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> |
| 24 | #include <linux/module.h> |
| 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> |
Steven Rostedt | 08d636b | 2011-08-16 09:57:10 -0400 | [diff] [blame] | 54 | #include <asm/ftrace.h> |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 55 | #include <asm/traps.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | #include <asm/desc.h> |
| 57 | #include <asm/i387.h> |
Linus Torvalds | 1361b83 | 2012-02-21 13:19:22 -0800 | [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 | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 63 | #include <asm/mpx.h> |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 64 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 65 | #ifdef CONFIG_X86_64 |
Thomas Gleixner | 428cf90 | 2009-08-20 10:35:46 +0200 | [diff] [blame] | 66 | #include <asm/x86_init.h> |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 67 | #include <asm/pgalloc.h> |
| 68 | #include <asm/proto.h> |
Kees Cook | 4df05f3 | 2013-07-16 11:34:41 -0700 | [diff] [blame] | 69 | |
| 70 | /* No need to be aligned, but done to keep all IDTs defined the same way. */ |
| 71 | gate_desc debug_idt_table[NR_VECTORS] __page_aligned_bss; |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 72 | #else |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 73 | #include <asm/processor-flags.h> |
Ingo Molnar | 8e6dafd | 2009-02-23 00:34:39 +0100 | [diff] [blame] | 74 | #include <asm/setup.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | asmlinkage int system_call(void); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 77 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | |
Kees Cook | 4df05f3 | 2013-07-16 11:34:41 -0700 | [diff] [blame] | 79 | /* Must be page-aligned because the real IDT is used in a fixmap. */ |
| 80 | gate_desc idt_table[NR_VECTORS] __page_aligned_bss; |
| 81 | |
Yinghai Lu | b77b881 | 2008-12-19 15:23:44 -0800 | [diff] [blame] | 82 | DECLARE_BITMAP(used_vectors, NR_VECTORS); |
| 83 | EXPORT_SYMBOL_GPL(used_vectors); |
| 84 | |
Alexander van Heukelum | 762db43 | 2008-09-09 21:55:55 +0200 | [diff] [blame] | 85 | static inline void conditional_sti(struct pt_regs *regs) |
| 86 | { |
| 87 | if (regs->flags & X86_EFLAGS_IF) |
| 88 | local_irq_enable(); |
| 89 | } |
| 90 | |
Alexander van Heukelum | 3d2a71a | 2008-09-30 18:41:37 +0200 | [diff] [blame] | 91 | static inline void preempt_conditional_sti(struct pt_regs *regs) |
| 92 | { |
Peter Zijlstra | bdb4380 | 2013-09-10 12:15:23 +0200 | [diff] [blame] | 93 | preempt_count_inc(); |
Alexander van Heukelum | 3d2a71a | 2008-09-30 18:41:37 +0200 | [diff] [blame] | 94 | if (regs->flags & X86_EFLAGS_IF) |
| 95 | local_irq_enable(); |
| 96 | } |
| 97 | |
Thomas Gleixner | be71661 | 2009-01-13 23:36:34 +0100 | [diff] [blame] | 98 | static inline void conditional_cli(struct pt_regs *regs) |
| 99 | { |
| 100 | if (regs->flags & X86_EFLAGS_IF) |
| 101 | local_irq_disable(); |
| 102 | } |
| 103 | |
Alexander van Heukelum | 3d2a71a | 2008-09-30 18:41:37 +0200 | [diff] [blame] | 104 | static inline void preempt_conditional_cli(struct pt_regs *regs) |
| 105 | { |
| 106 | if (regs->flags & X86_EFLAGS_IF) |
| 107 | local_irq_disable(); |
Peter Zijlstra | bdb4380 | 2013-09-10 12:15:23 +0200 | [diff] [blame] | 108 | preempt_count_dec(); |
Alexander van Heukelum | 3d2a71a | 2008-09-30 18:41:37 +0200 | [diff] [blame] | 109 | } |
| 110 | |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 111 | enum ctx_state ist_enter(struct pt_regs *regs) |
| 112 | { |
Andy Lutomirski | b926e6f | 2015-01-31 04:53:53 -0800 | [diff] [blame] | 113 | enum ctx_state prev_state; |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 114 | |
| 115 | if (user_mode_vm(regs)) { |
| 116 | /* Other than that, we're just an exception. */ |
Andy Lutomirski | b926e6f | 2015-01-31 04:53:53 -0800 | [diff] [blame] | 117 | prev_state = exception_enter(); |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 118 | } else { |
| 119 | /* |
| 120 | * We might have interrupted pretty much anything. In |
| 121 | * fact, if we're a machine check, we can even interrupt |
| 122 | * NMI processing. We don't want in_nmi() to return true, |
| 123 | * but we need to notify RCU. |
| 124 | */ |
| 125 | rcu_nmi_enter(); |
Andy Lutomirski | b926e6f | 2015-01-31 04:53:53 -0800 | [diff] [blame] | 126 | prev_state = IN_KERNEL; /* the value is irrelevant. */ |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 127 | } |
Andy Lutomirski | b926e6f | 2015-01-31 04:53:53 -0800 | [diff] [blame] | 128 | |
| 129 | /* |
| 130 | * We are atomic because we're on the IST stack (or we're on x86_32, |
| 131 | * in which case we still shouldn't schedule). |
| 132 | * |
| 133 | * This must be after exception_enter(), because exception_enter() |
| 134 | * won't do anything if in_interrupt() returns true. |
| 135 | */ |
| 136 | preempt_count_add(HARDIRQ_OFFSET); |
| 137 | |
| 138 | /* This code is a bit fragile. Test it. */ |
| 139 | rcu_lockdep_assert(rcu_is_watching(), "ist_enter didn't work"); |
| 140 | |
| 141 | return prev_state; |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 142 | } |
| 143 | |
| 144 | void ist_exit(struct pt_regs *regs, enum ctx_state prev_state) |
| 145 | { |
Andy Lutomirski | b926e6f | 2015-01-31 04:53:53 -0800 | [diff] [blame] | 146 | /* Must be before exception_exit. */ |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 147 | preempt_count_sub(HARDIRQ_OFFSET); |
| 148 | |
| 149 | if (user_mode_vm(regs)) |
| 150 | return exception_exit(prev_state); |
| 151 | else |
| 152 | rcu_nmi_exit(); |
| 153 | } |
| 154 | |
Andy Lutomirski | bced35b | 2014-11-19 17:59:41 -0800 | [diff] [blame] | 155 | /** |
| 156 | * ist_begin_non_atomic() - begin a non-atomic section in an IST exception |
| 157 | * @regs: regs passed to the IST exception handler |
| 158 | * |
| 159 | * IST exception handlers normally cannot schedule. As a special |
| 160 | * exception, if the exception interrupted userspace code (i.e. |
| 161 | * user_mode_vm(regs) would return true) and the exception was not |
| 162 | * a double fault, it can be safe to schedule. ist_begin_non_atomic() |
| 163 | * begins a non-atomic section within an ist_enter()/ist_exit() region. |
| 164 | * Callers are responsible for enabling interrupts themselves inside |
| 165 | * the non-atomic section, and callers must call is_end_non_atomic() |
| 166 | * before ist_exit(). |
| 167 | */ |
| 168 | void ist_begin_non_atomic(struct pt_regs *regs) |
| 169 | { |
| 170 | BUG_ON(!user_mode_vm(regs)); |
| 171 | |
| 172 | /* |
| 173 | * Sanity check: we need to be on the normal thread stack. This |
| 174 | * will catch asm bugs and any attempt to use ist_preempt_enable |
| 175 | * from double_fault. |
| 176 | */ |
| 177 | BUG_ON(((current_stack_pointer() ^ this_cpu_read_stable(kernel_stack)) |
| 178 | & ~(THREAD_SIZE - 1)) != 0); |
| 179 | |
| 180 | preempt_count_sub(HARDIRQ_OFFSET); |
| 181 | } |
| 182 | |
| 183 | /** |
| 184 | * ist_end_non_atomic() - begin a non-atomic section in an IST exception |
| 185 | * |
| 186 | * Ends a non-atomic section started with ist_begin_non_atomic(). |
| 187 | */ |
| 188 | void ist_end_non_atomic(void) |
| 189 | { |
| 190 | preempt_count_add(HARDIRQ_OFFSET); |
