Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Copyright (C) 1991, 1992 Linus Torvalds |
Alexander van Heukelum | a8c1be9 | 2008-07-02 01:29:44 +0200 | [diff] [blame] | 3 | * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * |
| 5 | * Pentium III FXSR, SSE support |
| 6 | * Gareth Hughes <gareth@valinux.com>, May 2000 |
| 7 | */ |
| 8 | |
| 9 | /* |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 10 | * Handle hardware traps and faults. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | */ |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 12 | |
| 13 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 14 | |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 15 | #include <linux/context_tracking.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/interrupt.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/kallsyms.h> |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 18 | #include <linux/spinlock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include <linux/kprobes.h> |
Andrew Morton | 1e2af92 | 2006-09-27 01:51:15 -0700 | [diff] [blame] | 20 | #include <linux/uaccess.h> |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 21 | #include <linux/kdebug.h> |
Jason Wessel | f503b5a | 2010-05-20 21:04:25 -0500 | [diff] [blame] | 22 | #include <linux/kgdb.h> |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 23 | #include <linux/kernel.h> |
Paul Gortmaker | 186f436 | 2016-07-13 20:18:56 -0400 | [diff] [blame] | 24 | #include <linux/export.h> |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 25 | #include <linux/ptrace.h> |
Oleg Nesterov | b02ef20 | 2014-05-12 18:24:45 +0200 | [diff] [blame] | 26 | #include <linux/uprobes.h> |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 27 | #include <linux/string.h> |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 28 | #include <linux/delay.h> |
| 29 | #include <linux/errno.h> |
| 30 | #include <linux/kexec.h> |
| 31 | #include <linux/sched.h> |
| 32 | #include <linux/timer.h> |
| 33 | #include <linux/init.h> |
Jeremy Fitzhardinge | 91768d6 | 2006-12-08 02:36:21 -0800 | [diff] [blame] | 34 | #include <linux/bug.h> |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 35 | #include <linux/nmi.h> |
| 36 | #include <linux/mm.h> |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 37 | #include <linux/smp.h> |
| 38 | #include <linux/io.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | |
| 40 | #ifdef CONFIG_EISA |
| 41 | #include <linux/ioport.h> |
| 42 | #include <linux/eisa.h> |
| 43 | #endif |
| 44 | |
Dave Jiang | c0d1217 | 2007-07-19 01:49:46 -0700 | [diff] [blame] | 45 | #if defined(CONFIG_EDAC) |
| 46 | #include <linux/edac.h> |
| 47 | #endif |
| 48 | |
Vegard Nossum | f856129 | 2008-04-04 00:53:23 +0200 | [diff] [blame] | 49 | #include <asm/kmemcheck.h> |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 50 | #include <asm/stacktrace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | #include <asm/processor.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | #include <asm/debugreg.h> |
Arun Sharma | 60063497 | 2011-07-26 16:09:06 -0700 | [diff] [blame] | 53 | #include <linux/atomic.h> |
Andy Lutomirski | 35de5b0 | 2016-04-26 12:23:24 -0700 | [diff] [blame] | 54 | #include <asm/text-patching.h> |
Steven Rostedt | 08d636b | 2011-08-16 09:57:10 -0400 | [diff] [blame] | 55 | #include <asm/ftrace.h> |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 56 | #include <asm/traps.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | #include <asm/desc.h> |
Ingo Molnar | 78f7f1e | 2015-04-24 02:54:44 +0200 | [diff] [blame] | 58 | #include <asm/fpu/internal.h> |
Hidetoshi Seto | 9e55e44 | 2009-06-15 17:22:15 +0900 | [diff] [blame] | 59 | #include <asm/mce.h> |
Kees Cook | 4eefbe7 | 2013-04-10 12:24:22 -0700 | [diff] [blame] | 60 | #include <asm/fixmap.h> |
Ingo Molnar | 1164dd0 | 2009-01-28 19:34:09 +0100 | [diff] [blame] | 61 | #include <asm/mach_traps.h> |
Jiri Kosina | 17f4157 | 2013-07-23 10:09:28 +0200 | [diff] [blame] | 62 | #include <asm/alternative.h> |
Dave Hansen | a84eeaa | 2015-06-07 11:37:01 -0700 | [diff] [blame] | 63 | #include <asm/fpu/xstate.h> |
Dave Hansen | e7126cf | 2015-06-07 11:37:03 -0700 | [diff] [blame] | 64 | #include <asm/trace/mpx.h> |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 65 | #include <asm/mpx.h> |
Brian Gerst | ba3e127 | 2015-07-29 01:41:21 -0400 | [diff] [blame] | 66 | #include <asm/vm86.h> |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 67 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 68 | #ifdef CONFIG_X86_64 |
Thomas Gleixner | 428cf90 | 2009-08-20 10:35:46 +0200 | [diff] [blame] | 69 | #include <asm/x86_init.h> |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 70 | #include <asm/pgalloc.h> |
| 71 | #include <asm/proto.h> |
Kees Cook | 4df05f3 | 2013-07-16 11:34:41 -0700 | [diff] [blame] | 72 | |
| 73 | /* No need to be aligned, but done to keep all IDTs defined the same way. */ |
| 74 | gate_desc debug_idt_table[NR_VECTORS] __page_aligned_bss; |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 75 | #else |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 76 | #include <asm/processor-flags.h> |
Ingo Molnar | 8e6dafd | 2009-02-23 00:34:39 +0100 | [diff] [blame] | 77 | #include <asm/setup.h> |
Ingo Molnar | b2502b4 | 2015-06-08 08:42:03 +0200 | [diff] [blame] | 78 | #include <asm/proto.h> |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 79 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | |
Kees Cook | 4df05f3 | 2013-07-16 11:34:41 -0700 | [diff] [blame] | 81 | /* Must be page-aligned because the real IDT is used in a fixmap. */ |
| 82 | gate_desc idt_table[NR_VECTORS] __page_aligned_bss; |
| 83 | |
Yinghai Lu | b77b881 | 2008-12-19 15:23:44 -0800 | [diff] [blame] | 84 | DECLARE_BITMAP(used_vectors, NR_VECTORS); |
| 85 | EXPORT_SYMBOL_GPL(used_vectors); |
| 86 | |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 87 | static inline void cond_local_irq_enable(struct pt_regs *regs) |
Alexander van Heukelum | 762db43 | 2008-09-09 21:55:55 +0200 | [diff] [blame] | 88 | { |
| 89 | if (regs->flags & X86_EFLAGS_IF) |
| 90 | local_irq_enable(); |
| 91 | } |
| 92 | |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 93 | static inline void cond_local_irq_disable(struct pt_regs *regs) |
Thomas Gleixner | be71661 | 2009-01-13 23:36:34 +0100 | [diff] [blame] | 94 | { |
| 95 | if (regs->flags & X86_EFLAGS_IF) |
| 96 | local_irq_disable(); |
| 97 | } |
| 98 | |
Andy Lutomirski | aaee8c3 | 2016-05-24 15:54:04 -0700 | [diff] [blame] | 99 | /* |
| 100 | * In IST context, we explicitly disable preemption. This serves two |
| 101 | * purposes: it makes it much less likely that we would accidentally |
| 102 | * schedule in IST context and it will force a warning if we somehow |
| 103 | * manage to schedule by accident. |
| 104 | */ |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 105 | void ist_enter(struct pt_regs *regs) |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 106 | { |
Andy Lutomirski | f39b6f0 | 2015-03-18 18:33:33 -0700 | [diff] [blame] | 107 | if (user_mode(regs)) { |
Linus Torvalds | 5778077 | 2015-09-01 08:40:25 -0700 | [diff] [blame] | 108 | RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 109 | } else { |
| 110 | /* |
| 111 | * We might have interrupted pretty much anything. In |
| 112 | * fact, if we're a machine check, we can even interrupt |
| 113 | * NMI processing. We don't want in_nmi() to return true, |
| 114 | * but we need to notify RCU. |
| 115 | */ |
| 116 | rcu_nmi_enter(); |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 117 | } |
Andy Lutomirski | b926e6f | 2015-01-31 04:53:53 -0800 | [diff] [blame] | 118 | |
