Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Kernel Probes (KProbes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | * |
| 18 | * Copyright (C) IBM Corporation, 2002, 2004 |
| 19 | * |
| 20 | * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel |
| 21 | * Probes initial implementation ( includes contributions from |
| 22 | * Rusty Russell). |
| 23 | * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes |
| 24 | * interface to access function arguments. |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 25 | * 2004-Oct Jim Keniston <jkenisto@us.ibm.com> and Prasanna S Panchamukhi |
| 26 | * <prasanna@in.ibm.com> adapted for x86_64 from i386. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | * 2005-Mar Roland McGrath <roland@redhat.com> |
| 28 | * Fixed to handle %rip-relative addressing mode correctly. |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 29 | * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston |
| 30 | * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi |
| 31 | * <prasanna@in.ibm.com> added function-return probes. |
| 32 | * 2005-May Rusty Lynch <rusty.lynch@intel.com> |
| 33 | * Added function return probes functionality |
| 34 | * 2006-Feb Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> added |
| 35 | * kprobe-booster and kretprobe-booster for i386. |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 36 | * 2007-Dec Masami Hiramatsu <mhiramat@redhat.com> added kprobe-booster |
| 37 | * and kretprobe-booster for x86-64 |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 38 | * 2007-Dec Masami Hiramatsu <mhiramat@redhat.com>, Arjan van de Ven |
| 39 | * <arjan@infradead.org> and Jim Keniston <jkenisto@us.ibm.com> |
| 40 | * unified x86 kprobes code. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | */ |
| 42 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | #include <linux/kprobes.h> |
| 44 | #include <linux/ptrace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | #include <linux/string.h> |
| 46 | #include <linux/slab.h> |
Quentin Barnes | b506a9d | 2008-01-30 13:32:32 +0100 | [diff] [blame] | 47 | #include <linux/hardirq.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | #include <linux/preempt.h> |
Prasanna S Panchamukhi | c28f896 | 2006-03-26 01:38:23 -0800 | [diff] [blame] | 49 | #include <linux/module.h> |
Christoph Hellwig | 1eeb66a | 2007-05-08 00:27:03 -0700 | [diff] [blame] | 50 | #include <linux/kdebug.h> |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 51 | |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 52 | #include <asm/cacheflush.h> |
| 53 | #include <asm/desc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | #include <asm/pgtable.h> |
Prasanna S Panchamukhi | c28f896 | 2006-03-26 01:38:23 -0800 | [diff] [blame] | 55 | #include <asm/uaccess.h> |
Andi Kleen | 19d36cc | 2007-07-22 11:12:31 +0200 | [diff] [blame] | 56 | #include <asm/alternative.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | void jprobe_return_end(void); |
| 59 | |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 60 | DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; |
| 61 | DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 63 | #ifdef CONFIG_X86_64 |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 64 | #define stack_addr(regs) ((unsigned long *)regs->sp) |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 65 | #else |
| 66 | /* |
| 67 | * "®s->sp" looks wrong, but it's correct for x86_32. x86_32 CPUs |
| 68 | * don't save the ss and esp registers if the CPU is already in kernel |
| 69 | * mode when it traps. So for kprobes, regs->sp and regs->ss are not |
| 70 | * the [nonexistent] saved stack pointer and ss register, but rather |
| 71 | * the top 8 bytes of the pre-int3 stack. So ®s->sp happens to |
| 72 | * point to the top of the pre-int3 stack. |
| 73 | */ |
| 74 | #define stack_addr(regs) ((unsigned long *)®s->sp) |
| 75 | #endif |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 76 | |
| 77 | #define W(row, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)\ |
| 78 | (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \ |
| 79 | (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \ |
| 80 | (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \ |
| 81 | (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \ |
| 82 | << (row % 32)) |
| 83 | /* |
| 84 | * Undefined/reserved opcodes, conditional jump, Opcode Extension |
| 85 | * Groups, and some special opcodes can not boost. |
| 86 | */ |
| 87 | static const u32 twobyte_is_boostable[256 / 32] = { |
| 88 | /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ |
| 89 | /* ---------------------------------------------- */ |
| 90 | W(0x00, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0) | /* 00 */ |
| 91 | W(0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 10 */ |
| 92 | W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 20 */ |
| 93 | W(0x30, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 30 */ |
| 94 | W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 40 */ |
| 95 | W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */ |
| 96 | W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1) | /* 60 */ |
| 97 | W(0x70, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) , /* 70 */ |
| 98 | W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 80 */ |
| 99 | W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 90 */ |
| 100 | W(0xa0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* a0 */ |
| 101 | W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) , /* b0 */ |
| 102 | W(0xc0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* c0 */ |
| 103 | W(0xd0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) , /* d0 */ |
| 104 | W(0xe0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* e0 */ |
| 105 | W(0xf0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0) /* f0 */ |
| 106 | /* ----------------------------------------------- */ |
| 107 | /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ |
| 108 | }; |
| 109 | static const u32 onebyte_has_modrm[256 / 32] = { |
| 110 | /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ |
| 111 | /* ----------------------------------------------- */ |
| 112 | W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 00 */ |
| 113 | W(0x10, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 10 */ |
| 114 | W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 20 */ |
| 115 | W(0x30, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 30 */ |
| 116 | W(0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 40 */ |
| 117 | W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */ |
| 118 | W(0x60, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0) | /* 60 */ |
| 119 | W(0x70, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 70 */ |
| 120 | W(0x80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 80 */ |
| 121 | W(0x90, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 90 */ |
| 122 | W(0xa0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* a0 */ |
| 123 | W(0xb0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* b0 */ |
| 124 | W(0xc0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* c0 */ |
| 125 | W(0xd0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) , /* d0 */ |
| 126 | W(0xe0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* e0 */ |
| 127 | W(0xf0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* f0 */ |
| 128 | /* ----------------------------------------------- */ |
| 129 | /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ |
| 130 | }; |
| 131 | static const u32 twobyte_has_modrm[256 / 32] = { |
| 132 | /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ |
| 133 | /* ----------------------------------------------- */ |
| 134 | W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1) | /* 0f */ |
| 135 | W(0x10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0) , /* 1f */ |
