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. | |
0bd7b798 AH |
14 | * |
15 | * Normal syscalls and interrupts don't save a full stack frame, this is | |
1da177e4 | 16 | * only done for syscall tracing, signals or fork/exec et.al. |
0bd7b798 AH |
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. | |
1da177e4 | 21 | * - partial stack frame: partially saved registers upto R11. |
0bd7b798 | 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 | 62 | .code64 |
606576ce | 63 | #ifdef CONFIG_FUNCTION_TRACER |
d61f82d0 SR |
64 | #ifdef CONFIG_DYNAMIC_FTRACE |
65 | ENTRY(mcount) | |
d61f82d0 SR |
66 | retq |
67 | END(mcount) | |
68 | ||
69 | ENTRY(ftrace_caller) | |
70 | ||
71 | /* taken from glibc */ | |
72 | subq $0x38, %rsp | |
73 | movq %rax, (%rsp) | |
74 | movq %rcx, 8(%rsp) | |
75 | movq %rdx, 16(%rsp) | |
76 | movq %rsi, 24(%rsp) | |
77 | movq %rdi, 32(%rsp) | |
78 | movq %r8, 40(%rsp) | |
79 | movq %r9, 48(%rsp) | |
80 | ||
81 | movq 0x38(%rsp), %rdi | |
82 | movq 8(%rbp), %rsi | |
395a59d0 | 83 | subq $MCOUNT_INSN_SIZE, %rdi |
d61f82d0 SR |
84 | |
85 | .globl ftrace_call | |
86 | ftrace_call: | |
87 | call ftrace_stub | |
88 | ||
89 | movq 48(%rsp), %r9 | |
90 | movq 40(%rsp), %r8 | |
91 | movq 32(%rsp), %rdi | |
92 | movq 24(%rsp), %rsi | |
93 | movq 16(%rsp), %rdx | |
94 | movq 8(%rsp), %rcx | |
95 | movq (%rsp), %rax | |
96 | addq $0x38, %rsp | |
97 | ||
98 | .globl ftrace_stub | |
99 | ftrace_stub: | |
100 | retq | |
101 | END(ftrace_caller) | |
102 | ||
103 | #else /* ! CONFIG_DYNAMIC_FTRACE */ | |
16444a8a ACM |
104 | ENTRY(mcount) |
105 | cmpq $ftrace_stub, ftrace_trace_function | |
106 | jnz trace | |
107 | .globl ftrace_stub | |
108 | ftrace_stub: | |
109 | retq | |
110 | ||
111 | trace: | |
112 | /* taken from glibc */ | |
113 | subq $0x38, %rsp | |
114 | movq %rax, (%rsp) | |
115 | movq %rcx, 8(%rsp) | |
116 | movq %rdx, 16(%rsp) | |
117 | movq %rsi, 24(%rsp) | |
118 | movq %rdi, 32(%rsp) | |
119 | movq %r8, 40(%rsp) | |
120 | movq %r9, 48(%rsp) | |
121 | ||
122 | movq 0x38(%rsp), %rdi | |
123 | movq 8(%rbp), %rsi | |
395a59d0 | 124 | subq $MCOUNT_INSN_SIZE, %rdi |
16444a8a ACM |
125 | |
126 | call *ftrace_trace_function | |
127 | ||
128 | movq 48(%rsp), %r9 | |
129 | movq 40(%rsp), %r8 | |
130 | movq 32(%rsp), %rdi | |
131 | movq 24(%rsp), %rsi | |
132 | movq 16(%rsp), %rdx | |
133 | movq 8(%rsp), %rcx | |
134 | movq (%rsp), %rax | |
135 | addq $0x38, %rsp | |
136 | ||
137 | jmp ftrace_stub | |
138 | END(mcount) | |
d61f82d0 | 139 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
606576ce | 140 | #endif /* CONFIG_FUNCTION_TRACER */ |
16444a8a | 141 | |
dc37db4d | 142 | #ifndef CONFIG_PREEMPT |
1da177e4 | 143 | #define retint_kernel retint_restore_args |
0bd7b798 | 144 | #endif |
2601e64d | 145 | |
72fe4858 | 146 | #ifdef CONFIG_PARAVIRT |
2be29982 | 147 | ENTRY(native_usergs_sysret64) |
72fe4858 GOC |
