Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/arch/x86_64/entry.S | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs | |
6 | * Copyright (C) 2000 Pavel Machek <pavel@suse.cz> | |
1da177e4 LT |
7 | */ |
8 | ||
9 | /* | |
10 | * entry.S contains the system-call and fault low-level handling routines. | |
11 | * | |
12 | * NOTE: This code handles signal-recognition, which happens every time | |
13 | * after an interrupt and after each system call. | |
14 | * | |
15 | * Normal syscalls and interrupts don't save a full stack frame, this is | |
16 | * only done for syscall tracing, signals or fork/exec et.al. | |
17 | * | |
18 | * A note on terminology: | |
19 | * - top of stack: Architecture defined interrupt frame from SS to RIP | |
20 | * at the top of the kernel process stack. | |
21 | * - partial stack frame: partially saved registers upto R11. | |
22 | * - full stack frame: Like partial stack frame, but all register saved. | |
2e91a17b AK |
23 | * |
24 | * Some macro usage: | |
25 | * - CFI macros are used to generate dwarf2 unwind information for better | |
26 | * backtraces. They don't change any code. | |
27 | * - SAVE_ALL/RESTORE_ALL - Save/restore all registers | |
28 | * - SAVE_ARGS/RESTORE_ARGS - Save/restore registers that C functions modify. | |
29 | * There are unfortunately lots of special cases where some registers | |
30 | * not touched. The macro is a big mess that should be cleaned up. | |
31 | * - SAVE_REST/RESTORE_REST - Handle the registers not saved by SAVE_ARGS. | |
32 | * Gives a full stack frame. | |
33 | * - ENTRY/END Define functions in the symbol table. | |
34 | * - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack | |
35 | * frame that is otherwise undefined after a SYSCALL | |
36 | * - TRACE_IRQ_* - Trace hard interrupt state for lock debugging. | |
37 | * - errorentry/paranoidentry/zeroentry - Define exception entry points. | |
1da177e4 LT |
38 | */ |
39 | ||
1da177e4 LT |
40 | #include <linux/linkage.h> |
41 | #include <asm/segment.h> | |
1da177e4 LT |
42 | #include <asm/cache.h> |
43 | #include <asm/errno.h> | |
44 | #include <asm/dwarf2.h> | |
45 | #include <asm/calling.h> | |
e2d5df93 | 46 | #include <asm/asm-offsets.h> |
1da177e4 LT |
47 | #include <asm/msr.h> |
48 | #include <asm/unistd.h> | |
49 | #include <asm/thread_info.h> | |
50 | #include <asm/hw_irq.h> | |
5f8efbb9 | 51 | #include <asm/page.h> |
2601e64d | 52 | #include <asm/irqflags.h> |
72fe4858 | 53 | #include <asm/paravirt.h> |
395a59d0 | 54 | #include <asm/ftrace.h> |
1da177e4 | 55 | |
86a1c34a RM |
56 | /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */ |
57 | #include <linux/elf-em.h> | |
58 | #define AUDIT_ARCH_X86_64 (EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE) | |
59 | #define __AUDIT_ARCH_64BIT 0x80000000 | |
60 | #define __AUDIT_ARCH_LE 0x40000000 | |
61 | ||
1da177e4 LT |
62 | .code64 |
63 | ||
606576ce | 64 | #ifdef CONFIG_FUNCTION_TRACER |
d61f82d0 SR |
65 | #ifdef CONFIG_DYNAMIC_FTRACE |
66 | ENTRY(mcount) | |
d61f82d0 SR |
67 | retq |
68 | END(mcount) | |
69 | ||
70 | ENTRY(ftrace_caller) | |
60a7ecf4 SR |
71 | cmpl $0, function_trace_stop |
72 | jne ftrace_stub | |
d61f82d0 SR |
73 | |
74 | /* taken from glibc */ | |
75 | subq $0x38, %rsp | |
76 | movq %rax, (%rsp) | |
77 | movq %rcx, 8(%rsp) | |
78 | movq %rdx, 16(%rsp) | |
79 | movq %rsi, 24(%rsp) | |
80 | movq %rdi, 32(%rsp) | |
81 | movq %r8, 40(%rsp) | |
82 | movq %r9, 48(%rsp) | |
83 | ||
84 | movq 0x38(%rsp), %rdi | |
85 | movq 8(%rbp), %rsi | |
395a59d0 | 86 | subq $MCOUNT_INSN_SIZE, %rdi |
d61f82d0 SR |
87 | |
88 | .globl ftrace_call | |
89 | ftrace_call: | |
90 | call ftrace_stub | |
91 | ||
92 | movq 48(%rsp), %r9 | |
93 | movq 40(%rsp), %r8 | |
94 | movq 32(%rsp), %rdi | |
95 | movq 24(%rsp), %rsi | |
96 | movq 16(%rsp), %rdx | |
97 | movq 8(%rsp), %rcx | |
98 | movq (%rsp), %rax | |
99 | addq $0x38, %rsp | |
100 | ||
101 | .globl ftrace_stub | |
102 | ftrace_stub: | |
103 | retq | |
104 | END(ftrace_caller) | |
105 | ||
106 | #else /* ! CONFIG_DYNAMIC_FTRACE */ | |
16444a8a | 107 | ENTRY(mcount) |
60a7ecf4 SR |
108 | cmpl $0, function_trace_stop |
109 | jne ftrace_stub | |
110 | ||
16444a8a ACM |
111 | cmpq $ftrace_stub, ftrace_trace_function |
112 | jnz trace | |
113 | .globl ftrace_stub | |
114 | ftrace_stub: | |
115 | retq | |
116 | ||
117 | trace: | |
118 | /* taken from glibc */ | |
119 | subq $0x38, %rsp | |
120 | movq %rax, (%rsp) | |
121 | movq %rcx, 8(%rsp) | |
122 | movq %rdx, 16(%rsp) | |
123 | movq %rsi, 24(%rsp) | |
124 | movq %rdi, 32(%rsp) | |
125 | movq %r8, 40(%rsp) | |
126 | movq %r9, 48(%rsp) | |
127 | ||
128 | movq 0x38(%rsp), %rdi | |
129 | movq 8(%rbp), %rsi | |
395a59d0 | 130 | subq $MCOUNT_INSN_SIZE, %rdi |
16444a8a ACM |
131 | |
132 | call *ftrace_trace_function | |
133 | ||
134 | movq 48(%rsp), %r9 | |
135 | movq 40(%rsp), %r8 | |
136 | movq 32(%rsp), %rdi | |
137 | movq 24(%rsp), %rsi | |
138 | movq 16(%rsp), %rdx | |
139 | movq 8(%rsp), %rcx | |
140 | movq (%rsp), %rax | |
141 | addq $0x38, %rsp | |
142 | ||
143 | jmp ftrace_stub | |
144 | END(mcount) | |
d61f82d0 | 145 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
606576ce | 146 | #endif /* CONFIG_FUNCTION_TRACER */ |
16444a8a | 147 | |
dc37db4d | 148 | #ifndef CONFIG_PREEMPT |
1da177e4 LT |
149 | #define retint_kernel retint_restore_args |
150 | #endif | |
2601e64d | 151 | |
72fe4858 | 152 | #ifdef CONFIG_PARAVIRT |
2be29982 | 153 | ENTRY(native_usergs_sysret64) |
72fe4858 GOC |
154 | swapgs |
155 | sysretq | |
156 | #endif /* CONFIG_PARAVIRT */ | |
157 | ||
2601e64d IM |
158 | |
159 | .macro TRACE_IRQS_IRETQ offset=ARGOFFSET | |
160 | #ifdef CONFIG_TRACE_IRQFLAGS | |
161 | bt $9,EFLAGS-\offset(%rsp) /* interrupts off? */ | |
162 | jnc 1f | |
163 | TRACE_IRQS_ON | |
164 | 1: | |
165 | #endif | |
166 | .endm | |
167 | ||
1da177e4 LT |
168 | /* |
169 | * C code is not supposed to know about undefined top of stack. Every time | |
170 | * a C function with an pt_regs argument is called from the SYSCALL based | |
171 | * fast path FIXUP_TOP_OF_STACK is needed. | |
172 | * RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs | |
173 | * manipulation. | |
174 | */ | |
175 | ||
176 | /* %rsp:at FRAMEEND */ | |
177 | .macro FIXUP_TOP_OF_STACK tmp | |
178 | movq %gs:pda_oldrsp,\tmp | |
179 | movq \tmp,RSP(%rsp) | |
180 | movq $__USER_DS,SS(%rsp) | |
181 | movq $__USER_CS,CS(%rsp) | |
182 | movq $-1,RCX(%rsp) | |
183 | movq R11(%rsp),\tmp /* get eflags */ | |
184 | movq \tmp,EFLAGS(%rsp) | |
185 | .endm | |
186 | ||
187 | .macro RESTORE_TOP_OF_STACK tmp,offset=0 | |
188 | movq RSP-\offset(%rsp),\tmp | |
189 | movq \tmp,%gs:pda_oldrsp | |
190 | movq EFLAGS-\offset(%rsp),\tmp | |
191 | movq \tmp,R11-\offset(%rsp) | |
192 | .endm | |
193 | ||
194 | .macro FAKE_STACK_FRAME child_rip | |