| 136 | W(0x20, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* 2f */ |
| 137 | W(0x30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 3f */ |
| 138 | W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 4f */ |
| 139 | W(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 5f */ |
| 140 | W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 6f */ |
| 141 | W(0x70, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1) , /* 7f */ |
| 142 | W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 8f */ |
| 143 | W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 9f */ |
| 144 | W(0xa0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) | /* af */ |
| 145 | W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1) , /* bf */ |
| 146 | W(0xc0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* cf */ |
| 147 | W(0xd0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* df */ |
| 148 | W(0xe0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* ef */ |
| 149 | W(0xf0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0) /* ff */ |
| 150 | /* ----------------------------------------------- */ |
| 151 | /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ |
| 152 | }; |
| 153 | #undef W |
| 154 | |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 155 | struct kretprobe_blackpoint kretprobe_blacklist[] = { |
| 156 | {"__switch_to", }, /* This function switches only current task, but |
| 157 | doesn't switch kernel stack.*/ |
| 158 | {NULL, NULL} /* Terminator */ |
| 159 | }; |
| 160 | const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist); |
| 161 | |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 162 | /* Insert a jump instruction at address 'from', which jumps to address 'to'.*/ |
Harvey Harrison | e7b5e11 | 2008-01-30 13:31:43 +0100 | [diff] [blame] | 163 | static void __kprobes set_jmp_op(void *from, void *to) |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 164 | { |
| 165 | struct __arch_jmp_op { |
| 166 | char op; |
| 167 | s32 raddr; |
| 168 | } __attribute__((packed)) * jop; |
| 169 | jop = (struct __arch_jmp_op *)from; |
| 170 | jop->raddr = (s32)((long)(to) - ((long)(from) + 5)); |
| 171 | jop->op = RELATIVEJUMP_INSTRUCTION; |
| 172 | } |
| 173 | |
| 174 | /* |
Harvey Harrison | 9930927 | 2008-01-30 13:32:14 +0100 | [diff] [blame] | 175 | * Check for the REX prefix which can only exist on X86_64 |
| 176 | * X86_32 always returns 0 |
| 177 | */ |
| 178 | static int __kprobes is_REX_prefix(kprobe_opcode_t *insn) |
| 179 | { |
| 180 | #ifdef CONFIG_X86_64 |
| 181 | if ((*insn & 0xf0) == 0x40) |
| 182 | return 1; |
| 183 | #endif |
| 184 | return 0; |
| 185 | } |
| 186 | |
| 187 | /* |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 188 | * Returns non-zero if opcode is boostable. |
| 189 | * RIP relative instructions are adjusted at copying time in 64 bits mode |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 190 | */ |
Harvey Harrison | e7b5e11 | 2008-01-30 13:31:43 +0100 | [diff] [blame] | 191 | static int __kprobes can_boost(kprobe_opcode_t *opcodes) |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 192 | { |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 193 | kprobe_opcode_t opcode; |
| 194 | kprobe_opcode_t *orig_opcodes = opcodes; |
| 195 | |
Jaswinder Singh Rajput | cde5edb | 2009-03-18 17:37:45 +0530 | [diff] [blame] | 196 | if (search_exception_tables((unsigned long)opcodes)) |
Masami Hiramatsu | 3039088 | 2009-03-16 18:57:22 -0400 | [diff] [blame] | 197 | return 0; /* Page fault may occur on this address. */ |
| 198 | |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 199 | retry: |
| 200 | if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1) |
| 201 | return 0; |
| 202 | opcode = *(opcodes++); |
| 203 | |
| 204 | /* 2nd-byte opcode */ |
| 205 | if (opcode == 0x0f) { |
| 206 | if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1) |
| 207 | return 0; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 208 | return test_bit(*opcodes, |
| 209 | (unsigned long *)twobyte_is_boostable); |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 210 | } |
| 211 | |
| 212 | switch (opcode & 0xf0) { |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 213 | #ifdef CONFIG_X86_64 |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 214 | case 0x40: |
| 215 | goto retry; /* REX prefix is boostable */ |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 216 | #endif |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 217 | case 0x60: |
| 218 | if (0x63 < opcode && opcode < 0x67) |
| 219 | goto retry; /* prefixes */ |
| 220 | /* can't boost Address-size override and bound */ |
| 221 | return (opcode != 0x62 && opcode != 0x67); |
| 222 | case 0x70: |
| 223 | return 0; /* can't boost conditional jump */ |
| 224 | case 0xc0: |
| 225 | /* can't boost software-interruptions */ |
| 226 | return (0xc1 < opcode && opcode < 0xcc) || opcode == 0xcf; |
| 227 | case 0xd0: |
| 228 | /* can boost AA* and XLAT */ |
| 229 | return (opcode == 0xd4 || opcode == 0xd5 || opcode == 0xd7); |
| 230 | case 0xe0: |
| 231 | /* can boost in/out and absolute jmps */ |
| 232 | return ((opcode & 0x04) || opcode == 0xea); |
| 233 | case 0xf0: |
| 234 | if ((opcode & 0x0c) == 0 && opcode != 0xf1) |
| 235 | goto retry; /* lock/rep(ne) prefix */ |
| 236 | /* clear and set flags are boostable */ |
| 237 | return (opcode == 0xf5 || (0xf7 < opcode && opcode < 0xfe)); |
| 238 | default: |
| 239 | /* segment override prefixes are boostable */ |
| 240 | if (opcode == 0x26 || opcode == 0x36 || opcode == 0x3e) |
| 241 | goto retry; /* prefixes */ |
| 242 | /* CS override prefix and call are not boostable */ |
| 243 | return (opcode != 0x2e && opcode != 0x9a); |
| 244 | } |
| 245 | } |
| 246 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | /* |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 248 | * Returns non-zero if opcode modifies the interrupt flag. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | */ |
Andrew Morton | 8645419 | 2007-11-26 20:42:19 +0100 | [diff] [blame] | 250 | static int __kprobes is_IF_modifier(kprobe_opcode_t *insn) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | { |
| 252 | switch (*insn) { |
| 253 | case 0xfa: /* cli */ |
| 254 | case 0xfb: /* sti */ |
| 255 | case 0xcf: /* iret/iretd */ |
| 256 | case 0x9d: /* popf/popfd */ |
| 257 | return 1; |
| 258 | } |
Harvey Harrison | 9930927 | 2008-01-30 13:32:14 +0100 | [diff] [blame] | 259 | |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 260 | /* |
Harvey Harrison | 9930927 | 2008-01-30 13:32:14 +0100 | [diff] [blame] | 261 | * on X86_64, 0x40-0x4f are REX prefixes so we need to look |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 262 | * at the next byte instead.. but of course not recurse infinitely |
| 263 | */ |
Harvey Harrison | 9930927 | 2008-01-30 13:32:14 +0100 | [diff] [blame] | 264 | if (is_REX_prefix(insn)) |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 265 | return is_IF_modifier(++insn); |
Harvey Harrison | 9930927 | 2008-01-30 13:32:14 +0100 | [diff] [blame] | 266 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | return 0; |
| 268 | } |
| 269 | |
| 270 | /* |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 271 | * Adjust the displacement if the instruction uses the %rip-relative |
| 272 | * addressing mode. |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 273 | * If it does, Return the address of the 32-bit displacement word. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | * If not, return null. |
Harvey Harrison | 31f80e4 | 2008-01-30 13:32:16 +0100 | [diff] [blame] | 275 | * Only applicable to 64-bit x86. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | */ |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 277 | static void __kprobes fix_riprel(struct kprobe *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | { |
Harvey Harrison | 31f80e4 | 2008-01-30 13:32:16 +0100 | [diff] [blame] | 279 | #ifdef CONFIG_X86_64 |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 280 | u8 *insn = p->ainsn.insn; |
