Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | ||
1da177e4 LT |
43 | #include <linux/linkage.h> |
44 | #include <asm/thread_info.h> | |
55f327fa | 45 | #include <asm/irqflags.h> |
1da177e4 LT |
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> | |
fe7cacc1 | 51 | #include <asm/dwarf2.h> |
1da177e4 LT |
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 | ||
0da5db31 RR |
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 | ||
1da177e4 | 86 | #ifdef CONFIG_PREEMPT |
0da5db31 | 87 | #define preempt_stop DISABLE_INTERRUPTS; TRACE_IRQS_OFF |
1da177e4 LT |
88 | #else |
89 | #define preempt_stop | |
90 | #define resume_kernel restore_nocheck | |
91 | #endif | |
92 | ||
55f327fa IM |
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 | ||
4031ff38 AG |
102 | #ifdef CONFIG_VM86 |
103 | #define resume_userspace_sig check_userspace | |
104 | #else | |
105 | #define resume_userspace_sig resume_userspace | |
106 | #endif | |
107 | ||
1da177e4 LT |
108 | #define SAVE_ALL \ |
109 | cld; \ | |
110 | pushl %es; \ | |
fe7cacc1 JB |
111 | CFI_ADJUST_CFA_OFFSET 4;\ |
112 | /*CFI_REL_OFFSET es, 0;*/\ | |
1da177e4 | 113 | pushl %ds; \ |
fe7cacc1 JB |
114 | CFI_ADJUST_CFA_OFFSET 4;\ |
115 | /*CFI_REL_OFFSET ds, 0;*/\ | |
1da177e4 | 116 | pushl %eax; \ |
fe7cacc1 JB |
117 | CFI_ADJUST_CFA_OFFSET 4;\ |
118 | CFI_REL_OFFSET eax, 0;\ | |
1da177e4 | 119 | pushl %ebp; \ |
fe7cacc1 JB |
120 | CFI_ADJUST_CFA_OFFSET 4;\ |
121 | CFI_REL_OFFSET ebp, 0;\ | |
1da177e4 | 122 | pushl %edi; \ |
fe7cacc1 JB |
123 | CFI_ADJUST_CFA_OFFSET 4;\ |
124 | CFI_REL_OFFSET edi, 0;\ | |
1da177e4 | 125 | pushl %esi; \ |
fe7cacc1 JB |
126 | CFI_ADJUST_CFA_OFFSET 4;\ |
127 | CFI_REL_OFFSET esi, 0;\ | |
1da177e4 | 128 | pushl %edx; \ |
fe7cacc1 JB |
129 | CFI_ADJUST_CFA_OFFSET 4;\ |
130 | CFI_REL_OFFSET edx, 0;\ | |
1da177e4 | 131 | pushl %ecx; \ |
fe7cacc1 JB |
132 | CFI_ADJUST_CFA_OFFSET 4;\ |
133 | CFI_REL_OFFSET ecx, 0;\ | |
1da177e4 | 134 | pushl %ebx; \ |
fe7cacc1 JB |
135 | CFI_ADJUST_CFA_OFFSET 4;\ |
136 | CFI_REL_OFFSET ebx, 0;\ | |
1da177e4 LT |
137 | movl $(__USER_DS), %edx; \ |
138 | movl %edx, %ds; \ | |
139 | movl %edx, %es; | |
140 | ||
141 | #define RESTORE_INT_REGS \ | |
142 | popl %ebx; \ | |
fe7cacc1 JB |
143 | CFI_ADJUST_CFA_OFFSET -4;\ |
144 | CFI_RESTORE ebx;\ | |
1da177e4 | 145 | popl %ecx; \ |
fe7cacc1 JB |
146 | CFI_ADJUST_CFA_OFFSET -4;\ |
147 | CFI_RESTORE ecx;\ | |
1da177e4 | 148 | popl %edx; \ |
fe7cacc1 JB |
149 | CFI_ADJUST_CFA_OFFSET -4;\ |
150 | CFI_RESTORE edx;\ | |
1da177e4 | 151 | popl %esi; \ |
fe7cacc1 JB |
152 | CFI_ADJUST_CFA_OFFSET -4;\ |
153 | CFI_RESTORE esi;\ | |
1da177e4 | 154 | popl %edi; \ |
fe7cacc1 JB |
155 | CFI_ADJUST_CFA_OFFSET -4;\ |
156 | CFI_RESTORE edi;\ | |
1da177e4 | 157 | popl %ebp; \ |
fe7cacc1 JB |
158 | CFI_ADJUST_CFA_OFFSET -4;\ |
159 | CFI_RESTORE ebp;\ | |
160 | popl %eax; \ | |
161 | CFI_ADJUST_CFA_OFFSET -4;\ | |
162 | CFI_RESTORE eax | |
1da177e4 LT |
163 | |
164 | #define RESTORE_REGS \ | |
165 | RESTORE_INT_REGS; \ | |
166 | 1: popl %ds; \ | |
fe7cacc1 JB |
167 | CFI_ADJUST_CFA_OFFSET -4;\ |
168 | /*CFI_RESTORE ds;*/\ | |
