From 8f6bb793b2be82f1f73bfb416486f156f70b4314 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Thu, 2 Apr 2020 19:52:27 +0800 Subject: [PATCH] csky: Add uprobes support This patch adds support for uprobes on csky architecture. Just like kprobe, it support single-step and simulate instructions. Signed-off-by: Guo Ren Cc: Arnd Bergmann Cc: Steven Rostedt (VMware) --- arch/csky/Kconfig | 3 + arch/csky/include/asm/thread_info.h | 2 + arch/csky/include/asm/uprobes.h | 33 ++++++ arch/csky/kernel/entry.S | 2 +- arch/csky/kernel/probes/Makefile | 1 + arch/csky/kernel/probes/uprobes.c | 150 ++++++++++++++++++++++++++++ arch/csky/kernel/signal.c | 3 + arch/csky/kernel/traps.c | 8 ++ 8 files changed, 201 insertions(+), 1 deletion(-) create mode 100644 arch/csky/include/asm/uprobes.h create mode 100644 arch/csky/kernel/probes/uprobes.c diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index f76c333758ca..94545d50d40f 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -75,6 +75,9 @@ config CSKY config LOCKDEP_SUPPORT def_bool y +config ARCH_SUPPORTS_UPROBES + def_bool y if !CPU_CK610 + config CPU_HAS_CACHEV2 bool diff --git a/arch/csky/include/asm/thread_info.h b/arch/csky/include/asm/thread_info.h index 0b546a55a8bf..442fedad0260 100644 --- a/arch/csky/include/asm/thread_info.h +++ b/arch/csky/include/asm/thread_info.h @@ -57,6 +57,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_SYSCALL_TRACE 3 /* syscall trace active */ #define TIF_SYSCALL_TRACEPOINT 4 /* syscall tracepoint instrumentation */ #define TIF_SYSCALL_AUDIT 5 /* syscall auditing */ +#define TIF_UPROBE 6 /* uprobe breakpoint or singlestep */ #define TIF_POLLING_NRFLAG 16 /* poll_idle() is TIF_NEED_RESCHED */ #define TIF_MEMDIE 18 /* is terminating due to OOM killer */ #define TIF_RESTORE_SIGMASK 20 /* restore signal mask in do_signal() */ @@ -68,6 +69,7 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) +#define _TIF_UPROBE (1 << TIF_UPROBE) #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) #define _TIF_MEMDIE (1 << TIF_MEMDIE) #define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK) diff --git a/arch/csky/include/asm/uprobes.h b/arch/csky/include/asm/uprobes.h new file mode 100644 index 000000000000..600388eb93c6 --- /dev/null +++ b/arch/csky/include/asm/uprobes.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef __ASM_CSKY_UPROBES_H +#define __ASM_CSKY_UPROBES_H + +#include + +#define MAX_UINSN_BYTES 4 + +#define UPROBE_SWBP_INSN USR_BKPT +#define UPROBE_SWBP_INSN_SIZE 2 +#define UPROBE_XOL_SLOT_BYTES MAX_UINSN_BYTES + +typedef u32 uprobe_opcode_t; + +struct arch_uprobe_task { + unsigned long saved_trap_no; +}; + +struct arch_uprobe { + union { + u8 insn[MAX_UINSN_BYTES]; + u8 ixol[MAX_UINSN_BYTES]; + }; + struct arch_probe_insn api; + unsigned long insn_size; + bool simulate; +}; + +int uprobe_breakpoint_handler(struct pt_regs *regs); +int uprobe_single_step_handler(struct pt_regs *regs); + +#endif /* __ASM_CSKY_UPROBES_H */ diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S index 8b040a1b11d0..364819536f2e 100644 --- a/arch/csky/kernel/entry.S +++ b/arch/csky/kernel/entry.S @@ -221,7 +221,7 @@ ret_from_exception: andn r9, r10 ldw r12, (r9, TINFO_FLAGS) - andi r12, (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED) + andi r12, (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | _TIF_UPROBE) cmpnei r12, 0 bt exit_work 1: diff --git a/arch/csky/kernel/probes/Makefile b/arch/csky/kernel/probes/Makefile index 3a857d081958..1c7c6e6cb25b 100644 --- a/arch/csky/kernel/probes/Makefile +++ b/arch/csky/kernel/probes/Makefile @@ -2,5 +2,6 @@ obj-$(CONFIG_KPROBES) += kprobes.o decode-insn.o simulate-insn.o obj-$(CONFIG_KPROBES) += kprobes_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/csky/kernel/probes/uprobes.c b/arch/csky/kernel/probes/uprobes.c new file mode 100644 index 000000000000..b3a56c260e3e --- /dev/null +++ b/arch/csky/kernel/probes/uprobes.c @@ -0,0 +1,150 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2014-2016 Pratyush Anand + */ +#include +#include +#include +#include + +#include "decode-insn.h" + +#define UPROBE_TRAP_NR UINT_MAX + +unsigned long uprobe_get_swbp_addr(struct pt_regs *regs) +{ + return instruction_pointer(regs); +} + +int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, + unsigned long addr) +{ + probe_opcode_t insn; + + insn = *(probe_opcode_t *)(&auprobe->insn[0]); + + auprobe->insn_size = is_insn32(insn) ? 