1/* 2 * 3 * Copyright (C) 1991, 1992 Linus Torvalds 4 */ 5 6/* 7 * entry.S contains the system-call and fault low-level handling routines. 8 * This also contains the timer-interrupt handler, as well as all interrupts 9 * and faults that can result in a task-switch. 10 * 11 * NOTE: This code handles signal-recognition, which happens every time 12 * after a timer-interrupt and after each system call. 13 * 14 * I changed all the .align's to 4 (16 byte alignment), as that's faster 15 * on a 486. 16 * 17 * Stack layout in 'syscall_exit': 18 * ptrace needs to have all regs on the stack. 19 * if the order here is changed, it needs to be 20 * updated in fork.c:copy_process, signal.c:do_signal, 21 * ptrace.c and ptrace.h 22 * 23 * 0(%esp) - %ebx 24 * 4(%esp) - %ecx 25 * 8(%esp) - %edx 26 * C(%esp) - %esi 27 * 10(%esp) - %edi 28 * 14(%esp) - %ebp 29 * 18(%esp) - %eax 30 * 1C(%esp) - %ds 31 * 20(%esp) - %es 32 * 24(%esp) - %fs 33 * 28(%esp) - %gs saved iff !CONFIG_X86_32_LAZY_GS 34 * 2C(%esp) - orig_eax 35 * 30(%esp) - %eip 36 * 34(%esp) - %cs 37 * 38(%esp) - %eflags 38 * 3C(%esp) - %oldesp 39 * 40(%esp) - %oldss 40 * 41 * "current" is in register %ebx during any slow entries. 42 */ 43 44#include <linux/linkage.h> 45#include <linux/err.h> 46#include <asm/thread_info.h> 47#include <asm/irqflags.h> 48#include <asm/errno.h> 49#include <asm/segment.h> 50#include <asm/smp.h> 51#include <asm/page_types.h> 52#include <asm/percpu.h> 53#include <asm/dwarf2.h> 54#include <asm/processor-flags.h> 55#include <asm/ftrace.h> 56#include <asm/irq_vectors.h> 57#include <asm/cpufeature.h> 58#include <asm/alternative-asm.h> 59#include <asm/asm.h> 60#include <asm/smap.h> 61 62/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */ 63#include <linux/elf-em.h> 64#define AUDIT_ARCH_I386 (EM_386|__AUDIT_ARCH_LE) 65#define __AUDIT_ARCH_LE 0x40000000 66 67#ifndef CONFIG_AUDITSYSCALL 68#define sysenter_audit syscall_trace_entry 69#define sysexit_audit syscall_exit_work 70#endif 71 72 .section .entry.text, "ax" 73 74/* 75 * We use macros for low-level operations which need to be overridden 76 * for paravirtualization. The following will never clobber any registers: 77 * INTERRUPT_RETURN (aka. "iret") 78 * GET_CR0_INTO_EAX (aka. "movl %cr0, %eax") 79 * ENABLE_INTERRUPTS_SYSEXIT (aka "sti; sysexit"). 80 * 81 * For DISABLE_INTERRUPTS/ENABLE_INTERRUPTS (aka "cli"/"sti"), you must 82 * specify what registers can be overwritten (CLBR_NONE, CLBR_EAX/EDX/ECX/ANY). 83 * Allowing a register to be clobbered can shrink the paravirt replacement 84 * enough to patch inline, increasing performance. 85 */ 86 87#ifdef CONFIG_PREEMPT 88#define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF 89#else 90#define preempt_stop(clobbers) 91#define resume_kernel restore_all 92#endif 93 94.macro TRACE_IRQS_IRET 95#ifdef CONFIG_TRACE_IRQFLAGS 96 testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off? 97 jz 1f 98 TRACE_IRQS_ON 991: 100#endif 101.endm 102 103/* 104 * User gs save/restore 105 * 106 * %gs is used for userland TLS and kernel only uses it for stack 107 * canary which is required to be at %gs:20 by gcc. Read the comment 108 * at the top of stackprotector.h for more info. 109 * 110 * Local labels 98 and 99 are used. 111 */ 112#ifdef CONFIG_X86_32_LAZY_GS 113 114 /* unfortunately push/pop can't be no-op */ 115.macro PUSH_GS 116 pushl_cfi $0 117.endm 118.macro POP_GS pop=0 119 addl $(4 + \pop), %esp 120 CFI_ADJUST_CFA_OFFSET -(4 + \pop) 121.endm 122.macro POP_GS_EX 123.endm 124 125 /* all the rest are no-op */ 126.macro PTGS_TO_GS 127.endm 128.macro PTGS_TO_GS_EX 129.endm 130.macro GS_TO_REG reg 131.endm 132.macro REG_TO_PTGS reg 133.endm 134.macro SET_KERNEL_GS reg 135.endm 136 137#else /* CONFIG_X86_32_LAZY_GS */ 138 139.macro PUSH_GS 140 pushl_cfi %gs 141 /*CFI_REL_OFFSET gs, 0*/ 142.endm 143 144.macro POP_GS pop=0 14598: popl_cfi %gs 146 /*CFI_RESTORE gs*/ 147 .if \pop <> 0 148 add $\pop, %esp 149 CFI_ADJUST_CFA_OFFSET -\pop 150 .endif 151.endm 152.macro POP_GS_EX 153.pushsection .fixup, "ax" 15499: movl $0, (%esp) 155 jmp 98b 156.popsection 157 _ASM_EXTABLE(98b,99b) 158.endm 159 160.macro PTGS_TO_GS 16198: mov PT_GS(%esp), %gs 162.endm 163.macro PTGS_TO_GS_EX 164.pushsection .fixup, "ax" 16599: movl $0, PT_GS(%esp) 166 jmp 98b 167.popsection 168 _ASM_EXTABLE(98b,99b) 169.endm 170 171.macro GS_TO_REG reg 172 movl %gs, \reg 173 /*CFI_REGISTER gs, \reg*/ 174.endm 175.macro REG_TO_PTGS reg 176 movl \reg, PT_GS(%esp) 177 /*CFI_REL_OFFSET gs, PT_GS*/ 178.endm 179.macro SET_KERNEL_GS reg 180 movl $(__KERNEL_STACK_CANARY), \reg 181 movl \reg, %gs 182.endm 183 184#endif /* CONFIG_X86_32_LAZY_GS */ 185 186.macro SAVE_ALL 187 cld 188 PUSH_GS 189 pushl_cfi %fs 190 /*CFI_REL_OFFSET fs, 0;*/ 191 pushl_cfi %es 192 /*CFI_REL_OFFSET es, 0;*/ 193 pushl_cfi %ds 194 /*CFI_REL_OFFSET ds, 0;*/ 195 pushl_cfi %eax 196 CFI_REL_OFFSET eax, 0 197 pushl_cfi %ebp 198 CFI_REL_OFFSET ebp, 0 199 pushl_cfi %edi 200 CFI_REL_OFFSET edi, 0 201 pushl_cfi %esi 202 CFI_REL_OFFSET esi, 0 203 pushl_cfi %edx 204 CFI_REL_OFFSET edx, 0 205 pushl_cfi %ecx 206 CFI_REL_OFFSET ecx, 0 207 pushl_cfi %ebx 208 CFI_REL_OFFSET ebx, 0 209 movl $(__USER_DS), %edx 210 movl %edx, %ds 211 movl %edx, %es 212 movl $(__KERNEL_PERCPU), %edx 213 movl %edx, %fs 214 SET_KERNEL_GS %edx 215.endm 216 217.macro RESTORE_INT_REGS 218 popl_cfi %ebx 219 CFI_RESTORE ebx 220 popl_cfi %ecx 221 CFI_RESTORE ecx 222 popl_cfi %edx 223 CFI_RESTORE edx 224 popl_cfi %esi 225 CFI_RESTORE esi 226 popl_cfi %edi 227 CFI_RESTORE edi 228 popl_cfi %ebp 229 CFI_RESTORE ebp 230 popl_cfi %eax 231 CFI_RESTORE eax 232.endm 233 234.macro RESTORE_REGS pop=0 235 RESTORE_INT_REGS 2361: popl_cfi %ds 237 /*CFI_RESTORE ds;*/ 2382: popl_cfi %es 239 /*CFI_RESTORE es;*/ 2403: popl_cfi %fs 241 /*CFI_RESTORE fs;*/ 242 POP_GS \pop 243.pushsection .fixup, "ax" 2444: movl $0, (%esp) 245 jmp 1b 2465: movl $0, (%esp) 247 jmp 2b 2486: movl $0, (%esp) 249 jmp 3b 250.popsection 251 _ASM_EXTABLE(1b,4b) 252 _ASM_EXTABLE(2b,5b) 253 _ASM_EXTABLE(3b,6b) 254 POP_GS_EX 255.endm 256 257.macro RING0_INT_FRAME 258 CFI_STARTPROC simple 259 CFI_SIGNAL_FRAME 260 CFI_DEF_CFA esp, 3*4 261 /*CFI_OFFSET cs, -2*4;*/ 262 CFI_OFFSET eip, -3*4 263.endm 264 265.macro RING0_EC_FRAME 266 CFI_STARTPROC simple 267 CFI_SIGNAL_FRAME 268 CFI_DEF_CFA esp, 4*4 269 /*CFI_OFFSET cs, -2*4;*/ 270 CFI_OFFSET eip, -3*4 271.endm 272 273.macro RING0_PTREGS_FRAME 274 CFI_STARTPROC simple 275 CFI_SIGNAL_FRAME 276 CFI_DEF_CFA esp, PT_OLDESP-PT_EBX 277 /*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/ 278 CFI_OFFSET eip, PT_EIP-PT_OLDESP 279 /*CFI_OFFSET es, PT_ES-PT_OLDESP;*/ 280 /*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/ 281 CFI_OFFSET eax, PT_EAX-PT_OLDESP 282 CFI_OFFSET ebp, PT_EBP-PT_OLDESP 283 CFI_OFFSET edi, PT_EDI-PT_OLDESP 284 CFI_OFFSET esi, PT_ESI-PT_OLDESP 285 CFI_OFFSET edx, PT_EDX-PT_OLDESP 286 CFI_OFFSET ecx, PT_ECX-PT_OLDESP 287 CFI_OFFSET ebx, PT_EBX-PT_OLDESP 288.endm 289 290ENTRY(ret_from_fork) 291 CFI_STARTPROC 292 pushl_cfi %eax 293 call schedule_tail 294 GET_THREAD_INFO(%ebp) 295 popl_cfi %eax 296 pushl_cfi $0x0202 # Reset kernel eflags 297 popfl_cfi 298 jmp syscall_exit 299 CFI_ENDPROC 300END(ret_from_fork) 301 302ENTRY(ret_from_kernel_thread) 303 CFI_STARTPROC 304 pushl_cfi %eax 305 call schedule_tail 306 GET_THREAD_INFO(%ebp) 307 popl_cfi %eax 308 pushl_cfi $0x0202 # Reset kernel eflags 309 popfl_cfi 310 movl PT_EBP(%esp),%eax 311 call *PT_EBX(%esp) 312 movl $0,PT_EAX(%esp) 313 jmp syscall_exit 314 CFI_ENDPROC 315ENDPROC(ret_from_kernel_thread) 316 317/* 318 * Return to user mode is not as complex as all this looks, 319 * but we want the default path for a system call return to 320 * go as quickly as possible which is why some of this is 321 * less clear than it otherwise should be. 322 */ 323 324 # userspace resumption stub bypassing syscall exit tracing 325 ALIGN 326 RING0_PTREGS_FRAME 327ret_from_exception: 328 preempt_stop(CLBR_ANY) 329ret_from_intr: 330 GET_THREAD_INFO(%ebp) 331#ifdef CONFIG_VM86 332 movl PT_EFLAGS(%esp), %eax # mix EFLAGS and CS 333 movb PT_CS(%esp), %al 334 andl $(X86_EFLAGS_VM | SEGMENT_RPL_MASK), %eax 335#else 336 /* 337 * We can be coming here from child spawned by kernel_thread(). 338 */ 339 movl PT_CS(%esp), %eax 340 andl $SEGMENT_RPL_MASK, %eax 341#endif 342 cmpl $USER_RPL, %eax 343 jb resume_kernel # not returning to v8086 or userspace 344 345ENTRY(resume_userspace) 346 LOCKDEP_SYS_EXIT 347 DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt 348 # setting need_resched or sigpending 349 # between sampling and the iret 350 TRACE_IRQS_OFF 351 movl TI_flags(%ebp), %ecx 352 andl $_TIF_WORK_MASK, %ecx # is there any work to be done on 353 # int/exception return? 354 jne work_pending 355 jmp restore_all 356END(ret_from_exception) 357 358#ifdef CONFIG_PREEMPT 359ENTRY(resume_kernel) 360 DISABLE_INTERRUPTS(CLBR_ANY) 361need_resched: 362 cmpl $0,PER_CPU_VAR(__preempt_count) 363 jnz restore_all 364 testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off (exception path) ? 365 jz restore_all 366 call preempt_schedule_irq 367 jmp need_resched 368END(resume_kernel) 369#endif 370 CFI_ENDPROC 371 372/* SYSENTER_RETURN points to after the "sysenter" instruction in 373 the vsyscall page. See vsyscall-sysentry.S, which defines the symbol. */ 374 375 # sysenter call handler stub 376ENTRY(ia32_sysenter_target) 377 CFI_STARTPROC simple 378 CFI_SIGNAL_FRAME 379 CFI_DEF_CFA esp, 0 380 CFI_REGISTER esp, ebp 381 movl TSS_sysenter_sp0(%esp),%esp 382sysenter_past_esp: 383 /* 384 * Interrupts are disabled here, but we can't trace it until 385 * enough kernel state to call TRACE_IRQS_OFF can be called - but 386 * we immediately enable interrupts at that point anyway. 