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Commit | Line | Data |
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1da177e4 | 1 | /* |
a49976d1 | 2 | * Copyright (C) 1991,1992 Linus Torvalds |
1da177e4 | 3 | * |
a49976d1 | 4 | * entry_32.S contains the system-call and low-level fault and trap handling routines. |
1da177e4 | 5 | * |
39e8701f | 6 | * Stack layout while running C code: |
a49976d1 IM |
7 | * ptrace needs to have all registers on the stack. |
8 | * If the order here is changed, it needs to be | |
9 | * updated in fork.c:copy_process(), signal.c:do_signal(), | |
1da177e4 LT |
10 | * ptrace.c and ptrace.h |
11 | * | |
12 | * 0(%esp) - %ebx | |
13 | * 4(%esp) - %ecx | |
14 | * 8(%esp) - %edx | |
9b47feb7 | 15 | * C(%esp) - %esi |
1da177e4 LT |
16 | * 10(%esp) - %edi |
17 | * 14(%esp) - %ebp | |
18 | * 18(%esp) - %eax | |
19 | * 1C(%esp) - %ds | |
20 | * 20(%esp) - %es | |
464d1a78 | 21 | * 24(%esp) - %fs |
ccbeed3a TH |
22 | * 28(%esp) - %gs saved iff !CONFIG_X86_32_LAZY_GS |
23 | * 2C(%esp) - orig_eax | |
24 | * 30(%esp) - %eip | |
25 | * 34(%esp) - %cs | |
26 | * 38(%esp) - %eflags | |
27 | * 3C(%esp) - %oldesp | |
28 | * 40(%esp) - %oldss | |
1da177e4 LT |
29 | */ |
30 | ||
1da177e4 | 31 | #include <linux/linkage.h> |
d7e7528b | 32 | #include <linux/err.h> |
1da177e4 | 33 | #include <asm/thread_info.h> |
55f327fa | 34 | #include <asm/irqflags.h> |
1da177e4 LT |
35 | #include <asm/errno.h> |
36 | #include <asm/segment.h> | |
37 | #include <asm/smp.h> | |
0341c14d | 38 | #include <asm/page_types.h> |
be44d2aa | 39 | #include <asm/percpu.h> |
ab68ed98 | 40 | #include <asm/processor-flags.h> |
395a59d0 | 41 | #include <asm/ftrace.h> |
9b7dc567 | 42 | #include <asm/irq_vectors.h> |
cd4d09ec | 43 | #include <asm/cpufeatures.h> |
b4ca46e4 | 44 | #include <asm/alternative-asm.h> |
6837a54d | 45 | #include <asm/asm.h> |
e59d1b0a | 46 | #include <asm/smap.h> |
784d5699 | 47 | #include <asm/export.h> |
1da177e4 | 48 | |
ea714547 JO |
49 | .section .entry.text, "ax" |
50 | ||
139ec7c4 RR |
51 | /* |
52 | * We use macros for low-level operations which need to be overridden | |
53 | * for paravirtualization. The following will never clobber any registers: | |
54 | * INTERRUPT_RETURN (aka. "iret") | |
55 | * GET_CR0_INTO_EAX (aka. "movl %cr0, %eax") | |
d75cd22f | 56 | * ENABLE_INTERRUPTS_SYSEXIT (aka "sti; sysexit"). |
139ec7c4 RR |
57 | * |
58 | * For DISABLE_INTERRUPTS/ENABLE_INTERRUPTS (aka "cli"/"sti"), you must | |
59 | * specify what registers can be overwritten (CLBR_NONE, CLBR_EAX/EDX/ECX/ANY). | |
60 | * Allowing a register to be clobbered can shrink the paravirt replacement | |
61 | * enough to patch inline, increasing performance. | |
62 | */ | |
63 | ||
1da177e4 | 64 | #ifdef CONFIG_PREEMPT |
a49976d1 | 65 | # define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF |
1da177e4 | 66 | #else |
a49976d1 IM |
67 | # define preempt_stop(clobbers) |
68 | # define resume_kernel restore_all | |
1da177e4 LT |
69 | #endif |
70 | ||
55f327fa IM |
71 | .macro TRACE_IRQS_IRET |
72 | #ifdef CONFIG_TRACE_IRQFLAGS | |
a49976d1 IM |
73 | testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off? |
74 | jz 1f | |
55f327fa IM |
75 | TRACE_IRQS_ON |
76 | 1: | |
77 | #endif | |
78 | .endm | |
79 | ||
ccbeed3a TH |
80 | /* |
81 | * User gs save/restore | |
82 | * | |
83 | * %gs is used for userland TLS and kernel only uses it for stack | |
84 | * canary which is required to be at %gs:20 by gcc. Read the comment | |
85 | * at the top of stackprotector.h for more info. | |
86 | * | |
87 | * Local labels 98 and 99 are used. | |
88 | */ | |
89 | #ifdef CONFIG_X86_32_LAZY_GS | |
90 | ||
91 | /* unfortunately push/pop can't be no-op */ | |
92 | .macro PUSH_GS | |
a49976d1 | 93 | pushl $0 |
ccbeed3a TH |
94 | .endm |
95 | .macro POP_GS pop=0 | |
a49976d1 | 96 | addl $(4 + \pop), %esp |
ccbeed3a TH |
97 | .endm |
98 | .macro POP_GS_EX | |
99 | .endm | |
100 | ||
101 | /* all the rest are no-op */ | |
102 | .macro PTGS_TO_GS | |
103 | .endm | |
104 | .macro PTGS_TO_GS_EX | |
105 | .endm | |
106 | .macro GS_TO_REG reg | |
107 | .endm | |
108 | .macro REG_TO_PTGS reg | |
109 | .endm | |
110 | .macro SET_KERNEL_GS reg | |
111 | .endm | |
112 | ||
113 | #else /* CONFIG_X86_32_LAZY_GS */ | |
114 | ||
115 | .macro PUSH_GS | |
a49976d1 | 116 | pushl %gs |
ccbeed3a TH |
117 | .endm |
118 | ||
119 | .macro POP_GS pop=0 | |
a49976d1 | 120 | 98: popl %gs |
ccbeed3a | 121 | .if \pop <> 0 |
9b47feb7 | 122 | add $\pop, %esp |
ccbeed3a TH |
123 | .endif |
124 | .endm | |
125 | .macro POP_GS_EX | |
126 | .pushsection .fixup, "ax" | |
a49976d1 IM |
127 | 99: movl $0, (%esp) |
128 | jmp 98b | |
ccbeed3a | 129 | .popsection |
a49976d1 | 130 | _ASM_EXTABLE(98b, 99b) |
ccbeed3a TH |
131 | .endm |
132 | ||
133 | .macro PTGS_TO_GS | |
a49976d1 | 134 | 98: mov PT_GS(%esp), %gs |
ccbeed3a TH |
135 | .endm |
136 | .macro PTGS_TO_GS_EX | |
137 | .pushsection .fixup, "ax" | |
a49976d1 IM |
138 | 99: movl $0, PT_GS(%esp) |
139 | jmp 98b | |
ccbeed3a | 140 | .popsection |
a49976d1 | 141 | _ASM_EXTABLE(98b, 99b) |
ccbeed3a TH |
142 | .endm |
143 | ||
144 | .macro GS_TO_REG reg | |
a49976d1 | 145 | movl %gs, \reg |
ccbeed3a TH |
146 | .endm |
147 | .macro REG_TO_PTGS reg | |
a49976d1 | 148 | movl \reg, PT_GS(%esp) |
ccbeed3a TH |
149 | .endm |
150 | .macro SET_KERNEL_GS reg | |
a49976d1 IM |
151 | movl $(__KERNEL_STACK_CANARY), \reg |
152 | movl \reg, %gs | |
ccbeed3a TH |
153 | .endm |
154 | ||
a49976d1 | 155 | #endif /* CONFIG_X86_32_LAZY_GS */ |
ccbeed3a | 156 | |
150ac78d | 157 | .macro SAVE_ALL pt_regs_ax=%eax |