1da177e4 | 169 | 2: popl %es; \ |
fe7cacc1 JB |
170 | CFI_ADJUST_CFA_OFFSET -4;\ |
171 | /*CFI_RESTORE es;*/\ | |
1da177e4 LT |
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 | ||
fe7cacc1 JB |
184 | #define RING0_INT_FRAME \ |
185 | CFI_STARTPROC simple;\ | |
adf14236 | 186 | CFI_SIGNAL_FRAME;\ |
fe7cacc1 JB |
187 | CFI_DEF_CFA esp, 3*4;\ |
188 | /*CFI_OFFSET cs, -2*4;*/\ | |
189 | CFI_OFFSET eip, -3*4 | |
190 | ||
191 | #define RING0_EC_FRAME \ | |
192 | CFI_STARTPROC simple;\ | |
adf14236 | 193 | CFI_SIGNAL_FRAME;\ |
fe7cacc1 JB |
194 | CFI_DEF_CFA esp, 4*4;\ |
195 | /*CFI_OFFSET cs, -2*4;*/\ | |
196 | CFI_OFFSET eip, -3*4 | |
197 | ||
198 | #define RING0_PTREGS_FRAME \ | |
199 | CFI_STARTPROC simple;\ | |
adf14236 | 200 | CFI_SIGNAL_FRAME;\ |
fe7cacc1 JB |
201 | CFI_DEF_CFA esp, OLDESP-EBX;\ |
202 | /*CFI_OFFSET cs, CS-OLDESP;*/\ | |
203 | CFI_OFFSET eip, EIP-OLDESP;\ | |
204 | /*CFI_OFFSET es, ES-OLDESP;*/\ | |
205 | /*CFI_OFFSET ds, DS-OLDESP;*/\ | |
206 | CFI_OFFSET eax, EAX-OLDESP;\ | |
207 | CFI_OFFSET ebp, EBP-OLDESP;\ | |
208 | CFI_OFFSET edi, EDI-OLDESP;\ | |
209 | CFI_OFFSET esi, ESI-OLDESP;\ | |
210 | CFI_OFFSET edx, EDX-OLDESP;\ | |
211 | CFI_OFFSET ecx, ECX-OLDESP;\ | |
212 | CFI_OFFSET ebx, EBX-OLDESP | |
1da177e4 LT |
213 | |
214 | ENTRY(ret_from_fork) | |
fe7cacc1 | 215 | CFI_STARTPROC |
1da177e4 | 216 | pushl %eax |
25d7dfda | 217 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 LT |
218 | call schedule_tail |
219 | GET_THREAD_INFO(%ebp) | |
220 | popl %eax | |
fe7cacc1 | 221 | CFI_ADJUST_CFA_OFFSET -4 |
47a5c6fa LT |
222 | pushl $0x0202 # Reset kernel eflags |
223 | CFI_ADJUST_CFA_OFFSET 4 | |
224 | popfl | |
225 | CFI_ADJUST_CFA_OFFSET -4 | |
1da177e4 | 226 | jmp syscall_exit |
fe7cacc1 | 227 | CFI_ENDPROC |
1da177e4 LT |
228 | |
229 | /* | |
230 | * Return to user mode is not as complex as all this looks, | |
231 | * but we want the default path for a system call return to | |
232 | * go as quickly as possible which is why some of this is | |
233 | * less clear than it otherwise should be. | |
234 | */ | |
235 | ||
236 | # userspace resumption stub bypassing syscall exit tracing | |
237 | ALIGN | |
fe7cacc1 | 238 | RING0_PTREGS_FRAME |
1da177e4 LT |
239 | ret_from_exception: |
240 | preempt_stop | |
241 | ret_from_intr: | |
242 | GET_THREAD_INFO(%ebp) | |
4031ff38 | 243 | check_userspace: |
1da177e4 LT |
244 | movl EFLAGS(%esp), %eax # mix EFLAGS and CS |
245 | movb CS(%esp), %al | |
78be3706 RR |
246 | andl $(VM_MASK | SEGMENT_RPL_MASK), %eax |
247 | cmpl $USER_RPL, %eax | |
248 | jb resume_kernel # not returning to v8086 or userspace | |
1da177e4 | 249 | ENTRY(resume_userspace) |
0da5db31 | 250 | DISABLE_INTERRUPTS # make sure we don't miss an interrupt |
1da177e4 LT |
251 | # setting need_resched or sigpending |
252 | # between sampling and the iret | |
253 | movl TI_flags(%ebp), %ecx | |
254 | andl $_TIF_WORK_MASK, %ecx # is there any work to be done on | |
255 | # int/exception return? | |
256 | jne work_pending | |
257 | jmp restore_all | |
258 | ||
259 | #ifdef CONFIG_PREEMPT | |
260 | ENTRY(resume_kernel) | |
