arch/i386/kernel/entry.S

   1 /*
   2  *  linux/arch/i386/entry.S
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 /*
   8  * entry.S contains the system-call and fault low-level handling routines.
   9  * This also contains the timer-interrupt handler, as well as all interrupts
  10  * and faults that can result in a task-switch.
  11  *
  12  * NOTE: This code handles signal-recognition, which happens every time
  13  * after a timer-interrupt and after each system call.
  14  *
  15  * I changed all the .align's to 4 (16 byte alignment), as that's faster
  16  * on a 486.
  17  *
  18  * Stack layout in 'ret_from_system_call':
  19  *      ptrace needs to have all regs on the stack.
  20  *      if the order here is changed, it needs to be
  21  *      updated in fork.c:copy_process, signal.c:do_signal,
  22  *      ptrace.c and ptrace.h
  23  *
  24  *       0(%esp) - %ebx
  25  *       4(%esp) - %ecx
  26  *       8(%esp) - %edx
  27  *       C(%esp) - %esi
  28  *      10(%esp) - %edi
  29  *      14(%esp) - %ebp
  30  *      18(%esp) - %eax
  31  *      1C(%esp) - %ds
  32  *      20(%esp) - %es
  33  *      24(%esp) - orig_eax
  34  *      28(%esp) - %eip
  35  *      2C(%esp) - %cs
  36  *      30(%esp) - %eflags
  37  *      34(%esp) - %oldesp
  38  *      38(%esp) - %oldss
  39  *
  40  * "current" is in register %ebx during any slow entries.
  41  */
  42
  43 #include <linux/linkage.h>
  44 #include <asm/thread_info.h>
  45 #include <asm/irqflags.h>
  46 #include <asm/errno.h>
  47 #include <asm/segment.h>
  48 #include <asm/smp.h>
  49 #include <asm/page.h>
  50 #include <asm/desc.h>
  51 #include <asm/dwarf2.h>
  52 #include "irq_vectors.h"
  53
  54 #define nr_syscalls ((syscall_table_size)/4)
  55
  56 EBX             = 0x00
  57 ECX             = 0x04
  58 EDX             = 0x08
  59 ESI             = 0x0C
  60 EDI             = 0x10
  61 EBP             = 0x14
  62 EAX             = 0x18
  63 DS              = 0x1C
  64 ES              = 0x20
  65 ORIG_EAX        = 0x24
  66 EIP             = 0x28
  67 CS              = 0x2C
  68 EFLAGS          = 0x30
  69 OLDESP          = 0x34
  70 OLDSS           = 0x38
  71
  72 CF_MASK         = 0x00000001
  73 TF_MASK         = 0x00000100
  74 IF_MASK         = 0x00000200
  75 DF_MASK         = 0x00000400
  76 NT_MASK         = 0x00004000
  77 VM_MASK         = 0x00020000
  78
  79 /* These are replaces for paravirtualization */
  80 #define DISABLE_INTERRUPTS              cli
  81 #define ENABLE_INTERRUPTS               sti
  82 #define ENABLE_INTERRUPTS_SYSEXIT       sti; sysexit
  83 #define INTERRUPT_RETURN                iret
  84 #define GET_CR0_INTO_EAX                movl %cr0, %eax
  85
  86 #ifdef CONFIG_PREEMPT
  87 #define preempt_stop            DISABLE_INTERRUPTS; TRACE_IRQS_OFF
  88 #else
  89 #define preempt_stop
  90 #define resume_kernel           restore_nocheck
  91 #endif
  92
  93 .macro TRACE_IRQS_IRET
  94 #ifdef CONFIG_TRACE_IRQFLAGS
  95         testl $IF_MASK,EFLAGS(%esp)     # interrupts off?
