1 /*-
2 * Copyright (c) 1989, 1990 William F. Jolitz.
3 * Copyright (c) 1990 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 4. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $FreeBSD$
31 */
32
33 #include "opt_apic.h"
34 #include "opt_npx.h"
35
36 #include <machine/asmacros.h>
37 #include <machine/psl.h>
38 #include <machine/trap.h>
39
40 #include "assym.s"
41
42 #define SEL_RPL_MASK 0x0003
43
44 .text
45
46 /*****************************************************************************/
47 /* Trap handling */
48 /*****************************************************************************/
49 /*
50 * Trap and fault vector routines.
51 *
52 * Most traps are 'trap gates', SDT_SYS386TGT. A trap gate pushes state on
53 * the stack that mostly looks like an interrupt, but does not disable
54 * interrupts. A few of the traps we are use are interrupt gates,
55 * SDT_SYS386IGT, which are nearly the same thing except interrupts are
56 * disabled on entry.
57 *
58 * The cpu will push a certain amount of state onto the kernel stack for
59 * the current process. The amount of state depends on the type of trap
60 * and whether the trap crossed rings or not. See i386/include/frame.h.
61 * At the very least the current EFLAGS (status register, which includes
62 * the interrupt disable state prior to the trap), the code segment register,
63 * and the return instruction pointer are pushed by the cpu. The cpu
64 * will also push an 'error' code for certain traps. We push a dummy
65 * error code for those traps where the cpu doesn't in order to maintain
66 * a consistent frame. We also push a contrived 'trap number'.
67 *
68 * The cpu does not push the general registers, we must do that, and we
69 * must restore them prior to calling 'iret'. The cpu adjusts the %cs and
70 * %ss segment registers, but does not mess with %ds, %es, or %fs. Thus we
71 * must load them with appropriate values for supervisor mode operation.
72 */
73
74 MCOUNT_LABEL(user)
75 MCOUNT_LABEL(btrap)
76
77 #define TRAP(a) pushl $(a) ; jmp alltraps
78
79 IDTVEC(div)
80 pushl $0; TRAP(T_DIVIDE)
81 IDTVEC(dbg)
82 pushl $0; TRAP(T_TRCTRAP)
83 IDTVEC(nmi)
84 pushl $0; TRAP(T_NMI)
85 IDTVEC(bpt)
86 pushl $0; TRAP(T_BPTFLT)
87 IDTVEC(ofl)
88 pushl $0; TRAP(T_OFLOW)
89 IDTVEC(bnd)
90 pushl $0; TRAP(T_BOUND)
91 IDTVEC(ill)
92 pushl $0; TRAP(T_PRIVINFLT)
93 IDTVEC(dna)
94 pushl $0; TRAP(T_DNA)
95 IDTVEC(fpusegm)
96 pushl $0; TRAP(T_FPOPFLT)
97 IDTVEC(tss)
98 TRAP(T_TSSFLT)
99 IDTVEC(missing)
100 TRAP(T_SEGNPFLT)
101 IDTVEC(stk)
102 TRAP(T_STKFLT)
103 IDTVEC(prot)
104 TRAP(T_PROTFLT)
105 IDTVEC(page)
106 TRAP(T_PAGEFLT)
107 IDTVEC(mchk)
108 pushl $0; TRAP(T_MCHK)
109 IDTVEC(rsvd)
110 pushl $0; TRAP(T_RESERVED)
111 IDTVEC(fpu)
112 pushl $0; TRAP(T_ARITHTRAP)
113 IDTVEC(align)
114 TRAP(T_ALIGNFLT)
115 IDTVEC(xmm)
116 pushl $0; TRAP(T_XMMFLT)
117
118 /*
119 * alltraps entry point. Interrupts are enabled if this was a trap
120 * gate (TGT), else disabled if this was an interrupt gate (IGT).
121 * Note that int0x80_syscall is a trap gate. Interrupt gates are
122 * used by page faults, non-maskable interrupts, debug and breakpoint
123 * exceptions.
124 */
125
126 SUPERALIGN_TEXT
127 .globl alltraps
128 .type alltraps,@function
129 alltraps:
130 pushal
131 pushl %ds
132 pushl %es
133 pushl %fs
134 alltraps_with_regs_pushed:
135 SET_KERNEL_SREGS
136 FAKE_MCOUNT(TF_EIP(%esp))
137 calltrap:
138 pushl %esp
139 call trap
140 add $4, %esp
141
142 /*
143 * Return via doreti to handle ASTs.
144 */
145 MEXITCOUNT
146 jmp doreti
147
148 /*
149 * SYSCALL CALL GATE (old entry point for a.out binaries)
150 *
151 * The intersegment call has been set up to specify one dummy parameter.
152 *
153 * This leaves a place to put eflags so that the call frame can be
154 * converted to a trap frame. Note that the eflags is (semi-)bogusly
155 * pushed into (what will be) tf_err and then copied later into the
156 * final spot. It has to be done this way because esp can't be just
157 * temporarily altered for the pushfl - an interrupt might come in
158 * and clobber the saved cs/eip.
159 */
160 SUPERALIGN_TEXT
161 IDTVEC(lcall_syscall)
162 pushfl /* save eflags */
163 popl 8(%esp) /* shuffle into tf_eflags */
164 pushl $7 /* sizeof "lcall 7,0" */
165 subl $4,%esp /* skip over tf_trapno */
166 pushal
167 pushl %ds
168 pushl %es
169 pushl %fs
170 SET_KERNEL_SREGS
171 FAKE_MCOUNT(TF_EIP(%esp))
172 pushl %esp
173 call syscall
174 add $4, %esp
175 MEXITCOUNT
176 jmp doreti
177
178 /*
179 * Call gate entry for FreeBSD ELF and Linux/NetBSD syscall (int 0x80)
180 *
181 * Even though the name says 'int0x80', this is actually a TGT (trap gate)
182 * rather then an IGT (interrupt gate). Thus interrupts are enabled on
183 * entry just as they are for a normal syscall.