387 */ 388 pushl_cfi $__USER_DS 389 /*CFI_REL_OFFSET ss, 0*/ 390 pushl_cfi %ebp 391 CFI_REL_OFFSET esp, 0 392 pushfl_cfi 393 orl $X86_EFLAGS_IF, (%esp) 394 pushl_cfi $__USER_CS 395 /*CFI_REL_OFFSET cs, 0*/ 396 /* 397 * Push current_thread_info()->sysenter_return to the stack. 398 * A tiny bit of offset fixup is necessary - 4*4 means the 4 words 399 * pushed above; +8 corresponds to copy_thread's esp0 setting. 400 */ 401 pushl_cfi ((TI_sysenter_return)-THREAD_SIZE+TOP_OF_KERNEL_STACK_PADDING+4*4)(%esp) 402 CFI_REL_OFFSET eip, 0 403 404 pushl_cfi %eax 405 SAVE_ALL 406 ENABLE_INTERRUPTS(CLBR_NONE) 407 408/* 409 * Load the potential sixth argument from user stack. 410 * Careful about security. 411 */ 412 cmpl $__PAGE_OFFSET-3,%ebp 413 jae syscall_fault 414 ASM_STAC 4151: movl (%ebp),%ebp 416 ASM_CLAC 417 movl %ebp,PT_EBP(%esp) 418 _ASM_EXTABLE(1b,syscall_fault) 419 420 GET_THREAD_INFO(%ebp) 421 422 testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp) 423 jnz sysenter_audit 424sysenter_do_call: 425 cmpl $(NR_syscalls), %eax 426 jae sysenter_badsys 427 call *sys_call_table(,%eax,4) 428sysenter_after_call: 429 movl %eax,PT_EAX(%esp) 430 LOCKDEP_SYS_EXIT 431 DISABLE_INTERRUPTS(CLBR_ANY) 432 TRACE_IRQS_OFF 433 movl TI_flags(%ebp), %ecx 434 testl $_TIF_ALLWORK_MASK, %ecx 435 jne sysexit_audit 436sysenter_exit: 437/* if something modifies registers it must also disable sysexit */ 438 movl PT_EIP(%esp), %edx 439 movl PT_OLDESP(%esp), %ecx 440 xorl %ebp,%ebp 441 TRACE_IRQS_ON 4421: mov PT_FS(%esp), %fs 443 PTGS_TO_GS 444 ENABLE_INTERRUPTS_SYSEXIT 445 446#ifdef CONFIG_AUDITSYSCALL 447sysenter_audit: 448 testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%ebp) 449 jnz syscall_trace_entry 450 /* movl PT_EAX(%esp), %eax already set, syscall number: 1st arg to audit */ 451 movl PT_EBX(%esp), %edx /* ebx/a0: 2nd arg to audit */ 452 /* movl PT_ECX(%esp), %ecx already set, a1: 3nd arg to audit */ 453 pushl_cfi PT_ESI(%esp) /* a3: 5th arg */ 454 pushl_cfi PT_EDX+4(%esp) /* a2: 4th arg */ 455 call __audit_syscall_entry 456 popl_cfi %ecx /* get that remapped edx off the stack */ 457 popl_cfi %ecx /* get that remapped esi off the stack */ 458 movl PT_EAX(%esp),%eax /* reload syscall number */ 459 jmp sysenter_do_call 460 461sysexit_audit: 462 testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx 463 jne syscall_exit_work 464 TRACE_IRQS_ON 465 ENABLE_INTERRUPTS(CLBR_ANY) 466 movl %eax,%edx /* second arg, syscall return value */ 467 cmpl $-MAX_ERRNO,%eax /* is it an error ? */ 468 setbe %al /* 1 if so, 0 if not */ 469 movzbl %al,%eax /* zero-extend that */ 470 call __audit_syscall_exit 471 DISABLE_INTERRUPTS(CLBR_ANY) 472 TRACE_IRQS_OFF 473 movl TI_flags(%ebp), %ecx 474 testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx 475 jne syscall_exit_work 476 movl PT_EAX(%esp),%eax /* reload syscall return value */ 477 jmp sysenter_exit 478#endif 479 480 CFI_ENDPROC 481.pushsection .fixup,"ax" 4822: movl $0,PT_FS(%esp) 483 jmp 1b 484.popsection 485 _ASM_EXTABLE(1b,2b) 486 PTGS_TO_GS_EX 487ENDPROC(ia32_sysenter_target) 488 489 # system call handler stub 490ENTRY(system_call) 491 RING0_INT_FRAME # can't unwind into user space anyway 492 ASM_CLAC 493 pushl_cfi %eax # save orig_eax 494 SAVE_ALL 495 GET_THREAD_INFO(%ebp) 496 # system call tracing in operation / emulation 497 testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp) 498 jnz syscall_trace_entry 499 cmpl $(NR_syscalls), %eax 500 jae syscall_badsys 501syscall_call: 502 call *sys_call_table(,%eax,4) 503syscall_after_call: 504 movl %eax,PT_EAX(%esp) # store the return value 505syscall_exit: 506 LOCKDEP_SYS_EXIT 507 DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt 508 # setting need_resched or sigpending 509 # between sampling and the iret 510 TRACE_IRQS_OFF 511 movl TI_flags(%ebp), %ecx 512 testl $_TIF_ALLWORK_MASK, %ecx # current->work 513 jne syscall_exit_work 514 515restore_all: 516 TRACE_IRQS_IRET 517restore_all_notrace: 518#ifdef CONFIG_X86_ESPFIX32 519 movl PT_EFLAGS(%esp), %eax # mix EFLAGS, SS and CS 520 # Warning: PT_OLDSS(%esp) contains the wrong/random values if we 521 # are returning to the kernel. 522 # See comments in process.c:copy_thread() for details. 