f0d96110 | 158 | cld |
ccbeed3a | 159 | PUSH_GS |
a49976d1 IM |
160 | pushl %fs |
161 | pushl %es | |
162 | pushl %ds | |
150ac78d | 163 | pushl \pt_regs_ax |
a49976d1 IM |
164 | pushl %ebp |
165 | pushl %edi | |
166 | pushl %esi | |
167 | pushl %edx | |
168 | pushl %ecx | |
169 | pushl %ebx | |
170 | movl $(__USER_DS), %edx | |
171 | movl %edx, %ds | |
172 | movl %edx, %es | |
173 | movl $(__KERNEL_PERCPU), %edx | |
174 | movl %edx, %fs | |
ccbeed3a | 175 | SET_KERNEL_GS %edx |
f0d96110 | 176 | .endm |
1da177e4 | 177 | |
f0d96110 | 178 | .macro RESTORE_INT_REGS |
a49976d1 IM |
179 | popl %ebx |
180 | popl %ecx | |
181 | popl %edx | |
182 | popl %esi | |
183 | popl %edi | |
184 | popl %ebp | |
185 | popl %eax | |
f0d96110 | 186 | .endm |
1da177e4 | 187 | |
ccbeed3a | 188 | .macro RESTORE_REGS pop=0 |
f0d96110 | 189 | RESTORE_INT_REGS |
a49976d1 IM |
190 | 1: popl %ds |
191 | 2: popl %es | |
192 | 3: popl %fs | |
ccbeed3a | 193 | POP_GS \pop |
f0d96110 | 194 | .pushsection .fixup, "ax" |
a49976d1 IM |
195 | 4: movl $0, (%esp) |
196 | jmp 1b | |
197 | 5: movl $0, (%esp) | |
198 | jmp 2b | |
199 | 6: movl $0, (%esp) | |
200 | jmp 3b | |
f95d47ca | 201 | .popsection |
a49976d1 IM |
202 | _ASM_EXTABLE(1b, 4b) |
203 | _ASM_EXTABLE(2b, 5b) | |
204 | _ASM_EXTABLE(3b, 6b) | |
ccbeed3a | 205 | POP_GS_EX |
f0d96110 | 206 | .endm |
1da177e4 | 207 | |
0100301b BG |
208 | /* |
209 | * %eax: prev task | |
210 | * %edx: next task | |
211 | */ | |
212 | ENTRY(__switch_to_asm) | |
213 | /* | |
214 | * Save callee-saved registers | |
215 | * This must match the order in struct inactive_task_frame | |
216 | */ | |
217 | pushl %ebp | |
218 | pushl %ebx | |
219 | pushl %edi | |
220 | pushl %esi | |
221 | ||
222 | /* switch stack */ | |
223 | movl %esp, TASK_threadsp(%eax) | |
224 | movl TASK_threadsp(%edx), %esp | |
225 | ||
226 | #ifdef CONFIG_CC_STACKPROTECTOR | |
227 | movl TASK_stack_canary(%edx), %ebx | |
228 | movl %ebx, PER_CPU_VAR(stack_canary)+stack_canary_offset | |
229 | #endif | |
230 | ||
231 | /* restore callee-saved registers */ | |
232 | popl %esi | |
233 | popl %edi | |
234 | popl %ebx | |
235 | popl %ebp | |
236 | ||
237 | jmp __switch_to | |
238 | END(__switch_to_asm) | |
239 | ||
240 | /* | |
241 | * A newly forked process directly context switches into this address. | |
242 | * | |
243 | * eax: prev task we switched from | |
616d2483 BG |
244 | * ebx: kernel thread func (NULL for user thread) |
245 | * edi: kernel thread arg | |
0100301b | 246 | */ |
1da177e4 | 247 | ENTRY(ret_from_fork) |
a49976d1 IM |
248 | pushl %eax |
249 | call schedule_tail | |
a49976d1 | 250 | popl %eax |
39e8701f | 251 | |
616d2483 BG |
252 | testl %ebx, %ebx |
253 | jnz 1f /* kernel threads are uncommon */ | |
254 | ||
255 | 2: | |
39e8701f AL |
256 | /* When we fork, we trace the syscall return in the child, too. */ |
257 | movl %esp, %eax | |
258 | call syscall_return_slowpath | |
259 | jmp restore_all | |
39e8701f | 260 | |
616d2483 BG |
261 | /* kernel thread */ |
262 | 1: movl %edi, %eax | |
263 | call *%ebx | |
39e8701f | 264 | /* |
616d2483 BG |
265 | * A kernel thread is allowed to return here after successfully |
266 | * calling do_execve(). Exit to userspace to complete the execve() | |
267 | * syscall. | |
39e8701f | 268 | */ |
616d2483 BG |
269 | movl $0, PT_EAX(%esp) |
270 | jmp 2b | |
271 | END(ret_from_fork) | |
6783eaa2 | 272 | |
1da177e4 LT |
273 | /* |
274 | * Return to user mode is not as complex as all this looks, | |
275 | * but we want the default path for a system call return to | |
276 | * go as quickly as possible which is why some of this is | |
277 | * less clear than it otherwise should be. | |
278 | */ | |
279 | ||
280 | # userspace resumption stub bypassing syscall exit tracing | |
281 | ALIGN | |
282 | ret_from_exception: | |
139ec7c4 | 283 | preempt_stop(CLBR_ANY) |
1da177e4 | 284 | ret_from_intr: |
29a2e283 | 285 | #ifdef CONFIG_VM86 |
a49976d1 IM |
286 | movl PT_EFLAGS(%esp), %eax # mix EFLAGS and CS |
287 | movb PT_CS(%esp), %al | |
288 | andl $(X86_EFLAGS_VM | SEGMENT_RPL_MASK), %eax | |
29a2e283 DA |
289 | #else |
290 | /* | |
6783eaa2 | 291 | * We can be coming here from child spawned by kernel_thread(). |
29a2e283 | 292 | */ |
a49976d1 IM |
293 | movl PT_CS(%esp), %eax |
294 | andl $SEGMENT_RPL_MASK, %eax | |
29a2e283 | 295 | #endif |
a49976d1 IM |
296 | cmpl $USER_RPL, %eax |
297 | jb resume_kernel # not returning to v8086 or userspace | |
f95d47ca | 298 | |
1da177e4 | 299 | ENTRY(resume_userspace) |
5d73fc70 | 300 | DISABLE_INTERRUPTS(CLBR_ANY) |
e32e58a9 | 301 | TRACE_IRQS_OFF |
5d73fc70 AL |
302 | movl %esp, %eax |
303 | call prepare_exit_to_usermode | |
a49976d1 | 304 | jmp restore_all |
47a55cd7 | 305 | END(ret_from_exception) |
1da177e4 LT |
306 | |
307 | #ifdef CONFIG_PREEMPT | |
308 | ENTRY(resume_kernel) | |
139ec7c4 | 309 | DISABLE_INTERRUPTS(CLBR_ANY) |
1da177e4 | 310 | need_resched: |
a49976d1 IM |
311 | cmpl $0, PER_CPU_VAR(__preempt_count) |
312 | jnz restore_all | |
313 | testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off (exception path) ? | |
314 | jz restore_all | |
315 | call preempt_schedule_irq | |
316 | jmp need_resched | |
47a55cd7 | 317 | END(resume_kernel) |
1da177e4 LT |
318 | #endif |
319 | ||
f2b37575 AL |
320 | GLOBAL(__begin_SYSENTER_singlestep_region) |
321 | /* | |
322 | * All code from here through __end_SYSENTER_singlestep_region is subject | |
323 | * to being single-stepped if a user program sets TF and executes SYSENTER. | |
324 | * There is absolutely nothing that we can do to prevent this from happening | |