195 | /* push in order ss, rsp, eflags, cs, rip */ | |
3829ee6b | 196 | xorl %eax, %eax |
e04e0a63 | 197 | pushq $__KERNEL_DS /* ss */ |
1da177e4 | 198 | CFI_ADJUST_CFA_OFFSET 8 |
7effaa88 | 199 | /*CFI_REL_OFFSET ss,0*/ |
1da177e4 LT |
200 | pushq %rax /* rsp */ |
201 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 202 | CFI_REL_OFFSET rsp,0 |
1da177e4 LT |
203 | pushq $(1<<9) /* eflags - interrupts on */ |
204 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 205 | /*CFI_REL_OFFSET rflags,0*/ |
1da177e4 LT |
206 | pushq $__KERNEL_CS /* cs */ |
207 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 208 | /*CFI_REL_OFFSET cs,0*/ |
1da177e4 LT |
209 | pushq \child_rip /* rip */ |
210 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 211 | CFI_REL_OFFSET rip,0 |
1da177e4 LT |
212 | pushq %rax /* orig rax */ |
213 | CFI_ADJUST_CFA_OFFSET 8 | |
214 | .endm | |
215 | ||
216 | .macro UNFAKE_STACK_FRAME | |
217 | addq $8*6, %rsp | |
218 | CFI_ADJUST_CFA_OFFSET -(6*8) | |
219 | .endm | |
220 | ||
7effaa88 JB |
221 | .macro CFI_DEFAULT_STACK start=1 |
222 | .if \start | |
223 | CFI_STARTPROC simple | |
adf14236 | 224 | CFI_SIGNAL_FRAME |
7effaa88 JB |
225 | CFI_DEF_CFA rsp,SS+8 |
226 | .else | |
227 | CFI_DEF_CFA_OFFSET SS+8 | |
228 | .endif | |
229 | CFI_REL_OFFSET r15,R15 | |
230 | CFI_REL_OFFSET r14,R14 | |
231 | CFI_REL_OFFSET r13,R13 | |
232 | CFI_REL_OFFSET r12,R12 | |
233 | CFI_REL_OFFSET rbp,RBP | |
234 | CFI_REL_OFFSET rbx,RBX | |
235 | CFI_REL_OFFSET r11,R11 | |
236 | CFI_REL_OFFSET r10,R10 | |
237 | CFI_REL_OFFSET r9,R9 | |
238 | CFI_REL_OFFSET r8,R8 | |
239 | CFI_REL_OFFSET rax,RAX | |
240 | CFI_REL_OFFSET rcx,RCX | |
241 | CFI_REL_OFFSET rdx,RDX | |
242 | CFI_REL_OFFSET rsi,RSI | |
243 | CFI_REL_OFFSET rdi,RDI | |
244 | CFI_REL_OFFSET rip,RIP | |
245 | /*CFI_REL_OFFSET cs,CS*/ | |
246 | /*CFI_REL_OFFSET rflags,EFLAGS*/ | |
247 | CFI_REL_OFFSET rsp,RSP | |
248 | /*CFI_REL_OFFSET ss,SS*/ | |
1da177e4 LT |
249 | .endm |
250 | /* | |
251 | * A newly forked process directly context switches into this. | |
252 | */ | |
253 | /* rdi: prev */ | |
254 | ENTRY(ret_from_fork) | |
1da177e4 | 255 | CFI_DEFAULT_STACK |
658fdbef | 256 | push kernel_eflags(%rip) |
e0a5a5d9 | 257 | CFI_ADJUST_CFA_OFFSET 8 |
658fdbef | 258 | popf # reset kernel eflags |
e0a5a5d9 | 259 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 LT |
260 | call schedule_tail |
261 | GET_THREAD_INFO(%rcx) | |
26ccb8a7 | 262 | testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_flags(%rcx) |
1da177e4 LT |
263 | jnz rff_trace |
264 | rff_action: | |
265 | RESTORE_REST | |
266 | testl $3,CS-ARGOFFSET(%rsp) # from kernel_thread? | |
267 | je int_ret_from_sys_call | |
26ccb8a7 | 268 | testl $_TIF_IA32,TI_flags(%rcx) |
1da177e4 LT |
269 | jnz int_ret_from_sys_call |
270 | RESTORE_TOP_OF_STACK %rdi,ARGOFFSET | |
271 | jmp ret_from_sys_call | |
272 | rff_trace: | |
273 | movq %rsp,%rdi | |
274 | call syscall_trace_leave | |
275 | GET_THREAD_INFO(%rcx) | |
276 | jmp rff_action | |
277 | CFI_ENDPROC | |
4b787e0b | 278 | END(ret_from_fork) |
1da177e4 LT |
279 | |
280 | /* | |
281 | * System call entry. Upto 6 arguments in registers are supported. | |
282 | * | |
283 | * SYSCALL does not save anything on the stack and does not change the | |
284 | * stack pointer. | |
285 | */ | |
286 | ||
287 | /* | |
288 | * Register setup: | |
289 | * rax system call number | |
290 | * rdi arg0 | |
291 | * rcx return address for syscall/sysret, C arg3 | |
292 | * rsi arg1 | |
293 | * rdx arg2 | |
294 | * r10 arg3 (--> moved to rcx for C) | |
295 | * r8 arg4 | |
296 | * r9 arg5 | |
297 | * r11 eflags for syscall/sysret, temporary for C | |
298 | * r12-r15,rbp,rbx saved by C code, not touched. | |
299 | * | |
300 | * Interrupts are off on entry. | |
301 | * Only called from user space. | |
302 | * | |
303 | * XXX if we had a free scratch register we could save the RSP into the stack frame | |
304 | * and report it properly in ps. Unfortunately we haven't. | |
7bf36bbc AK |
305 | * |
306 | * When user can change the frames always force IRET. That is because | |
307 | * it deals with uncanonical addresses better. SYSRET has trouble | |
308 | * with them due to bugs in both AMD and Intel CPUs. | |
1da177e4 LT |
309 | */ |
310 | ||
311 | ENTRY(system_call) | |
7effaa88 | 312 | CFI_STARTPROC simple |
adf14236 | 313 | CFI_SIGNAL_FRAME |
dffead4e | 314 | CFI_DEF_CFA rsp,PDA_STACKOFFSET |
7effaa88 JB |
315 | CFI_REGISTER rip,rcx |
316 | /*CFI_REGISTER rflags,r11*/ | |
72fe4858 GOC |
317 | SWAPGS_UNSAFE_STACK |
318 | /* | |
319 | * A hypervisor implementation might want to use a label | |
320 | * after the swapgs, so that it can do the swapgs | |
321 | * for the guest and jump here on syscall. | |
322 | */ | |
323 | ENTRY(system_call_after_swapgs) | |
324 | ||
1da177e4 LT |
325 | movq %rsp,%gs:pda_oldrsp |
326 | movq %gs:pda_kernelstack,%rsp | |
2601e64d IM |
327 | /* |
328 | * No need to follow this irqs off/on section - it's straight | |
329 | * and short: | |
330 | */ | |
72fe4858 | 331 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 LT |
332 | SAVE_ARGS 8,1 |
333 | movq %rax,ORIG_RAX-ARGOFFSET(%rsp) | |
7effaa88 JB |
334 | movq %rcx,RIP-ARGOFFSET(%rsp) |
335 | CFI_REL_OFFSET rip,RIP-ARGOFFSET | |
1da177e4 | 336 | GET_THREAD_INFO(%rcx) |
d4d67150 | 337 | testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%rcx) |
1da177e4 | 338 | jnz tracesys |
86a1c34a | 339 | system_call_fastpath: |
1da177e4 LT |
340 | cmpq $__NR_syscall_max,%rax |
341 | ja badsys | |
342 | movq %r10,%rcx | |
343 | call *sys_call_table(,%rax,8) # XXX: rip relative | |
344 | movq %rax,RAX-ARGOFFSET(%rsp) | |
345 | /* | |
346 | * Syscall return path ending with SYSRET (fast path) | |
347 | * Has incomplete stack frame and undefined top of stack. | |
348 | */ | |
1da177e4 | 349 | ret_from_sys_call: |
11b854b2 | 350 | movl $_TIF_ALLWORK_MASK,%edi |
1da177e4 LT |
351 | /* edi: flagmask */ |
352 | sysret_check: | |
10cd706d | 353 | LOCKDEP_SYS_EXIT |
1da177e4 | 354 | GET_THREAD_INFO(%rcx) |
72fe4858 | 355 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 356 | TRACE_IRQS_OFF |
26ccb8a7 | 357 | movl TI_flags(%rcx),%edx |
1da177e4 LT |
358 | andl %edi,%edx |
359 | jnz sysret_careful | |
bcddc015 | 360 | CFI_REMEMBER_STATE |
2601e64d IM |
361 | /* |
362 | * sysretq will re-enable interrupts: | |
363 | */ | |
364 | TRACE_IRQS_ON | |
1da177e4 | 365 | movq RIP-ARGOFFSET(%rsp),%rcx |
7effaa88 | 366 | CFI_REGISTER rip,rcx |
1da177e4 | 367 | RESTORE_ARGS 0,-ARG_SKIP,1 |
7effaa88 | 368 | /*CFI_REGISTER rflags,r11*/ |
c7245da6 | 369 | movq %gs:pda_oldrsp, %rsp |
2be29982 | 370 | USERGS_SYSRET64 |
1da177e4 | 371 | |
bcddc015 | 372 | CFI_RESTORE_STATE |
1da177e4 LT |
373 | /* Handle reschedules */ |
374 | /* edx: work, edi: workmask */ | |
375 | sysret_careful: | |
