprobe_saved_regs.sp;

		pr_err("current sp %lx does not match saved sp %lx\n",

		       orig_sp, stack_addr);

		pr_err("Saved registers for jprobe %p\n", jp);

		__show_regs(saved_regs);

		pr_err("Current registers\n");

		__show_regs(regs);

		BUG();

	}

	unpause_graph_tracing();

	*regs = kcb->jprobe_saved_regs;

	preempt_enable_no_resched();

	return 1;

}



bool arch_within_kprobe_blacklist(unsigned long addr)

{

	if ((addr >= (unsigned long)__kprobes_text_start &&