Commit bf3a9125 authored by Naveen N. Rao's avatar Naveen N. Rao Committed by Michael Ellerman
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powerpc/kprobes: Clean up jprobe detection in livepatch handler 



In commit c05b8c44 ("powerpc/kprobes: Skip livepatch_handler() for
jprobes"), we added a helper is_current_kprobe_addr() to help detect if
the modified regs->nip was due to a jprobe or livepatch. Masami felt
that the function name was not quite clear. To that end, this patch
renames is_current_kprobe_addr() to __is_active_jprobe() and adds a
comment to (hopefully) better clarify the purpose of this helper. The
helper has also now been moved to kprobes-ftrace.c so that it is only
available for KPROBES_ON_FTRACE.

Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent a7b44038

arch/powerpc/include/asm/kprobes.h

+1 −1
Original line number Diff line number Diff line
@@ -103,8 +103,8 @@ extern int kprobe_exceptions_notify(struct notifier_block *self, 
extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);

extern int kprobe_handler(struct pt_regs *regs);

extern int kprobe_post_handler(struct pt_regs *regs);

extern int is_current_kprobe_addr(unsigned long addr);

#ifdef CONFIG_KPROBES_ON_FTRACE

extern int __is_active_jprobe(unsigned long addr);

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

			   struct kprobe_ctlblk *kcb);

#else

arch/powerpc/kernel/kprobes-ftrace.c

+11 −0
Original line number Diff line number Diff line
@@ -25,6 +25,17 @@ 
#include <linux/preempt.h>

#include <linux/ftrace.h>



/*

 * This is called from ftrace code after invoking registered handlers to

 * disambiguate regs->nip changes done by jprobes and livepatch. We check if

 * there is an active jprobe at the provided address (mcount location).

 */

int __is_active_jprobe(unsigned long addr)

{

	struct kprobe *p = kprobe_running();

	return (p && (unsigned long)p->addr == addr) ? 1 : 0;

}



static nokprobe_inline

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

		      struct kprobe_ctlblk *kcb, unsigned long orig_nip)

arch/powerpc/kernel/kprobes.c

+0 −6
Original line number Diff line number Diff line
@@ -43,12 +43,6 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); 


struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}};



int is_current_kprobe_addr(unsigned long addr)

{

	struct kprobe *p = kprobe_running();

	return (p && (unsigned long)p->addr == addr) ? 1 : 0;

}



bool arch_within_kprobe_blacklist(unsigned long addr)

{

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

arch/powerpc/kernel/trace/ftrace_64_mprofile.S

+2 −2
Original line number Diff line number Diff line
@@ -110,9 +110,9 @@ ftrace_call: 
	/* NIP has not been altered, skip over further checks */

	beq	1f



	/* Check if there is an active kprobe on us */

	/* Check if there is an active jprobe on us */

	subi	r3, r14, 4

	bl	is_current_kprobe_addr

	bl	__is_active_jprobe

	nop



	/*

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