2 * Copyright (c) 1989, 1990 William F. Jolitz.
3 * Copyright (c) 1990 The Regents of the University of California.
4 * Copyright (c) 2007 The FreeBSD Foundation
7 * Portions of this software were developed by A. Joseph Koshy under
8 * sponsorship from the FreeBSD Foundation and Google, Inc.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 #include "opt_atpic.h"
39 #include "opt_hwpmc_hooks.h"
42 #include <machine/asmacros.h>
43 #include <machine/psl.h>
44 #include <machine/trap.h>
48 #define SEL_RPL_MASK 0x0003
49 #define GSEL_KPL 0x0020 /* GSEL(GCODE_SEL, SEL_KPL) */
53 .globl dtrace_invop_jump_addr
55 .type dtrace_invop_jump_addr, @object
56 .size dtrace_invop_jump_addr, 4
57 dtrace_invop_jump_addr:
59 .globl dtrace_invop_calltrap_addr
61 .type dtrace_invop_calltrap_addr, @object
62 .size dtrace_invop_calltrap_addr, 4
63 dtrace_invop_calltrap_addr:
68 ENTRY(start_exceptions)
70 /*****************************************************************************/
72 /*****************************************************************************/
74 * Trap and fault vector routines.
76 * Most traps are 'trap gates', SDT_SYS386TGT. A trap gate pushes state on
77 * the stack that mostly looks like an interrupt, but does not disable
78 * interrupts. A few of the traps we are use are interrupt gates,
79 * SDT_SYS386IGT, which are nearly the same thing except interrupts are
82 * The cpu will push a certain amount of state onto the kernel stack for
83 * the current process. The amount of state depends on the type of trap
84 * and whether the trap crossed rings or not. See i386/include/frame.h.
85 * At the very least the current EFLAGS (status register, which includes
86 * the interrupt disable state prior to the trap), the code segment register,
87 * and the return instruction pointer are pushed by the cpu. The cpu
88 * will also push an 'error' code for certain traps. We push a dummy
89 * error code for those traps where the cpu doesn't in order to maintain
90 * a consistent frame. We also push a contrived 'trap number'.
92 * The cpu does not push the general registers, we must do that, and we
93 * must restore them prior to calling 'iret'. The cpu adjusts the %cs and
94 * %ss segment registers, but does not mess with %ds, %es, or %fs. Thus we
95 * must load them with appropriate values for supervisor mode operation.
101 #define TRAP(a) pushl $(a) ; jmp alltraps
104 pushl $0; TRAP(T_DIVIDE)
106 pushl $0; TRAP(T_TRCTRAP)
108 pushl $0; TRAP(T_NMI)
110 pushl $0; TRAP(T_BPTFLT)
112 pushl $0; TRAP(T_DTRACE_RET)
114 pushl $0; TRAP(T_OFLOW)
116 pushl $0; TRAP(T_BOUND)
117 #ifndef KDTRACE_HOOKS
119 pushl $0; TRAP(T_PRIVINFLT)
122 pushl $0; TRAP(T_DNA)
124 pushl $0; TRAP(T_FPOPFLT)
136 pushl $0; TRAP(T_MCHK)
138 pushl $0; TRAP(T_RESERVED)
140 pushl $0; TRAP(T_ARITHTRAP)
144 pushl $0; TRAP(T_XMMFLT)
147 * All traps except ones for syscalls jump to alltraps. If
148 * interrupts were enabled when the trap occurred, then interrupts
149 * are enabled now if the trap was through a trap gate, else
150 * disabled if the trap was through an interrupt gate. Note that
151 * int0x80_syscall is a trap gate. Interrupt gates are used by
152 * page faults, non-maskable interrupts, debug and breakpoint
157 .type alltraps,@function
163 alltraps_with_regs_pushed:
166 FAKE_MCOUNT(TF_EIP(%esp))
173 * Return via doreti to handle ASTs.
179 * Privileged instruction fault.
184 /* Check if there is no DTrace hook registered. */
185 cmpl $0,dtrace_invop_jump_addr
188 /* Check if this is a user fault. */
189 cmpl $GSEL_KPL, 4(%esp) /* Check the code segment. */
191 /* If so, just handle it as a normal trap. */
195 * This is a kernel instruction fault that might have been caused
196 * by a DTrace provider.
198 pushal /* Push all registers onto the stack. */
201 * Set our jump address for the jump back in the event that
202 * the exception wasn't caused by DTrace at all.
204 movl $norm_ill, dtrace_invop_calltrap_addr
206 /* Jump to the code hooked in by DTrace. */
207 jmpl *dtrace_invop_jump_addr
210 * Process the instruction fault in the normal way.
218 * Call gate entry for syscalls (lcall 7,0).
219 * This is used by FreeBSD 1.x a.out executables and "old" NetBSD executables.
221 * The intersegment call has been set up to specify one dummy parameter.