Andy Lutomirski | aaee8c3 | 2016-05-24 15:54:04 -0700 | [diff] [blame] | 119 | preempt_disable(); |
Andy Lutomirski | b926e6f | 2015-01-31 04:53:53 -0800 | [diff] [blame] | 120 | |
| 121 | /* This code is a bit fragile. Test it. */ |
Paul E. McKenney | f78f5b9 | 2015-06-18 15:50:02 -0700 | [diff] [blame] | 122 | RCU_LOCKDEP_WARN(!rcu_is_watching(), "ist_enter didn't work"); |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 123 | } |
| 124 | |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 125 | void ist_exit(struct pt_regs *regs) |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 126 | { |
Andy Lutomirski | aaee8c3 | 2016-05-24 15:54:04 -0700 | [diff] [blame] | 127 | preempt_enable_no_resched(); |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 128 | |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 129 | if (!user_mode(regs)) |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 130 | rcu_nmi_exit(); |
| 131 | } |
| 132 | |
Andy Lutomirski | bced35b | 2014-11-19 17:59:41 -0800 | [diff] [blame] | 133 | /** |
| 134 | * ist_begin_non_atomic() - begin a non-atomic section in an IST exception |
| 135 | * @regs: regs passed to the IST exception handler |
| 136 | * |
| 137 | * IST exception handlers normally cannot schedule. As a special |
| 138 | * exception, if the exception interrupted userspace code (i.e. |
Andy Lutomirski | f39b6f0 | 2015-03-18 18:33:33 -0700 | [diff] [blame] | 139 | * user_mode(regs) would return true) and the exception was not |
Andy Lutomirski | bced35b | 2014-11-19 17:59:41 -0800 | [diff] [blame] | 140 | * a double fault, it can be safe to schedule. ist_begin_non_atomic() |
| 141 | * begins a non-atomic section within an ist_enter()/ist_exit() region. |
| 142 | * Callers are responsible for enabling interrupts themselves inside |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 143 | * the non-atomic section, and callers must call ist_end_non_atomic() |
Andy Lutomirski | bced35b | 2014-11-19 17:59:41 -0800 | [diff] [blame] | 144 | * before ist_exit(). |
| 145 | */ |
| 146 | void ist_begin_non_atomic(struct pt_regs *regs) |
| 147 | { |
Andy Lutomirski | f39b6f0 | 2015-03-18 18:33:33 -0700 | [diff] [blame] | 148 | BUG_ON(!user_mode(regs)); |
Andy Lutomirski | bced35b | 2014-11-19 17:59:41 -0800 | [diff] [blame] | 149 | |
| 150 | /* |
| 151 | * Sanity check: we need to be on the normal thread stack. This |
| 152 | * will catch asm bugs and any attempt to use ist_preempt_enable |
| 153 | * from double_fault. |
| 154 | */ |
Andy Lutomirski | a7fcf28 | 2015-03-06 17:50:19 -0800 | [diff] [blame] | 155 | BUG_ON((unsigned long)(current_top_of_stack() - |
| 156 | current_stack_pointer()) >= THREAD_SIZE); |
Andy Lutomirski | bced35b | 2014-11-19 17:59:41 -0800 | [diff] [blame] | 157 | |
Andy Lutomirski | aaee8c3 | 2016-05-24 15:54:04 -0700 | [diff] [blame] | 158 | preempt_enable_no_resched(); |
Andy Lutomirski | bced35b | 2014-11-19 17:59:41 -0800 | [diff] [blame] | 159 | } |
| 160 | |
| 161 | /** |
| 162 | * ist_end_non_atomic() - begin a non-atomic section in an IST exception |
| 163 | * |
| 164 | * Ends a non-atomic section started with ist_begin_non_atomic(). |
| 165 | */ |
| 166 | void ist_end_non_atomic(void) |
| 167 | { |
Andy Lutomirski | aaee8c3 | 2016-05-24 15:54:04 -0700 | [diff] [blame] | 168 | preempt_disable(); |
Andy Lutomirski | bced35b | 2014-11-19 17:59:41 -0800 | [diff] [blame] | 169 | } |
| 170 | |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 171 | static nokprobe_inline int |
Frederic Weisbecker | c416ddf | 2012-09-25 14:51:19 +0200 | [diff] [blame] | 172 | do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str, |
| 173 | struct pt_regs *regs, long error_code) |
| 174 | { |
Andy Lutomirski | d74ef11 | 2015-03-18 18:33:35 -0700 | [diff] [blame] | 175 | if (v8086_mode(regs)) { |
Frederic Weisbecker | c416ddf | 2012-09-25 14:51:19 +0200 | [diff] [blame] | 176 | /* |
| 177 | * Traps 0, 1, 3, 4, and 5 should be forwarded to vm86. |
| 178 | * On nmi (interrupt 2), do_trap should not be called. |
| 179 | */ |
| 180 | if (trapnr < X86_TRAP_UD) { |
| 181 | if (!handle_vm86_trap((struct kernel_vm86_regs *) regs, |
| 182 | error_code, trapnr)) |
| 183 | return 0; |
| 184 | } |
| 185 | return -1; |
| 186 | } |
Andy Lutomirski | d74ef11 | 2015-03-18 18:33:35 -0700 | [diff] [blame] | 187 | |
Ingo Molnar | 55474c4 | 2015-03-29 11:02:34 +0200 | [diff] [blame] | 188 | if (!user_mode(regs)) { |
Tony Luck | 548acf1 | 2016-02-17 10:20:12 -0800 | [diff] [blame] | 189 | if (!fixup_exception(regs, trapnr)) { |
Frederic Weisbecker | c416ddf | 2012-09-25 14:51:19 +0200 | [diff] [blame] | 190 | tsk->thread.error_code = error_code; |
| 191 | tsk->thread.trap_nr = trapnr; |
| 192 | die(str, regs, error_code); |
| 193 | } |
| 194 | return 0; |
| 195 | } |
| 196 | |
| 197 | return -1; |
| 198 | } |
| 199 | |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 200 | static siginfo_t *fill_trap_info(struct pt_regs *regs, int signr, int trapnr, |
| 201 | siginfo_t *info) |
Oleg Nesterov | 958d3d7 | 2014-05-07 17:59:39 +0200 | [diff] [blame] | 202 | { |
| 203 | unsigned long siaddr; |
| 204 | int sicode; |
| 205 | |
| 206 | switch (trapnr) { |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 207 | default: |
| 208 | return SEND_SIG_PRIV; |
| 209 | |
Oleg Nesterov | 958d3d7 | 2014-05-07 17:59:39 +0200 | [diff] [blame] | 210 | case X86_TRAP_DE: |
| 211 | sicode = FPE_INTDIV; |
Oleg Nesterov | b02ef20 | 2014-05-12 18:24:45 +0200 | [diff] [blame] | 212 | siaddr = uprobe_get_trap_addr(regs); |
Oleg Nesterov | 958d3d7 | 2014-05-07 17:59:39 +0200 | [diff] [blame] | 213 | break; |
| 214 | case X86_TRAP_UD: |
| 215 | sicode = ILL_ILLOPN; |
Oleg Nesterov | b02ef20 | 2014-05-12 18:24:45 +0200 | [diff] [blame] | 216 | siaddr = uprobe_get_trap_addr(regs); |
Oleg Nesterov | 958d3d7 | 2014-05-07 17:59:39 +0200 | [diff] [blame] | 217 | break; |
| 218 | case X86_TRAP_AC: |
| 219 | sicode = BUS_ADRALN; |
| 220 | siaddr = 0; |
| 221 | break; |
| 222 | } |
| 223 | |
| 224 | info->si_signo = signr; |
| 225 | info->si_errno = 0; |
| 226 | info->si_code = sicode; |
| 227 | info->si_addr = (void __user *)siaddr; |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 228 | return info; |
Oleg Nesterov | 958d3d7 | 2014-05-07 17:59:39 +0200 | [diff] [blame] | 229 | } |
| 230 | |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 231 | static void |
Alexander van Heukelum | 3c1326f | 2008-09-26 14:03:08 +0200 | [diff] [blame] | 232 | do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 233 | long error_code, siginfo_t *info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | { |
Alexander Nyberg | 4f339ec | 2005-06-25 14:58:27 -0700 | [diff] [blame] | 235 | struct task_struct *tsk = current; |
Alexander Nyberg | 4f339ec | 2005-06-25 14:58:27 -0700 | [diff] [blame] | 236 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | |
Frederic Weisbecker | c416ddf | 2012-09-25 14:51:19 +0200 | [diff] [blame] | 238 | if (!do_trap_no_signal(tsk, trapnr, str, regs, error_code)) |
| 239 | return; |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 240 | /* |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 241 | * We want error_code and trap_nr set for userspace faults and |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 242 | * kernelspace faults which result in die(), but not |
| 243 | * kernelspace faults which are fixed up. die() gives the |
| 244 | * process no chance to handle the signal and notice the |
| 245 | * kernel fault information, so that won't result in polluting |
| 246 | * the information about previously queued, but not yet |
| 247 | * delivered, faults. See also do_general_protection below. |
