Commit 33e53ae1 authored by Guo Ren's avatar Guo Ren
Browse files

csky: Add kprobes supported 



This patch enable kprobes, kretprobes, ftrace interface. It utilized
software breakpoint and single step debug exceptions, instructions
simulation on csky.

We use USR_BKPT replace origin instruction, and the kprobe handler
prepares an excutable memory slot for out-of-line execution with a
copy of the original instruction being probed. Most of instructions
could be executed by single-step, but some instructions need origin
pc value to execute and we need software simulate these instructions.

Signed-off-by: default avatarGuo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
parent 000591f1

arch/csky/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -46,6 +46,9 @@ config CSKY 
	select HAVE_KERNEL_GZIP

	select HAVE_KERNEL_LZO

	select HAVE_KERNEL_LZMA

	select HAVE_KPROBES if !CPU_CK610

	select HAVE_KPROBES_ON_FTRACE if !CPU_CK610

	select HAVE_KRETPROBES if !CPU_CK610

	select HAVE_PERF_EVENTS

	select HAVE_PERF_REGS

	select HAVE_PERF_USER_STACK_DUMP

arch/csky/include/asm/Kbuild

+0 −1
Original line number Diff line number Diff line
@@ -20,7 +20,6 @@ generic-y += irq_regs.h 
generic-y += irq_work.h

generic-y += kdebug.h

generic-y += kmap_types.h

generic-y += kprobes.h

generic-y += kvm_para.h

generic-y += linkage.h

generic-y += local.h

arch/csky/include/asm/kprobes.h

0 → 100644
+48 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */



#ifndef __ASM_CSKY_KPROBES_H

#define __ASM_CSKY_KPROBES_H



#include <asm-generic/kprobes.h>



#ifdef CONFIG_KPROBES

#include <linux/types.h>

#include <linux/ptrace.h>

#include <linux/percpu.h>



#define __ARCH_WANT_KPROBES_INSN_SLOT

#define MAX_INSN_SIZE			1



#define flush_insn_slot(p)		do { } while (0)

#define kretprobe_blacklist_size	0



#include <asm/probes.h>



struct prev_kprobe {

	struct kprobe *kp;

	unsigned int status;

};



/* Single step context for kprobe */

struct kprobe_step_ctx {

	unsigned long ss_pending;

	unsigned long match_addr;

};



/* per-cpu kprobe control block */

struct kprobe_ctlblk {

	unsigned int kprobe_status;

	unsigned long saved_sr;

	struct prev_kprobe prev_kprobe;

	struct kprobe_step_ctx ss_ctx;

};



void arch_remove_kprobe(struct kprobe *p);

int kprobe_fault_handler(struct pt_regs *regs, unsigned int trapnr);

int kprobe_breakpoint_handler(struct pt_regs *regs);

int kprobe_single_step_handler(struct pt_regs *regs);

void kretprobe_trampoline(void);

void __kprobes *trampoline_probe_handler(struct pt_regs *regs);



#endif /* CONFIG_KPROBES */

#endif /* __ASM_CSKY_KPROBES_H */

arch/csky/include/asm/probes.h

0 → 100644
+24 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */



#ifndef __ASM_CSKY_PROBES_H

#define __ASM_CSKY_PROBES_H



typedef u32 probe_opcode_t;

typedef void (probes_handler_t) (u32 opcode, long addr, struct pt_regs *);



/* architecture specific copy of original instruction */

struct arch_probe_insn {

	probe_opcode_t *insn;

	probes_handler_t *handler;

	/* restore address after simulation */

	unsigned long restore;

};



#ifdef CONFIG_KPROBES

typedef u32 kprobe_opcode_t;

struct arch_specific_insn {

	struct arch_probe_insn api;

};

#endif



#endif /* __ASM_CSKY_PROBES_H */

arch/csky/include/asm/ptrace.h

+2 −0
Original line number Diff line number Diff line
@@ -13,6 +13,8 @@ 


#define PS_S	0x80000000 /* Supervisor Mode */



#define USR_BKPT	0x1464



#define arch_has_single_step() (1)

#define current_pt_regs() \

({ (struct pt_regs *)((char *)current_thread_info() + THREAD_SIZE) - 1; })