  96         jz 1f
  97         TRACE_IRQS_ON
  98 1:
  99 #endif
 100 .endm
 101
 102 #ifdef CONFIG_VM86
 103 #define resume_userspace_sig    check_userspace
 104 #else
 105 #define resume_userspace_sig    resume_userspace
 106 #endif
 107
 108 #define SAVE_ALL \
 109         cld; \
 110         pushl %es; \
 111         CFI_ADJUST_CFA_OFFSET 4;\
 112         /*CFI_REL_OFFSET es, 0;*/\
 113         pushl %ds; \
 114         CFI_ADJUST_CFA_OFFSET 4;\
 115         /*CFI_REL_OFFSET ds, 0;*/\
 116         pushl %eax; \
 117         CFI_ADJUST_CFA_OFFSET 4;\
 118         CFI_REL_OFFSET eax, 0;\
 119         pushl %ebp; \
 120         CFI_ADJUST_CFA_OFFSET 4;\
 121         CFI_REL_OFFSET ebp, 0;\
 122         pushl %edi; \
 123         CFI_ADJUST_CFA_OFFSET 4;\
 124         CFI_REL_OFFSET edi, 0;\
 125         pushl %esi; \
 126         CFI_ADJUST_CFA_OFFSET 4;\
 127         CFI_REL_OFFSET esi, 0;\
 128         pushl %edx; \
 129         CFI_ADJUST_CFA_OFFSET 4;\
 130         CFI_REL_OFFSET edx, 0;\
 131         pushl %ecx; \
 132         CFI_ADJUST_CFA_OFFSET 4;\
 133         CFI_REL_OFFSET ecx, 0;\
 134         pushl %ebx; \
 135         CFI_ADJUST_CFA_OFFSET 4;\
 136         CFI_REL_OFFSET ebx, 0;\
 137         movl $(__USER_DS), %edx; \
 138         movl %edx, %ds; \
 139         movl %edx, %es;
 140
 141 #define RESTORE_INT_REGS \
 142         popl %ebx;      \
 143         CFI_ADJUST_CFA_OFFSET -4;\
 144         CFI_RESTORE ebx;\
 145         popl %ecx;      \
 146         CFI_ADJUST_CFA_OFFSET -4;\
 147         CFI_RESTORE ecx;\
 148         popl %edx;      \
 149         CFI_ADJUST_CFA_OFFSET -4;\
 150         CFI_RESTORE edx;\
 151         popl %esi;      \
 152         CFI_ADJUST_CFA_OFFSET -4;\
 153         CFI_RESTORE esi;\
 154         popl %edi;      \
 155         CFI_ADJUST_CFA_OFFSET -4;\
 156         CFI_RESTORE edi;\
 157         popl %ebp;      \
 158         CFI_ADJUST_CFA_OFFSET -4;\
 159         CFI_RESTORE ebp;\
 160         popl %eax;      \
 161         CFI_ADJUST_CFA_OFFSET -4;\
 162         CFI_RESTORE eax
 163
 164 #define RESTORE_REGS    \
 165         RESTORE_INT_REGS; \
 166 1:      popl %ds;       \
 167         CFI_ADJUST_CFA_OFFSET -4;\
 168         /*CFI_RESTORE ds;*/\
 169 2:      popl %es;       \
 170         CFI_ADJUST_CFA_OFFSET -4;\
 171         /*CFI_RESTORE es;*/\
 172 .section .fixup,"ax";   \
 173 3:      movl $0,(%esp); \
 174         jmp 1b;         \
 175 4:      movl $0,(%esp); \
 176         jmp 2b;         \
 177 .previous;              \
 178 .section __ex_table,"a";\
 179         .align 4;       \
 180         .long 1b,3b;    \
 181         .long 2b,4b;    \
 182 .previous
 183
 184 #define RING0_INT_FRAME \
 185         CFI_STARTPROC simple;\
 186         CFI_DEF_CFA esp, 3*4;\
 187         /*CFI_OFFSET cs, -2*4;*/\
 188         CFI_OFFSET eip, -3*4
 189
 190 #define RING0_EC_FRAME \
 191         CFI_STARTPROC simple;\
 192         CFI_DEF_CFA esp, 4*4;\
 193         /*CFI_OFFSET cs, -2*4;*/\
 194         CFI_OFFSET eip, -3*4
 195
 196 #define RING0_PTREGS_FRAME \
 197         CFI_STARTPROC simple;\
 198         CFI_DEF_CFA esp, OLDESP-EBX;\
 199         /*CFI_OFFSET cs, CS-OLDESP;*/\
 200         CFI_OFFSET eip, EIP-OLDESP;\
 201         /*CFI_OFFSET es, ES-OLDESP;*/\
 202         /*CFI_OFFSET ds, DS-OLDESP;*/\
 203         CFI_OFFSET eax, EAX-OLDESP;\
 204         CFI_OFFSET ebp, EBP-OLDESP;\
 205         CFI_OFFSET edi, EDI-OLDESP;\
 206         CFI_OFFSET esi, ESI-OLDESP;\
 207         CFI_OFFSET edx, EDX-OLDESP;\
 208         CFI_OFFSET ecx, ECX-OLDESP;\
 209         CFI_OFFSET ebx, EBX-OLDESP
 210
 211 ENTRY(ret_from_fork)
 212         CFI_STARTPROC
 213         pushl %eax
 214         CFI_ADJUST_CFA_OFFSET 4
 215         call schedule_tail
 216         GET_THREAD_INFO(%ebp)
 217         popl %eax
 218         CFI_ADJUST_CFA_OFFSET -4
 219         pushl $0x0202                   # Reset kernel eflags
 220         CFI_ADJUST_CFA_OFFSET 4
 221         popfl
 222         CFI_ADJUST_CFA_OFFSET -4
 223         jmp syscall_exit
 224         CFI_ENDPROC
 225
 226 /*
 227  * Return to user mode is not as complex as all this looks,
 228  * but we want the default path for a system call return to
 229  * go as quickly as possible which is why some of this is
 230  * less clear than it otherwise should be.