523 movb PT_OLDSS(%esp), %ah 524 movb PT_CS(%esp), %al 525 andl $(X86_EFLAGS_VM | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax 526 cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax 527 CFI_REMEMBER_STATE 528 je ldt_ss # returning to user-space with LDT SS 529#endif 530restore_nocheck: 531 RESTORE_REGS 4 # skip orig_eax/error_code 532irq_return: 533 INTERRUPT_RETURN 534.section .fixup,"ax" 535ENTRY(iret_exc) 536 pushl $0 # no error code 537 pushl $do_iret_error 538 jmp error_code 539.previous 540 _ASM_EXTABLE(irq_return,iret_exc) 541 542#ifdef CONFIG_X86_ESPFIX32 543 CFI_RESTORE_STATE 544ldt_ss: 545#ifdef CONFIG_PARAVIRT 546 /* 547 * The kernel can't run on a non-flat stack if paravirt mode 548 * is active. Rather than try to fixup the high bits of 549 * ESP, bypass this code entirely. This may break DOSemu 550 * and/or Wine support in a paravirt VM, although the option 551 * is still available to implement the setting of the high 552 * 16-bits in the INTERRUPT_RETURN paravirt-op. 553 */ 554 cmpl $0, pv_info+PARAVIRT_enabled 555 jne restore_nocheck 556#endif 557 558/* 559 * Setup and switch to ESPFIX stack 560 * 561 * We're returning to userspace with a 16 bit stack. The CPU will not 562 * restore the high word of ESP for us on executing iret... This is an 563 * "official" bug of all the x86-compatible CPUs, which we can work 564 * around to make dosemu and wine happy. We do this by preloading the 565 * high word of ESP with the high word of the userspace ESP while 566 * compensating for the offset by changing to the ESPFIX segment with 567 * a base address that matches for the difference. 568 */ 569#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + (GDT_ENTRY_ESPFIX_SS * 8) 570 mov %esp, %edx /* load kernel esp */ 571 mov PT_OLDESP(%esp), %eax /* load userspace esp */ 572 mov %dx, %ax /* eax: new kernel esp */ 573 sub %eax, %edx /* offset (low word is 0) */ 574 shr $16, %edx 575 mov %dl, GDT_ESPFIX_SS + 4 /* bits 16..23 */ 576 mov %dh, GDT_ESPFIX_SS + 7 /* bits 24..31 */ 577 pushl_cfi $__ESPFIX_SS 578 pushl_cfi %eax /* new kernel esp */ 579 /* Disable interrupts, but do not irqtrace this section: we 580 * will soon execute iret and the tracer was already set to 581 * the irqstate after the iret */ 582 DISABLE_INTERRUPTS(CLBR_EAX) 583 lss (%esp), %esp /* switch to espfix segment */ 584 CFI_ADJUST_CFA_OFFSET -8 585 jmp restore_nocheck 586#endif 587 CFI_ENDPROC 588ENDPROC(system_call) 589 590 # perform work that needs to be done immediately before resumption 591 ALIGN 592 RING0_PTREGS_FRAME # can't unwind into user space anyway 593work_pending: 594 testb $_TIF_NEED_RESCHED, %cl 595 jz work_notifysig 596work_resched: 597 call schedule 598 LOCKDEP_SYS_EXIT 599 DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt 600 # setting need_resched or sigpending 601 # between sampling and the iret 602 TRACE_IRQS_OFF 603 movl TI_flags(%ebp), %ecx 604 andl $_TIF_WORK_MASK, %ecx # is there any work to be done other 605 # than syscall tracing? 606 jz restore_all 607 testb $_TIF_NEED_RESCHED, %cl 608 jnz work_resched 609 610work_notifysig: # deal with pending signals and 611 # notify-resume requests 612#ifdef CONFIG_VM86 613 testl $X86_EFLAGS_VM, PT_EFLAGS(%esp) 614 movl %esp, %eax 615 jne work_notifysig_v86 # returning to kernel-space or 616 # vm86-space 6171: 618#else 619 movl %esp, %eax 620#endif 621 TRACE_IRQS_ON 622 ENABLE_INTERRUPTS(CLBR_NONE) 623 movb PT_CS(%esp), %bl 624 andb $SEGMENT_RPL_MASK, %bl 625 cmpb $USER_RPL, %bl 626 jb resume_kernel 627 xorl %edx, %edx 628 call do_notify_resume 629 jmp resume_userspace 630 631#ifdef CONFIG_VM86 632 ALIGN 633work_notifysig_v86: 634 pushl_cfi %ecx # save ti_flags for do_notify_resume 635 call save_v86_state # %eax contains pt_regs pointer 636 popl_cfi %ecx 637 movl %eax, %esp 638 jmp 1b 639#endif 640END(work_pending) 641 642 # perform syscall exit tracing 643 ALIGN 644syscall_trace_entry: 645 movl $-ENOSYS,PT_EAX(%esp) 646 movl %esp, %eax 647 call syscall_trace_enter 648 /* What it returned is what we'll actually use. */ 649 cmpl $(NR_syscalls), %eax 650 jnae syscall_call 651 jmp syscall_exit 652END(syscall_trace_entry) 653 654 # perform syscall exit tracing 655 ALIGN 656syscall_exit_work: 657 testl $_TIF_WORK_SYSCALL_EXIT, %ecx 658 jz work_pending 659 TRACE_IRQS_ON 660 ENABLE_INTERRUPTS(CLBR_ANY) # could let syscall_trace_leave() call 661 # schedule() instead 662 movl %esp, %eax 663 call syscall_trace_leave 664 jmp resume_userspace 665END(syscall_exit_work) 666 CFI_ENDPROC 667 668 RING0_INT_FRAME # can't unwind into user space anyway 669syscall_fault: 670 ASM_CLAC 671 GET_THREAD_INFO(%ebp) 672 movl $-EFAULT,PT_EAX(%esp) 673 jmp resume_userspace 674END(syscall_fault) 675 676syscall_badsys: 677 movl $-ENOSYS,%eax 678 jmp syscall_after_call 679END(syscall_badsys) 680 681sysenter_badsys: 682 movl $-ENOSYS,%eax 683 jmp sysenter_after_call 684END(sysenter_badsys) 685 CFI_ENDPROC 686 687.macro FIXUP_ESPFIX_STACK 688/* 689 * Switch back for ESPFIX stack to the normal zerobased stack 690 * 691 * We can't call C functions using the ESPFIX stack. This code reads 692 * the high word of the segment base from the GDT and swiches to the 693 * normal stack and adjusts ESP with the matching offset. 