| 191 | } |
| 192 | |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 193 | static nokprobe_inline int |
Frederic Weisbecker | c416ddf | 2012-09-25 14:51:19 +0200 | [diff] [blame] | 194 | do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str, |
| 195 | struct pt_regs *regs, long error_code) |
| 196 | { |
| 197 | #ifdef CONFIG_X86_32 |
| 198 | if (regs->flags & X86_VM_MASK) { |
| 199 | /* |
| 200 | * Traps 0, 1, 3, 4, and 5 should be forwarded to vm86. |
| 201 | * On nmi (interrupt 2), do_trap should not be called. |
| 202 | */ |
| 203 | if (trapnr < X86_TRAP_UD) { |
| 204 | if (!handle_vm86_trap((struct kernel_vm86_regs *) regs, |
| 205 | error_code, trapnr)) |
| 206 | return 0; |
| 207 | } |
| 208 | return -1; |
| 209 | } |
| 210 | #endif |
| 211 | if (!user_mode(regs)) { |
| 212 | if (!fixup_exception(regs)) { |
| 213 | tsk->thread.error_code = error_code; |
| 214 | tsk->thread.trap_nr = trapnr; |
| 215 | die(str, regs, error_code); |
| 216 | } |
| 217 | return 0; |
| 218 | } |
| 219 | |
| 220 | return -1; |
| 221 | } |
| 222 | |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 223 | static siginfo_t *fill_trap_info(struct pt_regs *regs, int signr, int trapnr, |
| 224 | siginfo_t *info) |
Oleg Nesterov | 958d3d7 | 2014-05-07 17:59:39 +0200 | [diff] [blame] | 225 | { |
| 226 | unsigned long siaddr; |
| 227 | int sicode; |
| 228 | |
| 229 | switch (trapnr) { |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 230 | default: |
| 231 | return SEND_SIG_PRIV; |
| 232 | |
Oleg Nesterov | 958d3d7 | 2014-05-07 17:59:39 +0200 | [diff] [blame] | 233 | case X86_TRAP_DE: |
| 234 | sicode = FPE_INTDIV; |
Oleg Nesterov | b02ef20 | 2014-05-12 18:24:45 +0200 | [diff] [blame] | 235 | siaddr = uprobe_get_trap_addr(regs); |
Oleg Nesterov | 958d3d7 | 2014-05-07 17:59:39 +0200 | [diff] [blame] | 236 | break; |
| 237 | case X86_TRAP_UD: |
| 238 | sicode = ILL_ILLOPN; |
Oleg Nesterov | b02ef20 | 2014-05-12 18:24:45 +0200 | [diff] [blame] | 239 | siaddr = uprobe_get_trap_addr(regs); |
Oleg Nesterov | 958d3d7 | 2014-05-07 17:59:39 +0200 | [diff] [blame] | 240 | break; |
| 241 | case X86_TRAP_AC: |
| 242 | sicode = BUS_ADRALN; |
| 243 | siaddr = 0; |
| 244 | break; |
| 245 | } |
| 246 | |
| 247 | info->si_signo = signr; |
| 248 | info->si_errno = 0; |
| 249 | info->si_code = sicode; |
| 250 | info->si_addr = (void __user *)siaddr; |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 251 | return info; |
Oleg Nesterov | 958d3d7 | 2014-05-07 17:59:39 +0200 | [diff] [blame] | 252 | } |
| 253 | |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 254 | static void |
Alexander van Heukelum | 3c1326f | 2008-09-26 14:03:08 +0200 | [diff] [blame] | 255 | do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 256 | long error_code, siginfo_t *info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | { |
Alexander Nyberg | 4f339ec | 2005-06-25 14:58:27 -0700 | [diff] [blame] | 258 | struct task_struct *tsk = current; |
Alexander Nyberg | 4f339ec | 2005-06-25 14:58:27 -0700 | [diff] [blame] | 259 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | |
Frederic Weisbecker | c416ddf | 2012-09-25 14:51:19 +0200 | [diff] [blame] | 261 | if (!do_trap_no_signal(tsk, trapnr, str, regs, error_code)) |
| 262 | return; |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 263 | /* |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 264 | * We want error_code and trap_nr set for userspace faults and |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 265 | * kernelspace faults which result in die(), but not |
| 266 | * kernelspace faults which are fixed up. die() gives the |
| 267 | * process no chance to handle the signal and notice the |
| 268 | * kernel fault information, so that won't result in polluting |
| 269 | * the information about previously queued, but not yet |
| 270 | * delivered, faults. See also do_general_protection below. |
| 271 | */ |
| 272 | tsk->thread.error_code = error_code; |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 273 | tsk->thread.trap_nr = trapnr; |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 274 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 275 | #ifdef CONFIG_X86_64 |
| 276 | if (show_unhandled_signals && unhandled_signal(tsk, signr) && |
| 277 | printk_ratelimit()) { |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 278 | pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx", |
| 279 | tsk->comm, tsk->pid, str, |
| 280 | regs->ip, regs->sp, error_code); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 281 | print_vma_addr(" in ", regs->ip); |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 282 | pr_cont("\n"); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 283 | } |
| 284 | #endif |
| 285 | |
Oleg Nesterov | 38cad57 | 2014-05-07 16:47:09 +0200 | [diff] [blame] | 286 | force_sig_info(signr, info ?: SEND_SIG_PRIV, tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 288 | NOKPROBE_SYMBOL(do_trap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | |
Oleg Nesterov | dff0796 | 2014-05-07 17:21:34 +0200 | [diff] [blame] | 290 | 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] | 291 | unsigned long trapnr, int signr) |
Oleg Nesterov | dff0796 | 2014-05-07 17:21:34 +0200 | [diff] [blame] | 292 | { |
| 293 | enum ctx_state prev_state = exception_enter(); |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 294 | siginfo_t info; |
Oleg Nesterov | dff0796 | 2014-05-07 17:21:34 +0200 | [diff] [blame] | 295 | |
| 296 | if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) != |
| 297 | NOTIFY_STOP) { |
| 298 | conditional_sti(regs); |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 299 | do_trap(trapnr, signr, str, regs, error_code, |
| 300 | fill_trap_info(regs, signr, trapnr, &info)); |
Oleg Nesterov | dff0796 | 2014-05-07 17:21:34 +0200 | [diff] [blame] | 301 | } |
| 302 | |
| 303 | exception_exit(prev_state); |
| 304 | } |
| 305 | |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 306 | #define DO_ERROR(trapnr, signr, str, name) \ |
Alexander van Heukelum | e407d620 | 2008-09-30 18:41:36 +0200 | [diff] [blame] | 307 | dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 308 | { \ |
Oleg Nesterov | 1c326c4 | 2014-05-08 20:04:11 +0200 | [diff] [blame] | 309 | do_error_trap(regs, error_code, str, trapnr, signr); \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | } |
| 311 | |
Oleg Nesterov | 0eb1483 | 2014-05-08 20:12:24 +0200 | [diff] [blame] | 312 | DO_ERROR(X86_TRAP_DE, SIGFPE, "divide error", divide_error) |
| 313 | DO_ERROR(X86_TRAP_OF, SIGSEGV, "overflow", overflow) |
Oleg Nesterov | 0eb1483 | 2014-05-08 20:12:24 +0200 | [diff] [blame] | 314 | DO_ERROR(X86_TRAP_UD, SIGILL, "invalid opcode", invalid_op) |
| 315 | DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, "coprocessor segment overrun",coprocessor_segment_overrun) |
| 316 | DO_ERROR(X86_TRAP_TS, SIGSEGV, "invalid TSS", invalid_TSS) |
| 317 | DO_ERROR(X86_TRAP_NP, SIGBUS, "segment not present", segment_not_present) |
Oleg Nesterov | 0eb1483 | 2014-05-08 20:12:24 +0200 | [diff] [blame] | 318 | DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment) |