148 | swapgs |
149 | sysretq | |
150 | #endif /* CONFIG_PARAVIRT */ | |
151 | ||
2601e64d IM |
152 | |
153 | .macro TRACE_IRQS_IRETQ offset=ARGOFFSET | |
154 | #ifdef CONFIG_TRACE_IRQFLAGS | |
155 | bt $9,EFLAGS-\offset(%rsp) /* interrupts off? */ | |
156 | jnc 1f | |
157 | TRACE_IRQS_ON | |
158 | 1: | |
159 | #endif | |
160 | .endm | |
161 | ||
1da177e4 | 162 | /* |
0bd7b798 AH |
163 | * C code is not supposed to know about undefined top of stack. Every time |
164 | * a C function with an pt_regs argument is called from the SYSCALL based | |
1da177e4 LT |
165 | * fast path FIXUP_TOP_OF_STACK is needed. |
166 | * RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs | |
167 | * manipulation. | |
0bd7b798 AH |
168 | */ |
169 | ||
170 | /* %rsp:at FRAMEEND */ | |
c002a1e6 AH |
171 | .macro FIXUP_TOP_OF_STACK tmp offset=0 |
172 | movq %gs:pda_oldrsp,\tmp | |
173 | movq \tmp,RSP+\offset(%rsp) | |
174 | movq $__USER_DS,SS+\offset(%rsp) | |
175 | movq $__USER_CS,CS+\offset(%rsp) | |
176 | movq $-1,RCX+\offset(%rsp) | |
177 | movq R11+\offset(%rsp),\tmp /* get eflags */ | |
178 | movq \tmp,EFLAGS+\offset(%rsp) | |
1da177e4 LT |
179 | .endm |
180 | ||
c002a1e6 AH |
181 | .macro RESTORE_TOP_OF_STACK tmp offset=0 |
182 | movq RSP+\offset(%rsp),\tmp | |
183 | movq \tmp,%gs:pda_oldrsp | |
184 | movq EFLAGS+\offset(%rsp),\tmp | |
185 | movq \tmp,R11+\offset(%rsp) | |
1da177e4 LT |
186 | .endm |
187 | ||
188 | .macro FAKE_STACK_FRAME child_rip | |
189 | /* push in order ss, rsp, eflags, cs, rip */ | |
3829ee6b | 190 | xorl %eax, %eax |
e04e0a63 | 191 | pushq $__KERNEL_DS /* ss */ |
1da177e4 | 192 | CFI_ADJUST_CFA_OFFSET 8 |
7effaa88 | 193 | /*CFI_REL_OFFSET ss,0*/ |
1da177e4 LT |
194 | pushq %rax /* rsp */ |
195 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 196 | CFI_REL_OFFSET rsp,0 |
33454539 | 197 | pushq $X86_EFLAGS_IF /* eflags - interrupts on */ |
1da177e4 | 198 | CFI_ADJUST_CFA_OFFSET 8 |
7effaa88 | 199 | /*CFI_REL_OFFSET rflags,0*/ |
1da177e4 LT |
200 | pushq $__KERNEL_CS /* cs */ |
201 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 202 | /*CFI_REL_OFFSET cs,0*/ |
1da177e4 LT |
203 | pushq \child_rip /* rip */ |
204 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 205 | CFI_REL_OFFSET rip,0 |
1da177e4 LT |
206 | pushq %rax /* orig rax */ |
207 | CFI_ADJUST_CFA_OFFSET 8 | |
208 | .endm | |
209 | ||
210 | .macro UNFAKE_STACK_FRAME | |
211 | addq $8*6, %rsp | |
212 | CFI_ADJUST_CFA_OFFSET -(6*8) | |
213 | .endm | |
214 | ||
dcd072e2 AH |
215 | /* |
216 | * initial frame state for interrupts (and exceptions without error code) | |
217 | */ | |
218 | .macro EMPTY_FRAME start=1 offset=0 | |
7effaa88 | 219 | .if \start |
dcd072e2 | 220 | CFI_STARTPROC simple |
adf14236 | 221 | CFI_SIGNAL_FRAME |
dcd072e2 | 222 | CFI_DEF_CFA rsp,8+\offset |
7effaa88 | 223 | .else |
dcd072e2 | 224 | CFI_DEF_CFA_OFFSET 8+\offset |
