LoongArch: Replace kretprobe with rethook

This is an adaptation of commit f3a112c0c4 ("x86,rethook,kprobes:
Replace kretprobe with rethook on x86") and commit b57c2f1240 ("riscv:
add riscv rethook implementation") to LoongArch. Mainly refer to commit
b57c2f1240 ("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: Haoran Jiang <jianghaoran@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Haoran Jiang 2023-06-29 20:58:44 +08:00 committed by Huacai Chen
parent f02644e32c
commit 7b0a096436
7 changed files with 44 additions and 28 deletions

View File

@ -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

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@ -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; }

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@ -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

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@ -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;

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@ -0,0 +1,28 @@
// 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);

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@ -0,0 +1,8 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LOONGARCH_RETHOOK_H
#define __LOONGARCH_RETHOOK_H
unsigned long arch_rethook_trampoline_callback(struct pt_regs *regs);
void arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, bool mcount);
#endif

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@ -75,7 +75,7 @@
csrxchg t0, t1, LOONGARCH_CSR_CRMD
.endm
SYM_CODE_START(__kretprobe_trampoline)
SYM_CODE_START(arch_rethook_trampoline)
addi.d sp, sp, -PT_SIZE
save_all_base_regs
@ -84,7 +84,7 @@ SYM_CODE_START(__kretprobe_trampoline)
move a0, sp /* pt_regs */
bl trampoline_probe_handler
bl arch_rethook_trampoline_callback
/* use the result as the return-address */
move ra, a0
@ -93,4 +93,4 @@ SYM_CODE_START(__kretprobe_trampoline)
addi.d sp, sp, PT_SIZE
jr ra
SYM_CODE_END(__kretprobe_trampoline)
SYM_CODE_END(arch_rethook_trampoline)