| 281 | s64 disp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 282 | int need_modrm; |
| 283 | |
| 284 | /* Skip legacy instruction prefixes. */ |
| 285 | while (1) { |
| 286 | switch (*insn) { |
| 287 | case 0x66: |
| 288 | case 0x67: |
| 289 | case 0x2e: |
| 290 | case 0x3e: |
| 291 | case 0x26: |
| 292 | case 0x64: |
| 293 | case 0x65: |
| 294 | case 0x36: |
| 295 | case 0xf0: |
| 296 | case 0xf3: |
| 297 | case 0xf2: |
| 298 | ++insn; |
| 299 | continue; |
| 300 | } |
| 301 | break; |
| 302 | } |
| 303 | |
| 304 | /* Skip REX instruction prefix. */ |
Harvey Harrison | 9930927 | 2008-01-30 13:32:14 +0100 | [diff] [blame] | 305 | if (is_REX_prefix(insn)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | ++insn; |
| 307 | |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 308 | if (*insn == 0x0f) { |
| 309 | /* Two-byte opcode. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | ++insn; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 311 | need_modrm = test_bit(*insn, |
| 312 | (unsigned long *)twobyte_has_modrm); |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 313 | } else |
| 314 | /* One-byte opcode. */ |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 315 | need_modrm = test_bit(*insn, |
| 316 | (unsigned long *)onebyte_has_modrm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | |
| 318 | if (need_modrm) { |
| 319 | u8 modrm = *++insn; |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 320 | if ((modrm & 0xc7) == 0x05) { |
| 321 | /* %rip+disp32 addressing mode */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | /* Displacement follows ModRM byte. */ |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 323 | ++insn; |
| 324 | /* |
| 325 | * The copied instruction uses the %rip-relative |
| 326 | * addressing mode. Adjust the displacement for the |
| 327 | * difference between the original location of this |
| 328 | * instruction and the location of the copy that will |
| 329 | * actually be run. The tricky bit here is making sure |
| 330 | * that the sign extension happens correctly in this |
| 331 | * calculation, since we need a signed 32-bit result to |
| 332 | * be sign-extended to 64 bits when it's added to the |
| 333 | * %rip value and yield the same 64-bit result that the |
| 334 | * sign-extension of the original signed 32-bit |
| 335 | * displacement would have given. |
| 336 | */ |
| 337 | disp = (u8 *) p->addr + *((s32 *) insn) - |
| 338 | (u8 *) p->ainsn.insn; |
| 339 | BUG_ON((s64) (s32) disp != disp); /* Sanity check. */ |
| 340 | *(s32 *)insn = (s32) disp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | } |
| 342 | } |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 343 | #endif |
Harvey Harrison | 31f80e4 | 2008-01-30 13:32:16 +0100 | [diff] [blame] | 344 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | |
Keshavamurthy Anil S | f709b12 | 2006-01-09 20:52:44 -0800 | [diff] [blame] | 346 | static void __kprobes arch_copy_kprobe(struct kprobe *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | { |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 348 | memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); |
Harvey Harrison | 31f80e4 | 2008-01-30 13:32:16 +0100 | [diff] [blame] | 349 | |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 350 | fix_riprel(p); |
Harvey Harrison | 31f80e4 | 2008-01-30 13:32:16 +0100 | [diff] [blame] | 351 | |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 352 | if (can_boost(p->addr)) |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 353 | p->ainsn.boostable = 0; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 354 | else |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 355 | p->ainsn.boostable = -1; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 356 | |
Rusty Lynch | 7e1048b | 2005-06-23 00:09:25 -0700 | [diff] [blame] | 357 | p->opcode = *p->addr; |
| 358 | } |
| 359 | |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 360 | int __kprobes arch_prepare_kprobe(struct kprobe *p) |
| 361 | { |
| 362 | /* insn: must be on special executable page on x86. */ |
| 363 | p->ainsn.insn = get_insn_slot(); |
| 364 | if (!p->ainsn.insn) |
| 365 | return -ENOMEM; |
| 366 | arch_copy_kprobe(p); |
| 367 | return 0; |
| 368 | } |
| 369 | |
Prasanna S Panchamukhi | 0f2fbdc | 2005-09-06 15:19:28 -0700 | [diff] [blame] | 370 | void __kprobes arch_arm_kprobe(struct kprobe *p) |
Rusty Lynch | 7e1048b | 2005-06-23 00:09:25 -0700 | [diff] [blame] | 371 | { |
Andi Kleen | 19d36cc | 2007-07-22 11:12:31 +0200 | [diff] [blame] | 372 | text_poke(p->addr, ((unsigned char []){BREAKPOINT_INSTRUCTION}), 1); |
Rusty Lynch | 7e1048b | 2005-06-23 00:09:25 -0700 | [diff] [blame] | 373 | } |
| 374 | |
Prasanna S Panchamukhi | 0f2fbdc | 2005-09-06 15:19:28 -0700 | [diff] [blame] | 375 | void __kprobes arch_disarm_kprobe(struct kprobe *p) |
Rusty Lynch | 7e1048b | 2005-06-23 00:09:25 -0700 | [diff] [blame] | 376 | { |
Andi Kleen | 19d36cc | 2007-07-22 11:12:31 +0200 | [diff] [blame] | 377 | text_poke(p->addr, &p->opcode, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 378 | } |
| 379 | |
Ananth N Mavinakayanahalli | 0498b63 | 2006-01-09 20:52:46 -0800 | [diff] [blame] | 380 | void __kprobes arch_remove_kprobe(struct kprobe *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | { |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 382 | if (p->ainsn.insn) { |
| 383 | free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1)); |
| 384 | p->ainsn.insn = NULL; |
| 385 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | } |
| 387 | |
Prasanna S Panchamukhi | 3b60211 | 2006-04-18 22:22:00 -0700 | [diff] [blame] | 388 | static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) |
Prasanna S Panchamukhi | aa3d7e3 | 2005-06-23 00:09:37 -0700 | [diff] [blame] | 389 | { |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 390 | kcb->prev_kprobe.kp = kprobe_running(); |
| 391 | kcb->prev_kprobe.status = kcb->kprobe_status; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 392 | kcb->prev_kprobe.old_flags = kcb->kprobe_old_flags; |
| 393 | kcb->prev_kprobe.saved_flags = kcb->kprobe_saved_flags; |
Prasanna S Panchamukhi | aa3d7e3 | 2005-06-23 00:09:37 -0700 | [diff] [blame] | 394 | } |
| 395 | |
Prasanna S Panchamukhi | 3b60211 | 2006-04-18 22:22:00 -0700 | [diff] [blame] | 396 | static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) |
Prasanna S Panchamukhi | aa3d7e3 | 2005-06-23 00:09:37 -0700 | [diff] [blame] | 397 | { |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 398 | __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; |
| 399 | kcb->kprobe_status = kcb->prev_kprobe.status; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 400 | kcb->kprobe_old_flags = kcb->prev_kprobe.old_flags; |
| 401 | kcb->kprobe_saved_flags = kcb->prev_kprobe.saved_flags; |
Prasanna S Panchamukhi | aa3d7e3 | 2005-06-23 00:09:37 -0700 | [diff] [blame] | 402 | } |
| 403 | |
Prasanna S Panchamukhi | 3b60211 | 2006-04-18 22:22:00 -0700 | [diff] [blame] | 404 | static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 405 | struct kprobe_ctlblk *kcb) |
Prasanna S Panchamukhi | aa3d7e3 | 2005-06-23 00:09:37 -0700 | [diff] [blame] | 406 | { |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 407 | __get_cpu_var(current_kprobe) = p; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 408 | kcb->kprobe_saved_flags = kcb->kprobe_old_flags |
Glauber de Oliveira Costa | 053de04 | 2008-01-30 13:31:27 +0100 | [diff] [blame] | 409 | = (regs->flags & (X86_EFLAGS_TF | X86_EFLAGS_IF)); |
Prasanna S Panchamukhi | aa3d7e3 | 2005-06-23 00:09:37 -0700 | [diff] [blame] | 410 | if (is_IF_modifier(p->ainsn.insn)) |
Glauber de Oliveira Costa | 053de04 | 2008-01-30 13:31:27 +0100 | [diff] [blame] | 411 | kcb->kprobe_saved_flags &= ~X86_EFLAGS_IF; |
Prasanna S Panchamukhi | aa3d7e3 | 2005-06-23 00:09:37 -0700 | [diff] [blame] | 412 | } |
| 413 | |