0da5db31 | 261 | DISABLE_INTERRUPTS |
1da177e4 LT |
262 | cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ? |
263 | jnz restore_nocheck | |
264 | need_resched: | |
265 | movl TI_flags(%ebp), %ecx # need_resched set ? | |
266 | testb $_TIF_NEED_RESCHED, %cl | |
267 | jz restore_all | |
268 | testl $IF_MASK,EFLAGS(%esp) # interrupts off (exception path) ? | |
269 | jz restore_all | |
270 | call preempt_schedule_irq | |
271 | jmp need_resched | |
272 | #endif | |
fe7cacc1 | 273 | CFI_ENDPROC |
1da177e4 LT |
274 | |
275 | /* SYSENTER_RETURN points to after the "sysenter" instruction in | |
276 | the vsyscall page. See vsyscall-sysentry.S, which defines the symbol. */ | |
277 | ||
278 | # sysenter call handler stub | |
279 | ENTRY(sysenter_entry) | |
fe7cacc1 | 280 | CFI_STARTPROC simple |
adf14236 | 281 | CFI_SIGNAL_FRAME |
fe7cacc1 JB |
282 | CFI_DEF_CFA esp, 0 |
283 | CFI_REGISTER esp, ebp | |
1da177e4 LT |
284 | movl TSS_sysenter_esp0(%esp),%esp |
285 | sysenter_past_esp: | |
55f327fa IM |
286 | /* |
287 | * No need to follow this irqs on/off section: the syscall | |
288 | * disabled irqs and here we enable it straight after entry: | |
289 | */ | |
0da5db31 | 290 | ENABLE_INTERRUPTS |
1da177e4 | 291 | pushl $(__USER_DS) |
fe7cacc1 JB |
292 | CFI_ADJUST_CFA_OFFSET 4 |
293 | /*CFI_REL_OFFSET ss, 0*/ | |
1da177e4 | 294 | pushl %ebp |
fe7cacc1 JB |
295 | CFI_ADJUST_CFA_OFFSET 4 |
296 | CFI_REL_OFFSET esp, 0 | |
1da177e4 | 297 | pushfl |
fe7cacc1 | 298 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 | 299 | pushl $(__USER_CS) |
fe7cacc1 JB |
300 | CFI_ADJUST_CFA_OFFSET 4 |
301 | /*CFI_REL_OFFSET cs, 0*/ | |
e6e5494c IM |
302 | /* |
303 | * Push current_thread_info()->sysenter_return to the stack. | |
304 | * A tiny bit of offset fixup is necessary - 4*4 means the 4 words | |
305 | * pushed above; +8 corresponds to copy_thread's esp0 setting. | |
306 | */ | |
307 | pushl (TI_sysenter_return-THREAD_SIZE+8+4*4)(%esp) | |
fe7cacc1 JB |
308 | CFI_ADJUST_CFA_OFFSET 4 |
309 | CFI_REL_OFFSET eip, 0 | |
1da177e4 LT |
310 | |
311 | /* | |
312 | * Load the potential sixth argument from user stack. | |
313 | * Careful about security. | |
314 | */ | |
315 | cmpl $__PAGE_OFFSET-3,%ebp | |
316 | jae syscall_fault | |
317 | 1: movl (%ebp),%ebp | |
318 | .section __ex_table,"a" | |
319 | .align 4 | |
320 | .long 1b,syscall_fault | |
321 | .previous | |
322 | ||
323 | pushl %eax | |
fe7cacc1 | 324 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 LT |
325 | SAVE_ALL |
326 | GET_THREAD_INFO(%ebp) | |
327 | ||
328 | /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */ | |
ed75e8d5 | 329 | testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp) |
1da177e4 LT |
330 | jnz syscall_trace_entry |
331 | cmpl $(nr_syscalls), %eax | |
332 | jae syscall_badsys | |
333 | call *sys_call_table(,%eax,4) | |
334 | movl %eax,EAX(%esp) | |
0da5db31 | 335 | DISABLE_INTERRUPTS |
55f327fa | 336 | TRACE_IRQS_OFF |
1da177e4 LT |
337 | movl TI_flags(%ebp), %ecx |
338 | testw $_TIF_ALLWORK_MASK, %cx | |
339 | jne syscall_exit_work | |
340 | /* if something modifies registers it must also disable sysexit */ | |