| 248 | */ |
| 249 | tsk->thread.error_code = error_code; |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 250 | tsk->thread.trap_nr = trapnr; |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 251 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 252 | if (show_unhandled_signals && unhandled_signal(tsk, signr) && |
| 253 | printk_ratelimit()) { |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 254 | pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx", |
| 255 | tsk->comm, tsk->pid, str, |
| 256 | regs->ip, regs->sp, error_code); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 257 | print_vma_addr(" in ", regs->ip); |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 258 | pr_cont("\n"); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 259 | } |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 260 | |
Oleg Nesterov | 38cad57 | 2014-05-07 16:47:09 +0200 | [diff] [blame] | 261 | force_sig_info(signr, info ?: SEND_SIG_PRIV, tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 263 | NOKPROBE_SYMBOL(do_trap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | |
Oleg Nesterov | dff0796 | 2014-05-07 17:21:34 +0200 | [diff] [blame] | 265 | static void do_error_trap(struct pt_regs *regs, long error_code, char *str, |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 266 | unsigned long trapnr, int signr) |
Oleg Nesterov | dff0796 | 2014-05-07 17:21:34 +0200 | [diff] [blame] | 267 | { |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 268 | siginfo_t info; |
Oleg Nesterov | dff0796 | 2014-05-07 17:21:34 +0200 | [diff] [blame] | 269 | |
Linus Torvalds | 5778077 | 2015-09-01 08:40:25 -0700 | [diff] [blame] | 270 | RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); |
Andy Lutomirski | 02fdcd5 | 2015-07-03 12:44:24 -0700 | [diff] [blame] | 271 | |
Oleg Nesterov | dff0796 | 2014-05-07 17:21:34 +0200 | [diff] [blame] | 272 | if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) != |
| 273 | NOTIFY_STOP) { |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 274 | cond_local_irq_enable(regs); |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 275 | do_trap(trapnr, signr, str, regs, error_code, |
| 276 | fill_trap_info(regs, signr, trapnr, &info)); |
Oleg Nesterov | dff0796 | 2014-05-07 17:21:34 +0200 | [diff] [blame] | 277 | } |
Oleg Nesterov | dff0796 | 2014-05-07 17:21:34 +0200 | [diff] [blame] | 278 | } |
| 279 | |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 280 | #define DO_ERROR(trapnr, signr, str, name) \ |
Alexander van Heukelum | e407d620 | 2008-09-30 18:41:36 +0200 | [diff] [blame] | 281 | dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 282 | { \ |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 283 | do_error_trap(regs, error_code, str, trapnr, signr); \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | } |
| 285 | |
Oleg Nesterov | 0eb1483 | 2014-05-08 20:12:24 +0200 | [diff] [blame] | 286 | DO_ERROR(X86_TRAP_DE, SIGFPE, "divide error", divide_error) |
| 287 | DO_ERROR(X86_TRAP_OF, SIGSEGV, "overflow", overflow) |
Oleg Nesterov | 0eb1483 | 2014-05-08 20:12:24 +0200 | [diff] [blame] | 288 | DO_ERROR(X86_TRAP_UD, SIGILL, "invalid opcode", invalid_op) |
| 289 | DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, "coprocessor segment overrun",coprocessor_segment_overrun) |
| 290 | DO_ERROR(X86_TRAP_TS, SIGSEGV, "invalid TSS", invalid_TSS) |
| 291 | DO_ERROR(X86_TRAP_NP, SIGBUS, "segment not present", segment_not_present) |
Oleg Nesterov | 0eb1483 | 2014-05-08 20:12:24 +0200 | [diff] [blame] | 292 | DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment) |
Oleg Nesterov | 0eb1483 | 2014-05-08 20:12:24 +0200 | [diff] [blame] | 293 | DO_ERROR(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 295 | #ifdef CONFIG_X86_64 |
| 296 | /* Runs on IST stack */ |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 297 | dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) |
| 298 | { |
| 299 | static const char str[] = "double fault"; |
| 300 | struct task_struct *tsk = current; |
| 301 | |
Andy Lutomirski | af726f2 | 2014-11-22 18:00:31 -0800 | [diff] [blame] | 302 | #ifdef CONFIG_X86_ESPFIX64 |
| 303 | extern unsigned char native_irq_return_iret[]; |
| 304 | |
| 305 | /* |
| 306 | * If IRET takes a non-IST fault on the espfix64 stack, then we |
| 307 | * end up promoting it to a doublefault. In that case, modify |
| 308 | * the stack to make it look like we just entered the #GP |
| 309 | * handler from user space, similar to bad_iret. |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 310 | * |
| 311 | * No need for ist_enter here because we don't use RCU. |
Andy Lutomirski | af726f2 | 2014-11-22 18:00:31 -0800 | [diff] [blame] | 312 | */ |
| 313 | if (((long)regs->sp >> PGDIR_SHIFT) == ESPFIX_PGD_ENTRY && |
| 314 | regs->cs == __KERNEL_CS && |
| 315 | regs->ip == (unsigned long)native_irq_return_iret) |
| 316 | { |
| 317 | struct pt_regs *normal_regs = task_pt_regs(current); |
| 318 | |
| 319 | /* Fake a #GP(0) from userspace. */ |
| 320 | memmove(&normal_regs->ip, (void *)regs->sp, 5*8); |
| 321 | normal_regs->orig_ax = 0; /* Missing (lost) #GP error code */ |
| 322 | regs->ip = (unsigned long)general_protection; |
| 323 | regs->sp = (unsigned long)&normal_regs->orig_ax; |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 324 | |
Andy Lutomirski | af726f2 | 2014-11-22 18:00:31 -0800 | [diff] [blame] | 325 | return; |
| 326 | } |
| 327 | #endif |
| 328 | |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 329 | ist_enter(regs); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 330 | notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 331 | |
| 332 | tsk->thread.error_code = error_code; |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 333 | tsk->thread.trap_nr = X86_TRAP_DF; |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 334 | |
Borislav Petkov | 4d067d8 | 2013-05-09 12:02:29 +0200 | [diff] [blame] | 335 | #ifdef CONFIG_DOUBLEFAULT |
| 336 | df_debug(regs, error_code); |
| 337 | #endif |
Ingo Molnar | bd8b96d | 2008-12-26 09:20:22 +0100 | [diff] [blame] | 338 | /* |
| 339 | * This is always a kernel trap and never fixable (and thus must |
| 340 | * never return). |
| 341 | */ |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 342 | for (;;) |
| 343 | die(str, regs, error_code); |
| 344 | } |
| 345 | #endif |
| 346 | |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 347 | dotraplinkage void do_bounds(struct pt_regs *regs, long error_code) |
| 348 | { |
Dave Hansen | 1126cb45 | 2015-09-02 16:31:29 -0700 | [diff] [blame] | 349 | const struct mpx_bndcsr *bndcsr; |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 350 | siginfo_t *info; |
| 351 | |
Linus Torvalds | 5778077 | 2015-09-01 08:40:25 -0700 | [diff] [blame] | 352 | RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 353 | if (notify_die(DIE_TRAP, "bounds", regs, error_code, |
| 354 | X86_TRAP_BR, SIGSEGV) == NOTIFY_STOP) |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 355 | return; |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 356 | cond_local_irq_enable(regs); |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 357 | |
Andy Lutomirski | f39b6f0 | 2015-03-18 18:33:33 -0700 | [diff] [blame] | 358 | if (!user_mode(regs)) |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 359 | die("bounds", regs, error_code); |
| 360 | |
| 361 | if (!cpu_feature_enabled(X86_FEATURE_MPX)) { |
| 362 | /* The exception is not from Intel MPX */ |
| 363 | goto exit_trap; |
| 364 | } |
| 365 | |
| 366 | /* |
| 367 | * We need to look at BNDSTATUS to resolve this exception. |