 231  */
 232
 233         # userspace resumption stub bypassing syscall exit tracing
 234         ALIGN
 235         RING0_PTREGS_FRAME
 236 ret_from_exception:
 237         preempt_stop
 238 ret_from_intr:
 239         GET_THREAD_INFO(%ebp)
 240 check_userspace:
 241         movl EFLAGS(%esp), %eax         # mix EFLAGS and CS
 242         movb CS(%esp), %al
 243         andl $(VM_MASK | SEGMENT_RPL_MASK), %eax
 244         cmpl $USER_RPL, %eax
 245         jb resume_kernel                # not returning to v8086 or userspace
 246 ENTRY(resume_userspace)
 247         DISABLE_INTERRUPTS              # make sure we don't miss an interrupt
 248                                         # setting need_resched or sigpending
 249                                         # between sampling and the iret
 250         movl TI_flags(%ebp), %ecx
 251         andl $_TIF_WORK_MASK, %ecx      # is there any work to be done on
 252                                         # int/exception return?
 253         jne work_pending
 254         jmp restore_all
 255
 256 #ifdef CONFIG_PREEMPT
 257 ENTRY(resume_kernel)
 258         DISABLE_INTERRUPTS
 259         cmpl $0,TI_preempt_count(%ebp)  # non-zero preempt_count ?
 260         jnz restore_nocheck
 261 need_resched:
 262         movl TI_flags(%ebp), %ecx       # need_resched set ?
 263         testb $_TIF_NEED_RESCHED, %cl
 264         jz restore_all
 265         testl $IF_MASK,EFLAGS(%esp)     # interrupts off (exception path) ?
 266         jz restore_all
 267         call preempt_schedule_irq
 268         jmp need_resched
 269 #endif
 270         CFI_ENDPROC
 271
 272 /* SYSENTER_RETURN points to after the "sysenter" instruction in
 273    the vsyscall page.  See vsyscall-sysentry.S, which defines the symbol.  */
 274
 275         # sysenter call handler stub
 276 ENTRY(sysenter_entry)
 277         CFI_STARTPROC simple
 278         CFI_DEF_CFA esp, 0
 279         CFI_REGISTER esp, ebp
 280         movl TSS_sysenter_esp0(%esp),%esp
 281 sysenter_past_esp:
 282         /*
 283          * No need to follow this irqs on/off section: the syscall
 284          * disabled irqs and here we enable it straight after entry:
 285          */
 286         ENABLE_INTERRUPTS
 287         pushl $(__USER_DS)
 288         CFI_ADJUST_CFA_OFFSET 4
 289         /*CFI_REL_OFFSET ss, 0*/
 290         pushl %ebp
 291         CFI_ADJUST_CFA_OFFSET 4
 292         CFI_REL_OFFSET esp, 0
 293         pushfl
 294         CFI_ADJUST_CFA_OFFSET 4
 295         pushl $(__USER_CS)
 296         CFI_ADJUST_CFA_OFFSET 4
 297         /*CFI_REL_OFFSET cs, 0*/
 298         /*
 299          * Push current_thread_info()->sysenter_return to the stack.
 300          * A tiny bit of offset fixup is necessary - 4*4 means the 4 words
 301          * pushed above; +8 corresponds to copy_thread's esp0 setting.
 302          */
 303         pushl (TI_sysenter_return-THREAD_SIZE+8+4*4)(%esp)
 304         CFI_ADJUST_CFA_OFFSET 4
 305         CFI_REL_OFFSET eip, 0
 306
 307 /*
 308  * Load the potential sixth argument from user stack.
 309  * Careful about security.
 310  */
 311         cmpl $__PAGE_OFFSET-3,%ebp
 312         jae syscall_fault
 313 1:      movl (%ebp),%ebp
 314 .section __ex_table,"a"
 315         .align 4
 316         .long 1b,syscall_fault
 317 .previous
 318
 319         pushl %eax
 320         CFI_ADJUST_CFA_OFFSET 4
 321         SAVE_ALL
 322         GET_THREAD_INFO(%ebp)
 323
 324         /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
 325         testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
 326         jnz syscall_trace_entry
 327         cmpl $(nr_syscalls), %eax
 328         jae syscall_badsys
 329         call *sys_call_table(,%eax,4)
 330         movl %eax,EAX(%esp)
 331         DISABLE_INTERRUPTS
 332         TRACE_IRQS_OFF
 333         movl TI_flags(%ebp), %ecx
 334         testw $_TIF_ALLWORK_MASK, %cx
 335         jne syscall_exit_work
 336 /* if something modifies registers it must also disable sysexit */
 337         movl EIP(%esp), %edx
 338         movl OLDESP(%esp), %ecx
 339         xorl %ebp,%ebp
 340         TRACE_IRQS_ON
 341         ENABLE_INTERRUPTS_SYSEXIT
 342         CFI_ENDPROC
 343
 344
 345         # system call handler stub
 346 ENTRY(system_call)
 347         RING0_INT_FRAME                 # can't unwind into user space anyway
 348         pushl %eax                      # save orig_eax
 349         CFI_ADJUST_CFA_OFFSET 4
 350         SAVE_ALL
 351         GET_THREAD_INFO(%ebp)
 352         testl $TF_MASK,EFLAGS(%esp)
 353         jz no_singlestep
 354         orl $_TIF_SINGLESTEP,TI_flags(%ebp)
 355 no_singlestep:
 356                                         # system call tracing in operation / emulation
 357         /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
 358         testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
 359         jnz syscall_trace_entry
 360         cmpl $(nr_syscalls), %eax
 361         jae syscall_badsys
 362 syscall_call:
 363         call *sys_call_table(,%eax,4)
 364         movl %eax,EAX(%esp)             # store the return value
 365 syscall_exit:
 366         DISABLE_INTERRUPTS              # make sure we don't miss an interrupt
 367                                         # setting need_resched or sigpending
 368                                         # between sampling and the iret
 369         TRACE_IRQS_OFF
 370         movl TI_flags(%ebp), %ecx
 371         testw $_TIF_ALLWORK_MASK, %cx   # current->work
 372         jne syscall_exit_work
 373
 374 restore_all:
 375         movl EFLAGS(%esp), %eax         # mix EFLAGS, SS and CS
 376         # Warning: OLDSS(%esp) contains the wrong/random values if we
 377         # are returning to the kernel.