341 | movl EIP(%esp), %edx | |
342 | movl OLDESP(%esp), %ecx | |
343 | xorl %ebp,%ebp | |
55f327fa | 344 | TRACE_IRQS_ON |
0da5db31 | 345 | ENABLE_INTERRUPTS_SYSEXIT |
fe7cacc1 | 346 | CFI_ENDPROC |
1da177e4 LT |
347 | |
348 | ||
349 | # system call handler stub | |
350 | ENTRY(system_call) | |
fe7cacc1 | 351 | RING0_INT_FRAME # can't unwind into user space anyway |
1da177e4 | 352 | pushl %eax # save orig_eax |
fe7cacc1 | 353 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 LT |
354 | SAVE_ALL |
355 | GET_THREAD_INFO(%ebp) | |
635cf99a CE |
356 | testl $TF_MASK,EFLAGS(%esp) |
357 | jz no_singlestep | |
358 | orl $_TIF_SINGLESTEP,TI_flags(%ebp) | |
359 | no_singlestep: | |
ed75e8d5 | 360 | # system call tracing in operation / emulation |
1da177e4 | 361 | /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */ |
ed75e8d5 | 362 | testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp) |
1da177e4 LT |
363 | jnz syscall_trace_entry |
364 | cmpl $(nr_syscalls), %eax | |
365 | jae syscall_badsys | |
366 | syscall_call: | |
367 | call *sys_call_table(,%eax,4) | |
368 | movl %eax,EAX(%esp) # store the return value | |
369 | syscall_exit: | |
0da5db31 | 370 | DISABLE_INTERRUPTS # make sure we don't miss an interrupt |
1da177e4 LT |
371 | # setting need_resched or sigpending |
372 | # between sampling and the iret | |
55f327fa | 373 | TRACE_IRQS_OFF |
1da177e4 LT |
374 | movl TI_flags(%ebp), %ecx |
375 | testw $_TIF_ALLWORK_MASK, %cx # current->work | |
376 | jne syscall_exit_work | |
377 | ||
378 | restore_all: | |
379 | movl EFLAGS(%esp), %eax # mix EFLAGS, SS and CS | |
5df24082 SS |
380 | # Warning: OLDSS(%esp) contains the wrong/random values if we |
381 | # are returning to the kernel. | |
382 | # See comments in process.c:copy_thread() for details. | |
1da177e4 LT |
383 | movb OLDSS(%esp), %ah |
384 | movb CS(%esp), %al | |
78be3706 RR |
385 | andl $(VM_MASK | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax |
386 | cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax | |
fe7cacc1 | 387 | CFI_REMEMBER_STATE |
1da177e4 LT |
388 | je ldt_ss # returning to user-space with LDT SS |
389 | restore_nocheck: | |
55f327fa IM |
390 | TRACE_IRQS_IRET |
391 | restore_nocheck_notrace: | |
1da177e4 LT |
392 | RESTORE_REGS |
393 | addl $4, %esp | |
fe7cacc1 | 394 | CFI_ADJUST_CFA_OFFSET -4 |
0da5db31 | 395 | 1: INTERRUPT_RETURN |
1da177e4 LT |
396 | .section .fixup,"ax" |
397 | iret_exc: | |
55f327fa | 398 | TRACE_IRQS_ON |
0da5db31 | 399 | ENABLE_INTERRUPTS |
a879cbbb LT |
400 | pushl $0 # no error code |
401 | pushl $do_iret_error | |
402 | jmp error_code | |
1da177e4 LT |
403 | .previous |
404 | .section __ex_table,"a" | |
405 | .align 4 | |
406 | .long 1b,iret_exc | |
407 | .previous | |
408 | ||
fe7cacc1 | 409 | CFI_RESTORE_STATE |
1da177e4 LT |
410 | ldt_ss: |
411 | larl OLDSS(%esp), %eax | |
412 | jnz restore_nocheck | |
413 | testl $0x00400000, %eax # returning to 32bit stack? | |
414 | jnz restore_nocheck # allright, normal return | |
415 | /* If returning to userspace with 16bit stack, | |
416 | * try to fix the higher word of ESP, as the CPU | |