Harvey Harrison | e7b5e11 | 2008-01-30 13:31:43 +0100 | [diff] [blame] | 414 | static void __kprobes clear_btf(void) |
Roland McGrath | 1ecc798 | 2008-01-30 13:30:54 +0100 | [diff] [blame] | 415 | { |
| 416 | if (test_thread_flag(TIF_DEBUGCTLMSR)) |
Jan Beulich | 5b0e508 | 2008-03-10 13:11:17 +0000 | [diff] [blame] | 417 | update_debugctlmsr(0); |
Roland McGrath | 1ecc798 | 2008-01-30 13:30:54 +0100 | [diff] [blame] | 418 | } |
| 419 | |
Harvey Harrison | e7b5e11 | 2008-01-30 13:31:43 +0100 | [diff] [blame] | 420 | static void __kprobes restore_btf(void) |
Roland McGrath | 1ecc798 | 2008-01-30 13:30:54 +0100 | [diff] [blame] | 421 | { |
| 422 | if (test_thread_flag(TIF_DEBUGCTLMSR)) |
Jan Beulich | 5b0e508 | 2008-03-10 13:11:17 +0000 | [diff] [blame] | 423 | update_debugctlmsr(current->thread.debugctlmsr); |
Roland McGrath | 1ecc798 | 2008-01-30 13:30:54 +0100 | [diff] [blame] | 424 | } |
| 425 | |
Prasanna S Panchamukhi | 0f2fbdc | 2005-09-06 15:19:28 -0700 | [diff] [blame] | 426 | static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | { |
Roland McGrath | 1ecc798 | 2008-01-30 13:30:54 +0100 | [diff] [blame] | 428 | clear_btf(); |
Glauber de Oliveira Costa | 053de04 | 2008-01-30 13:31:27 +0100 | [diff] [blame] | 429 | regs->flags |= X86_EFLAGS_TF; |
| 430 | regs->flags &= ~X86_EFLAGS_IF; |
Harvey Harrison | e7b5e11 | 2008-01-30 13:31:43 +0100 | [diff] [blame] | 431 | /* single step inline if the instruction is an int3 */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | if (p->opcode == BREAKPOINT_INSTRUCTION) |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 433 | regs->ip = (unsigned long)p->addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | else |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 435 | regs->ip = (unsigned long)p->ainsn.insn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | } |
| 437 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 438 | void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, |
Prasanna S Panchamukhi | 0f2fbdc | 2005-09-06 15:19:28 -0700 | [diff] [blame] | 439 | struct pt_regs *regs) |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 440 | { |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 441 | unsigned long *sara = stack_addr(regs); |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 442 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 443 | ri->ret_addr = (kprobe_opcode_t *) *sara; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 444 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 445 | /* Replace the return addr with trampoline addr */ |
| 446 | *sara = (unsigned long) &kretprobe_trampoline; |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 447 | } |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 448 | |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 449 | static void __kprobes setup_singlestep(struct kprobe *p, struct pt_regs *regs, |
| 450 | struct kprobe_ctlblk *kcb) |
| 451 | { |
Masami Hiramatsu | 5a4ccaf | 2009-01-06 21:15:32 +0100 | [diff] [blame] | 452 | #if !defined(CONFIG_PREEMPT) || defined(CONFIG_FREEZER) |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 453 | if (p->ainsn.boostable == 1 && !p->post_handler) { |
| 454 | /* Boost up -- we can execute copied instructions directly */ |
| 455 | reset_current_kprobe(); |
| 456 | regs->ip = (unsigned long)p->ainsn.insn; |
| 457 | preempt_enable_no_resched(); |
| 458 | return; |
| 459 | } |
| 460 | #endif |
| 461 | prepare_singlestep(p, regs); |
| 462 | kcb->kprobe_status = KPROBE_HIT_SS; |
| 463 | } |
| 464 | |
Harvey Harrison | 40102d4 | 2008-01-30 13:32:02 +0100 | [diff] [blame] | 465 | /* |
| 466 | * We have reentered the kprobe_handler(), since another probe was hit while |
| 467 | * within the handler. We save the original kprobes variables and just single |
| 468 | * step on the instruction of the new probe without calling any user handlers. |
| 469 | */ |
Masami Hiramatsu | 59e87cd | 2008-01-30 13:32:02 +0100 | [diff] [blame] | 470 | static int __kprobes reenter_kprobe(struct kprobe *p, struct pt_regs *regs, |
| 471 | struct kprobe_ctlblk *kcb) |
Harvey Harrison | 40102d4 | 2008-01-30 13:32:02 +0100 | [diff] [blame] | 472 | { |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 473 | switch (kcb->kprobe_status) { |
| 474 | case KPROBE_HIT_SSDONE: |
Masami Hiramatsu | 59e87cd | 2008-01-30 13:32:02 +0100 | [diff] [blame] | 475 | #ifdef CONFIG_X86_64 |
Masami Hiramatsu | 59e87cd | 2008-01-30 13:32:02 +0100 | [diff] [blame] | 476 | /* TODO: Provide re-entrancy from post_kprobes_handler() and |
| 477 | * avoid exception stack corruption while single-stepping on |
| 478 | * the instruction of the new probe. |
| 479 | */ |
| 480 | arch_disarm_kprobe(p); |
| 481 | regs->ip = (unsigned long)p->addr; |
| 482 | reset_current_kprobe(); |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 483 | preempt_enable_no_resched(); |
| 484 | break; |
Masami Hiramatsu | 59e87cd | 2008-01-30 13:32:02 +0100 | [diff] [blame] | 485 | #endif |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 486 | case KPROBE_HIT_ACTIVE: |
Abhishek Sagar | fb8830e | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 487 | save_previous_kprobe(kcb); |
| 488 | set_current_kprobe(p, regs, kcb); |
| 489 | kprobes_inc_nmissed_count(p); |
| 490 | prepare_singlestep(p, regs); |
| 491 | kcb->kprobe_status = KPROBE_REENTER; |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 492 | break; |
| 493 | case KPROBE_HIT_SS: |
Abhishek Sagar | fb8830e | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 494 | if (p == kprobe_running()) { |
gorcunov@gmail.com | a5c15d4 | 2008-03-28 17:56:56 +0300 | [diff] [blame] | 495 | regs->flags &= ~X86_EFLAGS_TF; |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 496 | regs->flags |= kcb->kprobe_saved_flags; |
| 497 | return 0; |
| 498 | } else { |
Abhishek Sagar | fb8830e | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 499 | /* A probe has been hit in the codepath leading up |
| 500 | * to, or just after, single-stepping of a probed |
| 501 | * instruction. This entire codepath should strictly |
| 502 | * reside in .kprobes.text section. Raise a warning |
| 503 | * to highlight this peculiar case. |
| 504 | */ |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 505 | } |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 506 | default: |
| 507 | /* impossible cases */ |
| 508 | WARN_ON(1); |
Abhishek Sagar | fb8830e | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 509 | return 0; |
Masami Hiramatsu | 59e87cd | 2008-01-30 13:32:02 +0100 | [diff] [blame] | 510 | } |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 511 | |
Masami Hiramatsu | 59e87cd | 2008-01-30 13:32:02 +0100 | [diff] [blame] | 512 | return 1; |
Harvey Harrison | 40102d4 | 2008-01-30 13:32:02 +0100 | [diff] [blame] | 513 | } |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 514 | |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 515 | /* |
| 516 | * Interrupts are disabled on entry as trap3 is an interrupt gate and they |
| 517 | * remain disabled thorough out this function. |
| 518 | */ |
| 519 | static int __kprobes kprobe_handler(struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | { |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 521 | kprobe_opcode_t *addr; |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 522 | struct kprobe *p; |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 523 | struct kprobe_ctlblk *kcb; |
| 524 | |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 525 | addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t)); |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 526 | if (*addr != BREAKPOINT_INSTRUCTION) { |
| 527 | /* |
| 528 | * The breakpoint instruction was removed right |
| 529 | * after we hit it. Another cpu has removed |
| 530 | * either a probepoint or a debugger breakpoint |
| 531 | * at this address. In either case, no further |
| 532 | * handling of this interrupt is appropriate. |