 378         # See comments in process.c:copy_thread() for details.
 379         movb OLDSS(%esp), %ah
 380         movb CS(%esp), %al
 381         andl $(VM_MASK | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax
 382         cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax
 383         CFI_REMEMBER_STATE
 384         je ldt_ss                       # returning to user-space with LDT SS
 385 restore_nocheck:
 386         TRACE_IRQS_IRET
 387 restore_nocheck_notrace:
 388         RESTORE_REGS
 389         addl $4, %esp
 390         CFI_ADJUST_CFA_OFFSET -4
 391 1:      INTERRUPT_RETURN
 392 .section .fixup,"ax"
 393 iret_exc:
 394         TRACE_IRQS_ON
 395         ENABLE_INTERRUPTS
 396         pushl $0                        # no error code
 397         pushl $do_iret_error
 398         jmp error_code
 399 .previous
 400 .section __ex_table,"a"
 401         .align 4
 402         .long 1b,iret_exc
 403 .previous
 404
 405         CFI_RESTORE_STATE
 406 ldt_ss:
 407         larl OLDSS(%esp), %eax
 408         jnz restore_nocheck
 409         testl $0x00400000, %eax         # returning to 32bit stack?
 410         jnz restore_nocheck             # allright, normal return
 411         /* If returning to userspace with 16bit stack,
 412          * try to fix the higher word of ESP, as the CPU
 413          * won't restore it.
 414          * This is an "official" bug of all the x86-compatible
 415          * CPUs, which we can try to work around to make
 416          * dosemu and wine happy. */
 417         subl $8, %esp           # reserve space for switch16 pointer
 418         CFI_ADJUST_CFA_OFFSET 8
 419         DISABLE_INTERRUPTS
 420         TRACE_IRQS_OFF
 421         movl %esp, %eax
 422         /* Set up the 16bit stack frame with switch32 pointer on top,
 423          * and a switch16 pointer on top of the current frame. */
 424         call setup_x86_bogus_stack
 425         CFI_ADJUST_CFA_OFFSET -8        # frame has moved
 426         TRACE_IRQS_IRET
 427         RESTORE_REGS
 428         lss 20+4(%esp), %esp    # switch to 16bit stack
 429 1:      INTERRUPT_RETURN
 430 .section __ex_table,"a"
 431         .align 4
 432         .long 1b,iret_exc
 433 .previous
 434         CFI_ENDPROC
 435
 436         # perform work that needs to be done immediately before resumption
 437         ALIGN
 438         RING0_PTREGS_FRAME              # can't unwind into user space anyway
 439 work_pending:
 440         testb $_TIF_NEED_RESCHED, %cl
 441         jz work_notifysig
 442 work_resched:
 443         call schedule
 444         DISABLE_INTERRUPTS              # make sure we don't miss an interrupt
 445                                         # setting need_resched or sigpending
 446                                         # between sampling and the iret
 447         TRACE_IRQS_OFF
 448         movl TI_flags(%ebp), %ecx
 449         andl $_TIF_WORK_MASK, %ecx      # is there any work to be done other
 450                                         # than syscall tracing?