376 | bt $TIF_NEED_RESCHED,%edx | |
377 | jnc sysret_signal | |
2601e64d | 378 | TRACE_IRQS_ON |
72fe4858 | 379 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 380 | pushq %rdi |
7effaa88 | 381 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
382 | call schedule |
383 | popq %rdi | |
7effaa88 | 384 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 LT |
385 | jmp sysret_check |
386 | ||
387 | /* Handle a signal */ | |
388 | sysret_signal: | |
2601e64d | 389 | TRACE_IRQS_ON |
72fe4858 | 390 | ENABLE_INTERRUPTS(CLBR_NONE) |
86a1c34a RM |
391 | #ifdef CONFIG_AUDITSYSCALL |
392 | bt $TIF_SYSCALL_AUDIT,%edx | |
393 | jc sysret_audit | |
394 | #endif | |
10ffdbb8 | 395 | /* edx: work flags (arg3) */ |
1da177e4 LT |
396 | leaq do_notify_resume(%rip),%rax |
397 | leaq -ARGOFFSET(%rsp),%rdi # &pt_regs -> arg1 | |
398 | xorl %esi,%esi # oldset -> arg2 | |
399 | call ptregscall_common | |
15e8f348 | 400 | movl $_TIF_WORK_MASK,%edi |
7bf36bbc AK |
401 | /* Use IRET because user could have changed frame. This |
402 | works because ptregscall_common has called FIXUP_TOP_OF_STACK. */ | |
72fe4858 | 403 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 404 | TRACE_IRQS_OFF |
7bf36bbc | 405 | jmp int_with_check |
1da177e4 | 406 | |
7effaa88 JB |
407 | badsys: |
408 | movq $-ENOSYS,RAX-ARGOFFSET(%rsp) | |
409 | jmp ret_from_sys_call | |
410 | ||
86a1c34a RM |
411 | #ifdef CONFIG_AUDITSYSCALL |
412 | /* | |
413 | * Fast path for syscall audit without full syscall trace. | |
414 | * We just call audit_syscall_entry() directly, and then | |
415 | * jump back to the normal fast path. | |
416 | */ | |
417 | auditsys: | |
418 | movq %r10,%r9 /* 6th arg: 4th syscall arg */ | |
419 | movq %rdx,%r8 /* 5th arg: 3rd syscall arg */ | |
420 | movq %rsi,%rcx /* 4th arg: 2nd syscall arg */ | |
421 | movq %rdi,%rdx /* 3rd arg: 1st syscall arg */ | |
422 | movq %rax,%rsi /* 2nd arg: syscall number */ | |
423 | movl $AUDIT_ARCH_X86_64,%edi /* 1st arg: audit arch */ | |
424 | call audit_syscall_entry | |
425 | LOAD_ARGS 0 /* reload call-clobbered registers */ | |
426 | jmp system_call_fastpath | |
427 | ||
428 | /* | |
429 | * Return fast path for syscall audit. Call audit_syscall_exit() | |
430 | * directly and then jump back to the fast path with TIF_SYSCALL_AUDIT | |
431 | * masked off. | |
432 | */ | |
433 | sysret_audit: | |
434 | movq %rax,%rsi /* second arg, syscall return value */ | |
435 | cmpq $0,%rax /* is it < 0? */ | |
436 | setl %al /* 1 if so, 0 if not */ | |
437 | movzbl %al,%edi /* zero-extend that into %edi */ | |
438 | inc %edi /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */ | |
439 | call audit_syscall_exit | |
440 | movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi | |
441 | jmp sysret_check | |
442 | #endif /* CONFIG_AUDITSYSCALL */ | |
443 | ||
1da177e4 LT |
444 | /* Do syscall tracing */ |
445 | tracesys: | |
86a1c34a RM |
446 | #ifdef CONFIG_AUDITSYSCALL |
447 | testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%rcx) | |
448 | jz auditsys | |
449 | #endif | |
1da177e4 | 450 | SAVE_REST |
a31f8dd7 | 451 | movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */ |
1da177e4 LT |
452 | FIXUP_TOP_OF_STACK %rdi |
453 | movq %rsp,%rdi | |
454 | call syscall_trace_enter | |
d4d67150 RM |
455 | /* |
456 | * Reload arg registers from stack in case ptrace changed them. | |
457 | * We don't reload %rax because syscall_trace_enter() returned | |
458 | * the value it wants us to use in the table lookup. | |
459 | */ | |
460 | LOAD_ARGS ARGOFFSET, 1 | |
1da177e4 LT |
461 | RESTORE_REST |
462 | cmpq $__NR_syscall_max,%rax | |
a31f8dd7 | 463 | ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */ |
1da177e4 LT |
464 | movq %r10,%rcx /* fixup for C */ |
465 | call *sys_call_table(,%rax,8) | |
a31f8dd7 | 466 | movq %rax,RAX-ARGOFFSET(%rsp) |
7bf36bbc | 467 | /* Use IRET because user could have changed frame */ |
1da177e4 | 468 | |
1da177e4 LT |
469 | /* |
470 | * Syscall return path ending with IRET. | |
471 | * Has correct top of stack, but partial stack frame. | |
bcddc015 JB |
472 | */ |
473 | .globl int_ret_from_sys_call | |
5cbf1565 | 474 | .globl int_with_check |
bcddc015 | 475 | int_ret_from_sys_call: |
72fe4858 | 476 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 477 | TRACE_IRQS_OFF |
1da177e4 LT |
478 | testl $3,CS-ARGOFFSET(%rsp) |
479 | je retint_restore_args | |
480 | movl $_TIF_ALLWORK_MASK,%edi | |
481 | /* edi: mask to check */ | |
482 | int_with_check: | |
10cd706d | 483 | LOCKDEP_SYS_EXIT_IRQ |
1da177e4 | 484 | GET_THREAD_INFO(%rcx) |
26ccb8a7 | 485 | movl TI_flags(%rcx),%edx |
1da177e4 LT |
486 | andl %edi,%edx |
487 | jnz int_careful | |
26ccb8a7 | 488 | andl $~TS_COMPAT,TI_status(%rcx) |
1da177e4 LT |
489 | jmp retint_swapgs |
490 | ||
491 | /* Either reschedule or signal or syscall exit tracking needed. */ | |
492 | /* First do a reschedule test. */ | |
493 | /* edx: work, edi: workmask */ | |
494 | int_careful: | |
495 | bt $TIF_NEED_RESCHED,%edx | |
496 | jnc int_very_careful | |
2601e64d | 497 | TRACE_IRQS_ON |
72fe4858 | 498 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 499 | pushq %rdi |
7effaa88 | 500 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
501 | call schedule |
502 | popq %rdi | |
7effaa88 | 503 | CFI_ADJUST_CFA_OFFSET -8 |
72fe4858 | 504 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 505 | TRACE_IRQS_OFF |
1da177e4 LT |
506 | jmp int_with_check |
507 | ||
508 | /* handle signals and tracing -- both require a full stack frame */ | |
509 | int_very_careful: | |
2601e64d | 510 | TRACE_IRQS_ON |
72fe4858 | 511 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 LT |
512 | SAVE_REST |
513 | /* Check for syscall exit trace */ | |
d4d67150 | 514 | testl $_TIF_WORK_SYSCALL_EXIT,%edx |
1da177e4 LT |
515 | jz int_signal |
516 | pushq %rdi | |
7effaa88 | 517 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
518 | leaq 8(%rsp),%rdi # &ptregs -> arg1 |
519 | call syscall_trace_leave | |
520 | popq %rdi | |
7effaa88 | 521 | CFI_ADJUST_CFA_OFFSET -8 |
d4d67150 | 522 | andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU),%edi |
1da177e4 LT |
523 | jmp int_restore_rest |
524 | ||
525 | int_signal: | |
8f4d37ec | 526 | testl $_TIF_DO_NOTIFY_MASK,%edx |
1da177e4 LT |
527 | jz 1f |
528 | movq %rsp,%rdi # &ptregs -> arg1 | |
529 | xorl %esi,%esi # oldset -> arg2 | |
530 | call do_notify_resume | |
eca91e78 | 531 | 1: movl $_TIF_WORK_MASK,%edi |
1da177e4 LT |
532 | int_restore_rest: |
533 | RESTORE_REST | |
72fe4858 | 534 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 535 | TRACE_IRQS_OFF |
1da177e4 LT |
536 | jmp int_with_check |
537 | CFI_ENDPROC | |
bcddc015 | 538 | END(system_call) |
1da177e4 LT |
539 | |
540 | /* | |
541 | * Certain special system calls that need to save a complete full stack frame. | |