7effaa88 | 225 | .endif |
1da177e4 | 226 | .endm |
d99015b1 AH |
227 | |
228 | /* | |
dcd072e2 | 229 | * initial frame state for interrupts (and exceptions without error code) |
d99015b1 | 230 | */ |
dcd072e2 | 231 | .macro INTR_FRAME start=1 offset=0 |
e8a0e276 IM |
232 | EMPTY_FRAME \start, SS+8+\offset-RIP |
233 | /*CFI_REL_OFFSET ss, SS+\offset-RIP*/ | |
234 | CFI_REL_OFFSET rsp, RSP+\offset-RIP | |
235 | /*CFI_REL_OFFSET rflags, EFLAGS+\offset-RIP*/ | |
236 | /*CFI_REL_OFFSET cs, CS+\offset-RIP*/ | |
237 | CFI_REL_OFFSET rip, RIP+\offset-RIP | |
d99015b1 AH |
238 | .endm |
239 | ||
d99015b1 AH |
240 | /* |
241 | * initial frame state for exceptions with error code (and interrupts | |
242 | * with vector already pushed) | |
243 | */ | |
dcd072e2 | 244 | .macro XCPT_FRAME start=1 offset=0 |
e8a0e276 | 245 | INTR_FRAME \start, RIP+\offset-ORIG_RAX |
dcd072e2 AH |
246 | /*CFI_REL_OFFSET orig_rax, ORIG_RAX-ORIG_RAX*/ |
247 | .endm | |
248 | ||
249 | /* | |
250 | * frame that enables calling into C. | |
251 | */ | |
252 | .macro PARTIAL_FRAME start=1 offset=0 | |
e8a0e276 IM |
253 | XCPT_FRAME \start, ORIG_RAX+\offset-ARGOFFSET |
254 | CFI_REL_OFFSET rdi, RDI+\offset-ARGOFFSET | |
255 | CFI_REL_OFFSET rsi, RSI+\offset-ARGOFFSET | |
256 | CFI_REL_OFFSET rdx, RDX+\offset-ARGOFFSET | |
257 | CFI_REL_OFFSET rcx, RCX+\offset-ARGOFFSET | |
258 | CFI_REL_OFFSET rax, RAX+\offset-ARGOFFSET | |
259 | CFI_REL_OFFSET r8, R8+\offset-ARGOFFSET | |
260 | CFI_REL_OFFSET r9, R9+\offset-ARGOFFSET | |
261 | CFI_REL_OFFSET r10, R10+\offset-ARGOFFSET | |
262 | CFI_REL_OFFSET r11, R11+\offset-ARGOFFSET | |
dcd072e2 AH |
263 | .endm |
264 | ||
265 | /* | |
266 | * frame that enables passing a complete pt_regs to a C function. | |
267 | */ | |
268 | .macro DEFAULT_FRAME start=1 offset=0 | |
e8a0e276 | 269 | PARTIAL_FRAME \start, R11+\offset-R15 |
dcd072e2 AH |
270 | CFI_REL_OFFSET rbx, RBX+\offset |
271 | CFI_REL_OFFSET rbp, RBP+\offset | |
272 | CFI_REL_OFFSET r12, R12+\offset | |
273 | CFI_REL_OFFSET r13, R13+\offset | |
274 | CFI_REL_OFFSET r14, R14+\offset | |
275 | CFI_REL_OFFSET r15, R15+\offset | |
276 | .endm | |
d99015b1 AH |
277 | |
278 | /* save partial stack frame */ | |
279 | ENTRY(save_args) | |
280 | XCPT_FRAME | |
281 | cld | |
14ae22ba IM |
282 | movq_cfi rdi, RDI+16-ARGOFFSET |
283 | movq_cfi rsi, RSI+16-ARGOFFSET | |
284 | movq_cfi rdx, RDX+16-ARGOFFSET | |
285 | movq_cfi rcx, RCX+16-ARGOFFSET | |
286 | movq_cfi rax, RAX+16-ARGOFFSET | |
287 | movq_cfi r8, R8+16-ARGOFFSET | |
288 | movq_cfi r9, R9+16-ARGOFFSET | |
289 | movq_cfi r10, R10+16-ARGOFFSET | |
290 | movq_cfi r11, R11+16-ARGOFFSET | |
291 | ||
d99015b1 | 292 | leaq -ARGOFFSET+16(%rsp),%rdi /* arg1 for handler */ |
14ae22ba | 293 | movq_cfi rbp, 8 /* push %rbp */ |
d99015b1 AH |
294 | leaq 8(%rsp), %rbp /* mov %rsp, %ebp */ |
295 | testl $3, CS(%rdi) | |
296 | je 1f | |
297 | SWAPGS | |
