From b57c2f124098459a4acc15d5044f87cba31c87f0 Mon Sep 17 00:00:00 2001 From: Binglei Wang Date: Tue, 25 Oct 2022 16:18:32 +0100 Subject: [PATCH] riscv: add riscv rethook implementation Implement the kretprobes on riscv arch by using rethook machenism which abstracts general kretprobe info into a struct rethook_node to be embedded in the struct kretprobe_instance. Acked-by: Masami Hiramatsu (Google) Signed-off-by: Binglei Wang Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20221025151831.1097417-1-conor@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/kprobes.h | 2 -- arch/riscv/kernel/probes/Makefile | 2 +- arch/riscv/kernel/probes/kprobes.c | 13 --------- arch/riscv/kernel/probes/rethook.c | 27 +++++++++++++++++++ arch/riscv/kernel/probes/rethook.h | 8 ++++++ ...obes_trampoline.S => rethook_trampoline.S} | 6 ++--- 7 files changed, 40 insertions(+), 19 deletions(-) create mode 100644 arch/riscv/kernel/probes/rethook.c create mode 100644 arch/riscv/kernel/probes/rethook.h rename arch/riscv/kernel/probes/{kprobes_trampoline.S => rethook_trampoline.S} (94%) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 8d47562be90c..ef8d66de5f38 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -101,6 +101,7 @@ config RISCV select HAVE_KPROBES if !XIP_KERNEL select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL select HAVE_KRETPROBES if !XIP_KERNEL + select HAVE_RETHOOK if !XIP_KERNEL select HAVE_MOVE_PMD select HAVE_MOVE_PUD select HAVE_PCI diff --git a/arch/riscv/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h index 217ef89f22b9..e7882ccb0fd4 100644 --- a/arch/riscv/include/asm/kprobes.h +++ b/arch/riscv/include/asm/kprobes.h @@ -40,8 +40,6 @@ void arch_remove_kprobe(struct kprobe *p); int kprobe_fault_handler(struct pt_regs *regs, unsigned int trapnr); bool kprobe_breakpoint_handler(struct pt_regs *regs); bool 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_RISCV_KPROBES_H */ diff --git a/arch/riscv/kernel/probes/Makefile b/arch/riscv/kernel/probes/Makefile index 7f0840dcc31b..c40139e9ca47 100644 --- a/arch/riscv/kernel/probes/Makefile +++ b/arch/riscv/kernel/probes/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_KPROBES) += kprobes.o decode-insn.o simulate-insn.o -obj-$(CONFIG_KPROBES) += kprobes_trampoline.o +obj-$(CONFIG_RETHOOK) += rethook.o rethook_trampoline.o obj-$(CONFIG_KPROBES_ON_FTRACE) += ftrace.o obj-$(CONFIG_UPROBES) += uprobes.o decode-insn.o simulate-insn.o CFLAGS_REMOVE_simulate-insn.o = $(CC_FLAGS_FTRACE) diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index e6e950b7cf32..f21592d20306 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -345,19 +345,6 @@ int __init arch_populate_kprobe_blacklist(void) return ret; } -void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) -{ - return (void *)kretprobe_trampoline_handler(regs, NULL); -} - -void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, - struct pt_regs *regs) -{ - ri->ret_addr = (kprobe_opcode_t *)regs->ra; - ri->fp = NULL; - regs->ra = (unsigned long) &__kretprobe_trampoline; -} - int __kprobes arch_trampoline_kprobe(struct kprobe *p) { return 0; diff --git a/arch/riscv/kernel/probes/rethook.c b/arch/riscv/kernel/probes/rethook.c new file mode 100644 index 000000000000..5c27c1f50989 --- /dev/null +++ b/arch/riscv/kernel/probes/rethook.c @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Generic return hook for riscv. + */ + +#include +#include +#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, regs->s0); +} + +NOKPROBE_SYMBOL(arch_rethook_trampoline_callback); + +void arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, bool mcount) +{ + rhn->ret_addr = regs->ra; + rhn->frame = regs->s0; + + /* replace return addr with trampoline */ + regs->ra = (unsigned long)arch_rethook_trampoline; +} + +NOKPROBE_SYMBOL(arch_rethook_prepare); diff --git a/arch/riscv/kernel/probes/rethook.h b/arch/riscv/kernel/probes/rethook.h new file mode 100644 index 000000000000..4758f7e3ce88 --- /dev/null +++ b/arch/riscv/kernel/probes/rethook.h @@ -0,0 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __RISCV_RETHOOK_H +#define __RISCV_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 diff --git a/arch/riscv/kernel/probes/kprobes_trampoline.S b/arch/riscv/kernel/probes/rethook_trampoline.S similarity index 94% rename from arch/riscv/kernel/probes/kprobes_trampoline.S rename to arch/riscv/kernel/probes/rethook_trampoline.S index 7bdb09ded39b..21bac92a170a 100644 --- a/arch/riscv/kernel/probes/kprobes_trampoline.S +++ b/arch/riscv/kernel/probes/rethook_trampoline.S @@ -75,13 +75,13 @@ REG_L x31, PT_T6(sp) .endm -ENTRY(__kretprobe_trampoline) +ENTRY(arch_rethook_trampoline) addi sp, sp, -(PT_SIZE_ON_STACK) save_all_base_regs move a0, sp /* pt_regs */ - call trampoline_probe_handler + call arch_rethook_trampoline_callback /* use the result as the return-address */ move ra, a0 @@ -90,4 +90,4 @@ ENTRY(__kretprobe_trampoline) addi sp, sp, PT_SIZE_ON_STACK ret -ENDPROC(__kretprobe_trampoline) +ENDPROC(arch_rethook_trampoline)