Dave Hansen | a84eeaa | 2015-06-07 11:37:01 -0700 | [diff] [blame] | 368 | * A NULL here might mean that it is in its 'init state', |
| 369 | * which is all zeros which indicates MPX was not |
| 370 | * responsible for the exception. |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 371 | */ |
Dave Hansen | d91cab7 | 2015-09-02 16:31:26 -0700 | [diff] [blame] | 372 | bndcsr = get_xsave_field_ptr(XFEATURE_MASK_BNDCSR); |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 373 | if (!bndcsr) |
| 374 | goto exit_trap; |
| 375 | |
Dave Hansen | e7126cf | 2015-06-07 11:37:03 -0700 | [diff] [blame] | 376 | trace_bounds_exception_mpx(bndcsr); |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 377 | /* |
| 378 | * The error code field of the BNDSTATUS register communicates status |
| 379 | * information of a bound range exception #BR or operation involving |
| 380 | * bound directory. |
| 381 | */ |
| 382 | switch (bndcsr->bndstatus & MPX_BNDSTA_ERROR_CODE) { |
| 383 | case 2: /* Bound directory has invalid entry. */ |
Dave Hansen | 46a6e0c | 2015-06-07 11:37:02 -0700 | [diff] [blame] | 384 | if (mpx_handle_bd_fault()) |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 385 | goto exit_trap; |
| 386 | break; /* Success, it was handled */ |
| 387 | case 1: /* Bound violation. */ |
Dave Hansen | 46a6e0c | 2015-06-07 11:37:02 -0700 | [diff] [blame] | 388 | info = mpx_generate_siginfo(regs); |
Dan Carpenter | e10abb2 | 2014-11-25 20:21:14 +0300 | [diff] [blame] | 389 | if (IS_ERR(info)) { |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 390 | /* |
| 391 | * We failed to decode the MPX instruction. Act as if |
| 392 | * the exception was not caused by MPX. |
| 393 | */ |
| 394 | goto exit_trap; |
| 395 | } |
| 396 | /* |
| 397 | * Success, we decoded the instruction and retrieved |
| 398 | * an 'info' containing the address being accessed |
| 399 | * which caused the exception. This information |
| 400 | * allows and application to possibly handle the |
| 401 | * #BR exception itself. |
| 402 | */ |
| 403 | do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, error_code, info); |
| 404 | kfree(info); |
| 405 | break; |
| 406 | case 0: /* No exception caused by Intel MPX operations. */ |
| 407 | goto exit_trap; |
| 408 | default: |
| 409 | die("bounds", regs, error_code); |
| 410 | } |
| 411 | |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 412 | return; |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 413 | |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 414 | exit_trap: |
| 415 | /* |
| 416 | * This path out is for all the cases where we could not |
| 417 | * handle the exception in some way (like allocating a |
| 418 | * table or telling userspace about it. We will also end |
| 419 | * up here if the kernel has MPX turned off at compile |
| 420 | * time.. |
| 421 | */ |
| 422 | do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, error_code, NULL); |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 423 | } |
| 424 | |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 425 | dotraplinkage void |
Alexander van Heukelum | 13485ab | 2008-07-02 01:32:04 +0200 | [diff] [blame] | 426 | do_general_protection(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | { |
Alexander van Heukelum | 13485ab | 2008-07-02 01:32:04 +0200 | [diff] [blame] | 428 | struct task_struct *tsk; |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 429 | |
Linus Torvalds | 5778077 | 2015-09-01 08:40:25 -0700 | [diff] [blame] | 430 | RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 431 | cond_local_irq_enable(regs); |
Alexander van Heukelum | c6df0d7 | 2008-09-09 21:56:07 +0200 | [diff] [blame] | 432 | |
Andy Lutomirski | d74ef11 | 2015-03-18 18:33:35 -0700 | [diff] [blame] | 433 | if (v8086_mode(regs)) { |
Frederic Weisbecker | ef3f628 | 2012-09-24 21:05:52 +0200 | [diff] [blame] | 434 | local_irq_enable(); |
| 435 | handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 436 | return; |
Frederic Weisbecker | ef3f628 | 2012-09-24 21:05:52 +0200 | [diff] [blame] | 437 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | |
Alexander van Heukelum | 13485ab | 2008-07-02 01:32:04 +0200 | [diff] [blame] | 439 | tsk = current; |
Ingo Molnar | 55474c4 | 2015-03-29 11:02:34 +0200 | [diff] [blame] | 440 | if (!user_mode(regs)) { |
Tony Luck | 548acf1 | 2016-02-17 10:20:12 -0800 | [diff] [blame] | 441 | if (fixup_exception(regs, X86_TRAP_GP)) |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 442 | return; |
Frederic Weisbecker | ef3f628 | 2012-09-24 21:05:52 +0200 | [diff] [blame] | 443 | |
| 444 | tsk->thread.error_code = error_code; |
| 445 | tsk->thread.trap_nr = X86_TRAP_GP; |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 446 | if (notify_die(DIE_GPF, "general protection fault", regs, error_code, |
| 447 | X86_TRAP_GP, SIGSEGV) != NOTIFY_STOP) |
Frederic Weisbecker | ef3f628 | 2012-09-24 21:05:52 +0200 | [diff] [blame] | 448 | die("general protection fault", regs, error_code); |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 449 | return; |
Frederic Weisbecker | ef3f628 | 2012-09-24 21:05:52 +0200 | [diff] [blame] | 450 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | |
Alexander van Heukelum | 13485ab | 2008-07-02 01:32:04 +0200 | [diff] [blame] | 452 | tsk->thread.error_code = error_code; |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 453 | tsk->thread.trap_nr = X86_TRAP_GP; |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 454 | |
Alexander van Heukelum | 13485ab | 2008-07-02 01:32:04 +0200 | [diff] [blame] | 455 | if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && |
| 456 | printk_ratelimit()) { |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 457 | pr_info("%s[%d] general protection ip:%lx sp:%lx error:%lx", |
Alexander van Heukelum | 13485ab | 2008-07-02 01:32:04 +0200 | [diff] [blame] | 458 | tsk->comm, task_pid_nr(tsk), |
| 459 | regs->ip, regs->sp, error_code); |
Andi Kleen | 0325291 | 2008-01-30 13:33:18 +0100 | [diff] [blame] | 460 | print_vma_addr(" in ", regs->ip); |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 461 | pr_cont("\n"); |
Andi Kleen | 0325291 | 2008-01-30 13:33:18 +0100 | [diff] [blame] | 462 | } |
Masoud Asgharifard Sharbiani | abd4f75 | 2007-07-22 11:12:28 +0200 | [diff] [blame] | 463 | |
Oleg Nesterov | 38cad57 | 2014-05-07 16:47:09 +0200 | [diff] [blame] | 464 | force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 466 | NOKPROBE_SYMBOL(do_general_protection); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 468 | /* May run on IST stack. */ |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 469 | dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | { |
Steven Rostedt | 08d636b | 2011-08-16 09:57:10 -0400 | [diff] [blame] | 471 | #ifdef CONFIG_DYNAMIC_FTRACE |
Steven Rostedt | a192cd0 | 2012-05-30 13:26:37 -0400 | [diff] [blame] | 472 | /* |
| 473 | * ftrace must be first, everything else may cause a recursive crash. |
| 474 | * See note by declaration of modifying_ftrace_code in ftrace.c |
| 475 | */ |
| 476 | if (unlikely(atomic_read(&modifying_ftrace_code)) && |
| 477 | ftrace_int3_handler(regs)) |
Steven Rostedt | 08d636b | 2011-08-16 09:57:10 -0400 | [diff] [blame] | 478 | return; |
| 479 | #endif |
Jiri Kosina | 17f4157 | 2013-07-23 10:09:28 +0200 | [diff] [blame] | 480 | if (poke_int3_handler(regs)) |
| 481 | return; |
| 482 | |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 483 | ist_enter(regs); |
Linus Torvalds | 5778077 | 2015-09-01 08:40:25 -0700 | [diff] [blame] | 484 | RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); |
Jason Wessel | f503b5a | 2010-05-20 21:04:25 -0500 | [diff] [blame] | 485 | #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 486 | if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, |