542 | */ | |
543 | ||
544 | .macro PTREGSCALL label,func,arg | |
545 | .globl \label | |
546 | \label: | |
547 | leaq \func(%rip),%rax | |
548 | leaq -ARGOFFSET+8(%rsp),\arg /* 8 for return address */ | |
549 | jmp ptregscall_common | |
4b787e0b | 550 | END(\label) |
1da177e4 LT |
551 | .endm |
552 | ||
7effaa88 JB |
553 | CFI_STARTPROC |
554 | ||
1da177e4 LT |
555 | PTREGSCALL stub_clone, sys_clone, %r8 |
556 | PTREGSCALL stub_fork, sys_fork, %rdi | |
557 | PTREGSCALL stub_vfork, sys_vfork, %rdi | |
1da177e4 LT |
558 | PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx |
559 | PTREGSCALL stub_iopl, sys_iopl, %rsi | |
560 | ||
561 | ENTRY(ptregscall_common) | |
1da177e4 | 562 | popq %r11 |
7effaa88 JB |
563 | CFI_ADJUST_CFA_OFFSET -8 |
564 | CFI_REGISTER rip, r11 | |
1da177e4 LT |
565 | SAVE_REST |
566 | movq %r11, %r15 | |
7effaa88 | 567 | CFI_REGISTER rip, r15 |
1da177e4 LT |
568 | FIXUP_TOP_OF_STACK %r11 |
569 | call *%rax | |
570 | RESTORE_TOP_OF_STACK %r11 | |
571 | movq %r15, %r11 | |
7effaa88 | 572 | CFI_REGISTER rip, r11 |
1da177e4 LT |
573 | RESTORE_REST |
574 | pushq %r11 | |
7effaa88 JB |
575 | CFI_ADJUST_CFA_OFFSET 8 |
576 | CFI_REL_OFFSET rip, 0 | |
1da177e4 LT |
577 | ret |
578 | CFI_ENDPROC | |
4b787e0b | 579 | END(ptregscall_common) |
1da177e4 LT |
580 | |
581 | ENTRY(stub_execve) | |
582 | CFI_STARTPROC | |
583 | popq %r11 | |
7effaa88 JB |
584 | CFI_ADJUST_CFA_OFFSET -8 |
585 | CFI_REGISTER rip, r11 | |
1da177e4 | 586 | SAVE_REST |
1da177e4 | 587 | FIXUP_TOP_OF_STACK %r11 |
5d119b2c | 588 | movq %rsp, %rcx |
1da177e4 | 589 | call sys_execve |
1da177e4 | 590 | RESTORE_TOP_OF_STACK %r11 |
1da177e4 LT |
591 | movq %rax,RAX(%rsp) |
592 | RESTORE_REST | |
593 | jmp int_ret_from_sys_call | |
594 | CFI_ENDPROC | |
4b787e0b | 595 | END(stub_execve) |
1da177e4 LT |
596 | |
597 | /* | |
598 | * sigreturn is special because it needs to restore all registers on return. | |
599 | * This cannot be done with SYSRET, so use the IRET return path instead. | |
600 | */ | |
601 | ENTRY(stub_rt_sigreturn) | |
602 | CFI_STARTPROC | |
7effaa88 JB |
603 | addq $8, %rsp |
604 | CFI_ADJUST_CFA_OFFSET -8 | |
1da177e4 LT |
605 | SAVE_REST |
606 | movq %rsp,%rdi | |
607 | FIXUP_TOP_OF_STACK %r11 | |
608 | call sys_rt_sigreturn | |
609 | movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer | |
610 | RESTORE_REST | |
611 | jmp int_ret_from_sys_call | |
612 | CFI_ENDPROC | |
4b787e0b | 613 | END(stub_rt_sigreturn) |
1da177e4 | 614 | |
7effaa88 JB |
615 | /* |
616 | * initial frame state for interrupts and exceptions | |
617 | */ | |
618 | .macro _frame ref | |
619 | CFI_STARTPROC simple | |
adf14236 | 620 | CFI_SIGNAL_FRAME |
7effaa88 JB |
621 | CFI_DEF_CFA rsp,SS+8-\ref |
622 | /*CFI_REL_OFFSET ss,SS-\ref*/ | |
623 | CFI_REL_OFFSET rsp,RSP-\ref | |
624 | /*CFI_REL_OFFSET rflags,EFLAGS-\ref*/ | |
625 | /*CFI_REL_OFFSET cs,CS-\ref*/ | |
626 | CFI_REL_OFFSET rip,RIP-\ref | |
627 | .endm | |
628 | ||
629 | /* initial frame state for interrupts (and exceptions without error code) */ | |
630 | #define INTR_FRAME _frame RIP | |
631 | /* initial frame state for exceptions with error code (and interrupts with | |
632 | vector already pushed) */ | |
633 | #define XCPT_FRAME _frame ORIG_RAX | |
634 | ||
1da177e4 LT |
635 | /* |
636 | * Interrupt entry/exit. | |
637 | * | |
638 | * Interrupt entry points save only callee clobbered registers in fast path. | |
639 | * | |
640 | * Entry runs with interrupts off. | |
641 | */ | |
642 | ||
643 | /* 0(%rsp): interrupt number */ | |
644 | .macro interrupt func | |
1da177e4 | 645 | cld |
1da177e4 LT |
646 | SAVE_ARGS |
647 | leaq -ARGOFFSET(%rsp),%rdi # arg1 for handler | |
1de9c3f6 | 648 | pushq %rbp |
097a0788 GC |
649 | /* |
650 | * Save rbp twice: One is for marking the stack frame, as usual, and the | |
651 | * other, to fill pt_regs properly. This is because bx comes right | |
652 | * before the last saved register in that structure, and not bp. If the | |
653 | * base pointer were in the place bx is today, this would not be needed. | |
654 | */ | |
655 | movq %rbp, -8(%rsp) | |
1de9c3f6 JB |
656 | CFI_ADJUST_CFA_OFFSET 8 |
657 | CFI_REL_OFFSET rbp, 0 | |
658 | movq %rsp,%rbp | |
659 | CFI_DEF_CFA_REGISTER rbp | |
1da177e4 LT |
660 | testl $3,CS(%rdi) |
661 | je 1f | |
72fe4858 | 662 | SWAPGS |
96e54049 AK |
663 | /* irqcount is used to check if a CPU is already on an interrupt |
664 | stack or not. While this is essentially redundant with preempt_count | |
665 | it is a little cheaper to use a separate counter in the PDA | |
666 | (short of moving irq_enter into assembly, which would be too | |
667 | much work) */ | |
668 | 1: incl %gs:pda_irqcount | |
1de9c3f6 | 669 | cmoveq %gs:pda_irqstackptr,%rsp |
2699500b | 670 | push %rbp # backlink for old unwinder |
2601e64d IM |
671 | /* |
672 | * We entered an interrupt context - irqs are off: | |
673 | */ | |
674 | TRACE_IRQS_OFF | |
1da177e4 LT |
675 | call \func |
676 | .endm | |
677 | ||
678 | ENTRY(common_interrupt) | |
7effaa88 | 679 | XCPT_FRAME |
1da177e4 LT |
680 | interrupt do_IRQ |
681 | /* 0(%rsp): oldrsp-ARGOFFSET */ | |
7effaa88 | 682 | ret_from_intr: |
72fe4858 | 683 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 684 | TRACE_IRQS_OFF |
3829ee6b | 685 | decl %gs:pda_irqcount |
1de9c3f6 | 686 | leaveq |
7effaa88 | 687 | CFI_DEF_CFA_REGISTER rsp |
1de9c3f6 | 688 | CFI_ADJUST_CFA_OFFSET -8 |
7effaa88 | 689 | exit_intr: |
1da177e4 LT |
690 | GET_THREAD_INFO(%rcx) |
691 | testl $3,CS-ARGOFFSET(%rsp) | |
692 | je retint_kernel | |
693 | ||
694 | /* Interrupt came from user space */ | |
695 | /* | |
696 | * Has a correct top of stack, but a partial stack frame | |
697 | * %rcx: thread info. Interrupts off. | |
698 | */ | |
699 | retint_with_reschedule: | |
700 | movl $_TIF_WORK_MASK,%edi | |
7effaa88 | 701 | retint_check: |
10cd706d | 702 | LOCKDEP_SYS_EXIT_IRQ |
26ccb8a7 | 703 | movl TI_flags(%rcx),%edx |
1da177e4 | 704 | andl %edi,%edx |
7effaa88 | 705 | CFI_REMEMBER_STATE |
1da177e4 | 706 | jnz retint_careful |
10cd706d PZ |
707 | |
708 | retint_swapgs: /* return to user-space */ | |
2601e64d IM |
709 | /* |
710 | * The iretq could re-enable interrupts: | |
711 | */ | |
72fe4858 | 712 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d | 713 | TRACE_IRQS_IRETQ |
72fe4858 | 714 | SWAPGS |
2601e64d IM |
715 | jmp restore_args |
716 | ||
10cd706d | 717 | retint_restore_args: /* return to kernel space */ |
72fe4858 | 718 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d IM |
719 | /* |
720 | * The iretq could re-enable interrupts: | |
721 | */ | |
722 | TRACE_IRQS_IRETQ | |
723 | restore_args: | |
3701d863 IM |
724 | RESTORE_ARGS 0,8,0 |
725 | ||
f7f3d791 | 726 | irq_return: |
72fe4858 | 727 | INTERRUPT_RETURN |
3701d863 IM |
728 | |