325 | * (thanks Intel!). To keep our handling of this situation as simple as | |
326 | * possible, we handle TF just like AC and NT, except that our #DB handler | |
327 | * will ignore all of the single-step traps generated in this range. | |
328 | */ | |
329 | ||
330 | #ifdef CONFIG_XEN | |
331 | /* | |
332 | * Xen doesn't set %esp to be precisely what the normal SYSENTER | |
333 | * entry point expects, so fix it up before using the normal path. | |
334 | */ | |
335 | ENTRY(xen_sysenter_target) | |
336 | addl $5*4, %esp /* remove xen-provided frame */ | |
337 | jmp sysenter_past_esp | |
338 | #endif | |
339 | ||
fda57b22 AL |
340 | /* |
341 | * 32-bit SYSENTER entry. | |
342 | * | |
343 | * 32-bit system calls through the vDSO's __kernel_vsyscall enter here | |
344 | * if X86_FEATURE_SEP is available. This is the preferred system call | |
345 | * entry on 32-bit systems. | |
346 | * | |
347 | * The SYSENTER instruction, in principle, should *only* occur in the | |
348 | * vDSO. In practice, a small number of Android devices were shipped | |
349 | * with a copy of Bionic that inlined a SYSENTER instruction. This | |
350 | * never happened in any of Google's Bionic versions -- it only happened | |
351 | * in a narrow range of Intel-provided versions. | |
352 | * | |
353 | * SYSENTER loads SS, ESP, CS, and EIP from previously programmed MSRs. | |
354 | * IF and VM in RFLAGS are cleared (IOW: interrupts are off). | |
355 | * SYSENTER does not save anything on the stack, | |
356 | * and does not save old EIP (!!!), ESP, or EFLAGS. | |
357 | * | |
358 | * To avoid losing track of EFLAGS.VM (and thus potentially corrupting | |
359 | * user and/or vm86 state), we explicitly disable the SYSENTER | |
360 | * instruction in vm86 mode by reprogramming the MSRs. | |
361 | * | |
362 | * Arguments: | |
363 | * eax system call number | |
364 | * ebx arg1 | |
365 | * ecx arg2 | |
366 | * edx arg3 | |
367 | * esi arg4 | |
368 | * edi arg5 | |
369 | * ebp user stack | |
370 | * 0(%ebp) arg6 | |
371 | */ | |
4c8cd0c5 | 372 | ENTRY(entry_SYSENTER_32) |
a49976d1 | 373 | movl TSS_sysenter_sp0(%esp), %esp |
1da177e4 | 374 | sysenter_past_esp: |
5f310f73 | 375 | pushl $__USER_DS /* pt_regs->ss */ |
30bfa7b3 | 376 | pushl %ebp /* pt_regs->sp (stashed in bp) */ |
5f310f73 AL |
377 | pushfl /* pt_regs->flags (except IF = 0) */ |
378 | orl $X86_EFLAGS_IF, (%esp) /* Fix IF */ | |
379 | pushl $__USER_CS /* pt_regs->cs */ | |
380 | pushl $0 /* pt_regs->ip = 0 (placeholder) */ | |
381 | pushl %eax /* pt_regs->orig_ax */ | |
382 | SAVE_ALL pt_regs_ax=$-ENOSYS /* save rest */ | |
383 | ||
67f590e8 | 384 | /* |
f2b37575 AL |
385 | * SYSENTER doesn't filter flags, so we need to clear NT, AC |
386 | * and TF ourselves. To save a few cycles, we can check whether | |
67f590e8 AL |
387 | * either was set instead of doing an unconditional popfq. |
388 | * This needs to happen before enabling interrupts so that | |
389 | * we don't get preempted with NT set. | |
390 | * | |
f2b37575 AL |
391 | * If TF is set, we will single-step all the way to here -- do_debug |
392 | * will ignore all the traps. (Yes, this is slow, but so is | |
393 | * single-stepping in general. This allows us to avoid having | |
394 | * a more complicated code to handle the case where a user program | |
395 | * forces us to single-step through the SYSENTER entry code.) | |
396 | * | |
67f590e8 AL |
397 | * NB.: .Lsysenter_fix_flags is a label with the code under it moved |
398 | * out-of-line as an optimization: NT is unlikely to be set in the | |
399 | * majority of the cases and instead of polluting the I$ unnecessarily, | |
400 | * we're keeping that code behind a branch which will predict as | |
401 | * not-taken and therefore its instructions won't be fetched. | |
402 | */ | |
f2b37575 | 403 | testl $X86_EFLAGS_NT|X86_EFLAGS_AC|X86_EFLAGS_TF, PT_EFLAGS(%esp) |
67f590e8 AL |
404 | jnz .Lsysenter_fix_flags |
405 | .Lsysenter_flags_fixed: | |
406 | ||
55f327fa | 407 | /* |
5f310f73 AL |
408 | * User mode is traced as though IRQs are on, and SYSENTER |
409 | * turned them off. | |
e6e5494c | 410 | */ |
55f327fa | 411 | TRACE_IRQS_OFF |
5f310f73 AL |
412 | |
413 | movl %esp, %eax | |
414 | call do_fast_syscall_32 | |
91e2eea9 BO |
415 | /* XEN PV guests always use IRET path */ |
416 | ALTERNATIVE "testl %eax, %eax; jz .Lsyscall_32_done", \ | |
417 | "jmp .Lsyscall_32_done", X86_FEATURE_XENPV | |
5f310f73 AL |
418 | |
419 | /* Opportunistic SYSEXIT */ | |
420 | TRACE_IRQS_ON /* User mode traces as IRQs on. */ | |
421 | movl PT_EIP(%esp), %edx /* pt_regs->ip */ | |
422 | movl PT_OLDESP(%esp), %ecx /* pt_regs->sp */ | |
3bd29515 AL |
423 | 1: mov PT_FS(%esp), %fs |
424 | PTGS_TO_GS | |
5f310f73 AL |
425 | popl %ebx /* pt_regs->bx */ |
426 | addl $2*4, %esp /* skip pt_regs->cx and pt_regs->dx */ | |
427 | popl %esi /* pt_regs->si */ | |
428 | popl %edi /* pt_regs->di */ | |
429 | popl %ebp /* pt_regs->bp */ | |
430 | popl %eax /* pt_regs->ax */ | |
5f310f73 | 431 | |
c2c9b52f AL |
432 | /* |
433 | * Restore all flags except IF. (We restore IF separately because | |
434 | * STI gives a one-instruction window in which we won't be interrupted, | |
435 | * whereas POPF does not.) | |
436 | */ | |
437 | addl $PT_EFLAGS-PT_DS, %esp /* point esp at pt_regs->flags */ | |
438 | btr $X86_EFLAGS_IF_BIT, (%esp) | |
439 | popfl | |
440 | ||
5f310f73 AL |
441 | /* |
442 | * Return back to the vDSO, which will pop ecx and edx. | |
443 | * Don't bother with DS and ES (they already contain __USER_DS). | |
444 | */ | |
88c15ec9 BO |
445 | sti |
446 | sysexit | |
af0575bb | 447 | |
a49976d1 IM |
448 | .pushsection .fixup, "ax" |