| 487 | SIGTRAP) == NOTIFY_STOP) |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 488 | goto exit; |
Jason Wessel | f503b5a | 2010-05-20 21:04:25 -0500 | [diff] [blame] | 489 | #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ |
Srikar Dronamraju | cc3a1bf | 2011-10-25 19:51:59 +0530 | [diff] [blame] | 490 | |
Masami Hiramatsu | 6f6343f | 2014-04-17 17:17:33 +0900 | [diff] [blame] | 491 | #ifdef CONFIG_KPROBES |
| 492 | if (kprobe_int3_handler(regs)) |
Masami Hiramatsu | 4cdf77a | 2014-06-14 06:47:12 +0000 | [diff] [blame] | 493 | goto exit; |
Masami Hiramatsu | 6f6343f | 2014-04-17 17:17:33 +0900 | [diff] [blame] | 494 | #endif |
| 495 | |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 496 | if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, |
| 497 | SIGTRAP) == NOTIFY_STOP) |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 498 | goto exit; |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 499 | |
Steven Rostedt | 4218118 | 2011-12-16 11:43:02 -0500 | [diff] [blame] | 500 | /* |
| 501 | * Let others (NMI) know that the debug stack is in use |
| 502 | * as we may switch to the interrupt stack. |
| 503 | */ |
| 504 | debug_stack_usage_inc(); |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 505 | preempt_disable(); |
| 506 | cond_local_irq_enable(regs); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 507 | do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL); |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 508 | cond_local_irq_disable(regs); |
| 509 | preempt_enable_no_resched(); |
Steven Rostedt | 4218118 | 2011-12-16 11:43:02 -0500 | [diff] [blame] | 510 | debug_stack_usage_dec(); |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 511 | exit: |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 512 | ist_exit(regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 514 | NOKPROBE_SYMBOL(do_int3); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 516 | #ifdef CONFIG_X86_64 |
Ingo Molnar | bd8b96d | 2008-12-26 09:20:22 +0100 | [diff] [blame] | 517 | /* |
Andy Lutomirski | 48e08d0 | 2014-11-11 12:49:41 -0800 | [diff] [blame] | 518 | * Help handler running on IST stack to switch off the IST stack if the |
| 519 | * interrupted code was in user mode. The actual stack switch is done in |
| 520 | * entry_64.S |
Ingo Molnar | bd8b96d | 2008-12-26 09:20:22 +0100 | [diff] [blame] | 521 | */ |
Andy Lutomirski | 7ddc6a2 | 2014-11-24 17:39:06 -0800 | [diff] [blame] | 522 | asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs) |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 523 | { |
Andy Lutomirski | 48e08d0 | 2014-11-11 12:49:41 -0800 | [diff] [blame] | 524 | struct pt_regs *regs = task_pt_regs(current); |
| 525 | *regs = *eregs; |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 526 | return regs; |
| 527 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 528 | NOKPROBE_SYMBOL(sync_regs); |
Andy Lutomirski | b645af2 | 2014-11-22 18:00:33 -0800 | [diff] [blame] | 529 | |
| 530 | struct bad_iret_stack { |
| 531 | void *error_entry_ret; |
| 532 | struct pt_regs regs; |
| 533 | }; |
| 534 | |
Andy Lutomirski | 7ddc6a2 | 2014-11-24 17:39:06 -0800 | [diff] [blame] | 535 | asmlinkage __visible notrace |
Andy Lutomirski | b645af2 | 2014-11-22 18:00:33 -0800 | [diff] [blame] | 536 | struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) |
| 537 | { |
| 538 | /* |
| 539 | * This is called from entry_64.S early in handling a fault |
| 540 | * caused by a bad iret to user mode. To handle the fault |
| 541 | * correctly, we want move our stack frame to task_pt_regs |
| 542 | * and we want to pretend that the exception came from the |
| 543 | * iret target. |
| 544 | */ |
| 545 | struct bad_iret_stack *new_stack = |
| 546 | container_of(task_pt_regs(current), |
| 547 | struct bad_iret_stack, regs); |
| 548 | |
| 549 | /* Copy the IRET target to the new stack. */ |
| 550 | memmove(&new_stack->regs.ip, (void *)s->regs.sp, 5*8); |
| 551 | |
| 552 | /* Copy the remainder of the stack from the current stack. */ |
| 553 | memmove(new_stack, s, offsetof(struct bad_iret_stack, regs.ip)); |
| 554 | |
Andy Lutomirski | f39b6f0 | 2015-03-18 18:33:33 -0700 | [diff] [blame] | 555 | BUG_ON(!user_mode(&new_stack->regs)); |
Andy Lutomirski | b645af2 | 2014-11-22 18:00:33 -0800 | [diff] [blame] | 556 | return new_stack; |
| 557 | } |
Andy Lutomirski | 7ddc6a2 | 2014-11-24 17:39:06 -0800 | [diff] [blame] | 558 | NOKPROBE_SYMBOL(fixup_bad_iret); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 559 | #endif |
| 560 | |
Andy Lutomirski | f2b3757 | 2016-03-09 19:00:30 -0800 | [diff] [blame] | 561 | static bool is_sysenter_singlestep(struct pt_regs *regs) |
| 562 | { |
| 563 | /* |
| 564 | * We don't try for precision here. If we're anywhere in the region of |
| 565 | * code that can be single-stepped in the SYSENTER entry path, then |
| 566 | * assume that this is a useless single-step trap due to SYSENTER |
| 567 | * being invoked with TF set. (We don't know in advance exactly |
| 568 | * which instructions will be hit because BTF could plausibly |
| 569 | * be set.) |
| 570 | */ |
| 571 | #ifdef CONFIG_X86_32 |
| 572 | return (regs->ip - (unsigned long)__begin_SYSENTER_singlestep_region) < |
| 573 | (unsigned long)__end_SYSENTER_singlestep_region - |
| 574 | (unsigned long)__begin_SYSENTER_singlestep_region; |
| 575 | #elif defined(CONFIG_IA32_EMULATION) |
| 576 | return (regs->ip - (unsigned long)entry_SYSENTER_compat) < |
| 577 | (unsigned long)__end_entry_SYSENTER_compat - |
| 578 | (unsigned long)entry_SYSENTER_compat; |
| 579 | #else |
| 580 | return false; |
| 581 | #endif |
| 582 | } |
| 583 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | /* |
| 585 | * Our handling of the processor debug registers is non-trivial. |
| 586 | * We do not clear them on entry and exit from the kernel. Therefore |
| 587 | * it is possible to get a watchpoint trap here from inside the kernel. |
| 588 | * However, the code in ./ptrace.c has ensured that the user can |
| 589 | * only set watchpoints on userspace addresses. Therefore the in-kernel |
| 590 | * watchpoint trap can only occur in code which is reading/writing |
| 591 | * from user space. Such code must not hold kernel locks (since it |
| 592 | * can equally take a page fault), therefore it is safe to call |
| 593 | * force_sig_info even though that claims and releases locks. |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 594 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 595 | * Code in ./signal.c ensures that the debug control register |
| 596 | * is restored before we deliver any signal, and therefore that |
| 597 | * user code runs with the correct debug control register even though |
| 598 | * we clear it here. |
| 599 | * |
| 600 | * Being careful here means that we don't have to be as careful in a |
| 601 | * lot of more complicated places (task switching can be a bit lazy |
| 602 | * about restoring all the debug state, and ptrace doesn't have to |
| 603 | * find every occurrence of the TF bit that could be saved away even |
| 604 | * by user code) |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 605 | * |
| 606 | * May run on IST stack. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | */ |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 608 | dotraplinkage void do_debug(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 610 | struct task_struct *tsk = current; |
Frederic Weisbecker | a1e80fa | 2010-06-30 15:09:06 +0200 | [diff] [blame] | 611 | int user_icebp = 0; |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 612 | unsigned long dr6; |