298 | /* | |
299 | * irqcount is used to check if a CPU is already on an interrupt stack | |
300 | * or not. While this is essentially redundant with preempt_count it is | |
301 | * a little cheaper to use a separate counter in the PDA (short of | |
302 | * moving irq_enter into assembly, which would be too much work) | |
303 | */ | |
304 | 1: incl %gs:pda_irqcount | |
305 | jne 2f | |
14ae22ba | 306 | popq_cfi %rax /* move return address... */ |
d99015b1 | 307 | mov %gs:pda_irqstackptr,%rsp |
dcd072e2 | 308 | EMPTY_FRAME 0 |
14ae22ba | 309 | pushq_cfi %rax /* ... to the new stack */ |
d99015b1 AH |
310 | /* |
311 | * We entered an interrupt context - irqs are off: | |
312 | */ | |
313 | 2: TRACE_IRQS_OFF | |
314 | ret | |
315 | CFI_ENDPROC | |
316 | END(save_args) | |
317 | ||
c002a1e6 AH |
318 | ENTRY(save_rest) |
319 | PARTIAL_FRAME 1 REST_SKIP+8 | |
320 | movq 5*8+16(%rsp), %r11 /* save return address */ | |
321 | movq_cfi rbx, RBX+16 | |
322 | movq_cfi rbp, RBP+16 | |
323 | movq_cfi r12, R12+16 | |
324 | movq_cfi r13, R13+16 | |
325 | movq_cfi r14, R14+16 | |
326 | movq_cfi r15, R15+16 | |
327 | movq %r11, 8(%rsp) /* return address */ | |
328 | FIXUP_TOP_OF_STACK %r11, 16 | |
329 | ret | |
330 | CFI_ENDPROC | |
331 | END(save_rest) | |
332 | ||
e2f6bc25 AH |
333 | /* save complete stack frame */ |
334 | ENTRY(save_paranoid) | |
335 | XCPT_FRAME 1 RDI+8 | |
336 | cld | |
337 | movq_cfi rdi, RDI+8 | |
338 | movq_cfi rsi, RSI+8 | |
339 | movq_cfi rdx, RDX+8 | |
340 | movq_cfi rcx, RCX+8 | |
341 | movq_cfi rax, RAX+8 | |
342 | movq_cfi r8, R8+8 | |
343 | movq_cfi r9, R9+8 | |
344 | movq_cfi r10, R10+8 | |
345 | movq_cfi r11, R11+8 | |
346 | movq_cfi rbx, RBX+8 | |
347 | movq_cfi rbp, RBP+8 | |
348 | movq_cfi r12, R12+8 | |
349 | movq_cfi r13, R13+8 | |
350 | movq_cfi r14, R14+8 | |
351 | movq_cfi r15, R15+8 | |
352 | movl $1,%ebx | |
353 | movl $MSR_GS_BASE,%ecx | |
354 | rdmsr | |
355 | testl %edx,%edx | |
356 | js 1f /* negative -> in kernel */ | |
357 | SWAPGS | |
358 | xorl %ebx,%ebx | |
359 | 1: ret | |
360 | CFI_ENDPROC | |
361 | END(save_paranoid) | |
362 | ||
1da177e4 | 363 | /* |
5b3eec0c IM |
364 | * A newly forked process directly context switches into this address. |
365 | * | |
366 | * rdi: prev task we switched from | |
0bd7b798 | 367 | */ |
1da177e4 | 368 | ENTRY(ret_from_fork) |
dcd072e2 | 369 | DEFAULT_FRAME |
5b3eec0c | 370 | |
658fdbef | 371 | push kernel_eflags(%rip) |
e0a5a5d9 | 372 | CFI_ADJUST_CFA_OFFSET 8 |
5b3eec0c | 373 | popf # reset kernel eflags |
e0a5a5d9 | 374 | CFI_ADJUST_CFA_OFFSET -8 |
5b3eec0c IM |
375 | |
376 | call schedule_tail # rdi: 'prev' task parameter | |
377 | ||
1da177e4 | 378 | GET_THREAD_INFO(%rcx) |
5b3eec0c | 379 | |
1cbd8b3f | 380 | CFI_REMEMBER_STATE |
1da177e4 | 381 | RESTORE_REST |
5b3eec0c IM |
382 | |
383 | testl $3, CS-ARGOFFSET(%rsp) # from kernel_thread? | |