449 | 2: movl $0, PT_FS(%esp) | |
450 | jmp 1b | |
f95d47ca | 451 | .popsection |
a49976d1 | 452 | _ASM_EXTABLE(1b, 2b) |
ccbeed3a | 453 | PTGS_TO_GS_EX |
67f590e8 AL |
454 | |
455 | .Lsysenter_fix_flags: | |
456 | pushl $X86_EFLAGS_FIXED | |
457 | popfl | |
458 | jmp .Lsysenter_flags_fixed | |
f2b37575 | 459 | GLOBAL(__end_SYSENTER_singlestep_region) |
4c8cd0c5 | 460 | ENDPROC(entry_SYSENTER_32) |
1da177e4 | 461 | |
fda57b22 AL |
462 | /* |
463 | * 32-bit legacy system call entry. | |
464 | * | |
465 | * 32-bit x86 Linux system calls traditionally used the INT $0x80 | |
466 | * instruction. INT $0x80 lands here. | |
467 | * | |
468 | * This entry point can be used by any 32-bit perform system calls. | |
469 | * Instances of INT $0x80 can be found inline in various programs and | |
470 | * libraries. It is also used by the vDSO's __kernel_vsyscall | |
471 | * fallback for hardware that doesn't support a faster entry method. | |
472 | * Restarted 32-bit system calls also fall back to INT $0x80 | |
473 | * regardless of what instruction was originally used to do the system | |
474 | * call. (64-bit programs can use INT $0x80 as well, but they can | |
475 | * only run on 64-bit kernels and therefore land in | |
476 | * entry_INT80_compat.) | |
477 | * | |
478 | * This is considered a slow path. It is not used by most libc | |
479 | * implementations on modern hardware except during process startup. | |
480 | * | |
481 | * Arguments: | |
482 | * eax system call number | |
483 | * ebx arg1 | |
484 | * ecx arg2 | |
485 | * edx arg3 | |
486 | * esi arg4 | |
487 | * edi arg5 | |
488 | * ebp arg6 | |
489 | */ | |
b2502b41 | 490 | ENTRY(entry_INT80_32) |
e59d1b0a | 491 | ASM_CLAC |
150ac78d | 492 | pushl %eax /* pt_regs->orig_ax */ |
5f310f73 | 493 | SAVE_ALL pt_regs_ax=$-ENOSYS /* save rest */ |
150ac78d AL |
494 | |
495 | /* | |
a798f091 AL |
496 | * User mode is traced as though IRQs are on, and the interrupt gate |
497 | * turned them off. | |
150ac78d | 498 | */ |
a798f091 | 499 | TRACE_IRQS_OFF |
150ac78d AL |
500 | |
501 | movl %esp, %eax | |
a798f091 | 502 | call do_int80_syscall_32 |
5f310f73 | 503 | .Lsyscall_32_done: |
1da177e4 LT |
504 | |
505 | restore_all: | |
2e04bc76 AH |
506 | TRACE_IRQS_IRET |
507 | restore_all_notrace: | |
34273f41 | 508 | #ifdef CONFIG_X86_ESPFIX32 |
58a5aac5 AL |
509 | ALTERNATIVE "jmp restore_nocheck", "", X86_BUG_ESPFIX |
510 | ||
a49976d1 IM |
511 | movl PT_EFLAGS(%esp), %eax # mix EFLAGS, SS and CS |
512 | /* | |
513 | * Warning: PT_OLDSS(%esp) contains the wrong/random values if we | |
514 | * are returning to the kernel. | |
515 | * See comments in process.c:copy_thread() for details. | |
516 | */ | |
517 | movb PT_OLDSS(%esp), %ah | |
518 | movb PT_CS(%esp), %al | |
519 | andl $(X86_EFLAGS_VM | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax | |
520 | cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax | |
521 | je ldt_ss # returning to user-space with LDT SS | |
34273f41 | 522 | #endif |
1da177e4 | 523 | restore_nocheck: |
a49976d1 | 524 | RESTORE_REGS 4 # skip orig_eax/error_code |
f7f3d791 | 525 | irq_return: |
3701d863 | 526 | INTERRUPT_RETURN |
a49976d1 IM |
527 | .section .fixup, "ax" |
528 | ENTRY(iret_exc ) | |
529 | pushl $0 # no error code | |
530 | pushl $do_iret_error | |
531 | jmp error_code | |
1da177e4 | 532 | .previous |
a49976d1 | 533 | _ASM_EXTABLE(irq_return, iret_exc) |
1da177e4 | 534 | |
34273f41 | 535 | #ifdef CONFIG_X86_ESPFIX32 |
1da177e4 | 536 | ldt_ss: |
dc4c2a0a AH |
537 | /* |
538 | * Setup and switch to ESPFIX stack | |
539 | * | |
540 | * We're returning to userspace with a 16 bit stack. The CPU will not | |
541 | * restore the high word of ESP for us on executing iret... This is an | |
542 | * "official" bug of all the x86-compatible CPUs, which we can work | |
543 | * around to make dosemu and wine happy. We do this by preloading the | |
544 | * high word of ESP with the high word of the userspace ESP while | |
545 | * compensating for the offset by changing to the ESPFIX segment with | |
546 | * a base address that matches for the difference. | |
547 | */ | |
72c511dd | 548 | #define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + (GDT_ENTRY_ESPFIX_SS * 8) |
a49976d1 IM |
549 | mov %esp, %edx /* load kernel esp */ |
550 | mov PT_OLDESP(%esp), %eax /* load userspace esp */ | |
551 | mov %dx, %ax /* eax: new kernel esp */ | |
9b47feb7 DV |
552 | sub %eax, %edx /* offset (low word is 0) */ |
553 | shr $16, %edx | |
a49976d1 IM |
554 | mov %dl, GDT_ESPFIX_SS + 4 /* bits 16..23 */ |
555 | mov %dh, GDT_ESPFIX_SS + 7 /* bits 24..31 */ | |
556 | pushl $__ESPFIX_SS | |
557 | pushl %eax /* new kernel esp */ | |
558 | /* | |
559 | * Disable interrupts, but do not irqtrace this section: we | |
2e04bc76 | 560 | * will soon execute iret and the tracer was already set to |
a49976d1 IM |
561 | * the irqstate after the IRET: |
562 | */ | |
139ec7c4 | 563 | DISABLE_INTERRUPTS(CLBR_EAX) |
a49976d1 IM |
564 | lss (%esp), %esp /* switch to espfix segment */ |
565 | jmp restore_nocheck | |
34273f41 | 566 | #endif |
b2502b41 | 567 | ENDPROC(entry_INT80_32) |
1da177e4 | 568 | |
f0d96110 | 569 | .macro FIXUP_ESPFIX_STACK |
dc4c2a0a AH |
570 | /* |
571 | * Switch back for ESPFIX stack to the normal zerobased stack | |
572 | * | |
573 | * We can't call C functions using the ESPFIX stack. This code reads | |
574 | * the high word of the segment base from the GDT and swiches to the | |
575 | * normal stack and adjusts ESP with the matching offset. | |
576 | */ | |
34273f41 | 577 | #ifdef CONFIG_X86_ESPFIX32 |
dc4c2a0a | 578 | /* fixup the stack */ |