 451         jz restore_all
 452         testb $_TIF_NEED_RESCHED, %cl
 453         jnz work_resched
 454
 455 work_notifysig:                         # deal with pending signals and
 456                                         # notify-resume requests
 457         testl $VM_MASK, EFLAGS(%esp)
 458         movl %esp, %eax
 459         jne work_notifysig_v86          # returning to kernel-space or
 460                                         # vm86-space
 461         xorl %edx, %edx
 462         call do_notify_resume
 463         jmp resume_userspace_sig
 464
 465         ALIGN
 466 work_notifysig_v86:
 467 #ifdef CONFIG_VM86
 468         pushl %ecx                      # save ti_flags for do_notify_resume
 469         CFI_ADJUST_CFA_OFFSET 4
 470         call save_v86_state             # %eax contains pt_regs pointer
 471         popl %ecx
 472         CFI_ADJUST_CFA_OFFSET -4
 473         movl %eax, %esp
 474         xorl %edx, %edx
 475         call do_notify_resume
 476         jmp resume_userspace_sig
 477 #endif
 478
 479         # perform syscall exit tracing
 480         ALIGN
 481 syscall_trace_entry:
 482         movl $-ENOSYS,EAX(%esp)
 483         movl %esp, %eax
 484         xorl %edx,%edx
 485         call do_syscall_trace
 486         cmpl $0, %eax
 487         jne resume_userspace            # ret != 0 -> running under PTRACE_SYSEMU,
 488                                         # so must skip actual syscall
 489         movl ORIG_EAX(%esp), %eax
 490         cmpl $(nr_syscalls), %eax
 491         jnae syscall_call
 492         jmp syscall_exit
 493
 494         # perform syscall exit tracing
 495         ALIGN
 496 syscall_exit_work:
 497         testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl
 498         jz work_pending
 499         TRACE_IRQS_ON
 500         ENABLE_INTERRUPTS               # could let do_syscall_trace() call
 501                                         # schedule() instead
 502         movl %esp, %eax
 503         movl $1, %edx
 504         call do_syscall_trace
 505         jmp resume_userspace
 506         CFI_ENDPROC
 507
 508         RING0_INT_FRAME                 # can't unwind into user space anyway
 509 syscall_fault:
 510         pushl %eax                      # save orig_eax
 511         CFI_ADJUST_CFA_OFFSET 4
 512         SAVE_ALL
 513         GET_THREAD_INFO(%ebp)
 514         movl $-EFAULT,EAX(%esp)
 515         jmp resume_userspace
 516
 517 syscall_badsys:
 518         movl $-ENOSYS,EAX(%esp)
 519         jmp resume_userspace
 520         CFI_ENDPROC
 521
 522 #define FIXUP_ESPFIX_STACK \
 523         movl %esp, %eax; \
 524         /* switch to 32bit stack using the pointer on top of 16bit stack */ \
 525         lss %ss:CPU_16BIT_STACK_SIZE-8, %esp; \
 526         /* copy data from 16bit stack to 32bit stack */ \
 527         call fixup_x86_bogus_stack; \
 528         /* put ESP to the proper location */ \
 529         movl %eax, %esp;
 530 #define UNWIND_ESPFIX_STACK \
 531         pushl %eax; \
 532         CFI_ADJUST_CFA_OFFSET 4; \
 533         movl %ss, %eax; \
 534         /* see if on 16bit stack */ \
 535         cmpw $__ESPFIX_SS, %ax; \
 536         je 28f; \
 537 27:     popl %eax; \
 538         CFI_ADJUST_CFA_OFFSET -4; \
 539 .section .fixup,"ax"; \
 540 28:     movl $__KERNEL_DS, %eax; \
 541         movl %eax, %ds; \
 542         movl %eax, %es; \
 543         /* switch to 32bit stack */ \
 544         FIXUP_ESPFIX_STACK; \
 545         jmp 27b; \
 546 .previous
 547
 548 /*
 549  * Build the entry stubs and pointer table with
 550  * some assembler magic.
 551  */
 552 .data
 553 ENTRY(interrupt)
 554 .text
 555
 556 vector=0
 557 ENTRY(irq_entries_start)
 558         RING0_INT_FRAME
 559 .rept NR_IRQS
 560         ALIGN
 561  .if vector
 562         CFI_ADJUST_CFA_OFFSET -4
 563  .endif
 564 1:      pushl $~(vector)
 565         CFI_ADJUST_CFA_OFFSET 4
 566         jmp common_interrupt
 567 .data
 568         .long 1b
 569 .text
 570 vector=vector+1
 571 .endr
 572
 573 /*
 574  * the CPU automatically disables interrupts when executing an IRQ vector,
 575  * so IRQ-flags tracing has to follow that:
 576  */
 577         ALIGN
 578 common_interrupt:
 579         SAVE_ALL
 580         TRACE_IRQS_OFF
 581         movl %esp,%eax
 582         call do_IRQ
 583         jmp ret_from_intr
 584         CFI_ENDPROC
 585
 586 #define BUILD_INTERRUPT(name, nr)       \
 587 ENTRY(name)                             \
 588         RING0_INT_FRAME;                \
 589         pushl $~(nr);                   \
 590         CFI_ADJUST_CFA_OFFSET 4;        \
 591         SAVE_ALL;                       \
 592         TRACE_IRQS_OFF                  \
 593         movl %esp,%eax;                 \
 594         call smp_/**/name;              \
 595         jmp ret_from_intr;              \
 596         CFI_ENDPROC
 597
 598 /* The include is where all of the SMP etc. interrupts come from */
 599 #include "entry_arch.h"
 600
 601 KPROBE_ENTRY(page_fault)
 602         RING0_EC_FRAME
 603         pushl $do_page_fault
 604         CFI_ADJUST_CFA_OFFSET 4
 605         ALIGN
 606 error_code:
 607         pushl %ds