417 | * won't restore it. | |
418 | * This is an "official" bug of all the x86-compatible | |
419 | * CPUs, which we can try to work around to make | |
420 | * dosemu and wine happy. */ | |
421 | subl $8, %esp # reserve space for switch16 pointer | |
fe7cacc1 | 422 | CFI_ADJUST_CFA_OFFSET 8 |
0da5db31 | 423 | DISABLE_INTERRUPTS |
55f327fa | 424 | TRACE_IRQS_OFF |
1da177e4 LT |
425 | movl %esp, %eax |
426 | /* Set up the 16bit stack frame with switch32 pointer on top, | |
427 | * and a switch16 pointer on top of the current frame. */ | |
428 | call setup_x86_bogus_stack | |
fe7cacc1 | 429 | CFI_ADJUST_CFA_OFFSET -8 # frame has moved |
55f327fa | 430 | TRACE_IRQS_IRET |
1da177e4 LT |
431 | RESTORE_REGS |
432 | lss 20+4(%esp), %esp # switch to 16bit stack | |
0da5db31 | 433 | 1: INTERRUPT_RETURN |
1da177e4 LT |
434 | .section __ex_table,"a" |
435 | .align 4 | |
436 | .long 1b,iret_exc | |
437 | .previous | |
fe7cacc1 | 438 | CFI_ENDPROC |
1da177e4 LT |
439 | |
440 | # perform work that needs to be done immediately before resumption | |
441 | ALIGN | |
fe7cacc1 | 442 | RING0_PTREGS_FRAME # can't unwind into user space anyway |
1da177e4 LT |
443 | work_pending: |
444 | testb $_TIF_NEED_RESCHED, %cl | |
445 | jz work_notifysig | |
446 | work_resched: | |
447 | call schedule | |
0da5db31 | 448 | DISABLE_INTERRUPTS # make sure we don't miss an interrupt |
1da177e4 LT |
449 | # setting need_resched or sigpending |
450 | # between sampling and the iret | |
55f327fa | 451 | TRACE_IRQS_OFF |
1da177e4 LT |
452 | movl TI_flags(%ebp), %ecx |
453 | andl $_TIF_WORK_MASK, %ecx # is there any work to be done other | |
454 | # than syscall tracing? | |
455 | jz restore_all | |
456 | testb $_TIF_NEED_RESCHED, %cl | |
457 | jnz work_resched | |
458 | ||
459 | work_notifysig: # deal with pending signals and | |
460 | # notify-resume requests | |
461 | testl $VM_MASK, EFLAGS(%esp) | |
462 | movl %esp, %eax | |
463 | jne work_notifysig_v86 # returning to kernel-space or | |
464 | # vm86-space | |
465 | xorl %edx, %edx | |
466 | call do_notify_resume | |
4031ff38 | 467 | jmp resume_userspace_sig |
1da177e4 LT |
468 | |
469 | ALIGN | |
470 | work_notifysig_v86: | |
64ca9004 | 471 | #ifdef CONFIG_VM86 |
1da177e4 | 472 | pushl %ecx # save ti_flags for do_notify_resume |
fe7cacc1 | 473 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 LT |
474 | call save_v86_state # %eax contains pt_regs pointer |
475 | popl %ecx | |
fe7cacc1 | 476 | CFI_ADJUST_CFA_OFFSET -4 |
1da177e4 LT |
477 | movl %eax, %esp |
478 | xorl %edx, %edx | |
479 | call do_notify_resume | |
4031ff38 | 480 | jmp resume_userspace_sig |
64ca9004 | 481 | #endif |
1da177e4 LT |
482 | |
483 | # perform syscall exit tracing | |
484 | ALIGN | |
485 | syscall_trace_entry: | |
486 | movl $-ENOSYS,EAX(%esp) | |
487 | movl %esp, %eax | |
488 | xorl %edx,%edx | |
489 | call do_syscall_trace | |
ed75e8d5 | 490 | cmpl $0, %eax |
640aa46e | 491 | jne resume_userspace # ret != 0 -> running under PTRACE_SYSEMU, |
ed75e8d5 | 492 | # so must skip actual syscall |
1da177e4 LT |
493 | movl ORIG_EAX(%esp), %eax |