Srinivasa Ds | da654b7 | 2008-09-23 15:23:52 +0530 | [diff] [blame] | 613 | int si_code; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 615 | ist_enter(regs); |
Masami Hiramatsu | 4cdf77a | 2014-06-14 06:47:12 +0000 | [diff] [blame] | 616 | |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 617 | get_debugreg(dr6, 6); |
Andy Lutomirski | 8bb5643 | 2016-03-09 19:00:29 -0800 | [diff] [blame] | 618 | /* |
| 619 | * The Intel SDM says: |
| 620 | * |
| 621 | * Certain debug exceptions may clear bits 0-3. The remaining |
| 622 | * contents of the DR6 register are never cleared by the |
| 623 | * processor. To avoid confusion in identifying debug |
| 624 | * exceptions, debug handlers should clear the register before |
| 625 | * returning to the interrupted task. |
| 626 | * |
| 627 | * Keep it simple: clear DR6 immediately. |
| 628 | */ |
| 629 | set_debugreg(0, 6); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 630 | |
K.Prasad | 40f9249 | 2010-01-28 16:44:01 +0530 | [diff] [blame] | 631 | /* Filter out all the reserved bits which are preset to 1 */ |
| 632 | dr6 &= ~DR6_RESERVED; |
| 633 | |
Frederic Weisbecker | a1e80fa | 2010-06-30 15:09:06 +0200 | [diff] [blame] | 634 | /* |
Andy Lutomirski | 81edd9f | 2016-03-09 19:00:28 -0800 | [diff] [blame] | 635 | * The SDM says "The processor clears the BTF flag when it |
| 636 | * generates a debug exception." Clear TIF_BLOCKSTEP to keep |
| 637 | * TIF_BLOCKSTEP in sync with the hardware BTF flag. |
| 638 | */ |
| 639 | clear_tsk_thread_flag(tsk, TIF_BLOCKSTEP); |
| 640 | |
Andy Lutomirski | f2b3757 | 2016-03-09 19:00:30 -0800 | [diff] [blame] | 641 | if (unlikely(!user_mode(regs) && (dr6 & DR_STEP) && |
| 642 | is_sysenter_singlestep(regs))) { |
| 643 | dr6 &= ~DR_STEP; |
| 644 | if (!dr6) |
| 645 | goto exit; |
| 646 | /* |
| 647 | * else we might have gotten a single-step trap and hit a |
| 648 | * watchpoint at the same time, in which case we should fall |
| 649 | * through and handle the watchpoint. |
| 650 | */ |
| 651 | } |
| 652 | |
Andy Lutomirski | 81edd9f | 2016-03-09 19:00:28 -0800 | [diff] [blame] | 653 | /* |
Frederic Weisbecker | a1e80fa | 2010-06-30 15:09:06 +0200 | [diff] [blame] | 654 | * If dr6 has no reason to give us about the origin of this trap, |
| 655 | * then it's very likely the result of an icebp/int01 trap. |
| 656 | * User wants a sigtrap for that. |
| 657 | */ |
Andy Lutomirski | f39b6f0 | 2015-03-18 18:33:33 -0700 | [diff] [blame] | 658 | if (!dr6 && user_mode(regs)) |
Frederic Weisbecker | a1e80fa | 2010-06-30 15:09:06 +0200 | [diff] [blame] | 659 | user_icebp = 1; |
| 660 | |
Andy Lutomirski | f2b3757 | 2016-03-09 19:00:30 -0800 | [diff] [blame] | 661 | /* Catch kmemcheck conditions! */ |
Ingo Molnar | eadb8a0 | 2009-06-17 12:52:15 +0200 | [diff] [blame] | 662 | if ((dr6 & DR_STEP) && kmemcheck_trap(regs)) |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 663 | goto exit; |
Vegard Nossum | f856129 | 2008-04-04 00:53:23 +0200 | [diff] [blame] | 664 | |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 665 | /* Store the virtualized DR6 value */ |
| 666 | tsk->thread.debugreg6 = dr6; |
| 667 | |
Masami Hiramatsu | 6f6343f | 2014-04-17 17:17:33 +0900 | [diff] [blame] | 668 | #ifdef CONFIG_KPROBES |
| 669 | if (kprobe_debug_handler(regs)) |
| 670 | goto exit; |
| 671 | #endif |
| 672 | |
Rusty Russell | 5a802e1 | 2013-06-16 14:12:47 +0930 | [diff] [blame] | 673 | if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, error_code, |
K.Prasad | 62edab9 | 2009-06-01 23:47:06 +0530 | [diff] [blame] | 674 | SIGTRAP) == NOTIFY_STOP) |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 675 | goto exit; |
Alexander van Heukelum | 3d2a71a | 2008-09-30 18:41:37 +0200 | [diff] [blame] | 676 | |
Steven Rostedt | 4218118 | 2011-12-16 11:43:02 -0500 | [diff] [blame] | 677 | /* |
| 678 | * Let others (NMI) know that the debug stack is in use |
| 679 | * as we may switch to the interrupt stack. |
| 680 | */ |
| 681 | debug_stack_usage_inc(); |
| 682 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 683 | /* It's safe to allow irq's after DR6 has been saved */ |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 684 | preempt_disable(); |
| 685 | cond_local_irq_enable(regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 686 | |
Andy Lutomirski | d74ef11 | 2015-03-18 18:33:35 -0700 | [diff] [blame] | 687 | if (v8086_mode(regs)) { |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 688 | handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, |
| 689 | X86_TRAP_DB); |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 690 | cond_local_irq_disable(regs); |
| 691 | preempt_enable_no_resched(); |
Steven Rostedt | 4218118 | 2011-12-16 11:43:02 -0500 | [diff] [blame] | 692 | debug_stack_usage_dec(); |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 693 | goto exit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 694 | } |
| 695 | |
Andy Lutomirski | f2b3757 | 2016-03-09 19:00:30 -0800 | [diff] [blame] | 696 | if (WARN_ON_ONCE((dr6 & DR_STEP) && !user_mode(regs))) { |
| 697 | /* |
| 698 | * Historical junk that used to handle SYSENTER single-stepping. |
| 699 | * This should be unreachable now. If we survive for a while |
| 700 | * without anyone hitting this warning, we'll turn this into |
| 701 | * an oops. |
| 702 | */ |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 703 | tsk->thread.debugreg6 &= ~DR_STEP; |
| 704 | set_tsk_thread_flag(tsk, TIF_SINGLESTEP); |
| 705 | regs->flags &= ~X86_EFLAGS_TF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | } |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 707 | si_code = get_si_code(tsk->thread.debugreg6); |
Frederic Weisbecker | a1e80fa | 2010-06-30 15:09:06 +0200 | [diff] [blame] | 708 | if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp) |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 709 | send_sigtrap(tsk, regs, error_code, si_code); |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 710 | cond_local_irq_disable(regs); |
| 711 | preempt_enable_no_resched(); |
Steven Rostedt | 4218118 | 2011-12-16 11:43:02 -0500 | [diff] [blame] | 712 | debug_stack_usage_dec(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 713 | |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 714 | exit: |
Andy Lutomirski | 2a41aa4 | 2016-03-09 19:00:33 -0800 | [diff] [blame] | 715 | #if defined(CONFIG_X86_32) |
| 716 | /* |
| 717 | * This is the most likely code path that involves non-trivial use |
| 718 | * of the SYSENTER stack. Check that we haven't overrun it. |
| 719 | */ |
| 720 | WARN(this_cpu_read(cpu_tss.SYSENTER_stack_canary) != STACK_END_MAGIC, |
| 721 | "Overran or corrupted SYSENTER stack\n"); |
| 722 | #endif |
Andy Lutomirski | 8c84014 | 2015-07-03 12:44:32 -0700 | [diff] [blame] | 723 | ist_exit(regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 725 | NOKPROBE_SYMBOL(do_debug); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | |
| 727 | /* |
| 728 | * Note that we play around with the 'TS' bit in an attempt to get |
| 729 | * the correct behaviour even in the presence of the asynchronous |
| 730 | * IRQ13 behaviour |
| 731 | */ |
Oleg Nesterov | 5e1b05b | 2014-05-08 20:34:00 +0200 | [diff] [blame] | 732 | static void math_error(struct pt_regs *regs, int error_code, int trapnr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 733 | { |
Brian Gerst | e2e75c9 | 2010-03-21 09:00:45 -0400 | [diff] [blame] | 734 | struct task_struct *task = current; |