Oleg Nesterov | 0eb1483 | 2014-05-08 20:12:24 +0200 | [diff] [blame] | 319 | DO_ERROR(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 321 | #ifdef CONFIG_X86_64 |
| 322 | /* Runs on IST stack */ |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 323 | dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) |
| 324 | { |
| 325 | static const char str[] = "double fault"; |
| 326 | struct task_struct *tsk = current; |
| 327 | |
Andy Lutomirski | af726f2 | 2014-11-22 18:00:31 -0800 | [diff] [blame] | 328 | #ifdef CONFIG_X86_ESPFIX64 |
| 329 | extern unsigned char native_irq_return_iret[]; |
| 330 | |
| 331 | /* |
| 332 | * If IRET takes a non-IST fault on the espfix64 stack, then we |
| 333 | * end up promoting it to a doublefault. In that case, modify |
| 334 | * the stack to make it look like we just entered the #GP |
| 335 | * handler from user space, similar to bad_iret. |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 336 | * |
| 337 | * No need for ist_enter here because we don't use RCU. |
Andy Lutomirski | af726f2 | 2014-11-22 18:00:31 -0800 | [diff] [blame] | 338 | */ |
| 339 | if (((long)regs->sp >> PGDIR_SHIFT) == ESPFIX_PGD_ENTRY && |
| 340 | regs->cs == __KERNEL_CS && |
| 341 | regs->ip == (unsigned long)native_irq_return_iret) |
| 342 | { |
| 343 | struct pt_regs *normal_regs = task_pt_regs(current); |
| 344 | |
| 345 | /* Fake a #GP(0) from userspace. */ |
| 346 | memmove(&normal_regs->ip, (void *)regs->sp, 5*8); |
| 347 | normal_regs->orig_ax = 0; /* Missing (lost) #GP error code */ |
| 348 | regs->ip = (unsigned long)general_protection; |
| 349 | regs->sp = (unsigned long)&normal_regs->orig_ax; |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 350 | |
Andy Lutomirski | af726f2 | 2014-11-22 18:00:31 -0800 | [diff] [blame] | 351 | return; |
| 352 | } |
| 353 | #endif |
| 354 | |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 355 | ist_enter(regs); /* Discard prev_state because we won't return. */ |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 356 | 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] | 357 | |
| 358 | tsk->thread.error_code = error_code; |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 359 | tsk->thread.trap_nr = X86_TRAP_DF; |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 360 | |
Borislav Petkov | 4d067d8 | 2013-05-09 12:02:29 +0200 | [diff] [blame] | 361 | #ifdef CONFIG_DOUBLEFAULT |
| 362 | df_debug(regs, error_code); |
| 363 | #endif |
Ingo Molnar | bd8b96d | 2008-12-26 09:20:22 +0100 | [diff] [blame] | 364 | /* |
| 365 | * This is always a kernel trap and never fixable (and thus must |
| 366 | * never return). |
| 367 | */ |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 368 | for (;;) |
| 369 | die(str, regs, error_code); |
| 370 | } |
| 371 | #endif |
| 372 | |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 373 | dotraplinkage void do_bounds(struct pt_regs *regs, long error_code) |
| 374 | { |
| 375 | struct task_struct *tsk = current; |
| 376 | struct xsave_struct *xsave_buf; |
| 377 | enum ctx_state prev_state; |
| 378 | struct bndcsr *bndcsr; |
| 379 | siginfo_t *info; |
| 380 | |
| 381 | prev_state = exception_enter(); |
| 382 | if (notify_die(DIE_TRAP, "bounds", regs, error_code, |
| 383 | X86_TRAP_BR, SIGSEGV) == NOTIFY_STOP) |
| 384 | goto exit; |
| 385 | conditional_sti(regs); |
| 386 | |
Andy Lutomirski | 394838c | 2015-03-09 17:42:31 -0700 | [diff] [blame] | 387 | if (!user_mode_vm(regs)) |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 388 | die("bounds", regs, error_code); |
| 389 | |
| 390 | if (!cpu_feature_enabled(X86_FEATURE_MPX)) { |
| 391 | /* The exception is not from Intel MPX */ |
| 392 | goto exit_trap; |
| 393 | } |
| 394 | |
| 395 | /* |
| 396 | * We need to look at BNDSTATUS to resolve this exception. |
| 397 | * It is not directly accessible, though, so we need to |
| 398 | * do an xsave and then pull it out of the xsave buffer. |
| 399 | */ |
| 400 | fpu_save_init(&tsk->thread.fpu); |
| 401 | xsave_buf = &(tsk->thread.fpu.state->xsave); |
| 402 | bndcsr = get_xsave_addr(xsave_buf, XSTATE_BNDCSR); |
| 403 | if (!bndcsr) |
| 404 | goto exit_trap; |
| 405 | |
| 406 | /* |
| 407 | * The error code field of the BNDSTATUS register communicates status |
| 408 | * information of a bound range exception #BR or operation involving |
| 409 | * bound directory. |
| 410 | */ |
| 411 | switch (bndcsr->bndstatus & MPX_BNDSTA_ERROR_CODE) { |
| 412 | case 2: /* Bound directory has invalid entry. */ |
| 413 | if (mpx_handle_bd_fault(xsave_buf)) |
| 414 | goto exit_trap; |
| 415 | break; /* Success, it was handled */ |
| 416 | case 1: /* Bound violation. */ |
| 417 | info = mpx_generate_siginfo(regs, xsave_buf); |
Dan Carpenter | e10abb2 | 2014-11-25 20:21:14 +0300 | [diff] [blame] | 418 | if (IS_ERR(info)) { |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 419 | /* |
| 420 | * We failed to decode the MPX instruction. Act as if |
| 421 | * the exception was not caused by MPX. |
| 422 | */ |
| 423 | goto exit_trap; |
| 424 | } |
| 425 | /* |
| 426 | * Success, we decoded the instruction and retrieved |
| 427 | * an 'info' containing the address being accessed |
| 428 | * which caused the exception. This information |
| 429 | * allows and application to possibly handle the |
| 430 | * #BR exception itself. |
| 431 | */ |
| 432 | do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, error_code, info); |
| 433 | kfree(info); |
| 434 | break; |
| 435 | case 0: /* No exception caused by Intel MPX operations. */ |
| 436 | goto exit_trap; |
| 437 | default: |
| 438 | die("bounds", regs, error_code); |
| 439 | } |
| 440 | |
| 441 | exit: |
| 442 | exception_exit(prev_state); |
| 443 | return; |
| 444 | exit_trap: |
| 445 | /* |
| 446 | * This path out is for all the cases where we could not |
| 447 | * handle the exception in some way (like allocating a |
| 448 | * table or telling userspace about it. We will also end |
| 449 | * up here if the kernel has MPX turned off at compile |
| 450 | * time.. |
| 451 | */ |
| 452 | do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, error_code, NULL); |
| 453 | exception_exit(prev_state); |
| 454 | } |
| 455 | |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 456 | dotraplinkage void |
Alexander van Heukelum | 13485ab | 2008-07-02 01:32:04 +0200 | [diff] [blame] | 457 | do_general_protection(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | { |
Alexander van Heukelum | 13485ab | 2008-07-02 01:32:04 +0200 | [diff] [blame] | 459 | struct task_struct *tsk; |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 460 | enum ctx_state prev_state; |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 461 | |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 462 | prev_state = exception_enter(); |
Alexander van Heukelum | c6df0d7 | 2008-09-09 21:56:07 +0200 | [diff] [blame] | 463 | conditional_sti(regs); |
| 464 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 465 | #ifdef CONFIG_X86_32 |
Frederic Weisbecker | ef3f628 | 2012-09-24 21:05:52 +0200 | [diff] [blame] | 466 | if (regs->flags & X86_VM_MASK) { |
| 467 | local_irq_enable(); |
| 468 | handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 469 | goto exit; |