| 533 | * Back up over the (now missing) int3 and run |
| 534 | * the original instruction. |
| 535 | */ |
| 536 | regs->ip = (unsigned long)addr; |
| 537 | return 1; |
| 538 | } |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 539 | |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 540 | /* |
| 541 | * We don't want to be preempted for the entire |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 542 | * duration of kprobe processing. We conditionally |
| 543 | * re-enable preemption at the end of this function, |
| 544 | * and also in reenter_kprobe() and setup_singlestep(). |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 545 | */ |
| 546 | preempt_disable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 548 | kcb = get_kprobe_ctlblk(); |
Harvey Harrison | b976015 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 549 | p = get_kprobe(addr); |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 550 | |
Harvey Harrison | b976015 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 551 | if (p) { |
Harvey Harrison | b976015 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 552 | if (kprobe_running()) { |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 553 | if (reenter_kprobe(p, regs, kcb)) |
| 554 | return 1; |
Harvey Harrison | b976015 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 555 | } else { |
| 556 | set_current_kprobe(p, regs, kcb); |
| 557 | kcb->kprobe_status = KPROBE_HIT_ACTIVE; |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 558 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | /* |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 560 | * If we have no pre-handler or it returned 0, we |
| 561 | * continue with normal processing. If we have a |
| 562 | * pre-handler and it returned non-zero, it prepped |
| 563 | * for calling the break_handler below on re-entry |
| 564 | * for jprobe processing, so get out doing nothing |
| 565 | * more here. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | */ |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 567 | if (!p->pre_handler || !p->pre_handler(p, regs)) |
| 568 | setup_singlestep(p, regs, kcb); |
| 569 | return 1; |
Harvey Harrison | b976015 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 570 | } |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 571 | } else if (kprobe_running()) { |
| 572 | p = __get_cpu_var(current_kprobe); |
| 573 | if (p->break_handler && p->break_handler(p, regs)) { |
| 574 | setup_singlestep(p, regs, kcb); |
| 575 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | } |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 577 | } /* else: not a kprobe fault; let the kernel handle it */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 579 | preempt_enable_no_resched(); |
Abhishek Sagar | f315dec | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 580 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | } |
| 582 | |
| 583 | /* |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 584 | * When a retprobed function returns, this code saves registers and |
| 585 | * calls trampoline_handler() runs, which calls the kretprobe's handler. |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 586 | */ |
Harvey Harrison | f1452d4 | 2008-02-14 15:23:53 -0800 | [diff] [blame] | 587 | static void __used __kprobes kretprobe_trampoline_holder(void) |
Harvey Harrison | 1017579 | 2008-01-30 13:33:01 +0100 | [diff] [blame] | 588 | { |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 589 | asm volatile ( |
| 590 | ".global kretprobe_trampoline\n" |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 591 | "kretprobe_trampoline: \n" |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 592 | #ifdef CONFIG_X86_64 |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 593 | /* We don't bother saving the ss register */ |
| 594 | " pushq %rsp\n" |
| 595 | " pushfq\n" |
| 596 | /* |
| 597 | * Skip cs, ip, orig_ax. |
| 598 | * trampoline_handler() will plug in these values |
| 599 | */ |
| 600 | " subq $24, %rsp\n" |
| 601 | " pushq %rdi\n" |
| 602 | " pushq %rsi\n" |
| 603 | " pushq %rdx\n" |
| 604 | " pushq %rcx\n" |
| 605 | " pushq %rax\n" |
| 606 | " pushq %r8\n" |
| 607 | " pushq %r9\n" |
| 608 | " pushq %r10\n" |
| 609 | " pushq %r11\n" |
| 610 | " pushq %rbx\n" |
| 611 | " pushq %rbp\n" |
| 612 | " pushq %r12\n" |
| 613 | " pushq %r13\n" |
| 614 | " pushq %r14\n" |
| 615 | " pushq %r15\n" |
| 616 | " movq %rsp, %rdi\n" |
| 617 | " call trampoline_handler\n" |
| 618 | /* Replace saved sp with true return address. */ |
| 619 | " movq %rax, 152(%rsp)\n" |
| 620 | " popq %r15\n" |
| 621 | " popq %r14\n" |
| 622 | " popq %r13\n" |
| 623 | " popq %r12\n" |
| 624 | " popq %rbp\n" |
| 625 | " popq %rbx\n" |
| 626 | " popq %r11\n" |
| 627 | " popq %r10\n" |
| 628 | " popq %r9\n" |
| 629 | " popq %r8\n" |
| 630 | " popq %rax\n" |
| 631 | " popq %rcx\n" |
| 632 | " popq %rdx\n" |
| 633 | " popq %rsi\n" |
| 634 | " popq %rdi\n" |
| 635 | /* Skip orig_ax, ip, cs */ |
| 636 | " addq $24, %rsp\n" |
| 637 | " popfq\n" |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 638 | #else |
| 639 | " pushf\n" |
| 640 | /* |
Masami Hiramatsu | fee039a | 2009-03-23 10:14:52 -0400 | [diff] [blame] | 641 | * Skip cs, ip, orig_ax and gs. |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 642 | * trampoline_handler() will plug in these values |
| 643 | */ |
Masami Hiramatsu | fee039a | 2009-03-23 10:14:52 -0400 | [diff] [blame] | 644 | " subl $16, %esp\n" |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 645 | " pushl %fs\n" |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 646 | " pushl %es\n" |
Masami Hiramatsu | fee039a | 2009-03-23 10:14:52 -0400 | [diff] [blame] | 647 | " pushl %ds\n" |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 648 | " pushl %eax\n" |
| 649 | " pushl %ebp\n" |
| 650 | " pushl %edi\n" |
| 651 | " pushl %esi\n" |
| 652 | " pushl %edx\n" |
| 653 | " pushl %ecx\n" |
| 654 | " pushl %ebx\n" |
| 655 | " movl %esp, %eax\n" |
| 656 | " call trampoline_handler\n" |
| 657 | /* Move flags to cs */ |
Masami Hiramatsu | fee039a | 2009-03-23 10:14:52 -0400 | [diff] [blame] | 658 | " movl 56(%esp), %edx\n" |
| 659 | " movl %edx, 52(%esp)\n" |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 660 | /* Replace saved flags with true return address. */ |
Masami Hiramatsu | fee039a | 2009-03-23 10:14:52 -0400 | [diff] [blame] | 661 | " movl %eax, 56(%esp)\n" |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 662 | " popl %ebx\n" |
| 663 | " popl %ecx\n" |
| 664 | " popl %edx\n" |
| 665 | " popl %esi\n" |
| 666 | " popl %edi\n" |
| 667 | " popl %ebp\n" |
| 668 | " popl %eax\n" |
Masami Hiramatsu | fee039a | 2009-03-23 10:14:52 -0400 | [diff] [blame] | 669 | /* Skip ds, es, fs, gs, orig_ax and ip */ |
| 670 | " addl $24, %esp\n" |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 671 | " popf\n" |
| 672 | #endif |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 673 | " ret\n"); |
Harvey Harrison | 1017579 | 2008-01-30 13:33:01 +0100 | [diff] [blame] | 674 | } |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 675 | |
| 676 | /* |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 677 | * Called from kretprobe_trampoline |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 678 | */ |
Harvey Harrison | f1452d4 | 2008-02-14 15:23:53 -0800 | [diff] [blame] | 679 | static __used __kprobes void *trampoline_handler(struct pt_regs *regs) |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 680 | { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 681 | struct kretprobe_instance *ri = NULL; |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 682 | struct hlist_head *head, empty_rp; |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 683 | struct hlist_node *node, *tmp; |