a49976d1 IM |
579 | mov GDT_ESPFIX_SS + 4, %al /* bits 16..23 */ |
580 | mov GDT_ESPFIX_SS + 7, %ah /* bits 24..31 */ | |
9b47feb7 | 581 | shl $16, %eax |
a49976d1 IM |
582 | addl %esp, %eax /* the adjusted stack pointer */ |
583 | pushl $__KERNEL_DS | |
584 | pushl %eax | |
585 | lss (%esp), %esp /* switch to the normal stack segment */ | |
34273f41 | 586 | #endif |
f0d96110 TH |
587 | .endm |
588 | .macro UNWIND_ESPFIX_STACK | |
34273f41 | 589 | #ifdef CONFIG_X86_ESPFIX32 |
a49976d1 | 590 | movl %ss, %eax |
f0d96110 | 591 | /* see if on espfix stack */ |
a49976d1 IM |
592 | cmpw $__ESPFIX_SS, %ax |
593 | jne 27f | |
594 | movl $__KERNEL_DS, %eax | |
595 | movl %eax, %ds | |
596 | movl %eax, %es | |
f0d96110 TH |
597 | /* switch to normal stack */ |
598 | FIXUP_ESPFIX_STACK | |
599 | 27: | |
34273f41 | 600 | #endif |
f0d96110 | 601 | .endm |
1da177e4 LT |
602 | |
603 | /* | |
3304c9c3 DV |
604 | * Build the entry stubs with some assembler magic. |
605 | * We pack 1 stub into every 8-byte block. | |
1da177e4 | 606 | */ |
3304c9c3 | 607 | .align 8 |
1da177e4 | 608 | ENTRY(irq_entries_start) |
3304c9c3 DV |
609 | vector=FIRST_EXTERNAL_VECTOR |
610 | .rept (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR) | |
a49976d1 | 611 | pushl $(~vector+0x80) /* Note: always in signed byte range */ |
3304c9c3 DV |
612 | vector=vector+1 |
613 | jmp common_interrupt | |
3304c9c3 DV |
614 | .align 8 |
615 | .endr | |
47a55cd7 JB |
616 | END(irq_entries_start) |
617 | ||
55f327fa IM |
618 | /* |
619 | * the CPU automatically disables interrupts when executing an IRQ vector, | |
620 | * so IRQ-flags tracing has to follow that: | |
621 | */ | |
b7c6244f | 622 | .p2align CONFIG_X86_L1_CACHE_SHIFT |
1da177e4 | 623 | common_interrupt: |
e59d1b0a | 624 | ASM_CLAC |
a49976d1 | 625 | addl $-0x80, (%esp) /* Adjust vector into the [-256, -1] range */ |
1da177e4 | 626 | SAVE_ALL |
55f327fa | 627 | TRACE_IRQS_OFF |
a49976d1 IM |
628 | movl %esp, %eax |
629 | call do_IRQ | |
630 | jmp ret_from_intr | |
47a55cd7 | 631 | ENDPROC(common_interrupt) |
1da177e4 | 632 | |
02cf94c3 | 633 | #define BUILD_INTERRUPT3(name, nr, fn) \ |
1da177e4 | 634 | ENTRY(name) \ |
e59d1b0a | 635 | ASM_CLAC; \ |
a49976d1 | 636 | pushl $~(nr); \ |
fe7cacc1 | 637 | SAVE_ALL; \ |
55f327fa | 638 | TRACE_IRQS_OFF \ |
a49976d1 IM |
639 | movl %esp, %eax; \ |
640 | call fn; \ | |
641 | jmp ret_from_intr; \ | |
47a55cd7 | 642 | ENDPROC(name) |
1da177e4 | 643 | |
cf910e83 SA |
644 | |
645 | #ifdef CONFIG_TRACING | |
a49976d1 | 646 | # define TRACE_BUILD_INTERRUPT(name, nr) BUILD_INTERRUPT3(trace_##name, nr, smp_trace_##name) |
cf910e83 | 647 | #else |
a49976d1 | 648 | # define TRACE_BUILD_INTERRUPT(name, nr) |
cf910e83 SA |
649 | #endif |
650 | ||
a49976d1 IM |
651 | #define BUILD_INTERRUPT(name, nr) \ |
652 | BUILD_INTERRUPT3(name, nr, smp_##name); \ | |
cf910e83 | 653 | TRACE_BUILD_INTERRUPT(name, nr) |
02cf94c3 | 654 | |
1da177e4 | 655 | /* The include is where all of the SMP etc. interrupts come from */ |
1164dd00 | 656 | #include <asm/entry_arch.h> |
1da177e4 | 657 | |
1da177e4 | 658 | ENTRY(coprocessor_error) |
e59d1b0a | 659 | ASM_CLAC |
a49976d1 IM |
660 | pushl $0 |
661 | pushl $do_coprocessor_error | |
662 | jmp error_code | |
47a55cd7 | 663 | END(coprocessor_error) |
1da177e4 LT |
664 | |
665 | ENTRY(simd_coprocessor_error) | |
e59d1b0a | 666 | ASM_CLAC |
a49976d1 | 667 | pushl $0 |
40d2e763 BG |
668 | #ifdef CONFIG_X86_INVD_BUG |
669 | /* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */ | |
a49976d1 IM |
670 | ALTERNATIVE "pushl $do_general_protection", \ |
671 | "pushl $do_simd_coprocessor_error", \ | |
8e65f6e0 | 672 | X86_FEATURE_XMM |
40d2e763 | 673 | #else |
a49976d1 | 674 | pushl $do_simd_coprocessor_error |
40d2e763 | 675 | #endif |
a49976d1 | 676 | jmp error_code |
47a55cd7 | 677 | END(simd_coprocessor_error) |
1da177e4 LT |
678 | |
679 | ENTRY(device_not_available) | |
e59d1b0a | 680 | ASM_CLAC |
a49976d1 IM |
681 | pushl $-1 # mark this as an int |
682 | pushl $do_device_not_available | |
683 | jmp error_code | |
47a55cd7 | 684 | END(device_not_available) |
1da177e4 | 685 | |
d3561b7f RR |
686 | #ifdef CONFIG_PARAVIRT |
687 | ENTRY(native_iret) | |
3701d863 | 688 | iret |
6837a54d | 689 | _ASM_EXTABLE(native_iret, iret_exc) |
47a55cd7 | 690 | END(native_iret) |
d3561b7f RR |
691 | #endif |
692 | ||
1da177e4 | 693 | ENTRY(overflow) |
e59d1b0a | 694 | ASM_CLAC |
a49976d1 IM |
695 | pushl $0 |
696 | pushl $do_overflow | |
697 | jmp error_code | |
47a55cd7 | 698 | END(overflow) |
1da177e4 LT |
699 | |
700 | ENTRY(bounds) | |
e59d1b0a | 701 | ASM_CLAC |
a49976d1 IM |
702 | pushl $0 |
703 | pushl $do_bounds | |
704 | jmp error_code | |
47a55cd7 | 705 | END(bounds) |
1da177e4 LT |
706 | |
707 | ENTRY(invalid_op) | |
e59d1b0a | 708 | ASM_CLAC |
a49976d1 IM |
709 | pushl $0 |
710 | pushl $do_invalid_op | |
711 | jmp error_code | |
47a55cd7 | 712 | END(invalid_op) |
1da177e4 LT |
713 | |
714 | ENTRY(coprocessor_segment_overrun) | |
e59d1b0a | 715 | ASM_CLAC |
a49976d1 IM |
716 | pushl $0 |
717 | pushl $do_coprocessor_segment_overrun | |
718 | jmp error_code | |
47a55cd7 | 719 | END(coprocessor_segment_overrun) |
1da177e4 LT |
720 | |
721 | ENTRY(invalid_TSS) | |
e59d1b0a | 722 | ASM_CLAC |
a49976d1 IM |
723 | pushl $do_invalid_TSS |
724 | jmp error_code | |
47a55cd7 | 725 | END(invalid_TSS) |
1da177e4 LT |
726 | |
727 | ENTRY(segment_not_present) | |
e59d1b0a | 728 | ASM_CLAC |
a49976d1 IM |
729 | pushl $do_segment_not_present |
730 | jmp error_code | |
47a55cd7 | 731 | END(segment_not_present) |
1da177e4 LT |
732 | |