Frederic Weisbecker | ef3f628 | 2012-09-24 21:05:52 +0200 | [diff] [blame] | 470 | } |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 471 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | |
Alexander van Heukelum | 13485ab | 2008-07-02 01:32:04 +0200 | [diff] [blame] | 473 | tsk = current; |
Frederic Weisbecker | ef3f628 | 2012-09-24 21:05:52 +0200 | [diff] [blame] | 474 | if (!user_mode(regs)) { |
| 475 | if (fixup_exception(regs)) |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 476 | goto exit; |
Frederic Weisbecker | ef3f628 | 2012-09-24 21:05:52 +0200 | [diff] [blame] | 477 | |
| 478 | tsk->thread.error_code = error_code; |
| 479 | tsk->thread.trap_nr = X86_TRAP_GP; |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 480 | if (notify_die(DIE_GPF, "general protection fault", regs, error_code, |
| 481 | X86_TRAP_GP, SIGSEGV) != NOTIFY_STOP) |
Frederic Weisbecker | ef3f628 | 2012-09-24 21:05:52 +0200 | [diff] [blame] | 482 | die("general protection fault", regs, error_code); |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 483 | goto exit; |
Frederic Weisbecker | ef3f628 | 2012-09-24 21:05:52 +0200 | [diff] [blame] | 484 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | |
Alexander van Heukelum | 13485ab | 2008-07-02 01:32:04 +0200 | [diff] [blame] | 486 | tsk->thread.error_code = error_code; |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 487 | tsk->thread.trap_nr = X86_TRAP_GP; |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 488 | |
Alexander van Heukelum | 13485ab | 2008-07-02 01:32:04 +0200 | [diff] [blame] | 489 | if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && |
| 490 | printk_ratelimit()) { |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 491 | 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] | 492 | tsk->comm, task_pid_nr(tsk), |
| 493 | regs->ip, regs->sp, error_code); |
Andi Kleen | 0325291 | 2008-01-30 13:33:18 +0100 | [diff] [blame] | 494 | print_vma_addr(" in ", regs->ip); |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 495 | pr_cont("\n"); |
Andi Kleen | 0325291 | 2008-01-30 13:33:18 +0100 | [diff] [blame] | 496 | } |
Masoud Asgharifard Sharbiani | abd4f75 | 2007-07-22 11:12:28 +0200 | [diff] [blame] | 497 | |
Oleg Nesterov | 38cad57 | 2014-05-07 16:47:09 +0200 | [diff] [blame] | 498 | force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk); |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 499 | exit: |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 500 | exception_exit(prev_state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 502 | NOKPROBE_SYMBOL(do_general_protection); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 504 | /* May run on IST stack. */ |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 505 | dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | { |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 507 | enum ctx_state prev_state; |
| 508 | |
Steven Rostedt | 08d636b | 2011-08-16 09:57:10 -0400 | [diff] [blame] | 509 | #ifdef CONFIG_DYNAMIC_FTRACE |
Steven Rostedt | a192cd0 | 2012-05-30 13:26:37 -0400 | [diff] [blame] | 510 | /* |
| 511 | * ftrace must be first, everything else may cause a recursive crash. |
| 512 | * See note by declaration of modifying_ftrace_code in ftrace.c |
| 513 | */ |
| 514 | if (unlikely(atomic_read(&modifying_ftrace_code)) && |
| 515 | ftrace_int3_handler(regs)) |
Steven Rostedt | 08d636b | 2011-08-16 09:57:10 -0400 | [diff] [blame] | 516 | return; |
| 517 | #endif |
Jiri Kosina | 17f4157 | 2013-07-23 10:09:28 +0200 | [diff] [blame] | 518 | if (poke_int3_handler(regs)) |
| 519 | return; |
| 520 | |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 521 | prev_state = ist_enter(regs); |
Jason Wessel | f503b5a | 2010-05-20 21:04:25 -0500 | [diff] [blame] | 522 | #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 523 | if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, |
| 524 | SIGTRAP) == NOTIFY_STOP) |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 525 | goto exit; |
Jason Wessel | f503b5a | 2010-05-20 21:04:25 -0500 | [diff] [blame] | 526 | #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ |
Srikar Dronamraju | cc3a1bf | 2011-10-25 19:51:59 +0530 | [diff] [blame] | 527 | |
Masami Hiramatsu | 6f6343f | 2014-04-17 17:17:33 +0900 | [diff] [blame] | 528 | #ifdef CONFIG_KPROBES |
| 529 | if (kprobe_int3_handler(regs)) |
Masami Hiramatsu | 4cdf77a | 2014-06-14 06:47:12 +0000 | [diff] [blame] | 530 | goto exit; |
Masami Hiramatsu | 6f6343f | 2014-04-17 17:17:33 +0900 | [diff] [blame] | 531 | #endif |
| 532 | |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 533 | if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, |
| 534 | SIGTRAP) == NOTIFY_STOP) |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 535 | goto exit; |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 536 | |
Steven Rostedt | 4218118 | 2011-12-16 11:43:02 -0500 | [diff] [blame] | 537 | /* |
| 538 | * Let others (NMI) know that the debug stack is in use |
| 539 | * as we may switch to the interrupt stack. |
| 540 | */ |
| 541 | debug_stack_usage_inc(); |
Alexander van Heukelum | 4915a35 | 2008-10-03 22:00:34 +0200 | [diff] [blame] | 542 | preempt_conditional_sti(regs); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 543 | do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL); |
Alexander van Heukelum | 4915a35 | 2008-10-03 22:00:34 +0200 | [diff] [blame] | 544 | preempt_conditional_cli(regs); |
Steven Rostedt | 4218118 | 2011-12-16 11:43:02 -0500 | [diff] [blame] | 545 | debug_stack_usage_dec(); |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 546 | exit: |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 547 | ist_exit(regs, prev_state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 549 | NOKPROBE_SYMBOL(do_int3); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 551 | #ifdef CONFIG_X86_64 |
Ingo Molnar | bd8b96d | 2008-12-26 09:20:22 +0100 | [diff] [blame] | 552 | /* |
Andy Lutomirski | 48e08d0 | 2014-11-11 12:49:41 -0800 | [diff] [blame] | 553 | * Help handler running on IST stack to switch off the IST stack if the |
| 554 | * interrupted code was in user mode. The actual stack switch is done in |
| 555 | * entry_64.S |
Ingo Molnar | bd8b96d | 2008-12-26 09:20:22 +0100 | [diff] [blame] | 556 | */ |
Andy Lutomirski | 7ddc6a2 | 2014-11-24 17:39:06 -0800 | [diff] [blame] | 557 | 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] | 558 | { |
Andy Lutomirski | 48e08d0 | 2014-11-11 12:49:41 -0800 | [diff] [blame] | 559 | struct pt_regs *regs = task_pt_regs(current); |
| 560 | *regs = *eregs; |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 561 | return regs; |
| 562 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 563 | NOKPROBE_SYMBOL(sync_regs); |
Andy Lutomirski | b645af2 | 2014-11-22 18:00:33 -0800 | [diff] [blame] | 564 | |
| 565 | struct bad_iret_stack { |
| 566 | void *error_entry_ret; |
| 567 | struct pt_regs regs; |
| 568 | }; |
| 569 | |
Andy Lutomirski | 7ddc6a2 | 2014-11-24 17:39:06 -0800 | [diff] [blame] | 570 | asmlinkage __visible notrace |
Andy Lutomirski | b645af2 | 2014-11-22 18:00:33 -0800 | [diff] [blame] | 571 | struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) |
| 572 | { |
| 573 | /* |
| 574 | * This is called from entry_64.S early in handling a fault |