Ingo Molnar | e1cebad | 2015-04-30 09:29:38 +0200 | [diff] [blame] | 735 | struct fpu *fpu = &task->thread.fpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 736 | siginfo_t info; |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 737 | char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" : |
| 738 | "simd exception"; |
Brian Gerst | e2e75c9 | 2010-03-21 09:00:45 -0400 | [diff] [blame] | 739 | |
| 740 | if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP) |
| 741 | return; |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 742 | cond_local_irq_enable(regs); |
Brian Gerst | e2e75c9 | 2010-03-21 09:00:45 -0400 | [diff] [blame] | 743 | |
Ingo Molnar | e1cebad | 2015-04-30 09:29:38 +0200 | [diff] [blame] | 744 | if (!user_mode(regs)) { |
Tony Luck | 548acf1 | 2016-02-17 10:20:12 -0800 | [diff] [blame] | 745 | if (!fixup_exception(regs, trapnr)) { |
Brian Gerst | e2e75c9 | 2010-03-21 09:00:45 -0400 | [diff] [blame] | 746 | task->thread.error_code = error_code; |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 747 | task->thread.trap_nr = trapnr; |
Brian Gerst | e2e75c9 | 2010-03-21 09:00:45 -0400 | [diff] [blame] | 748 | die(str, regs, error_code); |
| 749 | } |
| 750 | return; |
| 751 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 752 | |
| 753 | /* |
| 754 | * Save the info for the exception handler and clear the error. |
| 755 | */ |
Ingo Molnar | e1cebad | 2015-04-30 09:29:38 +0200 | [diff] [blame] | 756 | fpu__save(fpu); |
| 757 | |
| 758 | task->thread.trap_nr = trapnr; |
Brian Gerst | 9b6dba9 | 2010-03-21 09:00:44 -0400 | [diff] [blame] | 759 | task->thread.error_code = error_code; |
Ingo Molnar | e1cebad | 2015-04-30 09:29:38 +0200 | [diff] [blame] | 760 | info.si_signo = SIGFPE; |
| 761 | info.si_errno = 0; |
| 762 | info.si_addr = (void __user *)uprobe_get_trap_addr(regs); |
H. Peter Anvin | adf77ba | 2008-12-22 17:56:05 -0800 | [diff] [blame] | 763 | |
Ingo Molnar | e1cebad | 2015-04-30 09:29:38 +0200 | [diff] [blame] | 764 | info.si_code = fpu__exception_code(fpu, trapnr); |
H. Peter Anvin | adf77ba | 2008-12-22 17:56:05 -0800 | [diff] [blame] | 765 | |
Ingo Molnar | e1cebad | 2015-04-30 09:29:38 +0200 | [diff] [blame] | 766 | /* Retry when we get spurious exceptions: */ |
| 767 | if (!info.si_code) |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 768 | return; |
Ingo Molnar | e1cebad | 2015-04-30 09:29:38 +0200 | [diff] [blame] | 769 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 770 | force_sig_info(SIGFPE, &info, task); |
| 771 | } |
| 772 | |
Alexander van Heukelum | e407d620 | 2008-09-30 18:41:36 +0200 | [diff] [blame] | 773 | dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 774 | { |
Linus Torvalds | 5778077 | 2015-09-01 08:40:25 -0700 | [diff] [blame] | 775 | RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 776 | math_error(regs, error_code, X86_TRAP_MF); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | } |
| 778 | |
Alexander van Heukelum | e407d620 | 2008-09-30 18:41:36 +0200 | [diff] [blame] | 779 | dotraplinkage void |
| 780 | do_simd_coprocessor_error(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | { |
Linus Torvalds | 5778077 | 2015-09-01 08:40:25 -0700 | [diff] [blame] | 782 | RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 783 | math_error(regs, error_code, X86_TRAP_XF); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 784 | } |
| 785 | |
Alexander van Heukelum | e407d620 | 2008-09-30 18:41:36 +0200 | [diff] [blame] | 786 | dotraplinkage void |
| 787 | do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | { |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 789 | cond_local_irq_enable(regs); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 790 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 792 | dotraplinkage void |
Brian Gerst | aa78bcf | 2009-02-10 09:51:45 -0500 | [diff] [blame] | 793 | do_device_not_available(struct pt_regs *regs, long error_code) |
Alexander van Heukelum | 7643e9b | 2008-09-09 21:56:02 +0200 | [diff] [blame] | 794 | { |
Linus Torvalds | 5778077 | 2015-09-01 08:40:25 -0700 | [diff] [blame] | 795 | RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); |
Suresh Siddha | 304bced | 2012-08-24 14:13:02 -0700 | [diff] [blame] | 796 | |
Brian Gerst | a334fe4 | 2010-09-03 21:17:15 -0400 | [diff] [blame] | 797 | #ifdef CONFIG_MATH_EMULATION |
Andy Lutomirski | c6ab109 | 2016-01-24 14:38:09 -0800 | [diff] [blame] | 798 | if (!boot_cpu_has(X86_FEATURE_FPU) && (read_cr0() & X86_CR0_EM)) { |
Tejun Heo | d315760 | 2009-02-09 22:17:39 +0900 | [diff] [blame] | 799 | struct math_emu_info info = { }; |
| 800 | |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 801 | cond_local_irq_enable(regs); |
Tejun Heo | d315760 | 2009-02-09 22:17:39 +0900 | [diff] [blame] | 802 | |
Brian Gerst | aa78bcf | 2009-02-10 09:51:45 -0500 | [diff] [blame] | 803 | info.regs = regs; |
Tejun Heo | d315760 | 2009-02-09 22:17:39 +0900 | [diff] [blame] | 804 | math_emulate(&info); |
Brian Gerst | a334fe4 | 2010-09-03 21:17:15 -0400 | [diff] [blame] | 805 | return; |
Alexander van Heukelum | 7643e9b | 2008-09-09 21:56:02 +0200 | [diff] [blame] | 806 | } |
Brian Gerst | a334fe4 | 2010-09-03 21:17:15 -0400 | [diff] [blame] | 807 | #endif |
Ingo Molnar | e1884d6 | 2015-05-04 11:49:58 +0200 | [diff] [blame] | 808 | fpu__restore(¤t->thread.fpu); /* interrupts still off */ |
Brian Gerst | a334fe4 | 2010-09-03 21:17:15 -0400 | [diff] [blame] | 809 | #ifdef CONFIG_X86_32 |
Alexander Kuleshov | d99e1bd | 2016-01-25 20:41:46 +0100 | [diff] [blame] | 810 | cond_local_irq_enable(regs); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 811 | #endif |
Alexander van Heukelum | 7643e9b | 2008-09-09 21:56:02 +0200 | [diff] [blame] | 812 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 813 | NOKPROBE_SYMBOL(do_device_not_available); |
Alexander van Heukelum | 7643e9b | 2008-09-09 21:56:02 +0200 | [diff] [blame] | 814 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 815 | #ifdef CONFIG_X86_32 |
Alexander van Heukelum | e407d620 | 2008-09-30 18:41:36 +0200 | [diff] [blame] | 816 | dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) |
Alexander van Heukelum | f8e0870 | 2008-09-09 21:56:13 +0200 | [diff] [blame] | 817 | { |
| 818 | siginfo_t info; |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 819 | |
Linus Torvalds | 5778077 | 2015-09-01 08:40:25 -0700 | [diff] [blame] | 820 | RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); |
Alexander van Heukelum | f8e0870 | 2008-09-09 21:56:13 +0200 | [diff] [blame] | 821 | local_irq_enable(); |
| 822 | |
| 823 | info.si_signo = SIGILL; |
| 824 | info.si_errno = 0; |
| 825 | info.si_code = ILL_BADSTK; |
Hannes Eder | fc6fcdf | 2009-02-22 01:00:57 +0100 | [diff] [blame] | 826 | info.si_addr = NULL; |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 827 | if (notify_die(DIE_TRAP, "iret exception", regs, error_code, |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 828 | X86_TRAP_IRET, SIGILL) != NOTIFY_STOP) { |
| 829 | do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code, |
| 830 | &info); |
| 831 | } |
Alexander van Heukelum | f8e0870 | 2008-09-09 21:56:13 +0200 | [diff] [blame] | 832 | } |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 833 | #endif |
Alexander van Heukelum | f8e0870 | 2008-09-09 21:56:13 +0200 | [diff] [blame] | 834 | |
Jan Kiszka | 29c8439 | 2010-05-20 21:04:29 -0500 | [diff] [blame] | 835 | /* Set of traps needed for early debugging. */ |
| 836 | void __init early_trap_init(void) |
| 837 | { |
Wang Nan | b4d8327 | 2015-02-26 13:49:39 +0800 | [diff] [blame] | 838 | /* |
Wang Nan | 5eca745 | 2015-02-27 12:19:49 +0800 | [diff] [blame] | 839 | * Don't use IST to set DEBUG_STACK as it doesn't work until TSS |
| 840 | * is ready in cpu_init() <-- trap_init(). Before trap_init(), |