1da177e4 | 384 | je int_ret_from_sys_call |
5b3eec0c IM |
385 | |
386 | testl $_TIF_IA32, TI_flags(%rcx) # 32-bit compat task needs IRET | |
1da177e4 | 387 | jnz int_ret_from_sys_call |
5b3eec0c | 388 | |
c002a1e6 | 389 | RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET |
5b3eec0c IM |
390 | jmp ret_from_sys_call # go to the SYSRET fastpath |
391 | ||
1cbd8b3f | 392 | CFI_RESTORE_STATE |
1da177e4 | 393 | CFI_ENDPROC |
4b787e0b | 394 | END(ret_from_fork) |
1da177e4 LT |
395 | |
396 | /* | |
397 | * System call entry. Upto 6 arguments in registers are supported. | |
398 | * | |
399 | * SYSCALL does not save anything on the stack and does not change the | |
400 | * stack pointer. | |
401 | */ | |
0bd7b798 | 402 | |
1da177e4 | 403 | /* |
0bd7b798 | 404 | * Register setup: |
1da177e4 LT |
405 | * rax system call number |
406 | * rdi arg0 | |
0bd7b798 | 407 | * rcx return address for syscall/sysret, C arg3 |
1da177e4 | 408 | * rsi arg1 |
0bd7b798 | 409 | * rdx arg2 |
1da177e4 LT |
410 | * r10 arg3 (--> moved to rcx for C) |
411 | * r8 arg4 | |
412 | * r9 arg5 | |
413 | * r11 eflags for syscall/sysret, temporary for C | |
0bd7b798 AH |
414 | * r12-r15,rbp,rbx saved by C code, not touched. |
415 | * | |
1da177e4 LT |
416 | * Interrupts are off on entry. |
417 | * Only called from user space. | |
418 | * | |
419 | * XXX if we had a free scratch register we could save the RSP into the stack frame | |
420 | * and report it properly in ps. Unfortunately we haven't. | |
7bf36bbc AK |
421 | * |
422 | * When user can change the frames always force IRET. That is because | |
423 | * it deals with uncanonical addresses better. SYSRET has trouble | |
424 | * with them due to bugs in both AMD and Intel CPUs. | |
0bd7b798 | 425 | */ |
1da177e4 LT |
426 | |
427 | ENTRY(system_call) | |
7effaa88 | 428 | CFI_STARTPROC simple |
adf14236 | 429 | CFI_SIGNAL_FRAME |
dffead4e | 430 | CFI_DEF_CFA rsp,PDA_STACKOFFSET |
7effaa88 JB |
431 | CFI_REGISTER rip,rcx |
432 | /*CFI_REGISTER rflags,r11*/ | |
72fe4858 GOC |
433 | SWAPGS_UNSAFE_STACK |
434 | /* | |
435 | * A hypervisor implementation might want to use a label | |
436 | * after the swapgs, so that it can do the swapgs | |
437 | * for the guest and jump here on syscall. | |
438 | */ | |
439 | ENTRY(system_call_after_swapgs) | |
440 | ||
0bd7b798 | 441 | movq %rsp,%gs:pda_oldrsp |
1da177e4 | 442 | movq %gs:pda_kernelstack,%rsp |
2601e64d IM |
443 | /* |
444 | * No need to follow this irqs off/on section - it's straight | |
445 | * and short: | |
446 | */ | |
72fe4858 | 447 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 448 | SAVE_ARGS 8,1 |
0bd7b798 | 449 | movq %rax,ORIG_RAX-ARGOFFSET(%rsp) |
7effaa88 JB |
450 | movq %rcx,RIP-ARGOFFSET(%rsp) |
451 | CFI_REL_OFFSET rip,RIP-ARGOFFSET | |
1da177e4 | 452 | GET_THREAD_INFO(%rcx) |
d4d67150 | 453 | testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%rcx) |