| 575 | * caused by a bad iret to user mode. To handle the fault |
| 576 | * correctly, we want move our stack frame to task_pt_regs |
| 577 | * and we want to pretend that the exception came from the |
| 578 | * iret target. |
| 579 | */ |
| 580 | struct bad_iret_stack *new_stack = |
| 581 | container_of(task_pt_regs(current), |
| 582 | struct bad_iret_stack, regs); |
| 583 | |
| 584 | /* Copy the IRET target to the new stack. */ |
| 585 | memmove(&new_stack->regs.ip, (void *)s->regs.sp, 5*8); |
| 586 | |
| 587 | /* Copy the remainder of the stack from the current stack. */ |
| 588 | memmove(new_stack, s, offsetof(struct bad_iret_stack, regs.ip)); |
| 589 | |
| 590 | BUG_ON(!user_mode_vm(&new_stack->regs)); |
| 591 | return new_stack; |
| 592 | } |
Andy Lutomirski | 7ddc6a2 | 2014-11-24 17:39:06 -0800 | [diff] [blame] | 593 | NOKPROBE_SYMBOL(fixup_bad_iret); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 594 | #endif |
| 595 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | /* |
| 597 | * Our handling of the processor debug registers is non-trivial. |
| 598 | * We do not clear them on entry and exit from the kernel. Therefore |
| 599 | * it is possible to get a watchpoint trap here from inside the kernel. |
| 600 | * However, the code in ./ptrace.c has ensured that the user can |
| 601 | * only set watchpoints on userspace addresses. Therefore the in-kernel |
| 602 | * watchpoint trap can only occur in code which is reading/writing |
| 603 | * from user space. Such code must not hold kernel locks (since it |
| 604 | * can equally take a page fault), therefore it is safe to call |
| 605 | * force_sig_info even though that claims and releases locks. |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 606 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | * Code in ./signal.c ensures that the debug control register |
| 608 | * is restored before we deliver any signal, and therefore that |
| 609 | * user code runs with the correct debug control register even though |
| 610 | * we clear it here. |
| 611 | * |
| 612 | * Being careful here means that we don't have to be as careful in a |
| 613 | * lot of more complicated places (task switching can be a bit lazy |
| 614 | * about restoring all the debug state, and ptrace doesn't have to |
| 615 | * find every occurrence of the TF bit that could be saved away even |
| 616 | * by user code) |
Alexander van Heukelum | c1d518c | 2008-10-03 23:17:11 +0200 | [diff] [blame] | 617 | * |
| 618 | * May run on IST stack. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | */ |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 620 | dotraplinkage void do_debug(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 621 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 622 | struct task_struct *tsk = current; |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 623 | enum ctx_state prev_state; |
Frederic Weisbecker | a1e80fa | 2010-06-30 15:09:06 +0200 | [diff] [blame] | 624 | int user_icebp = 0; |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 625 | unsigned long dr6; |
Srinivasa Ds | da654b7 | 2008-09-23 15:23:52 +0530 | [diff] [blame] | 626 | int si_code; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 628 | prev_state = ist_enter(regs); |
Masami Hiramatsu | 4cdf77a | 2014-06-14 06:47:12 +0000 | [diff] [blame] | 629 | |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 630 | get_debugreg(dr6, 6); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | |
K.Prasad | 40f9249 | 2010-01-28 16:44:01 +0530 | [diff] [blame] | 632 | /* Filter out all the reserved bits which are preset to 1 */ |
| 633 | dr6 &= ~DR6_RESERVED; |
| 634 | |
Frederic Weisbecker | a1e80fa | 2010-06-30 15:09:06 +0200 | [diff] [blame] | 635 | /* |
| 636 | * If dr6 has no reason to give us about the origin of this trap, |
| 637 | * then it's very likely the result of an icebp/int01 trap. |
| 638 | * User wants a sigtrap for that. |
| 639 | */ |
Andy Lutomirski | 394838c | 2015-03-09 17:42:31 -0700 | [diff] [blame] | 640 | if (!dr6 && user_mode_vm(regs)) |
Frederic Weisbecker | a1e80fa | 2010-06-30 15:09:06 +0200 | [diff] [blame] | 641 | user_icebp = 1; |
| 642 | |
Vegard Nossum | f856129 | 2008-04-04 00:53:23 +0200 | [diff] [blame] | 643 | /* Catch kmemcheck conditions first of all! */ |
Ingo Molnar | eadb8a0 | 2009-06-17 12:52:15 +0200 | [diff] [blame] | 644 | if ((dr6 & DR_STEP) && kmemcheck_trap(regs)) |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 645 | goto exit; |
Vegard Nossum | f856129 | 2008-04-04 00:53:23 +0200 | [diff] [blame] | 646 | |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 647 | /* DR6 may or may not be cleared by the CPU */ |
| 648 | set_debugreg(0, 6); |
Roland McGrath | 10faa81 | 2008-01-30 13:30:54 +0100 | [diff] [blame] | 649 | |
Peter Zijlstra | ea8e61b | 2010-03-25 14:51:51 +0100 | [diff] [blame] | 650 | /* |
| 651 | * The processor cleared BTF, so don't mark that we need it set. |
| 652 | */ |
| 653 | clear_tsk_thread_flag(tsk, TIF_BLOCKSTEP); |
| 654 | |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 655 | /* Store the virtualized DR6 value */ |
| 656 | tsk->thread.debugreg6 = dr6; |
| 657 | |
Masami Hiramatsu | 6f6343f | 2014-04-17 17:17:33 +0900 | [diff] [blame] | 658 | #ifdef CONFIG_KPROBES |
| 659 | if (kprobe_debug_handler(regs)) |
| 660 | goto exit; |
| 661 | #endif |
| 662 | |
Rusty Russell | 5a802e1 | 2013-06-16 14:12:47 +0930 | [diff] [blame] | 663 | if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, error_code, |
K.Prasad | 62edab9 | 2009-06-01 23:47:06 +0530 | [diff] [blame] | 664 | SIGTRAP) == NOTIFY_STOP) |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 665 | goto exit; |
Alexander van Heukelum | 3d2a71a | 2008-09-30 18:41:37 +0200 | [diff] [blame] | 666 | |
Steven Rostedt | 4218118 | 2011-12-16 11:43:02 -0500 | [diff] [blame] | 667 | /* |
| 668 | * Let others (NMI) know that the debug stack is in use |
| 669 | * as we may switch to the interrupt stack. |
| 670 | */ |
| 671 | debug_stack_usage_inc(); |
| 672 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | /* It's safe to allow irq's after DR6 has been saved */ |
Alexander van Heukelum | 3d2a71a | 2008-09-30 18:41:37 +0200 | [diff] [blame] | 674 | preempt_conditional_sti(regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 676 | if (regs->flags & X86_VM_MASK) { |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 677 | handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, |
| 678 | X86_TRAP_DB); |
Bart Oldeman | 6554287 | 2010-09-23 13:16:58 -0400 | [diff] [blame] | 679 | preempt_conditional_cli(regs); |
Steven Rostedt | 4218118 | 2011-12-16 11:43:02 -0500 | [diff] [blame] | 680 | debug_stack_usage_dec(); |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 681 | goto exit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 682 | } |
| 683 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 684 | /* |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 685 | * Single-stepping through system calls: ignore any exceptions in |
| 686 | * kernel space, but re-enable TF when returning to user mode. |
| 687 | * |
| 688 | * We already checked v86 mode above, so we can check for kernel mode |