729 | .section __ex_table, "a" | |
730 | .quad irq_return, bad_iret | |
731 | .previous | |
732 | ||
733 | #ifdef CONFIG_PARAVIRT | |
72fe4858 | 734 | ENTRY(native_iret) |
1da177e4 LT |
735 | iretq |
736 | ||
737 | .section __ex_table,"a" | |
72fe4858 | 738 | .quad native_iret, bad_iret |
1da177e4 | 739 | .previous |
3701d863 IM |
740 | #endif |
741 | ||
1da177e4 | 742 | .section .fixup,"ax" |
1da177e4 | 743 | bad_iret: |
3aa4b37d RM |
744 | /* |
745 | * The iret traps when the %cs or %ss being restored is bogus. | |
746 | * We've lost the original trap vector and error code. | |
747 | * #GPF is the most likely one to get for an invalid selector. | |
748 | * So pretend we completed the iret and took the #GPF in user mode. | |
749 | * | |
750 | * We are now running with the kernel GS after exception recovery. | |
751 | * But error_entry expects us to have user GS to match the user %cs, | |
752 | * so swap back. | |
753 | */ | |
754 | pushq $0 | |
755 | ||
756 | SWAPGS | |
757 | jmp general_protection | |
758 | ||
72fe4858 GOC |
759 | .previous |
760 | ||
7effaa88 | 761 | /* edi: workmask, edx: work */ |
1da177e4 | 762 | retint_careful: |
7effaa88 | 763 | CFI_RESTORE_STATE |
1da177e4 LT |
764 | bt $TIF_NEED_RESCHED,%edx |
765 | jnc retint_signal | |
2601e64d | 766 | TRACE_IRQS_ON |
72fe4858 | 767 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 768 | pushq %rdi |
7effaa88 | 769 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
770 | call schedule |
771 | popq %rdi | |
7effaa88 | 772 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 | 773 | GET_THREAD_INFO(%rcx) |
72fe4858 | 774 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 775 | TRACE_IRQS_OFF |
1da177e4 LT |
776 | jmp retint_check |
777 | ||
778 | retint_signal: | |
8f4d37ec | 779 | testl $_TIF_DO_NOTIFY_MASK,%edx |
10ffdbb8 | 780 | jz retint_swapgs |
2601e64d | 781 | TRACE_IRQS_ON |
72fe4858 | 782 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 LT |
783 | SAVE_REST |
784 | movq $-1,ORIG_RAX(%rsp) | |
3829ee6b | 785 | xorl %esi,%esi # oldset |
1da177e4 LT |
786 | movq %rsp,%rdi # &pt_regs |
787 | call do_notify_resume | |
788 | RESTORE_REST | |
72fe4858 | 789 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 790 | TRACE_IRQS_OFF |
be9e6870 | 791 | GET_THREAD_INFO(%rcx) |
eca91e78 | 792 | jmp retint_with_reschedule |
1da177e4 LT |
793 | |
794 | #ifdef CONFIG_PREEMPT | |
795 | /* Returning to kernel space. Check if we need preemption */ | |
796 | /* rcx: threadinfo. interrupts off. */ | |
b06babac | 797 | ENTRY(retint_kernel) |
26ccb8a7 | 798 | cmpl $0,TI_preempt_count(%rcx) |
1da177e4 | 799 | jnz retint_restore_args |
26ccb8a7 | 800 | bt $TIF_NEED_RESCHED,TI_flags(%rcx) |
1da177e4 LT |
801 | jnc retint_restore_args |
802 | bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */ | |
803 | jnc retint_restore_args | |
804 | call preempt_schedule_irq | |
805 | jmp exit_intr | |
806 | #endif | |
4b787e0b | 807 | |
1da177e4 | 808 | CFI_ENDPROC |
4b787e0b | 809 | END(common_interrupt) |
1da177e4 LT |
810 | |
811 | /* | |
812 | * APIC interrupts. | |
813 | */ | |
814 | .macro apicinterrupt num,func | |
7effaa88 | 815 | INTR_FRAME |
19eadf98 | 816 | pushq $~(\num) |
7effaa88 | 817 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
818 | interrupt \func |
819 | jmp ret_from_intr | |
820 | CFI_ENDPROC | |
821 | .endm | |
822 | ||
823 | ENTRY(thermal_interrupt) | |
824 | apicinterrupt THERMAL_APIC_VECTOR,smp_thermal_interrupt | |
4b787e0b | 825 | END(thermal_interrupt) |
1da177e4 | 826 | |
89b831ef JS |
827 | ENTRY(threshold_interrupt) |
828 | apicinterrupt THRESHOLD_APIC_VECTOR,mce_threshold_interrupt | |
4b787e0b | 829 | END(threshold_interrupt) |
89b831ef | 830 | |
1da177e4 LT |
831 | #ifdef CONFIG_SMP |
832 | ENTRY(reschedule_interrupt) | |
833 | apicinterrupt RESCHEDULE_VECTOR,smp_reschedule_interrupt | |
4b787e0b | 834 | END(reschedule_interrupt) |
1da177e4 | 835 | |
e5bc8b6b AK |
836 | .macro INVALIDATE_ENTRY num |
837 | ENTRY(invalidate_interrupt\num) | |
838 | apicinterrupt INVALIDATE_TLB_VECTOR_START+\num,smp_invalidate_interrupt | |
4b787e0b | 839 | END(invalidate_interrupt\num) |
e5bc8b6b AK |
840 | .endm |
841 | ||
842 | INVALIDATE_ENTRY 0 | |
843 | INVALIDATE_ENTRY 1 | |
844 | INVALIDATE_ENTRY 2 | |
845 | INVALIDATE_ENTRY 3 | |
846 | INVALIDATE_ENTRY 4 | |
847 | INVALIDATE_ENTRY 5 | |
848 | INVALIDATE_ENTRY 6 | |
849 | INVALIDATE_ENTRY 7 | |
1da177e4 LT |
850 | |
851 | ENTRY(call_function_interrupt) | |
852 | apicinterrupt CALL_FUNCTION_VECTOR,smp_call_function_interrupt | |
4b787e0b | 853 | END(call_function_interrupt) |
3b16cf87 JA |
854 | ENTRY(call_function_single_interrupt) |
855 | apicinterrupt CALL_FUNCTION_SINGLE_VECTOR,smp_call_function_single_interrupt | |
856 | END(call_function_single_interrupt) | |
61014292 EB |
857 | ENTRY(irq_move_cleanup_interrupt) |
858 | apicinterrupt IRQ_MOVE_CLEANUP_VECTOR,smp_irq_move_cleanup_interrupt | |
859 | END(irq_move_cleanup_interrupt) | |
1da177e4 LT |
860 | #endif |
861 | ||
1da177e4 LT |
862 | ENTRY(apic_timer_interrupt) |
863 | apicinterrupt LOCAL_TIMER_VECTOR,smp_apic_timer_interrupt | |
4b787e0b | 864 | END(apic_timer_interrupt) |
1da177e4 | 865 | |
1812924b CW |
866 | ENTRY(uv_bau_message_intr1) |
867 | apicinterrupt 220,uv_bau_message_interrupt | |
868 | END(uv_bau_message_intr1) | |
869 | ||
1da177e4 LT |
870 | ENTRY(error_interrupt) |
871 | apicinterrupt ERROR_APIC_VECTOR,smp_error_interrupt | |
4b787e0b | 872 | END(error_interrupt) |
1da177e4 LT |
873 | |
874 | ENTRY(spurious_interrupt) | |
875 | apicinterrupt SPURIOUS_APIC_VECTOR,smp_spurious_interrupt | |
4b787e0b | 876 | END(spurious_interrupt) |
1da177e4 LT |
877 | |
878 | /* | |
879 | * Exception entry points. | |
880 | */ | |
881 | .macro zeroentry sym | |
7effaa88 | 882 | INTR_FRAME |
fab58420 | 883 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1da177e4 | 884 | pushq $0 /* push error code/oldrax */ |
7effaa88 | 885 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 | 886 | pushq %rax /* push real oldrax to the rdi slot */ |
7effaa88 | 887 | CFI_ADJUST_CFA_OFFSET 8 |
37550907 | 888 | CFI_REL_OFFSET rax,0 |
1da177e4 LT |
889 | leaq \sym(%rip),%rax |
890 | jmp error_entry | |
7effaa88 | 891 | CFI_ENDPROC |
1da177e4 LT |
892 | .endm |
893 | ||
894 | .macro errorentry sym | |
7effaa88 | 895 | XCPT_FRAME |
fab58420 | 896 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1da177e4 | 897 | pushq %rax |
7effaa88 | 898 | CFI_ADJUST_CFA_OFFSET 8 |
37550907 | 899 | CFI_REL_OFFSET rax,0 |
1da177e4 LT |
900 | leaq \sym(%rip),%rax |
901 | jmp error_entry | |
7effaa88 | 902 | CFI_ENDPROC |
1da177e4 LT |
903 | .endm |
904 | ||
905 | /* error code is on the stack already */ | |
906 | /* handle NMI like exceptions that can happen everywhere */ | |
2601e64d | 907 | .macro paranoidentry sym, ist=0, irqtrace=1 |