694 */ 695#ifdef CONFIG_X86_ESPFIX32 696 /* fixup the stack */ 697 mov GDT_ESPFIX_SS + 4, %al /* bits 16..23 */ 698 mov GDT_ESPFIX_SS + 7, %ah /* bits 24..31 */ 699 shl $16, %eax 700 addl %esp, %eax /* the adjusted stack pointer */ 701 pushl_cfi $__KERNEL_DS 702 pushl_cfi %eax 703 lss (%esp), %esp /* switch to the normal stack segment */ 704 CFI_ADJUST_CFA_OFFSET -8 705#endif 706.endm 707.macro UNWIND_ESPFIX_STACK 708#ifdef CONFIG_X86_ESPFIX32 709 movl %ss, %eax 710 /* see if on espfix stack */ 711 cmpw $__ESPFIX_SS, %ax 712 jne 27f 713 movl $__KERNEL_DS, %eax 714 movl %eax, %ds 715 movl %eax, %es 716 /* switch to normal stack */ 717 FIXUP_ESPFIX_STACK 71827: 719#endif 720.endm 721 722/* 723 * Build the entry stubs and pointer table with some assembler magic. 724 * We pack 7 stubs into a single 32-byte chunk, which will fit in a 725 * single cache line on all modern x86 implementations. 726 */ 727.section .init.rodata,"a" 728ENTRY(interrupt) 729.section .entry.text, "ax" 730 .p2align 5 731 .p2align CONFIG_X86_L1_CACHE_SHIFT 732ENTRY(irq_entries_start) 733 RING0_INT_FRAME 734vector=FIRST_EXTERNAL_VECTOR 735.rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7 736 .balign 32 737 .rept 7 738 .if vector < NR_VECTORS 739 .if vector <> FIRST_EXTERNAL_VECTOR 740 CFI_ADJUST_CFA_OFFSET -4 741 .endif 7421: pushl_cfi $(~vector+0x80) /* Note: always in signed byte range */ 743 .if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6 744 jmp 2f 745 .endif 746 .previous 747 .long 1b 748 .section .entry.text, "ax" 749vector=vector+1 750 .endif 751 .endr 7522: jmp common_interrupt 753.endr 754END(irq_entries_start) 755 756.previous 757END(interrupt) 758.previous 759 760/* 761 * the CPU automatically disables interrupts when executing an IRQ vector, 762 * so IRQ-flags tracing has to follow that: 763 */ 764 .p2align CONFIG_X86_L1_CACHE_SHIFT 765common_interrupt: 766 ASM_CLAC 767 addl $-0x80,(%esp) /* Adjust vector into the [-256,-1] range */ 768 SAVE_ALL 769 TRACE_IRQS_OFF 770 movl %esp,%eax 771 call do_IRQ 772 jmp ret_from_intr 773ENDPROC(common_interrupt) 774 CFI_ENDPROC 775 776#define BUILD_INTERRUPT3(name, nr, fn) \ 777ENTRY(name) \ 778 RING0_INT_FRAME; \ 779 ASM_CLAC; \ 780 pushl_cfi $~(nr); \ 781 SAVE_ALL; \ 782 TRACE_IRQS_OFF \ 783 movl %esp,%eax; \ 784 call fn; \ 785 jmp ret_from_intr; \ 786 CFI_ENDPROC; \ 787ENDPROC(name) 788 789 790#ifdef CONFIG_TRACING 791#define TRACE_BUILD_INTERRUPT(name, nr) \ 792 BUILD_INTERRUPT3(trace_##name, nr, smp_trace_##name) 793#else 794#define TRACE_BUILD_INTERRUPT(name, nr) 795#endif 796 797#define BUILD_INTERRUPT(name, nr) \ 798 BUILD_INTERRUPT3(name, nr, smp_##name); \ 799 TRACE_BUILD_INTERRUPT(name, nr) 800 801/* The include is where all of the SMP etc. interrupts come from */ 802#include <asm/entry_arch.h> 803 804ENTRY(coprocessor_error) 805 RING0_INT_FRAME 806 ASM_CLAC 807 pushl_cfi $0 808 pushl_cfi $do_coprocessor_error 809 jmp error_code 810 CFI_ENDPROC 811END(coprocessor_error) 812 813ENTRY(simd_coprocessor_error) 814 RING0_INT_FRAME 815 ASM_CLAC 816 pushl_cfi $0 817#ifdef CONFIG_X86_INVD_BUG 818 /* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */ 819661: pushl_cfi $do_general_protection 820662: 821.section .altinstructions,"a" 822 altinstruction_entry 661b, 663f, X86_FEATURE_XMM, 662b-661b, 664f-663f 823.previous 824.section .altinstr_replacement,"ax" 825663: pushl $do_simd_coprocessor_error 826664: 827.previous 828#else 829 pushl_cfi $do_simd_coprocessor_error 830#endif 831 jmp error_code 832 CFI_ENDPROC 833END(simd_coprocessor_error) 834 835ENTRY(device_not_available) 836 RING0_INT_FRAME 837 ASM_CLAC 838 pushl_cfi $-1 # mark this as an int 839 pushl_cfi $do_device_not_available 840 jmp error_code 841 CFI_ENDPROC 842END(device_not_available) 843 844#ifdef CONFIG_PARAVIRT 845ENTRY(native_iret) 846 iret 847 _ASM_EXTABLE(native_iret, iret_exc) 848END(native_iret) 849 850ENTRY(native_irq_enable_sysexit) 851 sti 852 sysexit 853END(native_irq_enable_sysexit) 854#endif 855 856ENTRY(overflow) 857 RING0_INT_FRAME 858 ASM_CLAC 859 pushl_cfi $0 860 pushl_cfi $do_overflow 861 jmp error_code 862 CFI_ENDPROC 863END(overflow) 864 865ENTRY(bounds) 866 RING0_INT_FRAME 867 ASM_CLAC 868 pushl_cfi $0 869 pushl_cfi $do_bounds 870 jmp error_code 871 CFI_ENDPROC 872END(bounds) 873 874ENTRY(invalid_op) 875 RING0_INT_FRAME 876 ASM_CLAC 877 pushl_cfi $0 878 pushl_cfi $do_invalid_op 879 jmp error_code 880 CFI_ENDPROC 881END(invalid_op) 882 883ENTRY(coprocessor_segment_overrun) 884 RING0_INT_FRAME 885 ASM_CLAC 886 pushl_cfi $0 887 pushl_cfi $do_coprocessor_segment_overrun 888 jmp error_code 889 CFI_ENDPROC 890END(coprocessor_segment_overrun) 891 892ENTRY(invalid_TSS) 893 RING0_EC_FRAME 894 ASM_CLAC 895 pushl_cfi $do_invalid_TSS 896 jmp error_code 897 CFI_ENDPROC 898END(invalid_TSS) 899 900ENTRY(segment_not_present) 901 RING0_EC_FRAME 902 ASM_CLAC 903 pushl_cfi $do_segment_not_present 904 jmp error_code 905 CFI_ENDPROC 906END(segment_not_present) 907 908ENTRY(stack_segment) 909 RING0_EC_FRAME 910 ASM_CLAC 911 pushl_cfi $do_stack_segment 912 jmp error_code 913 CFI_ENDPROC 914END(stack_segment) 915 916ENTRY(alignment_check) 917 RING0_EC_FRAME 918 ASM_CLAC 919 pushl_cfi $do_alignment_check 920 jmp error_code 921 CFI_ENDPROC 922END(alignment_check) 923 924ENTRY(divide_error) 925 RING0_INT_FRAME 926 ASM_CLAC 927 pushl_cfi $0 # no error code 928 pushl_cfi $do_divide_error 929 jmp error_code 930 CFI_ENDPROC 931END(divide_error) 932 933#ifdef CONFIG_X86_MCE 934ENTRY(machine_check) 935 RING0_INT_FRAME 936 ASM_CLAC 937 pushl_cfi $0 938 pushl_cfi machine_check_vector 939 jmp error_code 940 CFI_ENDPROC 941END(machine_check) 942#endif 943 944ENTRY(spurious_interrupt_bug) 945 RING0_INT_FRAME 946 ASM_CLAC 947 pushl_cfi $0 948 pushl_cfi $do_spurious_interrupt_bug 949 jmp error_code 950 CFI_ENDPROC 951END(spurious_interrupt_bug) 952 953#ifdef CONFIG_XEN 954/* Xen doesn't set %esp to be precisely what the normal sysenter 955 entrypoint expects, so fix it up before using the normal path. */ 956ENTRY(xen_sysenter_target) 957 RING0_INT_FRAME 958 addl $5*4, %esp /* remove xen-provided frame */ 959 CFI_ADJUST_CFA_OFFSET -5*4 960 jmp sysenter_past_esp 961 CFI_ENDPROC 962 963ENTRY(xen_hypervisor_callback) 964 CFI_STARTPROC 965 pushl_cfi $-1 /* orig_ax = -1 => not a system call */ 966 SAVE_ALL 967 TRACE_IRQS_OFF 968 969 /* Check to see if we got the event in the critical 970 region in xen_iret_direct, after we've reenabled 971 events and checked for pending events. This simulates 972 iret instruction's behaviour where it delivers a 973 pending interrupt when enabling interrupts. */ 974 movl PT_EIP(%esp),%eax 975 cmpl $xen_iret_start_crit,%eax 976 jb 1f 977 cmpl $xen_iret_end_crit,%eax 978 jae 1f 979 980 jmp xen_iret_crit_fixup 981 982ENTRY(xen_do_upcall) 9831: mov %esp, %eax 984 call xen_evtchn_do_upcall 985#ifndef CONFIG_PREEMPT 986 call xen_maybe_preempt_hcall 987#endif 988 jmp ret_from_intr 989 CFI_ENDPROC 990ENDPROC(xen_hypervisor_callback) 991 992# Hypervisor uses this for application faults while it executes. 993# We get here for two reasons: 994# 1. Fault while reloading DS, ES, FS or GS 995# 2. Fault while executing IRET 996# Category 1 we fix up by reattempting the load, and zeroing the segment 997# register if the load fails. 998# Category 2 we fix up by jumping to do_iret_error. We cannot use the 999# normal Linux return path in this case because if we use the IRET hypercall 1000# to pop the stack frame we end up in an infinite loop of failsafe callbacks. 1001# We distinguish between categories by maintaining a status value in EAX. 1002ENTRY(xen_failsafe_callback) 1003 CFI_STARTPROC 1004 pushl_cfi %eax 1005 movl $1,%eax 10061: mov 4(%esp),%ds 10072: mov 8(%esp),%es 10083: mov 12(%esp),%fs 10094: mov 16(%esp),%gs 1010 /* EAX == 0 => Category 1 (Bad segment) 1011 EAX != 0 => Category 2 (Bad IRET) */ 1012 testl %eax,%eax 1013 popl_cfi %eax 1014 lea 16(%esp),%esp 1015 CFI_ADJUST_CFA_OFFSET -16 1016 jz 5f 1017 jmp iret_exc 10185: pushl_cfi $-1 /* orig_ax = -1 => not a system call */ 1019 SAVE_ALL 1020 jmp ret_from_exception 1021 CFI_ENDPROC 1022 1023.section .fixup,"ax" 10246: xorl %eax,%eax 1025 movl %eax,4(%esp) 1026 jmp 1b 10277: xorl %eax,%eax 1028 movl %eax,8(%esp) 1029 jmp 2b 10308: xorl %eax,%eax 1031 movl %eax,12(%esp) 1032 jmp 3b 10339: xorl %eax,%eax 1034 movl %eax,16(%esp) 1035 jmp 4b 1036.previous 1037 _ASM_EXTABLE(1b,6b) 1038 _ASM_EXTABLE(2b,7b) 1039 _ASM_EXTABLE(3b,8b) 1040 _ASM_EXTABLE(4b,9b) 1041ENDPROC(xen_failsafe_callback) 1042 1043BUILD_INTERRUPT3(xen_hvm_callback_vector, HYPERVISOR_CALLBACK_VECTOR, 1044 xen_evtchn_do_upcall) 1045 1046#endif /* CONFIG_XEN */ 1047 1048#if IS_ENABLED(CONFIG_HYPERV) 1049 1050BUILD_INTERRUPT3(hyperv_callback_vector, HYPERVISOR_CALLBACK_VECTOR, 1051 hyperv_vector_handler) 1052 1053#endif /* CONFIG_HYPERV */ 1054 1055#ifdef CONFIG_FUNCTION_TRACER 1056#ifdef CONFIG_DYNAMIC_FTRACE 1057 1058ENTRY(mcount) 1059 ret 1060END(mcount) 1061 1062ENTRY(ftrace_caller) 1063 pushl %eax 1064 pushl %ecx 1065 pushl %edx 1066 pushl $0 /* Pass NULL as regs pointer */ 1067 movl 4*4(%esp), %eax 1068 movl 0x4(%ebp), %edx 1069 movl function_trace_op, %ecx 1070 subl $MCOUNT_INSN_SIZE, %eax 1071 1072.globl ftrace_call 1073ftrace_call: 1074 call ftrace_stub 1075 1076 addl $4,%esp /* skip NULL pointer */ 1077 popl %edx 1078 popl %ecx 1079 popl %eax 1080ftrace_ret: 1081#ifdef CONFIG_FUNCTION_GRAPH_TRACER 1082.globl ftrace_graph_call 1083ftrace_graph_call: 1084 jmp ftrace_stub 1085#endif 1086 1087.globl ftrace_stub 1088ftrace_stub: 1089 ret 1090END(ftrace_caller) 1091 1092ENTRY(ftrace_regs_caller) 1093 pushf /* push flags before compare (in cs location) */ 1094 1095 /* 1096 * i386 does not save SS and ESP when coming from kernel. 