733 | ENTRY(stack_segment) | |
e59d1b0a | 734 | ASM_CLAC |
a49976d1 IM |
735 | pushl $do_stack_segment |
736 | jmp error_code | |
47a55cd7 | 737 | END(stack_segment) |
1da177e4 | 738 | |
1da177e4 | 739 | ENTRY(alignment_check) |
e59d1b0a | 740 | ASM_CLAC |
a49976d1 IM |
741 | pushl $do_alignment_check |
742 | jmp error_code | |
47a55cd7 | 743 | END(alignment_check) |
1da177e4 | 744 | |
d28c4393 | 745 | ENTRY(divide_error) |
e59d1b0a | 746 | ASM_CLAC |
a49976d1 IM |
747 | pushl $0 # no error code |
748 | pushl $do_divide_error | |
749 | jmp error_code | |
47a55cd7 | 750 | END(divide_error) |
1da177e4 LT |
751 | |
752 | #ifdef CONFIG_X86_MCE | |
753 | ENTRY(machine_check) | |
e59d1b0a | 754 | ASM_CLAC |
a49976d1 IM |
755 | pushl $0 |
756 | pushl machine_check_vector | |
757 | jmp error_code | |
47a55cd7 | 758 | END(machine_check) |
1da177e4 LT |
759 | #endif |
760 | ||
761 | ENTRY(spurious_interrupt_bug) | |
e59d1b0a | 762 | ASM_CLAC |
a49976d1 IM |
763 | pushl $0 |
764 | pushl $do_spurious_interrupt_bug | |
765 | jmp error_code | |
47a55cd7 | 766 | END(spurious_interrupt_bug) |
1da177e4 | 767 | |
5ead97c8 JF |
768 | #ifdef CONFIG_XEN |
769 | ENTRY(xen_hypervisor_callback) | |
a49976d1 | 770 | pushl $-1 /* orig_ax = -1 => not a system call */ |
5ead97c8 JF |
771 | SAVE_ALL |
772 | TRACE_IRQS_OFF | |
9ec2b804 | 773 | |
a49976d1 IM |
774 | /* |
775 | * Check to see if we got the event in the critical | |
776 | * region in xen_iret_direct, after we've reenabled | |
777 | * events and checked for pending events. This simulates | |
778 | * iret instruction's behaviour where it delivers a | |
779 | * pending interrupt when enabling interrupts: | |
780 | */ | |
781 | movl PT_EIP(%esp), %eax | |
782 | cmpl $xen_iret_start_crit, %eax | |
783 | jb 1f | |
784 | cmpl $xen_iret_end_crit, %eax | |
785 | jae 1f | |
9ec2b804 | 786 | |
a49976d1 | 787 | jmp xen_iret_crit_fixup |
e2a81baf | 788 | |
e2a81baf | 789 | ENTRY(xen_do_upcall) |
a49976d1 IM |
790 | 1: mov %esp, %eax |
791 | call xen_evtchn_do_upcall | |
fdfd811d | 792 | #ifndef CONFIG_PREEMPT |
a49976d1 | 793 | call xen_maybe_preempt_hcall |
fdfd811d | 794 | #endif |
a49976d1 | 795 | jmp ret_from_intr |
5ead97c8 JF |
796 | ENDPROC(xen_hypervisor_callback) |
797 | ||
a49976d1 IM |
798 | /* |
799 | * Hypervisor uses this for application faults while it executes. | |
800 | * We get here for two reasons: | |
801 | * 1. Fault while reloading DS, ES, FS or GS | |
802 | * 2. Fault while executing IRET | |
803 | * Category 1 we fix up by reattempting the load, and zeroing the segment | |
804 | * register if the load fails. | |
805 | * Category 2 we fix up by jumping to do_iret_error. We cannot use the | |
806 | * normal Linux return path in this case because if we use the IRET hypercall | |
807 | * to pop the stack frame we end up in an infinite loop of failsafe callbacks. | |
808 | * We distinguish between categories by maintaining a status value in EAX. | |
809 | */ | |
5ead97c8 | 810 | ENTRY(xen_failsafe_callback) |
a49976d1 IM |
811 | pushl %eax |
812 | movl $1, %eax | |
813 | 1: mov 4(%esp), %ds | |
814 | 2: mov 8(%esp), %es | |
815 | 3: mov 12(%esp), %fs | |
816 | 4: mov 16(%esp), %gs | |
a349e23d DV |
817 | /* EAX == 0 => Category 1 (Bad segment) |
818 | EAX != 0 => Category 2 (Bad IRET) */ | |
a49976d1 IM |
819 | testl %eax, %eax |
820 | popl %eax | |
821 | lea 16(%esp), %esp | |
822 | jz 5f | |
823 | jmp iret_exc | |
824 | 5: pushl $-1 /* orig_ax = -1 => not a system call */ | |
5ead97c8 | 825 | SAVE_ALL |
a49976d1 IM |
826 | jmp ret_from_exception |
827 | ||
828 | .section .fixup, "ax" | |
829 | 6: xorl %eax, %eax | |
830 | movl %eax, 4(%esp) | |
831 | jmp 1b | |
832 | 7: xorl %eax, %eax | |
833 | movl %eax, 8(%esp) | |
834 | jmp 2b | |
835 | 8: xorl %eax, %eax | |
836 | movl %eax, 12(%esp) | |
837 | jmp 3b | |
838 | 9: xorl %eax, %eax | |
839 | movl %eax, 16(%esp) | |
840 | jmp 4b | |
5ead97c8 | 841 | .previous |
a49976d1 IM |
842 | _ASM_EXTABLE(1b, 6b) |
843 | _ASM_EXTABLE(2b, 7b) | |
844 | _ASM_EXTABLE(3b, 8b) | |
845 | _ASM_EXTABLE(4b, 9b) | |
5ead97c8 JF |
846 | ENDPROC(xen_failsafe_callback) |
847 | ||
bc2b0331 | 848 | BUILD_INTERRUPT3(xen_hvm_callback_vector, HYPERVISOR_CALLBACK_VECTOR, |
38e20b07 SY |
849 | xen_evtchn_do_upcall) |
850 | ||
a49976d1 | 851 | #endif /* CONFIG_XEN */ |
bc2b0331 S |
852 | |
853 | #if IS_ENABLED(CONFIG_HYPERV) | |
854 | ||
855 | BUILD_INTERRUPT3(hyperv_callback_vector, HYPERVISOR_CALLBACK_VECTOR, | |
856 | hyperv_vector_handler) | |
857 | ||
858 | #endif /* CONFIG_HYPERV */ | |
5ead97c8 | 859 | |
606576ce | 860 | #ifdef CONFIG_FUNCTION_TRACER |
d61f82d0 SR |
861 | #ifdef CONFIG_DYNAMIC_FTRACE |
862 | ||
863 | ENTRY(mcount) | |
d61f82d0 SR |
864 | ret |
865 | END(mcount) | |
866 | ||
867 | ENTRY(ftrace_caller) | |
a49976d1 IM |
868 | pushl %eax |
869 | pushl %ecx | |
870 | pushl %edx | |
871 | pushl $0 /* Pass NULL as regs pointer */ | |
872 | movl 4*4(%esp), %eax | |
873 | movl 0x4(%ebp), %edx | |
874 | movl function_trace_op, %ecx | |
875 | subl $MCOUNT_INSN_SIZE, %eax | |
d61f82d0 SR |
876 | |
877 | .globl ftrace_call | |
878 | ftrace_call: | |
a49976d1 | 879 | call ftrace_stub |
d61f82d0 | 880 | |
a49976d1 IM |
881 | addl $4, %esp /* skip NULL pointer */ |
882 | popl %edx | |
883 | popl %ecx | |
884 | popl %eax | |
4de72395 | 885 | ftrace_ret: |
5a45cfe1 SR |
886 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
887 | .globl ftrace_graph_call | |
888 | ftrace_graph_call: | |
a49976d1 | 889 | jmp ftrace_stub |
5a45cfe1 | 890 | #endif |
d61f82d0 SR |
891 | |
892 | .globl ftrace_stub | |
893 | ftrace_stub: | |
894 | ret | |