1da177e4 LT |
908 | SAVE_ALL |
909 | cld | |
910 | movl $1,%ebx | |
911 | movl $MSR_GS_BASE,%ecx | |
912 | rdmsr | |
913 | testl %edx,%edx | |
914 | js 1f | |
72fe4858 | 915 | SWAPGS |
1da177e4 | 916 | xorl %ebx,%ebx |
b556b35e JB |
917 | 1: |
918 | .if \ist | |
919 | movq %gs:pda_data_offset, %rbp | |
920 | .endif | |
7e61a793 AH |
921 | .if \irqtrace |
922 | TRACE_IRQS_OFF | |
923 | .endif | |
b556b35e | 924 | movq %rsp,%rdi |
1da177e4 LT |
925 | movq ORIG_RAX(%rsp),%rsi |
926 | movq $-1,ORIG_RAX(%rsp) | |
b556b35e | 927 | .if \ist |
5f8efbb9 | 928 | subq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) |
b556b35e | 929 | .endif |
1da177e4 | 930 | call \sym |
b556b35e | 931 | .if \ist |
5f8efbb9 | 932 | addq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) |
b556b35e | 933 | .endif |
72fe4858 | 934 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d IM |
935 | .if \irqtrace |
936 | TRACE_IRQS_OFF | |
937 | .endif | |
1da177e4 | 938 | .endm |
2601e64d IM |
939 | |
940 | /* | |
941 | * "Paranoid" exit path from exception stack. | |
942 | * Paranoid because this is used by NMIs and cannot take | |
943 | * any kernel state for granted. | |
944 | * We don't do kernel preemption checks here, because only | |
945 | * NMI should be common and it does not enable IRQs and | |
946 | * cannot get reschedule ticks. | |
947 | * | |
948 | * "trace" is 0 for the NMI handler only, because irq-tracing | |
949 | * is fundamentally NMI-unsafe. (we cannot change the soft and | |
950 | * hard flags at once, atomically) | |
951 | */ | |
952 | .macro paranoidexit trace=1 | |
953 | /* ebx: no swapgs flag */ | |
954 | paranoid_exit\trace: | |
955 | testl %ebx,%ebx /* swapgs needed? */ | |
956 | jnz paranoid_restore\trace | |
957 | testl $3,CS(%rsp) | |
958 | jnz paranoid_userspace\trace | |
959 | paranoid_swapgs\trace: | |
7a0a2dff | 960 | .if \trace |
2601e64d | 961 | TRACE_IRQS_IRETQ 0 |
7a0a2dff | 962 | .endif |
72fe4858 | 963 | SWAPGS_UNSAFE_STACK |
2601e64d IM |
964 | paranoid_restore\trace: |
965 | RESTORE_ALL 8 | |
3701d863 | 966 | jmp irq_return |
2601e64d IM |
967 | paranoid_userspace\trace: |
968 | GET_THREAD_INFO(%rcx) | |
26ccb8a7 | 969 | movl TI_flags(%rcx),%ebx |
2601e64d IM |
970 | andl $_TIF_WORK_MASK,%ebx |
971 | jz paranoid_swapgs\trace | |
972 | movq %rsp,%rdi /* &pt_regs */ | |
973 | call sync_regs | |
974 | movq %rax,%rsp /* switch stack for scheduling */ | |
975 | testl $_TIF_NEED_RESCHED,%ebx | |
976 | jnz paranoid_schedule\trace | |
977 | movl %ebx,%edx /* arg3: thread flags */ | |
978 | .if \trace | |
979 | TRACE_IRQS_ON | |
980 | .endif | |
72fe4858 | 981 | ENABLE_INTERRUPTS(CLBR_NONE) |
2601e64d IM |
982 | xorl %esi,%esi /* arg2: oldset */ |
983 | movq %rsp,%rdi /* arg1: &pt_regs */ | |
984 | call do_notify_resume | |
72fe4858 | 985 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d IM |
986 | .if \trace |
987 | TRACE_IRQS_OFF | |
988 | .endif | |
989 | jmp paranoid_userspace\trace | |
990 | paranoid_schedule\trace: | |
991 | .if \trace | |
992 | TRACE_IRQS_ON | |
993 | .endif | |
72fe4858 | 994 | ENABLE_INTERRUPTS(CLBR_ANY) |
2601e64d | 995 | call schedule |
72fe4858 | 996 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d IM |
997 | .if \trace |
998 | TRACE_IRQS_OFF | |
999 | .endif | |
1000 | jmp paranoid_userspace\trace | |
1001 | CFI_ENDPROC | |
1002 | .endm | |
1003 | ||
1da177e4 LT |
1004 | /* |
1005 | * Exception entry point. This expects an error code/orig_rax on the stack | |
1006 | * and the exception handler in %rax. | |
1007 | */ | |
d28c4393 | 1008 | KPROBE_ENTRY(error_entry) |
7effaa88 | 1009 | _frame RDI |
37550907 | 1010 | CFI_REL_OFFSET rax,0 |
1da177e4 LT |
1011 | /* rdi slot contains rax, oldrax contains error code */ |
1012 | cld | |
1013 | subq $14*8,%rsp | |
1014 | CFI_ADJUST_CFA_OFFSET (14*8) | |
1015 | movq %rsi,13*8(%rsp) | |
1016 | CFI_REL_OFFSET rsi,RSI | |
1017 | movq 14*8(%rsp),%rsi /* load rax from rdi slot */ | |
37550907 | 1018 | CFI_REGISTER rax,rsi |
1da177e4 LT |
1019 | movq %rdx,12*8(%rsp) |
1020 | CFI_REL_OFFSET rdx,RDX | |
1021 | movq %rcx,11*8(%rsp) | |
1022 | CFI_REL_OFFSET rcx,RCX | |
1023 | movq %rsi,10*8(%rsp) /* store rax */ | |
1024 | CFI_REL_OFFSET rax,RAX | |
1025 | movq %r8, 9*8(%rsp) | |
1026 | CFI_REL_OFFSET r8,R8 | |
1027 | movq %r9, 8*8(%rsp) | |
1028 | CFI_REL_OFFSET r9,R9 | |
1029 | movq %r10,7*8(%rsp) | |
1030 | CFI_REL_OFFSET r10,R10 | |
1031 | movq %r11,6*8(%rsp) | |
1032 | CFI_REL_OFFSET r11,R11 | |
1033 | movq %rbx,5*8(%rsp) | |
1034 | CFI_REL_OFFSET rbx,RBX | |
1035 | movq %rbp,4*8(%rsp) | |
1036 | CFI_REL_OFFSET rbp,RBP | |
1037 | movq %r12,3*8(%rsp) | |
1038 | CFI_REL_OFFSET r12,R12 | |
1039 | movq %r13,2*8(%rsp) | |
1040 | CFI_REL_OFFSET r13,R13 | |
1041 | movq %r14,1*8(%rsp) | |
1042 | CFI_REL_OFFSET r14,R14 | |
1043 | movq %r15,(%rsp) | |
1044 | CFI_REL_OFFSET r15,R15 | |
1045 | xorl %ebx,%ebx | |
1046 | testl $3,CS(%rsp) | |
1047 | je error_kernelspace | |
1048 | error_swapgs: | |
72fe4858 | 1049 | SWAPGS |
6b11d4ef AH |
1050 | error_sti: |
1051 | TRACE_IRQS_OFF | |
1da177e4 | 1052 | movq %rdi,RDI(%rsp) |
37550907 | 1053 | CFI_REL_OFFSET rdi,RDI |
1da177e4 LT |
1054 | movq %rsp,%rdi |
1055 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
1056 | movq $-1,ORIG_RAX(%rsp) | |
1057 | call *%rax | |
10cd706d PZ |
1058 | /* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */ |
1059 | error_exit: | |
1060 | movl %ebx,%eax | |
1da177e4 | 1061 | RESTORE_REST |
72fe4858 | 1062 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 1063 | TRACE_IRQS_OFF |
1da177e4 LT |
1064 | GET_THREAD_INFO(%rcx) |
1065 | testl %eax,%eax | |
1066 | jne retint_kernel | |
10cd706d | 1067 | LOCKDEP_SYS_EXIT_IRQ |
26ccb8a7 | 1068 | movl TI_flags(%rcx),%edx |
1da177e4 LT |
1069 | movl $_TIF_WORK_MASK,%edi |
1070 | andl %edi,%edx | |
1071 | jnz retint_careful | |
10cd706d | 1072 | jmp retint_swapgs |
1da177e4 LT |
1073 | CFI_ENDPROC |
1074 | ||
1075 | error_kernelspace: | |
1076 | incl %ebx | |
1077 | /* There are two places in the kernel that can potentially fault with | |
1078 | usergs. Handle them here. The exception handlers after | |
1079 | iret run with kernel gs again, so don't set the user space flag. | |
1080 | B stepping K8s sometimes report an truncated RIP for IRET | |
1081 | exceptions returning to compat mode. Check for these here too. */ | |
9d8ad5d6 VN |
1082 | leaq irq_return(%rip),%rcx |
1083 | cmpq %rcx,RIP(%rsp) | |
1da177e4 | 1084 | je error_swapgs |
9d8ad5d6 VN |
1085 | movl %ecx,%ecx /* zero extend */ |
1086 | cmpq %rcx,RIP(%rsp) | |
1da177e4 LT |
1087 | je error_swapgs |
1088 | cmpq $gs_change,RIP(%rsp) | |
1089 | je error_swapgs | |
1090 | jmp error_sti | |
d28c4393 | 1091 | KPROBE_END(error_entry) |
1da177e4 LT |
1092 | |
1093 | /* Reload gs selector with exception handling */ | |
