diff options
Diffstat (limited to 'arch/arm64/kernel/probes/simulate-insn.c')
| -rw-r--r-- | arch/arm64/kernel/probes/simulate-insn.c | 85 |
1 files changed, 57 insertions, 28 deletions
diff --git a/arch/arm64/kernel/probes/simulate-insn.c b/arch/arm64/kernel/probes/simulate-insn.c index be05868418ee..89fbeb32107e 100644 --- a/arch/arm64/kernel/probes/simulate-insn.c +++ b/arch/arm64/kernel/probes/simulate-insn.c @@ -1,16 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * arch/arm64/kernel/probes/simulate-insn.c * * Copyright (C) 2013 Linaro Limited. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. */ #include <linux/bitops.h> @@ -18,8 +10,10 @@ #include <linux/kprobes.h> #include <asm/ptrace.h> +#include <asm/traps.h> #include "simulate-insn.h" +#include "asm/gcs.h" #define bbl_displacement(insn) \ sign_extend32(((insn) & 0x3ffffff) << 2, 27) @@ -56,6 +50,21 @@ static inline u32 get_w_reg(struct pt_regs *regs, int reg) return lower_32_bits(pt_regs_read_reg(regs, reg)); } +static inline int update_lr(struct pt_regs *regs, long addr) +{ + int err = 0; + + if (user_mode(regs) && task_gcs_el0_enabled(current)) { + push_user_gcs(addr, &err); + if (err) { + force_sig(SIGSEGV); + return err; + } + } + procedure_link_pointer_set(regs, addr); + return err; +} + static bool __kprobes check_cbz(u32 opcode, struct pt_regs *regs) { int xn = opcode & 0x1f; @@ -114,9 +123,9 @@ simulate_b_bl(u32 opcode, long addr, struct pt_regs *regs) { int disp = bbl_displacement(opcode); - /* Link register is x30 */ if (opcode & (1 << 31)) - set_x_reg(regs, 30, addr + 4); + if (update_lr(regs, addr + 4)) + return; instruction_pointer_set(regs, addr + disp); } @@ -133,16 +142,34 @@ simulate_b_cond(u32 opcode, long addr, struct pt_regs *regs) } void __kprobes -simulate_br_blr_ret(u32 opcode, long addr, struct pt_regs *regs) +simulate_br_blr(u32 opcode, long addr, struct pt_regs *regs) { int xn = (opcode >> 5) & 0x1f; + u64 b_target = get_x_reg(regs, xn); - /* update pc first in case we're doing a "blr lr" */ - instruction_pointer_set(regs, get_x_reg(regs, xn)); - - /* Link register is x30 */ if (((opcode >> 21) & 0x3) == 1) - set_x_reg(regs, 30, addr + 4); + if (update_lr(regs, addr + 4)) + return; + + instruction_pointer_set(regs, b_target); +} + +void __kprobes +simulate_ret(u32 opcode, long addr, struct pt_regs *regs) +{ + u64 ret_addr; + int err = 0; + int xn = (opcode >> 5) & 0x1f; + u64 r_target = get_x_reg(regs, xn); + + if (user_mode(regs) && task_gcs_el0_enabled(current)) { + ret_addr = pop_user_gcs(&err); + if (err || ret_addr != r_target) { + force_sig(SIGSEGV); + return; + } + } + instruction_pointer_set(regs, r_target); } void __kprobes @@ -178,17 +205,15 @@ simulate_tbz_tbnz(u32 opcode, long addr, struct pt_regs *regs) void __kprobes simulate_ldr_literal(u32 opcode, long addr, struct pt_regs *regs) { - u64 *load_addr; + unsigned long load_addr; int xn = opcode & 0x1f; - int disp; - disp = ldr_displacement(opcode); - load_addr = (u64 *) (addr + disp); + load_addr = addr + ldr_displacement(opcode); if (opcode & (1 << 30)) /* x0-x30 */ - set_x_reg(regs, xn, *load_addr); + set_x_reg(regs, xn, READ_ONCE(*(u64 *)load_addr)); else /* w0-w30 */ - set_w_reg(regs, xn, *load_addr); + set_w_reg(regs, xn, READ_ONCE(*(u32 *)load_addr)); instruction_pointer_set(regs, instruction_pointer(regs) + 4); } @@ -196,14 +221,18 @@ simulate_ldr_literal(u32 opcode, long addr, struct pt_regs *regs) void __kprobes simulate_ldrsw_literal(u32 opcode, long addr, struct pt_regs *regs) { - s32 *load_addr; + unsigned long load_addr; int xn = opcode & 0x1f; - int disp; - disp = ldr_displacement(opcode); - load_addr = (s32 *) (addr + disp); + load_addr = addr + ldr_displacement(opcode); - set_x_reg(regs, xn, *load_addr); + set_x_reg(regs, xn, READ_ONCE(*(s32 *)load_addr)); instruction_pointer_set(regs, instruction_pointer(regs) + 4); } + +void __kprobes +simulate_nop(u32 opcode, long addr, struct pt_regs *regs) +{ + arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); +} |