1097 * Instead, to get sp, ®s->sp is used (see ptrace.h). 1098 * Unfortunately, that means eflags must be at the same location 1099 * as the current return ip is. We move the return ip into the 1100 * ip location, and move flags into the return ip location. 1101 */ 1102 pushl 4(%esp) /* save return ip into ip slot */ 1103 1104 pushl $0 /* Load 0 into orig_ax */ 1105 pushl %gs 1106 pushl %fs 1107 pushl %es 1108 pushl %ds 1109 pushl %eax 1110 pushl %ebp 1111 pushl %edi 1112 pushl %esi 1113 pushl %edx 1114 pushl %ecx 1115 pushl %ebx 1116 1117 movl 13*4(%esp), %eax /* Get the saved flags */ 1118 movl %eax, 14*4(%esp) /* Move saved flags into regs->flags location */ 1119 /* clobbering return ip */ 1120 movl $__KERNEL_CS,13*4(%esp) 1121 1122 movl 12*4(%esp), %eax /* Load ip (1st parameter) */ 1123 subl $MCOUNT_INSN_SIZE, %eax /* Adjust ip */ 1124 movl 0x4(%ebp), %edx /* Load parent ip (2nd parameter) */ 1125 movl function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */ 1126 pushl %esp /* Save pt_regs as 4th parameter */ 1127 1128GLOBAL(ftrace_regs_call) 1129 call ftrace_stub 1130 1131 addl $4, %esp /* Skip pt_regs */ 1132 movl 14*4(%esp), %eax /* Move flags back into cs */ 1133 movl %eax, 13*4(%esp) /* Needed to keep addl from modifying flags */ 1134 movl 12*4(%esp), %eax /* Get return ip from regs->ip */ 1135 movl %eax, 14*4(%esp) /* Put return ip back for ret */ 1136 1137 popl %ebx 1138 popl %ecx 1139 popl %edx 1140 popl %esi 1141 popl %edi 1142 popl %ebp 1143 popl %eax 1144 popl %ds 1145 popl %es 1146 popl %fs 1147 popl %gs 1148 addl $8, %esp /* Skip orig_ax and ip */ 1149 popf /* Pop flags at end (no addl to corrupt flags) */ 1150 jmp ftrace_ret 1151 1152 popf 1153 jmp ftrace_stub 1154#else /* ! CONFIG_DYNAMIC_FTRACE */ 1155 1156ENTRY(mcount) 1157 cmpl $__PAGE_OFFSET, %esp 1158 jb ftrace_stub /* Paging not enabled yet? */ 1159 1160 cmpl $ftrace_stub, ftrace_trace_function 1161 jnz trace 1162#ifdef CONFIG_FUNCTION_GRAPH_TRACER 1163 cmpl $ftrace_stub, ftrace_graph_return 1164 jnz ftrace_graph_caller 1165 1166 cmpl $ftrace_graph_entry_stub, ftrace_graph_entry 1167 jnz ftrace_graph_caller 1168#endif 1169.globl ftrace_stub 1170ftrace_stub: 1171 ret 1172 1173 /* taken from glibc */ 1174trace: 1175 pushl %eax 1176 pushl %ecx 1177 pushl %edx 1178 movl 0xc(%esp), %eax 1179 movl 0x4(%ebp), %edx 1180 subl $MCOUNT_INSN_SIZE, %eax 1181 1182 call *ftrace_trace_function 1183 1184 popl %edx 1185 popl %ecx 1186 popl %eax 1187 jmp ftrace_stub 1188END(mcount) 1189#endif /* CONFIG_DYNAMIC_FTRACE */ 1190#endif /* CONFIG_FUNCTION_TRACER */ 1191 1192#ifdef CONFIG_FUNCTION_GRAPH_TRACER 1193ENTRY(ftrace_graph_caller) 1194 pushl %eax 1195 pushl %ecx 1196 pushl %edx 1197 movl 0xc(%esp), %edx 1198 lea 0x4(%ebp), %eax 1199 movl (%ebp), %ecx 1200 subl $MCOUNT_INSN_SIZE, %edx 1201 call prepare_ftrace_return 1202 popl %edx 1203 popl %ecx 1204 popl %eax 1205 ret 1206END(ftrace_graph_caller) 1207 1208.globl return_to_handler 1209return_to_handler: 1210 pushl %eax 1211 pushl %edx 1212 movl %ebp, %eax 1213 call ftrace_return_to_handler 1214 movl %eax, %ecx 1215 popl %edx 1216 popl %eax 1217 jmp *%ecx 1218#endif 1219 1220#ifdef CONFIG_TRACING 1221ENTRY(trace_page_fault) 1222 RING0_EC_FRAME 1223 ASM_CLAC 1224 pushl_cfi $trace_do_page_fault 1225 jmp error_code 1226 CFI_ENDPROC 1227END(trace_page_fault) 1228#endif 1229 1230ENTRY(page_fault) 1231 RING0_EC_FRAME 1232 ASM_CLAC 1233 pushl_cfi $do_page_fault 1234 ALIGN 1235error_code: 1236 /* the function address is in %gs's slot on the stack */ 1237 pushl_cfi %fs 1238 /*CFI_REL_OFFSET fs, 0*/ 1239 pushl_cfi %es 1240 /*CFI_REL_OFFSET es, 0*/ 1241 pushl_cfi %ds 1242 /*CFI_REL_OFFSET ds, 0*/ 1243 pushl_cfi %eax 1244 CFI_REL_OFFSET eax, 0 1245 pushl_cfi %ebp 1246 CFI_REL_OFFSET ebp, 0 1247 pushl_cfi %edi 1248 CFI_REL_OFFSET edi, 0 1249 pushl_cfi %esi 1250 CFI_REL_OFFSET esi, 0 1251 pushl_cfi %edx 1252 CFI_REL_OFFSET edx, 0 1253 pushl_cfi %ecx 1254 CFI_REL_OFFSET ecx, 0 1255 pushl_cfi %ebx 1256 CFI_REL_OFFSET ebx, 0 1257 cld 1258 movl $(__KERNEL_PERCPU), %ecx 1259 movl %ecx, %fs 1260 UNWIND_ESPFIX_STACK 1261 GS_TO_REG %ecx 1262 movl PT_GS(%esp), %edi # get the function address 1263 movl PT_ORIG_EAX(%esp), %edx # get the error code 1264 movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart 1265 REG_TO_PTGS %ecx 1266 SET_KERNEL_GS %ecx 1267 movl $(__USER_DS), %ecx 1268 movl %ecx, %ds 1269 movl %ecx, %es 1270 TRACE_IRQS_OFF 1271 movl %esp,%eax # pt_regs pointer 1272 call *%edi 1273 jmp ret_from_exception 1274 CFI_ENDPROC 1275END(page_fault) 1276 1277/* 1278 * Debug traps and NMI can happen at the one SYSENTER instruction 1279 * that sets up the real kernel stack. Check here, since we can't 1280 * allow the wrong stack to be used. 1281 * 1282 * "TSS_sysenter_sp0+12" is because the NMI/debug handler will have 1283 * already pushed 3 words if it hits on the sysenter instruction: 1284 * eflags, cs and eip. 1285 * 1286 * We just load the right stack, and push the three (known) values 1287 * by hand onto the new stack - while updating the return eip past 1288 * the instruction that would have done it for sysenter. 1289 */ 1290.macro FIX_STACK offset ok label 1291 cmpw $__KERNEL_CS, 4(%esp) 1292 jne \ok 1293\label: 1294 movl TSS_sysenter_sp0 + \offset(%esp), %esp 1295 CFI_DEF_CFA esp, 0 1296 CFI_UNDEFINED eip 1297 pushfl_cfi 1298 pushl_cfi $__KERNEL_CS 1299 pushl_cfi $sysenter_past_esp 1300 CFI_REL_OFFSET eip, 0 1301.endm 1302 1303ENTRY(debug) 1304 RING0_INT_FRAME 1305 ASM_CLAC 1306 cmpl $ia32_sysenter_target,(%esp) 1307 jne debug_stack_correct 1308 FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn 1309debug_stack_correct: 1310 pushl_cfi $-1 # mark this as an int 1311 SAVE_ALL 1312 TRACE_IRQS_OFF 1313 xorl %edx,%edx # error code 0 1314 movl %esp,%eax # pt_regs pointer 1315 call do_debug 1316 jmp ret_from_exception 1317 CFI_ENDPROC 1318END(debug) 1319 1320/* 1321 * NMI is doubly nasty. It can happen _while_ we're handling 1322 * a debug fault, and the debug fault hasn't yet been able to 1323 * clear up the stack. So we first check whether we got an 1324 * NMI on the sysenter entry path, but after that we need to 1325 * check whether we got an NMI on the debug path where the debug 1326 * fault happened on the sysenter path. 1327 */ 1328ENTRY(nmi) 1329 RING0_INT_FRAME 1330 ASM_CLAC 1331#ifdef CONFIG_X86_ESPFIX32 1332 pushl_cfi %eax 1333 movl %ss, %eax 1334 cmpw $__ESPFIX_SS, %ax 1335 popl_cfi %eax 1336 je nmi_espfix_stack 1337#endif 1338 cmpl $ia32_sysenter_target,(%esp) 1339 je nmi_stack_fixup 1340 pushl_cfi %eax 1341 movl %esp,%eax 1342 /* Do not access memory above the end of our stack page, 1343 * it might not exist. 1344 */ 1345 andl $(THREAD_SIZE-1),%eax 1346 cmpl $(THREAD_SIZE-20),%eax 1347 popl_cfi %eax 1348 jae nmi_stack_correct 1349 cmpl $ia32_sysenter_target,12(%esp) 1350 je nmi_debug_stack_check 1351nmi_stack_correct: 1352 /* We have a RING0_INT_FRAME here */ 1353 pushl_cfi %eax 1354 SAVE_ALL 1355 xorl %edx,%edx # zero error code 1356 movl %esp,%eax # pt_regs pointer 1357 call do_nmi 1358 jmp restore_all_notrace 1359 CFI_ENDPROC 1360 1361nmi_stack_fixup: 1362 RING0_INT_FRAME 1363 FIX_STACK 12, nmi_stack_correct, 1 1364 jmp nmi_stack_correct 1365 1366nmi_debug_stack_check: 1367 /* We have a RING0_INT_FRAME here */ 1368 cmpw $__KERNEL_CS,16(%esp) 1369 jne nmi_stack_correct 1370 cmpl $debug,(%esp) 1371 jb nmi_stack_correct 1372 cmpl $debug_esp_fix_insn,(%esp) 1373 ja nmi_stack_correct 1374 FIX_STACK 24, nmi_stack_correct, 1 1375 jmp nmi_stack_correct 1376 1377#ifdef CONFIG_X86_ESPFIX32 1378nmi_espfix_stack: 1379 /* We have a RING0_INT_FRAME here. 1380 * 1381 * create the pointer to lss back 1382 */ 1383 pushl_cfi %ss 1384 pushl_cfi %esp 1385 addl $4, (%esp) 1386 /* copy the iret frame of 12 bytes */ 1387 .rept 3 1388 pushl_cfi 16(%esp) 1389 .endr 1390 pushl_cfi %eax 1391 SAVE_ALL 1392 FIXUP_ESPFIX_STACK # %eax == %esp 1393 xorl %edx,%edx # zero error code 1394 call do_nmi 1395 RESTORE_REGS 1396 lss 12+4(%esp), %esp # back to espfix stack 1397 CFI_ADJUST_CFA_OFFSET -24 1398 jmp irq_return 1399#endif 1400 CFI_ENDPROC 1401END(nmi) 1402 1403ENTRY(int3) 1404 RING0_INT_FRAME 1405 ASM_CLAC 1406 pushl_cfi $-1 # mark this as an int 1407 SAVE_ALL 1408 TRACE_IRQS_OFF 1409 xorl %edx,%edx # zero error code 1410 movl %esp,%eax # pt_regs pointer 1411 call do_int3 1412 jmp ret_from_exception 1413 CFI_ENDPROC 1414END(int3) 1415 1416ENTRY(general_protection) 1417 RING0_EC_FRAME 1418 pushl_cfi $do_general_protection 1419 jmp error_code 1420 CFI_ENDPROC 1421END(general_protection) 1422 1423#ifdef CONFIG_KVM_GUEST 1424ENTRY(async_page_fault) 1425 RING0_EC_FRAME 1426 ASM_CLAC 1427 pushl_cfi $do_async_page_fault 1428 jmp error_code 1429 CFI_ENDPROC 1430END(async_page_fault) 1431#endif 1432 1433