494 | cmpl $(nr_syscalls), %eax | |
495 | jnae syscall_call | |
496 | jmp syscall_exit | |
497 | ||
498 | # perform syscall exit tracing | |
499 | ALIGN | |
500 | syscall_exit_work: | |
501 | testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl | |
502 | jz work_pending | |
55f327fa | 503 | TRACE_IRQS_ON |
0da5db31 | 504 | ENABLE_INTERRUPTS # could let do_syscall_trace() call |
1da177e4 LT |
505 | # schedule() instead |
506 | movl %esp, %eax | |
507 | movl $1, %edx | |
508 | call do_syscall_trace | |
509 | jmp resume_userspace | |
fe7cacc1 | 510 | CFI_ENDPROC |
1da177e4 | 511 | |
fe7cacc1 | 512 | RING0_INT_FRAME # can't unwind into user space anyway |
1da177e4 LT |
513 | syscall_fault: |
514 | pushl %eax # save orig_eax | |
fe7cacc1 | 515 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 LT |
516 | SAVE_ALL |
517 | GET_THREAD_INFO(%ebp) | |
518 | movl $-EFAULT,EAX(%esp) | |
519 | jmp resume_userspace | |
520 | ||
1da177e4 LT |
521 | syscall_badsys: |
522 | movl $-ENOSYS,EAX(%esp) | |
523 | jmp resume_userspace | |
fe7cacc1 | 524 | CFI_ENDPROC |
1da177e4 LT |
525 | |
526 | #define FIXUP_ESPFIX_STACK \ | |
527 | movl %esp, %eax; \ | |
528 | /* switch to 32bit stack using the pointer on top of 16bit stack */ \ | |
529 | lss %ss:CPU_16BIT_STACK_SIZE-8, %esp; \ | |
530 | /* copy data from 16bit stack to 32bit stack */ \ | |
531 | call fixup_x86_bogus_stack; \ | |
532 | /* put ESP to the proper location */ \ | |
533 | movl %eax, %esp; | |
534 | #define UNWIND_ESPFIX_STACK \ | |
535 | pushl %eax; \ | |
fe7cacc1 | 536 | CFI_ADJUST_CFA_OFFSET 4; \ |
1da177e4 LT |
537 | movl %ss, %eax; \ |
538 | /* see if on 16bit stack */ \ | |
539 | cmpw $__ESPFIX_SS, %ax; \ | |
fe7cacc1 JB |
540 | je 28f; \ |
541 | 27: popl %eax; \ | |
542 | CFI_ADJUST_CFA_OFFSET -4; \ | |
543 | .section .fixup,"ax"; \ | |
544 | 28: movl $__KERNEL_DS, %eax; \ | |
545 | movl %eax, %ds; \ | |
546 | movl %eax, %es; \ | |
1da177e4 | 547 | /* switch to 32bit stack */ \ |
fe7cacc1 JB |
548 | FIXUP_ESPFIX_STACK; \ |
549 | jmp 27b; \ | |
550 | .previous | |
1da177e4 LT |
551 | |
552 | /* | |
553 | * Build the entry stubs and pointer table with | |
554 | * some assembler magic. | |
555 | */ | |
556 | .data | |
557 | ENTRY(interrupt) | |
558 | .text | |
559 | ||
560 | vector=0 | |
561 | ENTRY(irq_entries_start) | |
fe7cacc1 | 562 | RING0_INT_FRAME |
1da177e4 LT |
563 | .rept NR_IRQS |
564 | ALIGN | |
fe7cacc1 JB |
565 | .if vector |
566 | CFI_ADJUST_CFA_OFFSET -4 | |
567 | .endif | |
19eadf98 | 568 | 1: pushl $~(vector) |
fe7cacc1 | 569 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 LT |
570 | jmp common_interrupt |
571 | .data | |
572 | .long 1b | |
573 | .text | |
574 | vector=vector+1 | |
575 | .endr | |
576 | ||
55f327fa IM |
577 | /* |
578 | * the CPU automatically disables interrupts when executing an IRQ vector, | |
579 | * so IRQ-flags tracing has to follow that: | |
580 | */ | |
1da177e4 LT |
581 | ALIGN |
582 | common_interrupt: | |
583 | SAVE_ALL | |
55f327fa | 584 | TRACE_IRQS_OFF |
1da177e4 LT |
585 | movl %esp,%eax |
586 | call do_IRQ | |
587 | jmp ret_from_intr | |
fe7cacc1 | 588 | CFI_ENDPROC |