222 * This leaves a place to put eflags so that the call frame can be
223 * converted to a trap frame. Note that the eflags is (semi-)bogusly
224 * pushed into (what will be) tf_err and then copied later into the
225 * final spot. It has to be done this way because esp can't be just
226 * temporarily altered for the pushfl - an interrupt might come in
227 * and clobber the saved cs/eip.
230 IDTVEC(lcall_syscall)
231 pushfl /* save eflags */
232 popl 8(%esp) /* shuffle into tf_eflags */
233 pushl $7 /* sizeof "lcall 7,0" */
234 subl $4,%esp /* skip over tf_trapno */
241 FAKE_MCOUNT(TF_EIP(%esp))
249 * Trap gate entry for syscalls (int 0x80).
250 * This is used by FreeBSD ELF executables, "new" NetBSD executables, and all
253 * Even though the name says 'int0x80', this is actually a trap gate, not an
254 * interrupt gate. Thus interrupts are enabled on entry just as they are for
258 IDTVEC(int0x80_syscall)
259 pushl $2 /* sizeof "int 0x80" */
260 subl $4,%esp /* skip over tf_trapno */
267 FAKE_MCOUNT(TF_EIP(%esp))
274 ENTRY(fork_trampoline)
275 pushl %esp /* trapframe pointer */
276 pushl %ebx /* arg1 */
277 pushl %esi /* function */
280 /* cut from syscall */
283 * Return via doreti to handle ASTs.
290 * To efficiently implement classification of trap and interrupt handlers
291 * for profiling, there must be only trap handlers between the labels btrap
292 * and bintr, and only interrupt handlers between the labels bintr and
293 * eintr. This is implemented (partly) by including files that contain
294 * some of the handlers. Before including the files, set up a normal asm
295 * environment so that the included files doen't need to know that they are
306 #include <i386/i386/atpic_vector.s>
309 #if defined(DEV_APIC) && defined(DEV_ATPIC)
317 #include <i386/i386/apic_vector.s>
324 #include <i386/i386/vm86bios.s>
330 * void doreti(struct trapframe)
332 * Handle return from interrupts, traps and syscalls.
336 .type doreti,@function
338 FAKE_MCOUNT($bintr) /* init "from" bintr -> doreti */
341 * Check if ASTs can be handled now. ASTs cannot be safely
342 * processed when returning from an NMI.
344 cmpb $T_NMI,TF_TRAPNO(%esp)
351 * PSL_VM must be checked first since segment registers only
352 * have an RPL in non-VM86 mode.
353 * ASTs can not be handled now if we are in a vm86 call.
355 testl $PSL_VM,TF_EFLAGS(%esp)
357 movl PCPU(CURPCB),%ecx
358 testl $PCB_VM86CALL,PCB_FLAGS(%ecx)
363 testb $SEL_RPL_MASK,TF_CS(%esp) /* are we returning to user mode? */
364 jz doreti_exit /* can't handle ASTs now if not */
368 * Check for ASTs atomically with returning. Disabling CPU
369 * interrupts provides sufficient locking even in the SMP case,
370 * since we will be informed of any new ASTs by an IPI.
373 movl PCPU(CURTHREAD),%eax
374 testl $TDF_ASTPENDING | TDF_NEEDRESCHED,TD_FLAGS(%eax)
377 pushl %esp /* pass a pointer to the trapframe */
383 * doreti_exit: pop registers, iret.
385 * The segment register pop is a special case, since it may
386 * fault if (for example) a sigreturn specifies bad segment
387 * registers. The fault is handled in trap.c.
392 .globl doreti_popl_fs
395 .globl doreti_popl_es
398 .globl doreti_popl_ds
408 * doreti_iret_fault and friends. Alternative return code for
409 * the case where we get a fault in the doreti_exit code
410 * above. trap() (i386/i386/trap.c) catches this specific
411 * case, sends the process a signal and continues in the
412 * corresponding place in the code below.
415 .globl doreti_iret_fault
420 .globl doreti_popl_ds_fault
421 doreti_popl_ds_fault:
423 .globl doreti_popl_es_fault
424 doreti_popl_es_fault:
426 .globl doreti_popl_fs_fault
427 doreti_popl_fs_fault:
429 movl $0,TF_ERR(%esp) /* XXX should be the error code */
430 movl $T_PROTFLT,TF_TRAPNO(%esp)
431 jmp alltraps_with_regs_pushed
435 * Since we are returning from an NMI, check if the current trap
436 * was from user mode and if so whether the current thread
437 * needs a user call chain capture.
439 testb $SEL_RPL_MASK,TF_CS(%esp)
441 movl PCPU(CURTHREAD),%eax /* curthread present? */
444 testl $TDP_CALLCHAIN,TD_PFLAGS(%eax) /* flagged for capture? */
447 * Take the processor out of NMI mode by executing a fake "iret".
455 * Call the callchain capture hook after turning interrupts back on.
460 pushl %esp /* frame pointer */
461 pushl $PMC_FN_USER_CALLCHAIN /* command */
462 movl PCPU(CURTHREAD),%eax
463 pushl %eax /* curthread */
468 ENTRY(end_exceptions)