 608         CFI_ADJUST_CFA_OFFSET 4
 609         /*CFI_REL_OFFSET ds, 0*/
 610         pushl %eax
 611         CFI_ADJUST_CFA_OFFSET 4
 612         CFI_REL_OFFSET eax, 0
 613         xorl %eax, %eax
 614         pushl %ebp
 615         CFI_ADJUST_CFA_OFFSET 4
 616         CFI_REL_OFFSET ebp, 0
 617         pushl %edi
 618         CFI_ADJUST_CFA_OFFSET 4
 619         CFI_REL_OFFSET edi, 0
 620         pushl %esi
 621         CFI_ADJUST_CFA_OFFSET 4
 622         CFI_REL_OFFSET esi, 0
 623         pushl %edx
 624         CFI_ADJUST_CFA_OFFSET 4
 625         CFI_REL_OFFSET edx, 0
 626         decl %eax                       # eax = -1
 627         pushl %ecx
 628         CFI_ADJUST_CFA_OFFSET 4
 629         CFI_REL_OFFSET ecx, 0
 630         pushl %ebx
 631         CFI_ADJUST_CFA_OFFSET 4
 632         CFI_REL_OFFSET ebx, 0
 633         cld
 634         pushl %es
 635         CFI_ADJUST_CFA_OFFSET 4
 636         /*CFI_REL_OFFSET es, 0*/
 637         UNWIND_ESPFIX_STACK
 638         popl %ecx
 639         CFI_ADJUST_CFA_OFFSET -4
 640         /*CFI_REGISTER es, ecx*/
 641         movl ES(%esp), %edi             # get the function address
 642         movl ORIG_EAX(%esp), %edx       # get the error code
 643         movl %eax, ORIG_EAX(%esp)
 644         movl %ecx, ES(%esp)
 645         /*CFI_REL_OFFSET es, ES*/
 646         movl $(__USER_DS), %ecx
 647         movl %ecx, %ds
 648         movl %ecx, %es
 649         movl %esp,%eax                  # pt_regs pointer
 650         call *%edi
 651         jmp ret_from_exception
 652         CFI_ENDPROC
 653 KPROBE_END(page_fault)
 654
 655 ENTRY(coprocessor_error)
 656         RING0_INT_FRAME
 657         pushl $0
 658         CFI_ADJUST_CFA_OFFSET 4
 659         pushl $do_coprocessor_error
 660         CFI_ADJUST_CFA_OFFSET 4
 661         jmp error_code
 662         CFI_ENDPROC
 663
 664 ENTRY(simd_coprocessor_error)
 665         RING0_INT_FRAME
 666         pushl $0
 667         CFI_ADJUST_CFA_OFFSET 4
 668         pushl $do_simd_coprocessor_error
 669         CFI_ADJUST_CFA_OFFSET 4
 670         jmp error_code
 671         CFI_ENDPROC
 672
 673 ENTRY(device_not_available)
 674         RING0_INT_FRAME
 675         pushl $-1                       # mark this as an int
 676         CFI_ADJUST_CFA_OFFSET 4
 677         SAVE_ALL
 678         GET_CR0_INTO_EAX
 679         testl $0x4, %eax                # EM (math emulation bit)
 680         jne device_not_available_emulate
 681         preempt_stop
 682         call math_state_restore
 683         jmp ret_from_exception
 684 device_not_available_emulate:
 685         pushl $0                        # temporary storage for ORIG_EIP
 686         CFI_ADJUST_CFA_OFFSET 4
 687         call math_emulate
 688         addl $4, %esp
 689         CFI_ADJUST_CFA_OFFSET -4
 690         jmp ret_from_exception
 691         CFI_ENDPROC
 692
 693 /*
 694  * Debug traps and NMI can happen at the one SYSENTER instruction
 695  * that sets up the real kernel stack. Check here, since we can't
 696  * allow the wrong stack to be used.
 697  *
 698  * "TSS_sysenter_esp0+12" is because the NMI/debug handler will have
 699  * already pushed 3 words if it hits on the sysenter instruction:
 700  * eflags, cs and eip.
 701  *
 702  * We just load the right stack, and push the three (known) values
 703  * by hand onto the new stack - while updating the return eip past
 704  * the instruction that would have done it for sysenter.
 705  */
 706 #define FIX_STACK(offset, ok, label)            \
 707         cmpw $__KERNEL_CS,4(%esp);              \
 708         jne ok;                                 \
 709 label:                                          \
 710         movl TSS_sysenter_esp0+offset(%esp),%esp;       \
 711         CFI_DEF_CFA esp, 0;                     \
 712         CFI_UNDEFINED eip;                      \
 713         pushfl;                                 \
 714         CFI_ADJUST_CFA_OFFSET 4;                \
 715         pushl $__KERNEL_CS;                     \
 716         CFI_ADJUST_CFA_OFFSET 4;                \
 717         pushl $sysenter_past_esp;               \
 718         CFI_ADJUST_CFA_OFFSET 4;                \
 719         CFI_REL_OFFSET eip, 0
 720
 721 KPROBE_ENTRY(debug)
 722         RING0_INT_FRAME
 723         cmpl $sysenter_entry,(%esp)
 724         jne debug_stack_correct
 725         FIX_STACK(12, debug_stack_correct, debug_esp_fix_insn)
 726 debug_stack_correct:
 727         pushl $-1                       # mark this as an int
 728         CFI_ADJUST_CFA_OFFSET 4
 729         SAVE_ALL
 730         xorl %edx,%edx                  # error code 0
 731         movl %esp,%eax                  # pt_regs pointer
 732         call do_debug
 733         jmp ret_from_exception
 734         CFI_ENDPROC
 735 KPROBE_END(debug)
 736
 737 /*
 738  * NMI is doubly nasty. It can happen _while_ we're handling
 739  * a debug fault, and the debug fault hasn't yet been able to
 740  * clear up the stack. So we first check whether we got  an
 741  * NMI on the sysenter entry path, but after that we need to
 742  * check whether we got an NMI on the debug path where the debug
 743  * fault happened on the sysenter path.