895 | END(ftrace_caller) | |
896 | ||
4de72395 SR |
897 | ENTRY(ftrace_regs_caller) |
898 | pushf /* push flags before compare (in cs location) */ | |
4de72395 SR |
899 | |
900 | /* | |
901 | * i386 does not save SS and ESP when coming from kernel. | |
902 | * Instead, to get sp, ®s->sp is used (see ptrace.h). | |
903 | * Unfortunately, that means eflags must be at the same location | |
904 | * as the current return ip is. We move the return ip into the | |
905 | * ip location, and move flags into the return ip location. | |
906 | */ | |
a49976d1 IM |
907 | pushl 4(%esp) /* save return ip into ip slot */ |
908 | ||
909 | pushl $0 /* Load 0 into orig_ax */ | |
910 | pushl %gs | |
911 | pushl %fs | |
912 | pushl %es | |
913 | pushl %ds | |
914 | pushl %eax | |
915 | pushl %ebp | |
916 | pushl %edi | |
917 | pushl %esi | |
918 | pushl %edx | |
919 | pushl %ecx | |
920 | pushl %ebx | |
921 | ||
922 | movl 13*4(%esp), %eax /* Get the saved flags */ | |
923 | movl %eax, 14*4(%esp) /* Move saved flags into regs->flags location */ | |
924 | /* clobbering return ip */ | |
925 | movl $__KERNEL_CS, 13*4(%esp) | |
926 | ||
927 | movl 12*4(%esp), %eax /* Load ip (1st parameter) */ | |
928 | subl $MCOUNT_INSN_SIZE, %eax /* Adjust ip */ | |
929 | movl 0x4(%ebp), %edx /* Load parent ip (2nd parameter) */ | |
930 | movl function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */ | |
931 | pushl %esp /* Save pt_regs as 4th parameter */ | |
4de72395 SR |
932 | |
933 | GLOBAL(ftrace_regs_call) | |
a49976d1 IM |
934 | call ftrace_stub |
935 | ||
936 | addl $4, %esp /* Skip pt_regs */ | |
937 | movl 14*4(%esp), %eax /* Move flags back into cs */ | |
938 | movl %eax, 13*4(%esp) /* Needed to keep addl from modifying flags */ | |
939 | movl 12*4(%esp), %eax /* Get return ip from regs->ip */ | |
940 | movl %eax, 14*4(%esp) /* Put return ip back for ret */ | |
941 | ||
942 | popl %ebx | |
943 | popl %ecx | |
944 | popl %edx | |
945 | popl %esi | |
946 | popl %edi | |
947 | popl %ebp | |
948 | popl %eax | |
949 | popl %ds | |
950 | popl %es | |
951 | popl %fs | |
952 | popl %gs | |
953 | addl $8, %esp /* Skip orig_ax and ip */ | |
954 | popf /* Pop flags at end (no addl to corrupt flags) */ | |
955 | jmp ftrace_ret | |
4de72395 | 956 | |
4de72395 | 957 | popf |
a49976d1 | 958 | jmp ftrace_stub |
d61f82d0 SR |
959 | #else /* ! CONFIG_DYNAMIC_FTRACE */ |
960 | ||
16444a8a | 961 | ENTRY(mcount) |
a49976d1 IM |
962 | cmpl $__PAGE_OFFSET, %esp |
963 | jb ftrace_stub /* Paging not enabled yet? */ | |
af058ab0 | 964 | |
a49976d1 IM |
965 | cmpl $ftrace_stub, ftrace_trace_function |
966 | jnz trace | |
fb52607a | 967 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
a49976d1 IM |
968 | cmpl $ftrace_stub, ftrace_graph_return |
969 | jnz ftrace_graph_caller | |
e49dc19c | 970 | |
a49976d1 IM |
971 | cmpl $ftrace_graph_entry_stub, ftrace_graph_entry |
972 | jnz ftrace_graph_caller | |
caf4b323 | 973 | #endif |
16444a8a ACM |
974 | .globl ftrace_stub |
975 | ftrace_stub: | |
976 | ret | |
977 | ||
978 | /* taken from glibc */ | |
979 | trace: | |
a49976d1 IM |
980 | pushl %eax |
981 | pushl %ecx | |
982 | pushl %edx | |
983 | movl 0xc(%esp), %eax | |
984 | movl 0x4(%ebp), %edx | |
985 | subl $MCOUNT_INSN_SIZE, %eax | |
986 | ||
987 | call *ftrace_trace_function | |
988 | ||
989 | popl %edx | |
990 | popl %ecx | |
991 | popl %eax | |
992 | jmp ftrace_stub | |
16444a8a | 993 | END(mcount) |
d61f82d0 | 994 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
784d5699 | 995 | EXPORT_SYMBOL(mcount) |
606576ce | 996 | #endif /* CONFIG_FUNCTION_TRACER */ |
16444a8a | 997 | |
fb52607a FW |
998 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
999 | ENTRY(ftrace_graph_caller) | |
a49976d1 IM |
1000 | pushl %eax |
1001 | pushl %ecx | |
1002 | pushl %edx | |
1003 | movl 0xc(%esp), %eax | |
1004 | lea 0x4(%ebp), %edx | |
1005 | movl (%ebp), %ecx | |
1006 | subl $MCOUNT_INSN_SIZE, %eax | |
1007 | call prepare_ftrace_return | |
1008 | popl %edx | |
1009 | popl %ecx | |
1010 | popl %eax | |
e7d3737e | 1011 | ret |
fb52607a | 1012 | END(ftrace_graph_caller) |
caf4b323 FW |
1013 | |
1014 | .globl return_to_handler | |
1015 | return_to_handler: | |
a49976d1 IM |
1016 | pushl %eax |
1017 | pushl %edx | |
1018 | movl %ebp, %eax | |
1019 | call ftrace_return_to_handler | |
1020 | movl %eax, %ecx | |
1021 | popl %edx | |
1022 | popl %eax | |
1023 | jmp *%ecx | |
e7d3737e | 1024 | #endif |
16444a8a | 1025 | |
25c74b10 SA |
1026 | #ifdef CONFIG_TRACING |
1027 | ENTRY(trace_page_fault) | |
25c74b10 | 1028 | ASM_CLAC |
a49976d1 IM |
1029 | pushl $trace_do_page_fault |
1030 | jmp error_code | |
25c74b10 SA |
1031 | END(trace_page_fault) |
1032 | #endif | |
1033 | ||
d211af05 | 1034 | ENTRY(page_fault) |
e59d1b0a | 1035 | ASM_CLAC |
a49976d1 | 1036 | pushl $do_page_fault |
d211af05 AH |
1037 | ALIGN |
1038 | error_code: | |
ccbeed3a | 1039 | /* the function address is in %gs's slot on the stack */ |
a49976d1 IM |
1040 | pushl %fs |
1041 | pushl %es | |
1042 | pushl %ds | |
1043 | pushl %eax | |
1044 | pushl %ebp | |
1045 | pushl %edi | |
1046 | pushl %esi | |
1047 | pushl %edx | |
1048 | pushl %ecx | |
1049 | pushl %ebx | |
d211af05 | 1050 | cld |
a49976d1 IM |
1051 | movl $(__KERNEL_PERCPU), %ecx |
1052 | movl %ecx, %fs | |
d211af05 | 1053 | UNWIND_ESPFIX_STACK |
ccbeed3a | 1054 | GS_TO_REG %ecx |
a49976d1 IM |
1055 | movl PT_GS(%esp), %edi # get the function address |
1056 | movl PT_ORIG_EAX(%esp), %edx # get the error code | |
1057 | movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart | |
ccbeed3a TH |
1058 | REG_TO_PTGS %ecx |