Ananth N Mavinakayanahalli | 991a51d | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 684 | unsigned long flags, orig_ret_address = 0; |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 685 | unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline; |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 686 | |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 687 | INIT_HLIST_HEAD(&empty_rp); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 688 | kretprobe_hash_lock(current, &head, &flags); |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 689 | /* fixup registers */ |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 690 | #ifdef CONFIG_X86_64 |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 691 | regs->cs = __KERNEL_CS; |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 692 | #else |
| 693 | regs->cs = __KERNEL_CS | get_kernel_rpl(); |
Masami Hiramatsu | fee039a | 2009-03-23 10:14:52 -0400 | [diff] [blame] | 694 | regs->gs = 0; |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 695 | #endif |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 696 | regs->ip = trampoline_address; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 697 | regs->orig_ax = ~0UL; |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 698 | |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 699 | /* |
| 700 | * It is possible to have multiple instances associated with a given |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 701 | * task either because multiple functions in the call path have |
Frederik Schwarzer | 025dfda | 2008-10-16 19:02:37 +0200 | [diff] [blame] | 702 | * return probes installed on them, and/or more than one |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 703 | * return probe was registered for a target function. |
| 704 | * |
| 705 | * We can handle this because: |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 706 | * - instances are always pushed into the head of the list |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 707 | * - when multiple return probes are registered for the same |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 708 | * function, the (chronologically) first instance's ret_addr |
| 709 | * will be the real return address, and all the rest will |
| 710 | * point to kretprobe_trampoline. |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 711 | */ |
| 712 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 713 | if (ri->task != current) |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 714 | /* another task is sharing our hash bucket */ |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 715 | continue; |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 716 | |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 717 | if (ri->rp && ri->rp->handler) { |
| 718 | __get_cpu_var(current_kprobe) = &ri->rp->kp; |
| 719 | get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE; |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 720 | ri->rp->handler(ri, regs); |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 721 | __get_cpu_var(current_kprobe) = NULL; |
| 722 | } |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 723 | |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 724 | orig_ret_address = (unsigned long)ri->ret_addr; |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 725 | recycle_rp_inst(ri, &empty_rp); |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 726 | |
| 727 | if (orig_ret_address != trampoline_address) |
| 728 | /* |
| 729 | * This is the real return address. Any other |
| 730 | * instances associated with this task are for |
| 731 | * other calls deeper on the call stack |
| 732 | */ |
| 733 | break; |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 734 | } |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 735 | |
Ananth N Mavinakayanahalli | 0f95b7f | 2007-05-08 00:28:27 -0700 | [diff] [blame] | 736 | kretprobe_assert(ri, orig_ret_address, trampoline_address); |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 737 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 738 | kretprobe_hash_unlock(current, &flags); |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 739 | |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 740 | hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { |
| 741 | hlist_del(&ri->hlist); |
| 742 | kfree(ri); |
| 743 | } |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 744 | return (void *)orig_ret_address; |
Rusty Lynch | 73649da | 2005-06-23 00:09:23 -0700 | [diff] [blame] | 745 | } |
| 746 | |
| 747 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | * Called after single-stepping. p->addr is the address of the |
| 749 | * instruction whose first byte has been replaced by the "int 3" |
| 750 | * instruction. To avoid the SMP problems that can occur when we |
| 751 | * temporarily put back the original opcode to single-step, we |
| 752 | * single-stepped a copy of the instruction. The address of this |
| 753 | * copy is p->ainsn.insn. |
| 754 | * |
| 755 | * This function prepares to return from the post-single-step |
| 756 | * interrupt. We have to fix up the stack as follows: |
| 757 | * |
| 758 | * 0) Except in the case of absolute or indirect jump or call instructions, |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 759 | * the new ip is relative to the copied instruction. We need to make |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | * it relative to the original instruction. |
| 761 | * |
| 762 | * 1) If the single-stepped instruction was pushfl, then the TF and IF |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 763 | * flags are set in the just-pushed flags, and may need to be cleared. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | * |
| 765 | * 2) If the single-stepped instruction was a call, the return address |
| 766 | * that is atop the stack is the address following the copied instruction. |
| 767 | * We need to make it the address following the original instruction. |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 768 | * |
| 769 | * If this is the first time we've single-stepped the instruction at |
| 770 | * this probepoint, and the instruction is boostable, boost it: add a |
| 771 | * jump instruction after the copied instruction, that jumps to the next |
| 772 | * instruction after the probepoint. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | */ |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 774 | static void __kprobes resume_execution(struct kprobe *p, |
| 775 | struct pt_regs *regs, struct kprobe_ctlblk *kcb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 776 | { |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 777 | unsigned long *tos = stack_addr(regs); |
| 778 | unsigned long copy_ip = (unsigned long)p->ainsn.insn; |
| 779 | unsigned long orig_ip = (unsigned long)p->addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | kprobe_opcode_t *insn = p->ainsn.insn; |
| 781 | |
| 782 | /*skip the REX prefix*/ |
Harvey Harrison | 9930927 | 2008-01-30 13:32:14 +0100 | [diff] [blame] | 783 | if (is_REX_prefix(insn)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 784 | insn++; |
| 785 | |
Glauber de Oliveira Costa | 053de04 | 2008-01-30 13:31:27 +0100 | [diff] [blame] | 786 | regs->flags &= ~X86_EFLAGS_TF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | switch (*insn) { |
Masami Hiramatsu | 0b0122f | 2007-12-18 18:05:58 +0100 | [diff] [blame] | 788 | case 0x9c: /* pushfl */ |
Glauber de Oliveira Costa | 053de04 | 2008-01-30 13:31:27 +0100 | [diff] [blame] | 789 | *tos &= ~(X86_EFLAGS_TF | X86_EFLAGS_IF); |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 790 | *tos |= kcb->kprobe_old_flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | break; |
Masami Hiramatsu | 0b0122f | 2007-12-18 18:05:58 +0100 | [diff] [blame] | 792 | case 0xc2: /* iret/ret/lret */ |
| 793 | case 0xc3: |
Prasanna S Panchamukhi | 0b9e2ca | 2005-05-05 16:15:40 -0700 | [diff] [blame] | 794 | case 0xca: |
Masami Hiramatsu | 0b0122f | 2007-12-18 18:05:58 +0100 | [diff] [blame] | 795 | case 0xcb: |
| 796 | case 0xcf: |