1094 | /* edi: new selector */ | |
9f9d489a | 1095 | ENTRY(native_load_gs_index) |
7effaa88 | 1096 | CFI_STARTPROC |
1da177e4 | 1097 | pushf |
7effaa88 | 1098 | CFI_ADJUST_CFA_OFFSET 8 |
72fe4858 GOC |
1099 | DISABLE_INTERRUPTS(CLBR_ANY | ~(CLBR_RDI)) |
1100 | SWAPGS | |
1da177e4 LT |
1101 | gs_change: |
1102 | movl %edi,%gs | |
1103 | 2: mfence /* workaround */ | |
72fe4858 | 1104 | SWAPGS |
1da177e4 | 1105 | popf |
7effaa88 | 1106 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 | 1107 | ret |
7effaa88 | 1108 | CFI_ENDPROC |
9f9d489a | 1109 | ENDPROC(native_load_gs_index) |
1da177e4 LT |
1110 | |
1111 | .section __ex_table,"a" | |
1112 | .align 8 | |
1113 | .quad gs_change,bad_gs | |
1114 | .previous | |
1115 | .section .fixup,"ax" | |
1116 | /* running with kernelgs */ | |
1117 | bad_gs: | |
72fe4858 | 1118 | SWAPGS /* switch back to user gs */ |
1da177e4 LT |
1119 | xorl %eax,%eax |
1120 | movl %eax,%gs | |
1121 | jmp 2b | |
1122 | .previous | |
1123 | ||
1124 | /* | |
1125 | * Create a kernel thread. | |
1126 | * | |
1127 | * C extern interface: | |
1128 | * extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
1129 | * | |
1130 | * asm input arguments: | |
1131 | * rdi: fn, rsi: arg, rdx: flags | |
1132 | */ | |
1133 | ENTRY(kernel_thread) | |
1134 | CFI_STARTPROC | |
1135 | FAKE_STACK_FRAME $child_rip | |
1136 | SAVE_ALL | |
1137 | ||
1138 | # rdi: flags, rsi: usp, rdx: will be &pt_regs | |
1139 | movq %rdx,%rdi | |
1140 | orq kernel_thread_flags(%rip),%rdi | |
1141 | movq $-1, %rsi | |
1142 | movq %rsp, %rdx | |
1143 | ||
1144 | xorl %r8d,%r8d | |
1145 | xorl %r9d,%r9d | |
1146 | ||
1147 | # clone now | |
1148 | call do_fork | |
1149 | movq %rax,RAX(%rsp) | |
1150 | xorl %edi,%edi | |
1151 | ||
1152 | /* | |
1153 | * It isn't worth to check for reschedule here, | |
1154 | * so internally to the x86_64 port you can rely on kernel_thread() | |
1155 | * not to reschedule the child before returning, this avoids the need | |
1156 | * of hacks for example to fork off the per-CPU idle tasks. | |
1157 | * [Hopefully no generic code relies on the reschedule -AK] | |
1158 | */ | |
1159 | RESTORE_ALL | |
1160 | UNFAKE_STACK_FRAME | |
1161 | ret | |
1162 | CFI_ENDPROC | |
4b787e0b | 1163 | ENDPROC(kernel_thread) |
1da177e4 LT |
1164 | |
1165 | child_rip: | |
c05991ed AK |
1166 | pushq $0 # fake return address |
1167 | CFI_STARTPROC | |
1da177e4 LT |
1168 | /* |
1169 | * Here we are in the child and the registers are set as they were | |
1170 | * at kernel_thread() invocation in the parent. | |
1171 | */ | |
1172 | movq %rdi, %rax | |
1173 | movq %rsi, %rdi | |
1174 | call *%rax | |
1175 | # exit | |
1c5b5cfd | 1176 | mov %eax, %edi |
1da177e4 | 1177 | call do_exit |
c05991ed | 1178 | CFI_ENDPROC |
4b787e0b | 1179 | ENDPROC(child_rip) |
1da177e4 LT |
1180 | |
1181 | /* | |
1182 | * execve(). This function needs to use IRET, not SYSRET, to set up all state properly. | |
1183 | * | |
1184 | * C extern interface: | |
1185 | * extern long execve(char *name, char **argv, char **envp) | |
1186 | * | |
1187 | * asm input arguments: | |
1188 | * rdi: name, rsi: argv, rdx: envp | |
1189 | * | |
1190 | * We want to fallback into: | |
5d119b2c | 1191 | * extern long sys_execve(char *name, char **argv,char **envp, struct pt_regs *regs) |
1da177e4 LT |
1192 | * |
1193 | * do_sys_execve asm fallback arguments: | |
5d119b2c | 1194 | * rdi: name, rsi: argv, rdx: envp, rcx: fake frame on the stack |
1da177e4 | 1195 | */ |
3db03b4a | 1196 | ENTRY(kernel_execve) |
1da177e4 LT |
1197 | CFI_STARTPROC |
1198 | FAKE_STACK_FRAME $0 | |
1199 | SAVE_ALL | |
5d119b2c | 1200 | movq %rsp,%rcx |
1da177e4 LT |
1201 | call sys_execve |
1202 | movq %rax, RAX(%rsp) | |
1203 | RESTORE_REST | |
1204 | testq %rax,%rax | |
1205 | je int_ret_from_sys_call | |
1206 | RESTORE_ARGS | |
1207 | UNFAKE_STACK_FRAME | |
1208 | ret | |
1209 | CFI_ENDPROC | |
3db03b4a | 1210 | ENDPROC(kernel_execve) |
1da177e4 | 1211 | |
0f2fbdcb | 1212 | KPROBE_ENTRY(page_fault) |
1da177e4 | 1213 | errorentry do_page_fault |
d28c4393 | 1214 | KPROBE_END(page_fault) |
1da177e4 LT |
1215 | |
1216 | ENTRY(coprocessor_error) | |
1217 | zeroentry do_coprocessor_error | |
4b787e0b | 1218 | END(coprocessor_error) |
1da177e4 LT |
1219 | |
1220 | ENTRY(simd_coprocessor_error) | |
1221 | zeroentry do_simd_coprocessor_error | |
4b787e0b | 1222 | END(simd_coprocessor_error) |
1da177e4 LT |
1223 | |
1224 | ENTRY(device_not_available) | |
e407d620 | 1225 | zeroentry do_device_not_available |
4b787e0b | 1226 | END(device_not_available) |
1da177e4 LT |
1227 | |
1228 | /* runs on exception stack */ | |
0f2fbdcb | 1229 | KPROBE_ENTRY(debug) |
7effaa88 | 1230 | INTR_FRAME |
09402947 | 1231 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1da177e4 LT |
1232 | pushq $0 |
1233 | CFI_ADJUST_CFA_OFFSET 8 | |
5f8efbb9 | 1234 | paranoidentry do_debug, DEBUG_STACK |
2601e64d | 1235 | paranoidexit |
d28c4393 | 1236 | KPROBE_END(debug) |
1da177e4 LT |
1237 | |
1238 | /* runs on exception stack */ | |
eddb6fb9 | 1239 | KPROBE_ENTRY(nmi) |
7effaa88 | 1240 | INTR_FRAME |
09402947 | 1241 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1da177e4 | 1242 | pushq $-1 |
7effaa88 | 1243 | CFI_ADJUST_CFA_OFFSET 8 |
2601e64d IM |
1244 | paranoidentry do_nmi, 0, 0 |
1245 | #ifdef CONFIG_TRACE_IRQFLAGS | |
1246 | paranoidexit 0 | |
1247 | #else | |
1248 | jmp paranoid_exit1 | |
1249 | CFI_ENDPROC | |
1250 | #endif | |
d28c4393 | 1251 | KPROBE_END(nmi) |
6fefb0d1 | 1252 | |
0f2fbdcb | 1253 | KPROBE_ENTRY(int3) |
b556b35e | 1254 | INTR_FRAME |
09402947 | 1255 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
b556b35e JB |
1256 | pushq $0 |
1257 | CFI_ADJUST_CFA_OFFSET 8 | |
5f8efbb9 | 1258 | paranoidentry do_int3, DEBUG_STACK |
2601e64d | 1259 | jmp paranoid_exit1 |
b556b35e | 1260 | CFI_ENDPROC |
d28c4393 | 1261 | KPROBE_END(int3) |
1da177e4 LT |
1262 | |
1263 | ENTRY(overflow) | |
1264 | zeroentry do_overflow | |
4b787e0b | 1265 | END(overflow) |
1da177e4 LT |
1266 | |
1267 | ENTRY(bounds) | |
1268 | zeroentry do_bounds | |
4b787e0b | 1269 | END(bounds) |
1da177e4 LT |
1270 | |
1271 | ENTRY(invalid_op) | |
1272 | zeroentry do_invalid_op | |
4b787e0b | 1273 | END(invalid_op) |
1da177e4 LT |
1274 | |
1275 | ENTRY(coprocessor_segment_overrun) | |
1276 | zeroentry do_coprocessor_segment_overrun | |
4b787e0b | 1277 | END(coprocessor_segment_overrun) |
1da177e4 | 1278 | |
1da177e4 LT |
1279 | /* runs on exception stack */ |
1280 | ENTRY(double_fault) | |
7effaa88 | 1281 | XCPT_FRAME |
09402947 | 1282 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1da177e4 | 1283 | paranoidentry do_double_fault |
2601e64d | 1284 | jmp paranoid_exit1 |
1da177e4 | 1285 | CFI_ENDPROC |
4b787e0b | 1286 | END(double_fault) |
1da177e4 LT |
1287 | |