184 */
185 SUPERALIGN_TEXT
186 IDTVEC(int0x80_syscall)
187 pushl $2 /* sizeof "int 0x80" */
188 subl $4,%esp /* skip over tf_trapno */
189 pushal
190 pushl %ds
191 pushl %es
192 pushl %fs
193 SET_KERNEL_SREGS
194 FAKE_MCOUNT(TF_EIP(%esp))
195 pushl %esp
196 call syscall
197 add $4, %esp
198 MEXITCOUNT
199 jmp doreti
200
201 ENTRY(fork_trampoline)
202 pushl %esp /* trapframe pointer */
203 pushl %ebx /* arg1 */
204 pushl %esi /* function */
205 call fork_exit
206 addl $12,%esp
207 /* cut from syscall */
208
209 /*
210 * Return via doreti to handle ASTs.
211 */
212 MEXITCOUNT
213 jmp doreti
214
215
216 /*
217 * To efficiently implement classification of trap and interrupt handlers
218 * for profiling, there must be only trap handlers between the labels btrap
219 * and bintr, and only interrupt handlers between the labels bintr and
220 * eintr. This is implemented (partly) by including files that contain
221 * some of the handlers. Before including the files, set up a normal asm
222 * environment so that the included files doen't need to know that they are
223 * included.
224 */
225
226 .data
227 .p2align 4
228 .text
229 SUPERALIGN_TEXT
230 MCOUNT_LABEL(bintr)
231
232 #include <i386/isa/atpic_vector.s>
233
234 #ifdef DEV_APIC
235 .data
236 .p2align 4
237 .text
238 SUPERALIGN_TEXT
239
240 #include <i386/i386/apic_vector.s>
241 #endif
242
243 .data
244 .p2align 4
245 .text
246 SUPERALIGN_TEXT
247 #include <i386/i386/vm86bios.s>
248
249 .text
250 MCOUNT_LABEL(eintr)
251
252 /*
253 * void doreti(struct trapframe)
254 *
255 * Handle return from interrupts, traps and syscalls.
256 */
257 .text
258 SUPERALIGN_TEXT
259 .type doreti,@function
260 doreti:
261 FAKE_MCOUNT($bintr) /* init "from" bintr -> doreti */
262 doreti_next:
263 /*
264 * Check if ASTs can be handled now. PSL_VM must be checked first
265 * since segment registers only have an RPL in non-VM86 mode.
266 */
267 testl $PSL_VM,TF_EFLAGS(%esp) /* are we in vm86 mode? */
268 jz doreti_notvm86
269 movl PCPU(CURPCB),%ecx
270 testl $PCB_VM86CALL,PCB_FLAGS(%ecx) /* are we in a vm86 call? */
271 jz doreti_ast /* can handle ASTS now if not */
272 jmp doreti_exit
273
274 doreti_notvm86:
275 testb $SEL_RPL_MASK,TF_CS(%esp) /* are we returning to user mode? */
276 jz doreti_exit /* can't handle ASTs now if not */
277
278 doreti_ast:
279 /*
280 * Check for ASTs atomically with returning. Disabling CPU
281 * interrupts provides sufficient locking even in the SMP case,
282 * since we will be informed of any new ASTs by an IPI.
283 */
284 cli
285 movl PCPU(CURTHREAD),%eax
286 testl $TDF_ASTPENDING | TDF_NEEDRESCHED,TD_FLAGS(%eax)
287 je doreti_exit
288 sti
289 pushl %esp /* pass a pointer to the trapframe */
290 call ast
291 add $4,%esp
292 jmp doreti_ast
293
294 /*
295 * doreti_exit: pop registers, iret.
296 *
297 * The segment register pop is a special case, since it may
298 * fault if (for example) a sigreturn specifies bad segment
299 * registers. The fault is handled in trap.c.
300 */
301 doreti_exit:
302 MEXITCOUNT
303
304 .globl doreti_popl_fs
305 doreti_popl_fs:
306 popl %fs
307 .globl doreti_popl_es
308 doreti_popl_es:
309 popl %es
310 .globl doreti_popl_ds
311 doreti_popl_ds:
312 popl %ds
313 popal
314 addl $8,%esp
315 .globl doreti_iret
316 doreti_iret:
317 iret
318
319 /*
320 * doreti_iret_fault and friends. Alternative return code for
321 * the case where we get a fault in the doreti_exit code
322 * above. trap() (i386/i386/trap.c) catches this specific
323 * case, sends the process a signal and continues in the
324 * corresponding place in the code below.
325 */
326 ALIGN_TEXT
327 .globl doreti_iret_fault
328 doreti_iret_fault:
329 subl $8,%esp
330 pushal
331 pushl %ds
332 .globl doreti_popl_ds_fault
333 doreti_popl_ds_fault:
334 pushl %es
335 .globl doreti_popl_es_fault
336 doreti_popl_es_fault:
337 pushl %fs
338 .globl doreti_popl_fs_fault
339 doreti_popl_fs_fault:
340 movl $0,TF_ERR(%esp) /* XXX should be the error code */
341 movl $T_PROTFLT,TF_TRAPNO(%esp)
342 jmp alltraps_with_regs_pushed
Cache object: cabad3acd86d6e9a98c7b70edaf53f20
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