| 797 | case 0xea: /* jmp absolute -- ip is correct */ |
| 798 | /* ip is already adjusted, no more changes required */ |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 799 | p->ainsn.boostable = 1; |
Masami Hiramatsu | 0b0122f | 2007-12-18 18:05:58 +0100 | [diff] [blame] | 800 | goto no_change; |
| 801 | case 0xe8: /* call relative - Fix return addr */ |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 802 | *tos = orig_ip + (*tos - copy_ip); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 803 | break; |
Harvey Harrison | e7b5e11 | 2008-01-30 13:31:43 +0100 | [diff] [blame] | 804 | #ifdef CONFIG_X86_32 |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 805 | case 0x9a: /* call absolute -- same as call absolute, indirect */ |
| 806 | *tos = orig_ip + (*tos - copy_ip); |
| 807 | goto no_change; |
| 808 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 809 | case 0xff: |
Satoshi Oshima | dc49e34 | 2006-05-20 15:00:21 -0700 | [diff] [blame] | 810 | if ((insn[1] & 0x30) == 0x10) { |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 811 | /* |
| 812 | * call absolute, indirect |
| 813 | * Fix return addr; ip is correct. |
| 814 | * But this is not boostable |
| 815 | */ |
| 816 | *tos = orig_ip + (*tos - copy_ip); |
Masami Hiramatsu | 0b0122f | 2007-12-18 18:05:58 +0100 | [diff] [blame] | 817 | goto no_change; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 818 | } else if (((insn[1] & 0x31) == 0x20) || |
| 819 | ((insn[1] & 0x31) == 0x21)) { |
| 820 | /* |
| 821 | * jmp near and far, absolute indirect |
| 822 | * ip is correct. And this is boostable |
| 823 | */ |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 824 | p->ainsn.boostable = 1; |
Masami Hiramatsu | 0b0122f | 2007-12-18 18:05:58 +0100 | [diff] [blame] | 825 | goto no_change; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | default: |
| 828 | break; |
| 829 | } |
| 830 | |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 831 | if (p->ainsn.boostable == 0) { |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 832 | if ((regs->ip > copy_ip) && |
| 833 | (regs->ip - copy_ip) + 5 < MAX_INSN_SIZE) { |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 834 | /* |
| 835 | * These instructions can be executed directly if it |
| 836 | * jumps back to correct address. |
| 837 | */ |
| 838 | set_jmp_op((void *)regs->ip, |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 839 | (void *)orig_ip + (regs->ip - copy_ip)); |
Masami Hiramatsu | aa47014 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 840 | p->ainsn.boostable = 1; |
| 841 | } else { |
| 842 | p->ainsn.boostable = -1; |
| 843 | } |
| 844 | } |
| 845 | |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 846 | regs->ip += orig_ip - copy_ip; |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 847 | |
Masami Hiramatsu | 0b0122f | 2007-12-18 18:05:58 +0100 | [diff] [blame] | 848 | no_change: |
Roland McGrath | 1ecc798 | 2008-01-30 13:30:54 +0100 | [diff] [blame] | 849 | restore_btf(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | } |
| 851 | |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 852 | /* |
| 853 | * Interrupts are disabled on entry as trap1 is an interrupt gate and they |
| 854 | * remain disabled thoroughout this function. |
| 855 | */ |
| 856 | static int __kprobes post_kprobe_handler(struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | { |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 858 | struct kprobe *cur = kprobe_running(); |
| 859 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
| 860 | |
| 861 | if (!cur) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 862 | return 0; |
| 863 | |
Yakov Lerner | acb5b8a | 2008-03-16 03:21:21 -0500 | [diff] [blame] | 864 | resume_execution(cur, regs, kcb); |
| 865 | regs->flags |= kcb->kprobe_saved_flags; |
Yakov Lerner | acb5b8a | 2008-03-16 03:21:21 -0500 | [diff] [blame] | 866 | |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 867 | if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { |
| 868 | kcb->kprobe_status = KPROBE_HIT_SSDONE; |
| 869 | cur->post_handler(cur, regs, 0); |
Prasanna S Panchamukhi | aa3d7e3 | 2005-06-23 00:09:37 -0700 | [diff] [blame] | 870 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 871 | |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 872 | /* Restore back the original saved kprobes variables and continue. */ |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 873 | if (kcb->kprobe_status == KPROBE_REENTER) { |
| 874 | restore_previous_kprobe(kcb); |
Prasanna S Panchamukhi | aa3d7e3 | 2005-06-23 00:09:37 -0700 | [diff] [blame] | 875 | goto out; |
Prasanna S Panchamukhi | aa3d7e3 | 2005-06-23 00:09:37 -0700 | [diff] [blame] | 876 | } |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 877 | reset_current_kprobe(); |
Prasanna S Panchamukhi | aa3d7e3 | 2005-06-23 00:09:37 -0700 | [diff] [blame] | 878 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 879 | preempt_enable_no_resched(); |
| 880 | |
| 881 | /* |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 882 | * if somebody else is singlestepping across a probe point, flags |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 883 | * will have TF set, in which case, continue the remaining processing |
| 884 | * of do_debug, as if this is not a probe hit. |
| 885 | */ |
Glauber de Oliveira Costa | 053de04 | 2008-01-30 13:31:27 +0100 | [diff] [blame] | 886 | if (regs->flags & X86_EFLAGS_TF) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 887 | return 0; |
| 888 | |
| 889 | return 1; |
| 890 | } |
| 891 | |
Prasanna S Panchamukhi | 0f2fbdc | 2005-09-06 15:19:28 -0700 | [diff] [blame] | 892 | int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 893 | { |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 894 | struct kprobe *cur = kprobe_running(); |
| 895 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
| 896 | |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 897 | switch (kcb->kprobe_status) { |
Prasanna S Panchamukhi | c28f896 | 2006-03-26 01:38:23 -0800 | [diff] [blame] | 898 | case KPROBE_HIT_SS: |
| 899 | case KPROBE_REENTER: |
| 900 | /* |
| 901 | * We are here because the instruction being single |
| 902 | * stepped caused a page fault. We reset the current |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 903 | * kprobe and the ip points back to the probe address |
Prasanna S Panchamukhi | c28f896 | 2006-03-26 01:38:23 -0800 | [diff] [blame] | 904 | * and allow the page fault handler to continue as a |
| 905 | * normal page fault. |
| 906 | */ |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 907 | regs->ip = (unsigned long)cur->addr; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 908 | regs->flags |= kcb->kprobe_old_flags; |
Prasanna S Panchamukhi | c28f896 | 2006-03-26 01:38:23 -0800 | [diff] [blame] | 909 | if (kcb->kprobe_status == KPROBE_REENTER) |
| 910 | restore_previous_kprobe(kcb); |
| 911 | else |
| 912 | reset_current_kprobe(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 913 | preempt_enable_no_resched(); |
Prasanna S Panchamukhi | c28f896 | 2006-03-26 01:38:23 -0800 | [diff] [blame] | 914 | break; |
| 915 | case KPROBE_HIT_ACTIVE: |
| 916 | case KPROBE_HIT_SSDONE: |
| 917 | /* |
| 918 | * We increment the nmissed count for accounting, |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 919 | * we can also use npre/npostfault count for accounting |
Prasanna S Panchamukhi | c28f896 | 2006-03-26 01:38:23 -0800 | [diff] [blame] | 920 | * these specific fault cases. |
| 921 | */ |
| 922 | kprobes_inc_nmissed_count(cur); |
| 923 | |
| 924 | /* |
| 925 | * We come here because instructions in the pre/post |
| 926 | * handler caused the page_fault, this could happen |
| 927 | * if handler tries to access user space by |
| 928 | * copy_from_user(), get_user() etc. Let the |
| 929 | * user-specified handler try to fix it first. |
| 930 | */ |
| 931 | if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) |