 744  */
 745 KPROBE_ENTRY(nmi)
 746         RING0_INT_FRAME
 747         pushl %eax
 748         CFI_ADJUST_CFA_OFFSET 4
 749         movl %ss, %eax
 750         cmpw $__ESPFIX_SS, %ax
 751         popl %eax
 752         CFI_ADJUST_CFA_OFFSET -4
 753         je nmi_16bit_stack
 754         cmpl $sysenter_entry,(%esp)
 755         je nmi_stack_fixup
 756         pushl %eax
 757         CFI_ADJUST_CFA_OFFSET 4
 758         movl %esp,%eax
 759         /* Do not access memory above the end of our stack page,
 760          * it might not exist.
 761          */
 762         andl $(THREAD_SIZE-1),%eax
 763         cmpl $(THREAD_SIZE-20),%eax
 764         popl %eax
 765         CFI_ADJUST_CFA_OFFSET -4
 766         jae nmi_stack_correct
 767         cmpl $sysenter_entry,12(%esp)
 768         je nmi_debug_stack_check
 769 nmi_stack_correct:
 770         /* We have a RING0_INT_FRAME here */
 771         pushl %eax
 772         CFI_ADJUST_CFA_OFFSET 4
 773         SAVE_ALL
 774         xorl %edx,%edx          # zero error code
 775         movl %esp,%eax          # pt_regs pointer
 776         call do_nmi
 777         jmp restore_nocheck_notrace
 778         CFI_ENDPROC
 779
 780 nmi_stack_fixup:
 781         RING0_INT_FRAME
 782         FIX_STACK(12,nmi_stack_correct, 1)
 783         jmp nmi_stack_correct
 784
 785 nmi_debug_stack_check:
 786         /* We have a RING0_INT_FRAME here */
 787         cmpw $__KERNEL_CS,16(%esp)
 788         jne nmi_stack_correct
 789         cmpl $debug,(%esp)
 790         jb nmi_stack_correct
 791         cmpl $debug_esp_fix_insn,(%esp)
 792         ja nmi_stack_correct
 793         FIX_STACK(24,nmi_stack_correct, 1)
 794         jmp nmi_stack_correct
 795
 796 nmi_16bit_stack:
 797         /* We have a RING0_INT_FRAME here.
 798          *
 799          * create the pointer to lss back
 800          */
 801         pushl %ss
 802         CFI_ADJUST_CFA_OFFSET 4
 803         pushl %esp
 804         CFI_ADJUST_CFA_OFFSET 4
 805         movzwl %sp, %esp
 806         addw $4, (%esp)
 807         /* copy the iret frame of 12 bytes */
 808         .rept 3
 809         pushl 16(%esp)
 810         CFI_ADJUST_CFA_OFFSET 4
 811         .endr
 812         pushl %eax
 813         CFI_ADJUST_CFA_OFFSET 4
 814         SAVE_ALL
 815         FIXUP_ESPFIX_STACK              # %eax == %esp
 816         CFI_ADJUST_CFA_OFFSET -20       # the frame has now moved
 817         xorl %edx,%edx                  # zero error code
 818         call do_nmi
 819         RESTORE_REGS
 820         lss 12+4(%esp), %esp            # back to 16bit stack
 821 1:      INTERRUPT_RETURN
 822         CFI_ENDPROC
 823 .section __ex_table,"a"
 824         .align 4
 825         .long 1b,iret_exc
 826 .previous
 827 KPROBE_END(nmi)
 828
 829 KPROBE_ENTRY(int3)
 830         RING0_INT_FRAME
 831         pushl $-1                       # mark this as an int
 832         CFI_ADJUST_CFA_OFFSET 4
 833         SAVE_ALL
 834         xorl %edx,%edx          # zero error code
 835         movl %esp,%eax          # pt_regs pointer
 836         call do_int3
 837         jmp ret_from_exception
 838         CFI_ENDPROC
 839 KPROBE_END(int3)
 840
 841 ENTRY(overflow)
 842         RING0_INT_FRAME
 843         pushl $0
 844         CFI_ADJUST_CFA_OFFSET 4
 845         pushl $do_overflow
 846         CFI_ADJUST_CFA_OFFSET 4
 847         jmp error_code
 848         CFI_ENDPROC
 849
 850 ENTRY(bounds)
 851         RING0_INT_FRAME
 852         pushl $0
 853         CFI_ADJUST_CFA_OFFSET 4
 854         pushl $do_bounds
 855         CFI_ADJUST_CFA_OFFSET 4
 856         jmp error_code
 857         CFI_ENDPROC
 858
 859 ENTRY(invalid_op)
 860         RING0_INT_FRAME
 861         pushl $0
 862         CFI_ADJUST_CFA_OFFSET 4
 863         pushl $do_invalid_op