1da177e4 LT |
589 | |
590 | #define BUILD_INTERRUPT(name, nr) \ | |
591 | ENTRY(name) \ | |
fe7cacc1 | 592 | RING0_INT_FRAME; \ |
19eadf98 | 593 | pushl $~(nr); \ |
fe7cacc1 JB |
594 | CFI_ADJUST_CFA_OFFSET 4; \ |
595 | SAVE_ALL; \ | |
55f327fa | 596 | TRACE_IRQS_OFF \ |
1da177e4 LT |
597 | movl %esp,%eax; \ |
598 | call smp_/**/name; \ | |
55f327fa | 599 | jmp ret_from_intr; \ |
fe7cacc1 | 600 | CFI_ENDPROC |
1da177e4 LT |
601 | |
602 | /* The include is where all of the SMP etc. interrupts come from */ | |
603 | #include "entry_arch.h" | |
604 | ||
d28c4393 P |
605 | KPROBE_ENTRY(page_fault) |
606 | RING0_EC_FRAME | |
607 | pushl $do_page_fault | |
fe7cacc1 | 608 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 LT |
609 | ALIGN |
610 | error_code: | |
611 | pushl %ds | |
fe7cacc1 JB |
612 | CFI_ADJUST_CFA_OFFSET 4 |
613 | /*CFI_REL_OFFSET ds, 0*/ | |
1da177e4 | 614 | pushl %eax |
fe7cacc1 JB |
615 | CFI_ADJUST_CFA_OFFSET 4 |
616 | CFI_REL_OFFSET eax, 0 | |
1da177e4 LT |
617 | xorl %eax, %eax |
618 | pushl %ebp | |
fe7cacc1 JB |
619 | CFI_ADJUST_CFA_OFFSET 4 |
620 | CFI_REL_OFFSET ebp, 0 | |
1da177e4 | 621 | pushl %edi |
fe7cacc1 JB |
622 | CFI_ADJUST_CFA_OFFSET 4 |
623 | CFI_REL_OFFSET edi, 0 | |
1da177e4 | 624 | pushl %esi |
fe7cacc1 JB |
625 | CFI_ADJUST_CFA_OFFSET 4 |
626 | CFI_REL_OFFSET esi, 0 | |
1da177e4 | 627 | pushl %edx |
fe7cacc1 JB |
628 | CFI_ADJUST_CFA_OFFSET 4 |
629 | CFI_REL_OFFSET edx, 0 | |
1da177e4 LT |
630 | decl %eax # eax = -1 |
631 | pushl %ecx | |
fe7cacc1 JB |
632 | CFI_ADJUST_CFA_OFFSET 4 |
633 | CFI_REL_OFFSET ecx, 0 | |
1da177e4 | 634 | pushl %ebx |
fe7cacc1 JB |
635 | CFI_ADJUST_CFA_OFFSET 4 |
636 | CFI_REL_OFFSET ebx, 0 | |
1da177e4 LT |
637 | cld |
638 | pushl %es | |
fe7cacc1 JB |
639 | CFI_ADJUST_CFA_OFFSET 4 |
640 | /*CFI_REL_OFFSET es, 0*/ | |
1da177e4 LT |
641 | UNWIND_ESPFIX_STACK |
642 | popl %ecx | |
fe7cacc1 JB |
643 | CFI_ADJUST_CFA_OFFSET -4 |
644 | /*CFI_REGISTER es, ecx*/ | |
1da177e4 LT |
645 | movl ES(%esp), %edi # get the function address |
646 | movl ORIG_EAX(%esp), %edx # get the error code | |
647 | movl %eax, ORIG_EAX(%esp) | |
648 | movl %ecx, ES(%esp) | |
fe7cacc1 | 649 | /*CFI_REL_OFFSET es, ES*/ |
1da177e4 LT |
650 | movl $(__USER_DS), %ecx |
651 | movl %ecx, %ds | |
652 | movl %ecx, %es | |
653 | movl %esp,%eax # pt_regs pointer | |
654 | call *%edi | |
655 | jmp ret_from_exception | |
fe7cacc1 | 656 | CFI_ENDPROC |
d28c4393 | 657 | KPROBE_END(page_fault) |
1da177e4 LT |
658 | |
659 | ENTRY(coprocessor_error) | |
fe7cacc1 | 660 | RING0_INT_FRAME |
1da177e4 | 661 | pushl $0 |
fe7cacc1 | 662 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 | 663 | pushl $do_coprocessor_error |
fe7cacc1 | 664 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 | 665 | jmp error_code |
fe7cacc1 | 666 | CFI_ENDPROC |
1da177e4 LT |
667 | |
668 | ENTRY(simd_coprocessor_error) | |
fe7cacc1 | 669 | RING0_INT_FRAME |
1da177e4 | 670 | pushl $0 |
fe7cacc1 | 671 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 | 672 | pushl $do_simd_coprocessor_error |
fe7cacc1 | 673 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 | 674 | jmp error_code |