| 932 | return 1; |
| 933 | |
| 934 | /* |
| 935 | * In case the user-specified fault handler returned |
| 936 | * zero, try to fix up. |
| 937 | */ |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 938 | if (fixup_exception(regs)) |
| 939 | return 1; |
Harvey Harrison | 6d48583 | 2008-01-30 13:31:41 +0100 | [diff] [blame] | 940 | |
Prasanna S Panchamukhi | c28f896 | 2006-03-26 01:38:23 -0800 | [diff] [blame] | 941 | /* |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 942 | * fixup routine could not handle it, |
Prasanna S Panchamukhi | c28f896 | 2006-03-26 01:38:23 -0800 | [diff] [blame] | 943 | * Let do_page_fault() fix it. |
| 944 | */ |
| 945 | break; |
| 946 | default: |
| 947 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 948 | } |
| 949 | return 0; |
| 950 | } |
| 951 | |
| 952 | /* |
| 953 | * Wrapper routine for handling exceptions. |
| 954 | */ |
Prasanna S Panchamukhi | 0f2fbdc | 2005-09-06 15:19:28 -0700 | [diff] [blame] | 955 | int __kprobes kprobe_exceptions_notify(struct notifier_block *self, |
| 956 | unsigned long val, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 957 | { |
Jan Engelhardt | ade1af7 | 2008-01-30 13:33:23 +0100 | [diff] [blame] | 958 | struct die_args *args = data; |
Ananth N Mavinakayanahalli | 66ff2d0 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 959 | int ret = NOTIFY_DONE; |
| 960 | |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 961 | if (args->regs && user_mode_vm(args->regs)) |
bibo,mao | 2326c77 | 2006-03-26 01:38:21 -0800 | [diff] [blame] | 962 | return ret; |
| 963 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 964 | switch (val) { |
| 965 | case DIE_INT3: |
| 966 | if (kprobe_handler(args->regs)) |
Ananth N Mavinakayanahalli | 66ff2d0 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 967 | ret = NOTIFY_STOP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 968 | break; |
| 969 | case DIE_DEBUG: |
| 970 | if (post_kprobe_handler(args->regs)) |
Ananth N Mavinakayanahalli | 66ff2d0 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 971 | ret = NOTIFY_STOP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 972 | break; |
| 973 | case DIE_GPF: |
Quentin Barnes | b506a9d | 2008-01-30 13:32:32 +0100 | [diff] [blame] | 974 | /* |
| 975 | * To be potentially processing a kprobe fault and to |
| 976 | * trust the result from kprobe_running(), we have |
| 977 | * be non-preemptible. |
| 978 | */ |
| 979 | if (!preemptible() && kprobe_running() && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 980 | kprobe_fault_handler(args->regs, args->trapnr)) |
Ananth N Mavinakayanahalli | 66ff2d0 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 981 | ret = NOTIFY_STOP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 982 | break; |
| 983 | default: |
| 984 | break; |
| 985 | } |
Ananth N Mavinakayanahalli | 66ff2d0 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 986 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 987 | } |
| 988 | |
Prasanna S Panchamukhi | 0f2fbdc | 2005-09-06 15:19:28 -0700 | [diff] [blame] | 989 | int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 990 | { |
| 991 | struct jprobe *jp = container_of(p, struct jprobe, kp); |
| 992 | unsigned long addr; |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 993 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 995 | kcb->jprobe_saved_regs = *regs; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 996 | kcb->jprobe_saved_sp = stack_addr(regs); |
| 997 | addr = (unsigned long)(kcb->jprobe_saved_sp); |
| 998 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 999 | /* |
| 1000 | * As Linus pointed out, gcc assumes that the callee |
| 1001 | * owns the argument space and could overwrite it, e.g. |
| 1002 | * tailcall optimization. So, to be absolutely safe |
| 1003 | * we also save and restore enough stack bytes to cover |
| 1004 | * the argument area. |
| 1005 | */ |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 1006 | memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr, |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 1007 | MIN_STACK_SIZE(addr)); |
Glauber de Oliveira Costa | 053de04 | 2008-01-30 13:31:27 +0100 | [diff] [blame] | 1008 | regs->flags &= ~X86_EFLAGS_IF; |
Peter Zijlstra | 58dfe88 | 2007-10-11 22:25:25 +0200 | [diff] [blame] | 1009 | trace_hardirqs_off(); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 1010 | regs->ip = (unsigned long)(jp->entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | return 1; |
| 1012 | } |
| 1013 | |
Prasanna S Panchamukhi | 0f2fbdc | 2005-09-06 15:19:28 -0700 | [diff] [blame] | 1014 | void __kprobes jprobe_return(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1015 | { |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 1016 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
| 1017 | |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 1018 | asm volatile ( |
| 1019 | #ifdef CONFIG_X86_64 |
| 1020 | " xchg %%rbx,%%rsp \n" |
| 1021 | #else |
| 1022 | " xchgl %%ebx,%%esp \n" |
| 1023 | #endif |
| 1024 | " int3 \n" |
| 1025 | " .globl jprobe_return_end\n" |
| 1026 | " jprobe_return_end: \n" |
| 1027 | " nop \n"::"b" |
| 1028 | (kcb->jprobe_saved_sp):"memory"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1029 | } |
| 1030 | |
Prasanna S Panchamukhi | 0f2fbdc | 2005-09-06 15:19:28 -0700 | [diff] [blame] | 1031 | int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1032 | { |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 1033 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 1034 | u8 *addr = (u8 *) (regs->ip - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1035 | struct jprobe *jp = container_of(p, struct jprobe, kp); |
| 1036 | |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 1037 | if ((addr > (u8 *) jprobe_return) && |
| 1038 | (addr < (u8 *) jprobe_return_end)) { |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 1039 | if (stack_addr(regs) != kcb->jprobe_saved_sp) { |
Masami Hiramatsu | 29b6cd7 | 2007-12-18 18:05:58 +0100 | [diff] [blame] | 1040 | struct pt_regs *saved_regs = &kcb->jprobe_saved_regs; |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 1041 | printk(KERN_ERR |
| 1042 | "current sp %p does not match saved sp %p\n", |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 1043 | stack_addr(regs), kcb->jprobe_saved_sp); |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 1044 | printk(KERN_ERR "Saved registers for jprobe %p\n", jp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1045 | show_registers(saved_regs); |
Masami Hiramatsu | d6be29b | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 1046 | printk(KERN_ERR "Current registers\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1047 | show_registers(regs); |
| 1048 | BUG(); |
| 1049 | } |
Ananth N Mavinakayanahalli | e7a510f | 2005-11-07 01:00:12 -0800 | [diff] [blame] | 1050 | *regs = kcb->jprobe_saved_regs; |
Masami Hiramatsu | 8533bbe | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 1051 | memcpy((kprobe_opcode_t *)(kcb->jprobe_saved_sp), |
| 1052 | kcb->jprobes_stack, |
| 1053 | MIN_STACK_SIZE(kcb->jprobe_saved_sp)); |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 1054 | preempt_enable_no_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1055 | return 1; |
| 1056 | } |
| 1057 | return 0; |
| 1058 | } |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 1059 | |
Rusty Lynch | 6772926 | 2005-07-05 18:54:50 -0700 | [diff] [blame] | 1060 | int __init arch_init_kprobes(void) |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 1061 | { |
Masami Hiramatsu | da07ab0 | 2008-01-30 13:31:21 +0100 | [diff] [blame] | 1062 | return 0; |
Rusty Lynch | ba8af12 | 2005-06-27 15:17:10 -0700 | [diff] [blame] | 1063 | } |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1064 | |
| 1065 | int __kprobes arch_trampoline_kprobe(struct kprobe *p) |
| 1066 | { |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1067 | return 0; |
| 1068 | } |