Commit 7b0a0964 authored by Haoran Jiang's avatar Haoran Jiang Committed by Huacai Chen
Browse files

LoongArch: Replace kretprobe with rethook 



This is an adaptation of commit f3a112c0 ("x86,rethook,kprobes:
Replace kretprobe with rethook on x86") and commit b57c2f12 ("riscv:
add riscv rethook implementation") to LoongArch. Mainly refer to commit
b57c2f12 ("riscv: add riscv rethook implementation").

Replaces the kretprobe code with rethook on LoongArch. With this patch,
kretprobe on LoongArch uses the rethook instead of kretprobe specific
trampoline code.

Signed-off-by: default avatarHaoran Jiang <jianghaoran@kylinos.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent f02644e3

arch/loongarch/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -127,6 +127,7 @@ config LOONGARCH 
	select HAVE_PERF_REGS

	select HAVE_PERF_USER_STACK_DUMP

	select HAVE_REGS_AND_STACK_ACCESS_API

	select HAVE_RETHOOK

	select HAVE_RSEQ

	select HAVE_SAMPLE_FTRACE_DIRECT

	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI

arch/loongarch/include/asm/kprobes.h

+0 −3
Original line number Diff line number Diff line
@@ -49,9 +49,6 @@ bool kprobe_fault_handler(struct pt_regs *regs, int trapnr); 
bool kprobe_breakpoint_handler(struct pt_regs *regs);

bool kprobe_singlestep_handler(struct pt_regs *regs);



void __kretprobe_trampoline(void);

void *trampoline_probe_handler(struct pt_regs *regs);



#else /* !CONFIG_KPROBES */



static inline bool kprobe_breakpoint_handler(struct pt_regs *regs) { return false; }

arch/loongarch/kernel/Makefile

+4 −1
Original line number Diff line number Diff line
@@ -28,6 +28,8 @@ ifdef CONFIG_FUNCTION_TRACER 
  CFLAGS_REMOVE_inst.o = $(CC_FLAGS_FTRACE)

  CFLAGS_REMOVE_time.o = $(CC_FLAGS_FTRACE)

  CFLAGS_REMOVE_perf_event.o = $(CC_FLAGS_FTRACE)

  CFLAGS_REMOVE_rethook.o = $(CC_FLAGS_FTRACE)

  CFLAGS_REMOVE_rethook_trampoline.o = $(CC_FLAGS_FTRACE)

endif



obj-$(CONFIG_MODULES)		+= module.o module-sections.o
@@ -52,7 +54,8 @@ obj-$(CONFIG_UNWINDER_PROLOGUE) += unwind_prologue.o 
obj-$(CONFIG_PERF_EVENTS)	+= perf_event.o perf_regs.o

obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o



obj-$(CONFIG_KPROBES)		+= kprobes.o kprobes_trampoline.o

obj-$(CONFIG_KPROBES)		+= kprobes.o

obj-$(CONFIG_RETHOOK)		+= rethook.o rethook_trampoline.o



obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o

arch/loongarch/kernel/kprobes.c

+0 −21
Original line number Diff line number Diff line
@@ -378,27 +378,6 @@ int __init arch_init_kprobes(void) 
	return 0;

}



/* ASM function that handles the kretprobes must not be probed */

NOKPROBE_SYMBOL(__kretprobe_trampoline);



/* Called from __kretprobe_trampoline */

void __used *trampoline_probe_handler(struct pt_regs *regs)

{

	return (void *)kretprobe_trampoline_handler(regs, NULL);

}

NOKPROBE_SYMBOL(trampoline_probe_handler);



void arch_prepare_kretprobe(struct kretprobe_instance *ri,

			    struct pt_regs *regs)

{

	ri->ret_addr = (kprobe_opcode_t *)regs->regs[1];

	ri->fp = NULL;



	/* Replace the return addr with trampoline addr */

	regs->regs[1] = (unsigned long)&__kretprobe_trampoline;

}

NOKPROBE_SYMBOL(arch_prepare_kretprobe);



int arch_trampoline_kprobe(struct kprobe *p)

{

	return 0;

arch/loongarch/kernel/rethook.c

0 → 100644
+28 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Generic return hook for LoongArch.

 */



#include <linux/kprobes.h>

#include <linux/rethook.h>

#include "rethook.h"



/* This is called from arch_rethook_trampoline() */

unsigned long __used arch_rethook_trampoline_callback(struct pt_regs *regs)

{

	return rethook_trampoline_handler(regs, 0);

}

NOKPROBE_SYMBOL(arch_rethook_trampoline_callback);



void arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, bool mcount)

{

	rhn->frame = 0;

	rhn->ret_addr = regs->regs[1];



	/* replace return addr with trampoline */

	regs->regs[1] = (unsigned long)arch_rethook_trampoline;

}

NOKPROBE_SYMBOL(arch_rethook_prepare);



/* ASM function that handles the rethook must not be probed itself */

NOKPROBE_SYMBOL(arch_rethook_trampoline);