| 841 | * CPU runs at ring 0 so it is impossible to hit an invalid |
| 842 | * stack. Using the original stack works well enough at this |
| 843 | * early stage. DEBUG_STACK will be equipped after cpu_init() in |
Wang Nan | b4d8327 | 2015-02-26 13:49:39 +0800 | [diff] [blame] | 844 | * trap_init(). |
Wang Nan | 5eca745 | 2015-02-27 12:19:49 +0800 | [diff] [blame] | 845 | * |
| 846 | * We don't need to set trace_idt_table like set_intr_gate(), |
| 847 | * since we don't have trace_debug and it will be reset to |
| 848 | * 'debug' in trap_init() by set_intr_gate_ist(). |
Wang Nan | b4d8327 | 2015-02-26 13:49:39 +0800 | [diff] [blame] | 849 | */ |
Wang Nan | 5eca745 | 2015-02-27 12:19:49 +0800 | [diff] [blame] | 850 | set_intr_gate_notrace(X86_TRAP_DB, debug); |
Jan Kiszka | 29c8439 | 2010-05-20 21:04:29 -0500 | [diff] [blame] | 851 | /* int3 can be called from all */ |
Wang Nan | 5eca745 | 2015-02-27 12:19:49 +0800 | [diff] [blame] | 852 | set_system_intr_gate(X86_TRAP_BP, &int3); |
H. Peter Anvin | 8170e6b | 2013-01-24 12:19:52 -0800 | [diff] [blame] | 853 | #ifdef CONFIG_X86_32 |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 854 | set_intr_gate(X86_TRAP_PF, page_fault); |
H. Peter Anvin | 8170e6b | 2013-01-24 12:19:52 -0800 | [diff] [blame] | 855 | #endif |
Jan Kiszka | 29c8439 | 2010-05-20 21:04:29 -0500 | [diff] [blame] | 856 | load_idt(&idt_descr); |
| 857 | } |
| 858 | |
H. Peter Anvin | 8170e6b | 2013-01-24 12:19:52 -0800 | [diff] [blame] | 859 | void __init early_trap_pf_init(void) |
| 860 | { |
| 861 | #ifdef CONFIG_X86_64 |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 862 | set_intr_gate(X86_TRAP_PF, page_fault); |
H. Peter Anvin | 8170e6b | 2013-01-24 12:19:52 -0800 | [diff] [blame] | 863 | #endif |
| 864 | } |
| 865 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 866 | void __init trap_init(void) |
| 867 | { |
Rusty Russell | dbeb2be | 2007-10-19 20:35:03 +0200 | [diff] [blame] | 868 | int i; |
| 869 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 870 | #ifdef CONFIG_EISA |
Ingo Molnar | 927222b | 2008-01-30 13:33:49 +0100 | [diff] [blame] | 871 | void __iomem *p = early_ioremap(0x0FFFD9, 4); |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 872 | |
| 873 | if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 874 | EISA_bus = 1; |
Ingo Molnar | 927222b | 2008-01-30 13:33:49 +0100 | [diff] [blame] | 875 | early_iounmap(p, 4); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 876 | #endif |
| 877 | |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 878 | set_intr_gate(X86_TRAP_DE, divide_error); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 879 | set_intr_gate_ist(X86_TRAP_NMI, &nmi, NMI_STACK); |
Alexander van Heukelum | 699d293 | 2008-10-03 22:00:32 +0200 | [diff] [blame] | 880 | /* int4 can be called from all */ |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 881 | set_system_intr_gate(X86_TRAP_OF, &overflow); |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 882 | set_intr_gate(X86_TRAP_BR, bounds); |
| 883 | set_intr_gate(X86_TRAP_UD, invalid_op); |
| 884 | set_intr_gate(X86_TRAP_NM, device_not_available); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 885 | #ifdef CONFIG_X86_32 |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 886 | set_task_gate(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 887 | #else |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 888 | set_intr_gate_ist(X86_TRAP_DF, &double_fault, DOUBLEFAULT_STACK); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 889 | #endif |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 890 | set_intr_gate(X86_TRAP_OLD_MF, coprocessor_segment_overrun); |
| 891 | set_intr_gate(X86_TRAP_TS, invalid_TSS); |
| 892 | set_intr_gate(X86_TRAP_NP, segment_not_present); |
Andy Lutomirski | 6f442be | 2014-11-22 18:00:32 -0800 | [diff] [blame] | 893 | set_intr_gate(X86_TRAP_SS, stack_segment); |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 894 | set_intr_gate(X86_TRAP_GP, general_protection); |
| 895 | set_intr_gate(X86_TRAP_SPURIOUS, spurious_interrupt_bug); |
| 896 | set_intr_gate(X86_TRAP_MF, coprocessor_error); |
| 897 | set_intr_gate(X86_TRAP_AC, alignment_check); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 898 | #ifdef CONFIG_X86_MCE |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 899 | set_intr_gate_ist(X86_TRAP_MC, &machine_check, MCE_STACK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 900 | #endif |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 901 | set_intr_gate(X86_TRAP_XF, simd_coprocessor_error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 902 | |
Yinghai Lu | bb3f0b5 | 2009-01-25 02:38:09 -0800 | [diff] [blame] | 903 | /* Reserve all the builtin and the syscall vector: */ |
| 904 | for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) |
| 905 | set_bit(i, used_vectors); |
| 906 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 907 | #ifdef CONFIG_IA32_EMULATION |
Ingo Molnar | 2cd2355 | 2015-06-08 08:28:07 +0200 | [diff] [blame] | 908 | set_system_intr_gate(IA32_SYSCALL_VECTOR, entry_INT80_compat); |
Yinghai Lu | bb3f0b5 | 2009-01-25 02:38:09 -0800 | [diff] [blame] | 909 | set_bit(IA32_SYSCALL_VECTOR, used_vectors); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 910 | #endif |
| 911 | |
| 912 | #ifdef CONFIG_X86_32 |
Andy Lutomirski | a798f09 | 2016-03-09 13:24:32 -0800 | [diff] [blame] | 913 | set_system_intr_gate(IA32_SYSCALL_VECTOR, entry_INT80_32); |
Brian Gerst | 51bb928 | 2015-05-09 11:36:52 -0400 | [diff] [blame] | 914 | set_bit(IA32_SYSCALL_VECTOR, used_vectors); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 915 | #endif |
Yinghai Lu | bb3f0b5 | 2009-01-25 02:38:09 -0800 | [diff] [blame] | 916 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 917 | /* |
Kees Cook | 4eefbe7 | 2013-04-10 12:24:22 -0700 | [diff] [blame] | 918 | * Set the IDT descriptor to a fixed read-only location, so that the |
| 919 | * "sidt" instruction will not leak the location of the kernel, and |
| 920 | * to defend the IDT against arbitrary memory write vulnerabilities. |
| 921 | * It will be reloaded in cpu_init() */ |
| 922 | __set_fixmap(FIX_RO_IDT, __pa_symbol(idt_table), PAGE_KERNEL_RO); |
| 923 | idt_descr.address = fix_to_virt(FIX_RO_IDT); |
| 924 | |
| 925 | /* |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 926 | * Should be a barrier for any external CPU state: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 927 | */ |
| 928 | cpu_init(); |
| 929 | |
Wang Nan | b4d8327 | 2015-02-26 13:49:39 +0800 | [diff] [blame] | 930 | /* |
| 931 | * X86_TRAP_DB and X86_TRAP_BP have been set |
Wang Nan | 5eca745 | 2015-02-27 12:19:49 +0800 | [diff] [blame] | 932 | * in early_trap_init(). However, ITS works only after |
Wang Nan | b4d8327 | 2015-02-26 13:49:39 +0800 | [diff] [blame] | 933 | * cpu_init() loads TSS. See comments in early_trap_init(). |
| 934 | */ |
| 935 | set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK); |
| 936 | /* int3 can be called from all */ |
| 937 | set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK); |
| 938 | |
Thomas Gleixner | 428cf90 | 2009-08-20 10:35:46 +0200 | [diff] [blame] | 939 | x86_init.irqs.trap_init(); |
Steven Rostedt | 228bdaa | 2011-12-09 03:02:19 -0500 | [diff] [blame] | 940 | |
| 941 | #ifdef CONFIG_X86_64 |
Seiji Aguchi | 629f4f9 | 2013-06-20 11:45:44 -0400 | [diff] [blame] | 942 | memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 943 | set_nmi_gate(X86_TRAP_DB, &debug); |
| 944 | set_nmi_gate(X86_TRAP_BP, &int3); |
Steven Rostedt | 228bdaa | 2011-12-09 03:02:19 -0500 | [diff] [blame] | 945 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 946 | } |