1059 | SET_KERNEL_GS %ecx | |
a49976d1 IM |
1060 | movl $(__USER_DS), %ecx |
1061 | movl %ecx, %ds | |
1062 | movl %ecx, %es | |
d211af05 | 1063 | TRACE_IRQS_OFF |
a49976d1 IM |
1064 | movl %esp, %eax # pt_regs pointer |
1065 | call *%edi | |
1066 | jmp ret_from_exception | |
d211af05 AH |
1067 | END(page_fault) |
1068 | ||
d211af05 | 1069 | ENTRY(debug) |
7536656f AL |
1070 | /* |
1071 | * #DB can happen at the first instruction of | |
1072 | * entry_SYSENTER_32 or in Xen's SYSENTER prologue. If this | |
1073 | * happens, then we will be running on a very small stack. We | |
1074 | * need to detect this condition and switch to the thread | |
1075 | * stack before calling any C code at all. | |
1076 | * | |
1077 | * If you edit this code, keep in mind that NMIs can happen in here. | |
1078 | */ | |
e59d1b0a | 1079 | ASM_CLAC |
a49976d1 | 1080 | pushl $-1 # mark this as an int |
d211af05 | 1081 | SAVE_ALL |
a49976d1 IM |
1082 | xorl %edx, %edx # error code 0 |
1083 | movl %esp, %eax # pt_regs pointer | |
7536656f AL |
1084 | |
1085 | /* Are we currently on the SYSENTER stack? */ | |
1086 | PER_CPU(cpu_tss + CPU_TSS_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx) | |
1087 | subl %eax, %ecx /* ecx = (end of SYSENTER_stack) - esp */ | |
1088 | cmpl $SIZEOF_SYSENTER_stack, %ecx | |
1089 | jb .Ldebug_from_sysenter_stack | |
1090 | ||
1091 | TRACE_IRQS_OFF | |
1092 | call do_debug | |
1093 | jmp ret_from_exception | |
1094 | ||
1095 | .Ldebug_from_sysenter_stack: | |
1096 | /* We're on the SYSENTER stack. Switch off. */ | |
1097 | movl %esp, %ebp | |
1098 | movl PER_CPU_VAR(cpu_current_top_of_stack), %esp | |
1099 | TRACE_IRQS_OFF | |
a49976d1 | 1100 | call do_debug |
7536656f | 1101 | movl %ebp, %esp |
a49976d1 | 1102 | jmp ret_from_exception |
d211af05 AH |
1103 | END(debug) |
1104 | ||
1105 | /* | |
7536656f AL |
1106 | * NMI is doubly nasty. It can happen on the first instruction of |
1107 | * entry_SYSENTER_32 (just like #DB), but it can also interrupt the beginning | |
1108 | * of the #DB handler even if that #DB in turn hit before entry_SYSENTER_32 | |
1109 | * switched stacks. We handle both conditions by simply checking whether we | |
1110 | * interrupted kernel code running on the SYSENTER stack. | |
d211af05 AH |
1111 | */ |
1112 | ENTRY(nmi) | |
e59d1b0a | 1113 | ASM_CLAC |
34273f41 | 1114 | #ifdef CONFIG_X86_ESPFIX32 |
a49976d1 IM |
1115 | pushl %eax |
1116 | movl %ss, %eax | |
1117 | cmpw $__ESPFIX_SS, %ax | |
1118 | popl %eax | |
1119 | je nmi_espfix_stack | |
34273f41 | 1120 | #endif |
7536656f AL |
1121 | |
1122 | pushl %eax # pt_regs->orig_ax | |
d211af05 | 1123 | SAVE_ALL |
a49976d1 IM |
1124 | xorl %edx, %edx # zero error code |
1125 | movl %esp, %eax # pt_regs pointer | |
7536656f AL |
1126 | |
1127 | /* Are we currently on the SYSENTER stack? */ | |
1128 | PER_CPU(cpu_tss + CPU_TSS_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx) | |
1129 | subl %eax, %ecx /* ecx = (end of SYSENTER_stack) - esp */ | |
1130 | cmpl $SIZEOF_SYSENTER_stack, %ecx | |
1131 | jb .Lnmi_from_sysenter_stack | |
1132 | ||
1133 | /* Not on SYSENTER stack. */ | |
a49976d1 IM |
1134 | call do_nmi |
1135 | jmp restore_all_notrace | |
d211af05 | 1136 | |
7536656f AL |
1137 | .Lnmi_from_sysenter_stack: |
1138 | /* | |
1139 | * We're on the SYSENTER stack. Switch off. No one (not even debug) | |
1140 | * is using the thread stack right now, so it's safe for us to use it. | |
1141 | */ | |
1142 | movl %esp, %ebp | |
1143 | movl PER_CPU_VAR(cpu_current_top_of_stack), %esp | |
1144 | call do_nmi | |
1145 | movl %ebp, %esp | |
1146 | jmp restore_all_notrace | |
d211af05 | 1147 | |
34273f41 | 1148 | #ifdef CONFIG_X86_ESPFIX32 |
d211af05 | 1149 | nmi_espfix_stack: |
131484c8 | 1150 | /* |
d211af05 AH |
1151 | * create the pointer to lss back |
1152 | */ | |
a49976d1 IM |
1153 | pushl %ss |
1154 | pushl %esp | |
1155 | addl $4, (%esp) | |
d211af05 AH |
1156 | /* copy the iret frame of 12 bytes */ |
1157 | .rept 3 | |
a49976d1 | 1158 | pushl 16(%esp) |
d211af05 | 1159 | .endr |
a49976d1 | 1160 | pushl %eax |
d211af05 | 1161 | SAVE_ALL |
a49976d1 IM |
1162 | FIXUP_ESPFIX_STACK # %eax == %esp |
1163 | xorl %edx, %edx # zero error code | |
1164 | call do_nmi | |
d211af05 | 1165 | RESTORE_REGS |
a49976d1 IM |
1166 | lss 12+4(%esp), %esp # back to espfix stack |
1167 | jmp irq_return | |
34273f41 | 1168 | #endif |
d211af05 AH |
1169 | END(nmi) |
1170 | ||
1171 | ENTRY(int3) | |
e59d1b0a | 1172 | ASM_CLAC |
a49976d1 | 1173 | pushl $-1 # mark this as an int |
d211af05 AH |
1174 | SAVE_ALL |
1175 | TRACE_IRQS_OFF | |
a49976d1 IM |
1176 | xorl %edx, %edx # zero error code |
1177 | movl %esp, %eax # pt_regs pointer | |
1178 | call do_int3 | |
1179 | jmp ret_from_exception | |
d211af05 AH |
1180 | END(int3) |
1181 | ||
1182 | ENTRY(general_protection) | |
a49976d1 IM |
1183 | pushl $do_general_protection |
1184 | jmp error_code | |
d211af05 AH |
1185 | END(general_protection) |
1186 | ||
631bc487 GN |
1187 | #ifdef CONFIG_KVM_GUEST |
1188 | ENTRY(async_page_fault) | |
e59d1b0a | 1189 | ASM_CLAC |
a49976d1 IM |
1190 | pushl $do_async_page_fault |
1191 | jmp error_code | |
2ae9d293 | 1192 | END(async_page_fault) |
631bc487 | 1193 | #endif |
2deb4be2 AL |
1194 | |
1195 | ENTRY(rewind_stack_do_exit) | |
1196 | /* Prevent any naive code from trying to unwind to our caller. */ | |
1197 | xorl %ebp, %ebp | |
1198 | ||
1199 | movl PER_CPU_VAR(cpu_current_top_of_stack), %esi | |
1200 | leal -TOP_OF_KERNEL_STACK_PADDING-PTREGS_SIZE(%esi), %esp | |
1201 | ||
1202 | call do_exit | |
1203 | 1: jmp 1b | |
1204 | END(rewind_stack_do_exit) |