| 689 | * by just checking the CPL of CS. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | */ |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 691 | if ((dr6 & DR_STEP) && !user_mode(regs)) { |
| 692 | tsk->thread.debugreg6 &= ~DR_STEP; |
| 693 | set_tsk_thread_flag(tsk, TIF_SINGLESTEP); |
| 694 | regs->flags &= ~X86_EFLAGS_TF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | } |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 696 | si_code = get_si_code(tsk->thread.debugreg6); |
Frederic Weisbecker | a1e80fa | 2010-06-30 15:09:06 +0200 | [diff] [blame] | 697 | if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp) |
K.Prasad | 08d6832 | 2009-06-01 23:44:08 +0530 | [diff] [blame] | 698 | send_sigtrap(tsk, regs, error_code, si_code); |
Alexander van Heukelum | 3d2a71a | 2008-09-30 18:41:37 +0200 | [diff] [blame] | 699 | preempt_conditional_cli(regs); |
Steven Rostedt | 4218118 | 2011-12-16 11:43:02 -0500 | [diff] [blame] | 700 | debug_stack_usage_dec(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 701 | |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 702 | exit: |
Andy Lutomirski | 9592747 | 2014-11-19 17:41:09 -0800 | [diff] [blame] | 703 | ist_exit(regs, prev_state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 705 | NOKPROBE_SYMBOL(do_debug); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | |
| 707 | /* |
| 708 | * Note that we play around with the 'TS' bit in an attempt to get |
| 709 | * the correct behaviour even in the presence of the asynchronous |
| 710 | * IRQ13 behaviour |
| 711 | */ |
Oleg Nesterov | 5e1b05b | 2014-05-08 20:34:00 +0200 | [diff] [blame] | 712 | 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] | 713 | { |
Brian Gerst | e2e75c9 | 2010-03-21 09:00:45 -0400 | [diff] [blame] | 714 | struct task_struct *task = current; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 715 | siginfo_t info; |
Brian Gerst | 9b6dba9 | 2010-03-21 09:00:44 -0400 | [diff] [blame] | 716 | unsigned short err; |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 717 | char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" : |
| 718 | "simd exception"; |
Brian Gerst | e2e75c9 | 2010-03-21 09:00:45 -0400 | [diff] [blame] | 719 | |
| 720 | if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP) |
| 721 | return; |
| 722 | conditional_sti(regs); |
| 723 | |
| 724 | if (!user_mode_vm(regs)) |
| 725 | { |
| 726 | if (!fixup_exception(regs)) { |
| 727 | task->thread.error_code = error_code; |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 728 | task->thread.trap_nr = trapnr; |
Brian Gerst | e2e75c9 | 2010-03-21 09:00:45 -0400 | [diff] [blame] | 729 | die(str, regs, error_code); |
| 730 | } |
| 731 | return; |
| 732 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 733 | |
| 734 | /* |
| 735 | * Save the info for the exception handler and clear the error. |
| 736 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | save_init_fpu(task); |
Srikar Dronamraju | 51e7dc7 | 2012-03-12 14:55:55 +0530 | [diff] [blame] | 738 | task->thread.trap_nr = trapnr; |
Brian Gerst | 9b6dba9 | 2010-03-21 09:00:44 -0400 | [diff] [blame] | 739 | task->thread.error_code = error_code; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | info.si_signo = SIGFPE; |
| 741 | info.si_errno = 0; |
Oleg Nesterov | b02ef20 | 2014-05-12 18:24:45 +0200 | [diff] [blame] | 742 | info.si_addr = (void __user *)uprobe_get_trap_addr(regs); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 743 | if (trapnr == X86_TRAP_MF) { |
Brian Gerst | 9b6dba9 | 2010-03-21 09:00:44 -0400 | [diff] [blame] | 744 | unsigned short cwd, swd; |
| 745 | /* |
| 746 | * (~cwd & swd) will mask out exceptions that are not set to unmasked |
| 747 | * status. 0x3f is the exception bits in these regs, 0x200 is the |
| 748 | * C1 reg you need in case of a stack fault, 0x040 is the stack |
| 749 | * fault bit. We should only be taking one exception at a time, |
| 750 | * so if this combination doesn't produce any single exception, |
| 751 | * then we have a bad program that isn't synchronizing its FPU usage |
| 752 | * and it will suffer the consequences since we won't be able to |
| 753 | * fully reproduce the context of the exception |
| 754 | */ |
| 755 | cwd = get_fpu_cwd(task); |
| 756 | swd = get_fpu_swd(task); |
H. Peter Anvin | adf77ba | 2008-12-22 17:56:05 -0800 | [diff] [blame] | 757 | |
Brian Gerst | 9b6dba9 | 2010-03-21 09:00:44 -0400 | [diff] [blame] | 758 | err = swd & ~cwd; |
| 759 | } else { |
| 760 | /* |
| 761 | * The SIMD FPU exceptions are handled a little differently, as there |
| 762 | * is only a single status/control register. Thus, to determine which |
| 763 | * unmasked exception was caught we must mask the exception mask bits |
| 764 | * at 0x1f80, and then use these to mask the exception bits at 0x3f. |
| 765 | */ |
| 766 | unsigned short mxcsr = get_fpu_mxcsr(task); |
| 767 | err = ~(mxcsr >> 7) & mxcsr; |
| 768 | } |
H. Peter Anvin | adf77ba | 2008-12-22 17:56:05 -0800 | [diff] [blame] | 769 | |
| 770 | if (err & 0x001) { /* Invalid op */ |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 771 | /* |
| 772 | * swd & 0x240 == 0x040: Stack Underflow |
| 773 | * swd & 0x240 == 0x240: Stack Overflow |
| 774 | * User must clear the SF bit (0x40) if set |
| 775 | */ |
| 776 | info.si_code = FPE_FLTINV; |
H. Peter Anvin | adf77ba | 2008-12-22 17:56:05 -0800 | [diff] [blame] | 777 | } else if (err & 0x004) { /* Divide by Zero */ |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 778 | info.si_code = FPE_FLTDIV; |
H. Peter Anvin | adf77ba | 2008-12-22 17:56:05 -0800 | [diff] [blame] | 779 | } else if (err & 0x008) { /* Overflow */ |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 780 | info.si_code = FPE_FLTOVF; |
H. Peter Anvin | adf77ba | 2008-12-22 17:56:05 -0800 | [diff] [blame] | 781 | } else if (err & 0x012) { /* Denormal, Underflow */ |
| 782 | info.si_code = FPE_FLTUND; |
| 783 | } else if (err & 0x020) { /* Precision */ |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 784 | info.si_code = FPE_FLTRES; |
H. Peter Anvin | adf77ba | 2008-12-22 17:56:05 -0800 | [diff] [blame] | 785 | } else { |
Ingo Molnar | bd8b96d | 2008-12-26 09:20:22 +0100 | [diff] [blame] | 786 | /* |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 787 | * If we're using IRQ 13, or supposedly even some trap |
| 788 | * X86_TRAP_MF implementations, it's possible |
| 789 | * we get a spurious trap, which is not an error. |
Ingo Molnar | bd8b96d | 2008-12-26 09:20:22 +0100 | [diff] [blame] | 790 | */ |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 791 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 792 | } |
| 793 | force_sig_info(SIGFPE, &info, task); |
| 794 | } |
| 795 | |
Alexander van Heukelum | e407d620 | 2008-09-30 18:41:36 +0200 | [diff] [blame] | 796 | dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 797 | { |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 798 | enum ctx_state prev_state; |
| 799 | |
| 800 | prev_state = exception_enter(); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 801 | math_error(regs, error_code, X86_TRAP_MF); |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 802 | exception_exit(prev_state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 803 | } |