fe7cacc1 | 675 | CFI_ENDPROC |
1da177e4 LT |
676 | |
677 | ENTRY(device_not_available) | |
fe7cacc1 | 678 | RING0_INT_FRAME |
1da177e4 | 679 | pushl $-1 # mark this as an int |
fe7cacc1 | 680 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 | 681 | SAVE_ALL |
0da5db31 | 682 | GET_CR0_INTO_EAX |
1da177e4 LT |
683 | testl $0x4, %eax # EM (math emulation bit) |
684 | jne device_not_available_emulate | |
685 | preempt_stop | |
686 | call math_state_restore | |
687 | jmp ret_from_exception | |
688 | device_not_available_emulate: | |
689 | pushl $0 # temporary storage for ORIG_EIP | |
fe7cacc1 | 690 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 LT |
691 | call math_emulate |
692 | addl $4, %esp | |
fe7cacc1 | 693 | CFI_ADJUST_CFA_OFFSET -4 |
1da177e4 | 694 | jmp ret_from_exception |
fe7cacc1 | 695 | CFI_ENDPROC |
1da177e4 LT |
696 | |
697 | /* | |
698 | * Debug traps and NMI can happen at the one SYSENTER instruction | |
699 | * that sets up the real kernel stack. Check here, since we can't | |
700 | * allow the wrong stack to be used. | |
701 | * | |
702 | * "TSS_sysenter_esp0+12" is because the NMI/debug handler will have | |
703 | * already pushed 3 words if it hits on the sysenter instruction: | |
704 | * eflags, cs and eip. | |
705 | * | |
706 | * We just load the right stack, and push the three (known) values | |
707 | * by hand onto the new stack - while updating the return eip past | |
708 | * the instruction that would have done it for sysenter. | |
709 | */ | |
710 | #define FIX_STACK(offset, ok, label) \ | |
711 | cmpw $__KERNEL_CS,4(%esp); \ | |
712 | jne ok; \ | |
713 | label: \ | |
714 | movl TSS_sysenter_esp0+offset(%esp),%esp; \ | |
a549b86d CE |
715 | CFI_DEF_CFA esp, 0; \ |
716 | CFI_UNDEFINED eip; \ | |
1da177e4 | 717 | pushfl; \ |
a549b86d | 718 | CFI_ADJUST_CFA_OFFSET 4; \ |
1da177e4 | 719 | pushl $__KERNEL_CS; \ |
a549b86d CE |
720 | CFI_ADJUST_CFA_OFFSET 4; \ |
721 | pushl $sysenter_past_esp; \ | |
722 | CFI_ADJUST_CFA_OFFSET 4; \ | |
723 | CFI_REL_OFFSET eip, 0 | |
1da177e4 | 724 | |
3d97ae5b | 725 | KPROBE_ENTRY(debug) |
fe7cacc1 | 726 | RING0_INT_FRAME |
1da177e4 LT |
727 | cmpl $sysenter_entry,(%esp) |
728 | jne debug_stack_correct | |
729 | FIX_STACK(12, debug_stack_correct, debug_esp_fix_insn) | |
730 | debug_stack_correct: | |
731 | pushl $-1 # mark this as an int | |
fe7cacc1 | 732 | CFI_ADJUST_CFA_OFFSET 4 |
1da177e4 LT |
733 | SAVE_ALL |
734 | xorl %edx,%edx # error code 0 | |
735 | movl %esp,%eax # pt_regs pointer | |
736 | call do_debug | |
1da177e4 | 737 | jmp ret_from_exception |
fe7cacc1 | 738 | CFI_ENDPROC |
d28c4393 P |
739 | KPROBE_END(debug) |
740 | ||
1da177e4 LT |
741 | /* |
742 | * NMI is doubly nasty. It can happen _while_ we're handling | |
743 | * a debug fault, and the debug fault hasn't yet been able to | |
744 | * clear up the stack. So we first check whether we got an | |
745 | * NMI on the sysenter entry path, but after that we need to | |
746 | * check whether we got an NMI on the debug path where the debug | |
747 | * fault happened on the sysenter path. | |
748 | */ | |