1288 | ENTRY(invalid_TSS) | |
1289 | errorentry do_invalid_TSS | |
4b787e0b | 1290 | END(invalid_TSS) |
1da177e4 LT |
1291 | |
1292 | ENTRY(segment_not_present) | |
1293 | errorentry do_segment_not_present | |
4b787e0b | 1294 | END(segment_not_present) |
1da177e4 LT |
1295 | |
1296 | /* runs on exception stack */ | |
1297 | ENTRY(stack_segment) | |
7effaa88 | 1298 | XCPT_FRAME |
09402947 | 1299 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1da177e4 | 1300 | paranoidentry do_stack_segment |
2601e64d | 1301 | jmp paranoid_exit1 |
1da177e4 | 1302 | CFI_ENDPROC |
4b787e0b | 1303 | END(stack_segment) |
1da177e4 | 1304 | |
0f2fbdcb | 1305 | KPROBE_ENTRY(general_protection) |
1da177e4 | 1306 | errorentry do_general_protection |
d28c4393 | 1307 | KPROBE_END(general_protection) |
1da177e4 LT |
1308 | |
1309 | ENTRY(alignment_check) | |
1310 | errorentry do_alignment_check | |
4b787e0b | 1311 | END(alignment_check) |
1da177e4 LT |
1312 | |
1313 | ENTRY(divide_error) | |
1314 | zeroentry do_divide_error | |
4b787e0b | 1315 | END(divide_error) |
1da177e4 LT |
1316 | |
1317 | ENTRY(spurious_interrupt_bug) | |
1318 | zeroentry do_spurious_interrupt_bug | |
4b787e0b | 1319 | END(spurious_interrupt_bug) |
1da177e4 LT |
1320 | |
1321 | #ifdef CONFIG_X86_MCE | |
1322 | /* runs on exception stack */ | |
1323 | ENTRY(machine_check) | |
7effaa88 | 1324 | INTR_FRAME |
09402947 | 1325 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1da177e4 LT |
1326 | pushq $0 |
1327 | CFI_ADJUST_CFA_OFFSET 8 | |
1328 | paranoidentry do_machine_check | |
2601e64d | 1329 | jmp paranoid_exit1 |
1da177e4 | 1330 | CFI_ENDPROC |
4b787e0b | 1331 | END(machine_check) |
1da177e4 LT |
1332 | #endif |
1333 | ||
2699500b | 1334 | /* Call softirq on interrupt stack. Interrupts are off. */ |
ed6b676c | 1335 | ENTRY(call_softirq) |
7effaa88 | 1336 | CFI_STARTPROC |
2699500b AK |
1337 | push %rbp |
1338 | CFI_ADJUST_CFA_OFFSET 8 | |
1339 | CFI_REL_OFFSET rbp,0 | |
1340 | mov %rsp,%rbp | |
1341 | CFI_DEF_CFA_REGISTER rbp | |
ed6b676c | 1342 | incl %gs:pda_irqcount |
2699500b AK |
1343 | cmove %gs:pda_irqstackptr,%rsp |
1344 | push %rbp # backlink for old unwinder | |
ed6b676c | 1345 | call __do_softirq |
2699500b | 1346 | leaveq |
7effaa88 | 1347 | CFI_DEF_CFA_REGISTER rsp |
2699500b | 1348 | CFI_ADJUST_CFA_OFFSET -8 |
ed6b676c | 1349 | decl %gs:pda_irqcount |
ed6b676c | 1350 | ret |
7effaa88 | 1351 | CFI_ENDPROC |
4b787e0b | 1352 | ENDPROC(call_softirq) |
75154f40 AK |
1353 | |
1354 | KPROBE_ENTRY(ignore_sysret) | |
1355 | CFI_STARTPROC | |
1356 | mov $-ENOSYS,%eax | |
1357 | sysret | |
1358 | CFI_ENDPROC | |
1359 | ENDPROC(ignore_sysret) | |
3d75e1b8 JF |
1360 | |
1361 | #ifdef CONFIG_XEN | |
1362 | ENTRY(xen_hypervisor_callback) | |
1363 | zeroentry xen_do_hypervisor_callback | |
1364 | END(xen_hypervisor_callback) | |
1365 | ||
1366 | /* | |
1367 | # A note on the "critical region" in our callback handler. | |
1368 | # We want to avoid stacking callback handlers due to events occurring | |
1369 | # during handling of the last event. To do this, we keep events disabled | |
1370 | # until we've done all processing. HOWEVER, we must enable events before | |
1371 | # popping the stack frame (can't be done atomically) and so it would still | |
1372 | # be possible to get enough handler activations to overflow the stack. | |
1373 | # Although unlikely, bugs of that kind are hard to track down, so we'd | |
1374 | # like to avoid the possibility. | |
1375 | # So, on entry to the handler we detect whether we interrupted an | |
1376 | # existing activation in its critical region -- if so, we pop the current | |
1377 | # activation and restart the handler using the previous one. | |
1378 | */ | |
1379 | ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs) | |
1380 | CFI_STARTPROC | |
1381 | /* Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will | |
1382 | see the correct pointer to the pt_regs */ | |
1383 | movq %rdi, %rsp # we don't return, adjust the stack frame | |
1384 | CFI_ENDPROC | |
1385 | CFI_DEFAULT_STACK | |
1386 | 11: incl %gs:pda_irqcount | |
1387 | movq %rsp,%rbp | |
1388 | CFI_DEF_CFA_REGISTER rbp | |
1389 | cmovzq %gs:pda_irqstackptr,%rsp | |
1390 | pushq %rbp # backlink for old unwinder | |
1391 | call xen_evtchn_do_upcall | |
1392 | popq %rsp | |
1393 | CFI_DEF_CFA_REGISTER rsp | |
1394 | decl %gs:pda_irqcount | |
1395 | jmp error_exit | |
1396 | CFI_ENDPROC | |
1397 | END(do_hypervisor_callback) | |
1398 | ||
1399 | /* | |
1400 | # Hypervisor uses this for application faults while it executes. | |
1401 | # We get here for two reasons: | |
1402 | # 1. Fault while reloading DS, ES, FS or GS | |
1403 | # 2. Fault while executing IRET | |
1404 | # Category 1 we do not need to fix up as Xen has already reloaded all segment | |
1405 | # registers that could be reloaded and zeroed the others. | |
1406 | # Category 2 we fix up by killing the current process. We cannot use the | |
1407 | # normal Linux return path in this case because if we use the IRET hypercall | |
1408 | # to pop the stack frame we end up in an infinite loop of failsafe callbacks. | |
1409 | # We distinguish between categories by comparing each saved segment register | |
1410 | # with its current contents: any discrepancy means we in category 1. | |
1411 | */ | |
1412 | ENTRY(xen_failsafe_callback) | |
4a5c3e77 JF |
1413 | framesz = (RIP-0x30) /* workaround buggy gas */ |
1414 | _frame framesz | |
3d75e1b8 JF |
1415 | CFI_REL_OFFSET rcx, 0 |
1416 | CFI_REL_OFFSET r11, 8 | |
1417 | movw %ds,%cx | |
1418 | cmpw %cx,0x10(%rsp) | |
1419 | CFI_REMEMBER_STATE | |
1420 | jne 1f | |
1421 | movw %es,%cx | |
1422 | cmpw %cx,0x18(%rsp) | |
1423 | jne 1f | |
1424 | movw %fs,%cx | |
1425 | cmpw %cx,0x20(%rsp) | |
1426 | jne 1f | |
1427 | movw %gs,%cx | |
1428 | cmpw %cx,0x28(%rsp) | |
1429 | jne 1f | |
1430 | /* All segments match their saved values => Category 2 (Bad IRET). */ | |
1431 | movq (%rsp),%rcx | |
1432 | CFI_RESTORE rcx | |
1433 | movq 8(%rsp),%r11 | |
1434 | CFI_RESTORE r11 | |
1435 | addq $0x30,%rsp | |
1436 | CFI_ADJUST_CFA_OFFSET -0x30 | |
4a5c3e77 JF |
1437 | pushq $0 |
1438 | CFI_ADJUST_CFA_OFFSET 8 | |
1439 | pushq %r11 | |
1440 | CFI_ADJUST_CFA_OFFSET 8 | |
1441 | pushq %rcx | |
1442 | CFI_ADJUST_CFA_OFFSET 8 | |
1443 | jmp general_protection | |
3d75e1b8 JF |
1444 | CFI_RESTORE_STATE |
1445 | 1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */ | |
1446 | movq (%rsp),%rcx | |
1447 | CFI_RESTORE rcx | |
1448 | movq 8(%rsp),%r11 | |
1449 | CFI_RESTORE r11 | |
1450 | addq $0x30,%rsp | |
1451 | CFI_ADJUST_CFA_OFFSET -0x30 | |
1452 | pushq $0 | |
1453 | CFI_ADJUST_CFA_OFFSET 8 | |
1454 | SAVE_ALL | |
1455 | jmp error_exit | |
1456 | CFI_ENDPROC | |
3d75e1b8 JF |
1457 | END(xen_failsafe_callback) |
1458 | ||
1459 | #endif /* CONFIG_XEN */ |