 864         CFI_ADJUST_CFA_OFFSET 4
 865         jmp error_code
 866         CFI_ENDPROC
 867
 868 ENTRY(coprocessor_segment_overrun)
 869         RING0_INT_FRAME
 870         pushl $0
 871         CFI_ADJUST_CFA_OFFSET 4
 872         pushl $do_coprocessor_segment_overrun
 873         CFI_ADJUST_CFA_OFFSET 4
 874         jmp error_code
 875         CFI_ENDPROC
 876
 877 ENTRY(invalid_TSS)
 878         RING0_EC_FRAME
 879         pushl $do_invalid_TSS
 880         CFI_ADJUST_CFA_OFFSET 4
 881         jmp error_code
 882         CFI_ENDPROC
 883
 884 ENTRY(segment_not_present)
 885         RING0_EC_FRAME
 886         pushl $do_segment_not_present
 887         CFI_ADJUST_CFA_OFFSET 4
 888         jmp error_code
 889         CFI_ENDPROC
 890
 891 ENTRY(stack_segment)
 892         RING0_EC_FRAME
 893         pushl $do_stack_segment
 894         CFI_ADJUST_CFA_OFFSET 4
 895         jmp error_code
 896         CFI_ENDPROC
 897
 898 KPROBE_ENTRY(general_protection)
 899         RING0_EC_FRAME
 900         pushl $do_general_protection
 901         CFI_ADJUST_CFA_OFFSET 4
 902         jmp error_code
 903         CFI_ENDPROC
 904 KPROBE_END(general_protection)
 905
 906 ENTRY(alignment_check)
 907         RING0_EC_FRAME
 908         pushl $do_alignment_check
 909         CFI_ADJUST_CFA_OFFSET 4
 910         jmp error_code
 911         CFI_ENDPROC
 912
 913 ENTRY(divide_error)
 914         RING0_INT_FRAME
 915         pushl $0                        # no error code
 916         CFI_ADJUST_CFA_OFFSET 4
 917         pushl $do_divide_error
 918         CFI_ADJUST_CFA_OFFSET 4
 919         jmp error_code
 920         CFI_ENDPROC
 921
 922 #ifdef CONFIG_X86_MCE
 923 ENTRY(machine_check)
 924         RING0_INT_FRAME
 925         pushl $0
 926         CFI_ADJUST_CFA_OFFSET 4
 927         pushl machine_check_vector
 928         CFI_ADJUST_CFA_OFFSET 4
 929         jmp error_code
 930         CFI_ENDPROC
 931 #endif
 932
 933 ENTRY(spurious_interrupt_bug)
 934         RING0_INT_FRAME
 935         pushl $0
 936         CFI_ADJUST_CFA_OFFSET 4
 937         pushl $do_spurious_interrupt_bug
 938         CFI_ADJUST_CFA_OFFSET 4
 939         jmp error_code
 940         CFI_ENDPROC
 941
 942 #ifdef CONFIG_STACK_UNWIND
 943 ENTRY(arch_unwind_init_running)
 944         CFI_STARTPROC
 945         movl    4(%esp), %edx
 946         movl    (%esp), %ecx
 947         leal    4(%esp), %eax
 948         movl    %ebx, EBX(%edx)
 949         xorl    %ebx, %ebx
 950         movl    %ebx, ECX(%edx)
 951         movl    %ebx, EDX(%edx)
 952         movl    %esi, ESI(%edx)
 953         movl    %edi, EDI(%edx)
 954         movl    %ebp, EBP(%edx)
 955         movl    %ebx, EAX(%edx)
 956         movl    $__USER_DS, DS(%edx)
 957         movl    $__USER_DS, ES(%edx)
 958         movl    %ebx, ORIG_EAX(%edx)
 959         movl    %ecx, EIP(%edx)
 960         movl    12(%esp), %ecx
 961         movl    $__KERNEL_CS, CS(%edx)
 962         movl    %ebx, EFLAGS(%edx)
 963         movl    %eax, OLDESP(%edx)
 964         movl    8(%esp), %eax
 965         movl    %ecx, 8(%esp)
 966         movl    EBX(%edx), %ebx
 967         movl    $__KERNEL_DS, OLDSS(%edx)
 968         jmpl    *%eax
 969         CFI_ENDPROC
 970 ENDPROC(arch_unwind_init_running)
 971 #endif
 972
 973 ENTRY(kernel_thread_helper)
 974         pushl $0                # fake return address for unwinder
 975         CFI_STARTPROC
 976         movl %edx,%eax
 977         push %edx
 978         CFI_ADJUST_CFA_OFFSET 4
 979         call *%ebx
 980         push %eax
 981         CFI_ADJUST_CFA_OFFSET 4
 982         call do_exit
 983         CFI_ENDPROC
 984 ENDPROC(kernel_thread_helper)
 985
 986 .section .rodata,"a"
 987 #include "syscall_table.S"
 988
 989 syscall_table_size=(.-sys_call_table)