4 : 2; + + switch (csky_probe_decode_insn(&insn, &auprobe->api)) { + case INSN_REJECTED: + return -EINVAL; + + case INSN_GOOD_NO_SLOT: + auprobe->simulate = true; + break; + + default: + break; + } + + return 0; +} + +int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + struct uprobe_task *utask = current->utask; + + utask->autask.saved_trap_no = current->thread.trap_no; + current->thread.trap_no = UPROBE_TRAP_NR; + + instruction_pointer_set(regs, utask->xol_vaddr); + + user_enable_single_step(current); + + return 0; +} + +int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + struct uprobe_task *utask = current->utask; + + WARN_ON_ONCE(current->thread.trap_no != UPROBE_TRAP_NR); + + instruction_pointer_set(regs, utask->vaddr + auprobe->insn_size); + + user_disable_single_step(current); + + return 0; +} + +bool arch_uprobe_xol_was_trapped(struct task_struct *t) +{ + if (t->thread.trap_no != UPROBE_TRAP_NR) + return true; + + return false; +} + +bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + probe_opcode_t insn; + unsigned long addr; + + if (!auprobe->simulate) + return false; + + insn = *(probe_opcode_t *)(&auprobe->insn[0]); + addr = instruction_pointer(regs); + + if (auprobe->api.handler) + auprobe->api.handler(insn, addr, regs); + + return true; +} + +void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + struct uprobe_task *utask = current->utask; + + /* + * Task has received a fatal signal, so reset back to probbed + * address. + */ + instruction_pointer_set(regs, utask->vaddr); + + user_disable_single_step(current); +} + +bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx, + struct pt_regs *regs) +{ + if (ctx == RP_CHECK_CHAIN_CALL) + return regs->usp <= ret->stack; + else + return regs->usp < ret->stack; +} + +unsigned long +arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, + struct pt_regs *regs) +{ + unsigned long ra; + + ra = regs->lr; + + regs->lr = trampoline_vaddr; + + return ra; +} + +int arch_uprobe_exception_notify(struct notifier_block *self, + unsigned long val, void *data) +{ + return NOTIFY_DONE; +} + +int uprobe_breakpoint_handler(struct pt_regs *regs) +{ + if (uprobe_pre_sstep_notifier(regs)) + return 1; + + return 0; +} + +int uprobe_single_step_handler(struct pt_regs *regs) +{ + if (uprobe_post_sstep_notifier(regs)) + return 1; + + return 0; +} diff --git a/arch/csky/kernel/signal.c b/arch/csky/kernel/signal.c index 3d6b728cbb72..9452d6570b7e 100644 --- a/arch/csky/kernel/signal.c +++ b/arch/csky/kernel/signal.c @@ -253,6 +253,9 @@ static void do_signal(struct pt_regs *regs) asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags) { + if (thread_info_flags & _TIF_UPROBE) + uprobe_notify_resume(regs); + /* Handle pending signal delivery */ if (thread_info_flags & _TIF_SIGPENDING) do_signal(regs); diff --git a/arch/csky/kernel/traps.c b/arch/csky/kernel/traps.c index c6a40806977f..fcc3a69831ad 100644 --- a/arch/csky/kernel/traps.c +++ b/arch/csky/kernel/traps.c @@ -129,6 +129,10 @@ asmlinkage void trap_c(struct pt_regs *regs) #ifdef CONFIG_KPROBES if (kprobe_single_step_handler(regs)) return; +#endif +#ifdef CONFIG_UPROBES + if (uprobe_single_step_handler(regs)) + return; #endif info.si_code = TRAP_TRACE; sig = SIGTRAP; @@ -138,6 +142,10 @@ asmlinkage void trap_c(struct pt_regs *regs) #ifdef CONFIG_KPROBES if (kprobe_breakpoint_handler(regs)) return; +#endif +#ifdef CONFIG_UPROBES + if (uprobe_breakpoint_handler(regs)) + return; #endif die_if_kernel("Kernel mode ILLEGAL", regs, vector); #ifndef CONFIG_CPU_NO_USER_BKPT -- 2.20.1