| 804 | |
Alexander van Heukelum | e407d620 | 2008-09-30 18:41:36 +0200 | [diff] [blame] | 805 | dotraplinkage void |
| 806 | do_simd_coprocessor_error(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | { |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 808 | enum ctx_state prev_state; |
| 809 | |
| 810 | prev_state = exception_enter(); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 811 | math_error(regs, error_code, X86_TRAP_XF); |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 812 | exception_exit(prev_state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | } |
| 814 | |
Alexander van Heukelum | e407d620 | 2008-09-30 18:41:36 +0200 | [diff] [blame] | 815 | dotraplinkage void |
| 816 | do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 817 | { |
Alexander van Heukelum | cf81978 | 2008-09-09 21:56:08 +0200 | [diff] [blame] | 818 | conditional_sti(regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | #if 0 |
| 820 | /* No need to warn about this any longer. */ |
Joe Perches | c767a54 | 2012-05-21 19:50:07 -0700 | [diff] [blame] | 821 | pr_info("Ignoring P6 Local APIC Spurious Interrupt Bug...\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 822 | #endif |
| 823 | } |
| 824 | |
Andi Kleen | 2605fc2 | 2014-05-02 00:44:37 +0200 | [diff] [blame] | 825 | asmlinkage __visible void __attribute__((weak)) smp_thermal_interrupt(void) |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 826 | { |
| 827 | } |
| 828 | |
Andi Kleen | 2605fc2 | 2014-05-02 00:44:37 +0200 | [diff] [blame] | 829 | asmlinkage __visible void __attribute__((weak)) smp_threshold_interrupt(void) |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 830 | { |
| 831 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 832 | |
| 833 | /* |
Linus Torvalds | 34ddc81 | 2012-02-18 12:56:35 -0800 | [diff] [blame] | 834 | * 'math_state_restore()' saves the current math information in the |
| 835 | * old math state array, and gets the new ones from the current task |
| 836 | * |
| 837 | * Careful.. There are problems with IBM-designed IRQ13 behaviour. |
| 838 | * Don't touch unless you *really* know how it works. |
| 839 | * |
| 840 | * Must be called with kernel preemption disabled (eg with local |
| 841 | * local interrupts as in the case of do_device_not_available). |
| 842 | */ |
| 843 | void math_state_restore(void) |
| 844 | { |
| 845 | struct task_struct *tsk = current; |
| 846 | |
| 847 | if (!tsk_used_math(tsk)) { |
| 848 | local_irq_enable(); |
| 849 | /* |
| 850 | * does a slab alloc which can sleep |
| 851 | */ |
| 852 | if (init_fpu(tsk)) { |
| 853 | /* |
| 854 | * ran out of memory! |
| 855 | */ |
| 856 | do_group_exit(SIGKILL); |
| 857 | return; |
| 858 | } |
| 859 | local_irq_disable(); |
| 860 | } |
| 861 | |
Oleg Nesterov | 7575637 | 2015-01-15 20:20:28 +0100 | [diff] [blame] | 862 | /* Avoid __kernel_fpu_begin() right after __thread_fpu_begin() */ |
| 863 | kernel_fpu_disable(); |
Linus Torvalds | 34ddc81 | 2012-02-18 12:56:35 -0800 | [diff] [blame] | 864 | __thread_fpu_begin(tsk); |
Linus Torvalds | 80ab6f1 | 2012-02-19 11:48:44 -0800 | [diff] [blame] | 865 | if (unlikely(restore_fpu_checking(tsk))) { |
Suresh Siddha | 304bced | 2012-08-24 14:13:02 -0700 | [diff] [blame] | 866 | drop_init_fpu(tsk); |
Oleg Nesterov | 38cad57 | 2014-05-07 16:47:09 +0200 | [diff] [blame] | 867 | force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk); |
Oleg Nesterov | 7575637 | 2015-01-15 20:20:28 +0100 | [diff] [blame] | 868 | } else { |
| 869 | tsk->thread.fpu_counter++; |
Linus Torvalds | 80ab6f1 | 2012-02-19 11:48:44 -0800 | [diff] [blame] | 870 | } |
Oleg Nesterov | 7575637 | 2015-01-15 20:20:28 +0100 | [diff] [blame] | 871 | kernel_fpu_enable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 872 | } |
Rusty Russell | 5992b6d | 2007-07-19 01:49:21 -0700 | [diff] [blame] | 873 | EXPORT_SYMBOL_GPL(math_state_restore); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 874 | |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 875 | dotraplinkage void |
Brian Gerst | aa78bcf | 2009-02-10 09:51:45 -0500 | [diff] [blame] | 876 | do_device_not_available(struct pt_regs *regs, long error_code) |
Alexander van Heukelum | 7643e9b | 2008-09-09 21:56:02 +0200 | [diff] [blame] | 877 | { |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 878 | enum ctx_state prev_state; |
| 879 | |
| 880 | prev_state = exception_enter(); |
Suresh Siddha | 5d2bd70 | 2012-09-06 14:58:52 -0700 | [diff] [blame] | 881 | BUG_ON(use_eager_fpu()); |
Suresh Siddha | 304bced | 2012-08-24 14:13:02 -0700 | [diff] [blame] | 882 | |
Brian Gerst | a334fe4 | 2010-09-03 21:17:15 -0400 | [diff] [blame] | 883 | #ifdef CONFIG_MATH_EMULATION |
Alexander van Heukelum | 7643e9b | 2008-09-09 21:56:02 +0200 | [diff] [blame] | 884 | if (read_cr0() & X86_CR0_EM) { |
Tejun Heo | d315760 | 2009-02-09 22:17:39 +0900 | [diff] [blame] | 885 | struct math_emu_info info = { }; |
| 886 | |
Alexander van Heukelum | 7643e9b | 2008-09-09 21:56:02 +0200 | [diff] [blame] | 887 | conditional_sti(regs); |
Tejun Heo | d315760 | 2009-02-09 22:17:39 +0900 | [diff] [blame] | 888 | |
Brian Gerst | aa78bcf | 2009-02-10 09:51:45 -0500 | [diff] [blame] | 889 | info.regs = regs; |
Tejun Heo | d315760 | 2009-02-09 22:17:39 +0900 | [diff] [blame] | 890 | math_emulate(&info); |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 891 | exception_exit(prev_state); |
Brian Gerst | a334fe4 | 2010-09-03 21:17:15 -0400 | [diff] [blame] | 892 | return; |
Alexander van Heukelum | 7643e9b | 2008-09-09 21:56:02 +0200 | [diff] [blame] | 893 | } |
Brian Gerst | a334fe4 | 2010-09-03 21:17:15 -0400 | [diff] [blame] | 894 | #endif |
| 895 | math_state_restore(); /* interrupts still off */ |
| 896 | #ifdef CONFIG_X86_32 |
| 897 | conditional_sti(regs); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 898 | #endif |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 899 | exception_exit(prev_state); |
Alexander van Heukelum | 7643e9b | 2008-09-09 21:56:02 +0200 | [diff] [blame] | 900 | } |
Masami Hiramatsu | 9326638 | 2014-04-17 17:18:14 +0900 | [diff] [blame] | 901 | NOKPROBE_SYMBOL(do_device_not_available); |
Alexander van Heukelum | 7643e9b | 2008-09-09 21:56:02 +0200 | [diff] [blame] | 902 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 903 | #ifdef CONFIG_X86_32 |
Alexander van Heukelum | e407d620 | 2008-09-30 18:41:36 +0200 | [diff] [blame] | 904 | 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] | 905 | { |
| 906 | siginfo_t info; |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 907 | enum ctx_state prev_state; |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 908 | |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 909 | prev_state = exception_enter(); |
Alexander van Heukelum | f8e0870 | 2008-09-09 21:56:13 +0200 | [diff] [blame] | 910 | local_irq_enable(); |
| 911 | |
| 912 | info.si_signo = SIGILL; |
| 913 | info.si_errno = 0; |
| 914 | info.si_code = ILL_BADSTK; |
Hannes Eder | fc6fcdf | 2009-02-22 01:00:57 +0100 | [diff] [blame] | 915 | info.si_addr = NULL; |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 916 | if (notify_die(DIE_TRAP, "iret exception", regs, error_code, |
Frederic Weisbecker | 6ba3c97 | 2012-07-11 20:26:35 +0200 | [diff] [blame] | 917 | X86_TRAP_IRET, SIGILL) != NOTIFY_STOP) { |
| 918 | do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code, |
| 919 | &info); |
| 920 | } |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 921 | exception_exit(prev_state); |
Alexander van Heukelum | f8e0870 | 2008-09-09 21:56:13 +0200 | [diff] [blame] | 922 | } |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 923 | #endif |
Alexander van Heukelum | f8e0870 | 2008-09-09 21:56:13 +0200 | [diff] [blame] | 924 | |
Jan Kiszka | 29c8439 | 2010-05-20 21:04:29 -0500 | [diff] [blame] | 925 | /* Set of traps needed for early debugging. */ |
| 926 | void __init early_trap_init(void) |
| 927 | { |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 928 | set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK); |
Jan Kiszka | 29c8439 | 2010-05-20 21:04:29 -0500 | [diff] [blame] | 929 | /* int3 can be called from all */ |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 930 | set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK); |
H. Peter Anvin | 8170e6b | 2013-01-24 12:19:52 -0800 | [diff] [blame] | 931 | #ifdef CONFIG_X86_32 |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 932 | set_intr_gate(X86_TRAP_PF, page_fault); |
H. Peter Anvin | 8170e6b | 2013-01-24 12:19:52 -0800 | [diff] [blame] | 933 | #endif |
Jan Kiszka | 29c8439 | 2010-05-20 21:04:29 -0500 | [diff] [blame] | 934 | load_idt(&idt_descr); |
| 935 | } |
| 936 | |
H. Peter Anvin | 8170e6b | 2013-01-24 12:19:52 -0800 | [diff] [blame] | 937 | void __init early_trap_pf_init(void) |
| 938 | { |
| 939 | #ifdef CONFIG_X86_64 |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 940 | set_intr_gate(X86_TRAP_PF, page_fault); |
H. Peter Anvin | 8170e6b | 2013-01-24 12:19:52 -0800 | [diff] [blame] | 941 | #endif |
| 942 | } |
| 943 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 944 | void __init trap_init(void) |
| 945 | { |
Rusty Russell | dbeb2be | 2007-10-19 20:35:03 +0200 | [diff] [blame] | 946 | int i; |
| 947 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 948 | #ifdef CONFIG_EISA |
Ingo Molnar | 927222b | 2008-01-30 13:33:49 +0100 | [diff] [blame] | 949 | void __iomem *p = early_ioremap(0x0FFFD9, 4); |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 950 | |
| 951 | if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 952 | EISA_bus = 1; |
Ingo Molnar | 927222b | 2008-01-30 13:33:49 +0100 | [diff] [blame] | 953 | early_iounmap(p, 4); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 954 | #endif |
| 955 | |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 956 | set_intr_gate(X86_TRAP_DE, divide_error); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 957 | set_intr_gate_ist(X86_TRAP_NMI, &nmi, NMI_STACK); |
Alexander van Heukelum | 699d293 | 2008-10-03 22:00:32 +0200 | [diff] [blame] | 958 | /* int4 can be called from all */ |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 959 | set_system_intr_gate(X86_TRAP_OF, &overflow); |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 960 | set_intr_gate(X86_TRAP_BR, bounds); |
| 961 | set_intr_gate(X86_TRAP_UD, invalid_op); |
| 962 | set_intr_gate(X86_TRAP_NM, device_not_available); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 963 | #ifdef CONFIG_X86_32 |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 964 | set_task_gate(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 965 | #else |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 966 | set_intr_gate_ist(X86_TRAP_DF, &double_fault, DOUBLEFAULT_STACK); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 967 | #endif |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 968 | set_intr_gate(X86_TRAP_OLD_MF, coprocessor_segment_overrun); |
| 969 | set_intr_gate(X86_TRAP_TS, invalid_TSS); |
| 970 | set_intr_gate(X86_TRAP_NP, segment_not_present); |
Andy Lutomirski | 6f442be | 2014-11-22 18:00:32 -0800 | [diff] [blame] | 971 | set_intr_gate(X86_TRAP_SS, stack_segment); |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 972 | set_intr_gate(X86_TRAP_GP, general_protection); |
| 973 | set_intr_gate(X86_TRAP_SPURIOUS, spurious_interrupt_bug); |
| 974 | set_intr_gate(X86_TRAP_MF, coprocessor_error); |
| 975 | set_intr_gate(X86_TRAP_AC, alignment_check); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | #ifdef CONFIG_X86_MCE |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 977 | set_intr_gate_ist(X86_TRAP_MC, &machine_check, MCE_STACK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | #endif |
Seiji Aguchi | 25c74b1 | 2013-10-30 16:37:00 -0400 | [diff] [blame] | 979 | set_intr_gate(X86_TRAP_XF, simd_coprocessor_error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 980 | |
Yinghai Lu | bb3f0b5 | 2009-01-25 02:38:09 -0800 | [diff] [blame] | 981 | /* Reserve all the builtin and the syscall vector: */ |
| 982 | for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) |
| 983 | set_bit(i, used_vectors); |
| 984 | |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 985 | #ifdef CONFIG_IA32_EMULATION |
| 986 | set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall); |
Yinghai Lu | bb3f0b5 | 2009-01-25 02:38:09 -0800 | [diff] [blame] | 987 | set_bit(IA32_SYSCALL_VECTOR, used_vectors); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 988 | #endif |
| 989 | |
| 990 | #ifdef CONFIG_X86_32 |
Alexander van Heukelum | 699d293 | 2008-10-03 22:00:32 +0200 | [diff] [blame] | 991 | set_system_trap_gate(SYSCALL_VECTOR, &system_call); |
Rusty Russell | dbeb2be | 2007-10-19 20:35:03 +0200 | [diff] [blame] | 992 | set_bit(SYSCALL_VECTOR, used_vectors); |
Alexander van Heukelum | 081f75b | 2008-10-03 22:00:39 +0200 | [diff] [blame] | 993 | #endif |
Yinghai Lu | bb3f0b5 | 2009-01-25 02:38:09 -0800 | [diff] [blame] | 994 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 995 | /* |
Kees Cook | 4eefbe7 | 2013-04-10 12:24:22 -0700 | [diff] [blame] | 996 | * Set the IDT descriptor to a fixed read-only location, so that the |
| 997 | * "sidt" instruction will not leak the location of the kernel, and |
| 998 | * to defend the IDT against arbitrary memory write vulnerabilities. |
| 999 | * It will be reloaded in cpu_init() */ |
| 1000 | __set_fixmap(FIX_RO_IDT, __pa_symbol(idt_table), PAGE_KERNEL_RO); |
| 1001 | idt_descr.address = fix_to_virt(FIX_RO_IDT); |
| 1002 | |
| 1003 | /* |
Ingo Molnar | b596440 | 2008-02-26 11:15:50 +0100 | [diff] [blame] | 1004 | * Should be a barrier for any external CPU state: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1005 | */ |
| 1006 | cpu_init(); |
| 1007 | |
Thomas Gleixner | 428cf90 | 2009-08-20 10:35:46 +0200 | [diff] [blame] | 1008 | x86_init.irqs.trap_init(); |
Steven Rostedt | 228bdaa | 2011-12-09 03:02:19 -0500 | [diff] [blame] | 1009 | |
| 1010 | #ifdef CONFIG_X86_64 |
Seiji Aguchi | 629f4f9 | 2013-06-20 11:45:44 -0400 | [diff] [blame] | 1011 | memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16); |
Kees Cook | c940826 | 2012-03-09 16:07:10 -0800 | [diff] [blame] | 1012 | set_nmi_gate(X86_TRAP_DB, &debug); |
| 1013 | set_nmi_gate(X86_TRAP_BP, &int3); |
Steven Rostedt | 228bdaa | 2011-12-09 03:02:19 -0500 | [diff] [blame] | 1014 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1015 | } |