1da177e4 | 454 | jnz tracesys |
86a1c34a | 455 | system_call_fastpath: |
1da177e4 LT |
456 | cmpq $__NR_syscall_max,%rax |
457 | ja badsys | |
458 | movq %r10,%rcx | |
459 | call *sys_call_table(,%rax,8) # XXX: rip relative | |
460 | movq %rax,RAX-ARGOFFSET(%rsp) | |
461 | /* | |
462 | * Syscall return path ending with SYSRET (fast path) | |
0bd7b798 AH |
463 | * Has incomplete stack frame and undefined top of stack. |
464 | */ | |
1da177e4 | 465 | ret_from_sys_call: |
11b854b2 | 466 | movl $_TIF_ALLWORK_MASK,%edi |
1da177e4 | 467 | /* edi: flagmask */ |
0bd7b798 | 468 | sysret_check: |
10cd706d | 469 | LOCKDEP_SYS_EXIT |
1da177e4 | 470 | GET_THREAD_INFO(%rcx) |
72fe4858 | 471 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 472 | TRACE_IRQS_OFF |
26ccb8a7 | 473 | movl TI_flags(%rcx),%edx |
1da177e4 | 474 | andl %edi,%edx |
0bd7b798 | 475 | jnz sysret_careful |
bcddc015 | 476 | CFI_REMEMBER_STATE |
2601e64d IM |
477 | /* |
478 | * sysretq will re-enable interrupts: | |
479 | */ | |
480 | TRACE_IRQS_ON | |
1da177e4 | 481 | movq RIP-ARGOFFSET(%rsp),%rcx |
7effaa88 | 482 | CFI_REGISTER rip,rcx |
1da177e4 | 483 | RESTORE_ARGS 0,-ARG_SKIP,1 |
7effaa88 | 484 | /*CFI_REGISTER rflags,r11*/ |
c7245da6 | 485 | movq %gs:pda_oldrsp, %rsp |
2be29982 | 486 | USERGS_SYSRET64 |
1da177e4 | 487 | |
bcddc015 | 488 | CFI_RESTORE_STATE |
1da177e4 | 489 | /* Handle reschedules */ |
0bd7b798 | 490 | /* edx: work, edi: workmask */ |
1da177e4 LT |
491 | sysret_careful: |
492 | bt $TIF_NEED_RESCHED,%edx | |
493 | jnc sysret_signal | |
2601e64d | 494 | TRACE_IRQS_ON |
72fe4858 | 495 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 496 | pushq %rdi |
7effaa88 | 497 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
498 | call schedule |
499 | popq %rdi | |
7effaa88 | 500 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 LT |
501 | jmp sysret_check |
502 | ||
0bd7b798 | 503 | /* Handle a signal */ |
1da177e4 | 504 | sysret_signal: |
2601e64d | 505 | TRACE_IRQS_ON |
72fe4858 | 506 | ENABLE_INTERRUPTS(CLBR_NONE) |
86a1c34a RM |
507 | #ifdef CONFIG_AUDITSYSCALL |
508 | bt $TIF_SYSCALL_AUDIT,%edx | |
509 | jc sysret_audit | |
510 | #endif | |
10ffdbb8 | 511 | /* edx: work flags (arg3) */ |
1da177e4 LT |
512 | leaq -ARGOFFSET(%rsp),%rdi # &pt_regs -> arg1 |
513 | xorl %esi,%esi # oldset -> arg2 | |
c8108411 AH |
514 | SAVE_REST |
515 | FIXUP_TOP_OF_STACK %r11 | |
516 | call do_notify_resume | |
517 | RESTORE_TOP_OF_STACK %r11 | |
518 | RESTORE_REST | |
15e8f348 | 519 | movl $_TIF_WORK_MASK,%edi |
7bf36bbc AK |
520 | /* Use IRET because user could have changed frame. This |
521 | works because ptregscall_common has called FIXUP_TOP_OF_STACK. */ | |
72fe4858 | 522 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 523 | TRACE_IRQS_OFF |
7bf36bbc | 524 | jmp int_with_check |
0bd7b798 | 525 | |
7effaa88 JB |
526 | badsys: |
527 | movq $-ENOSYS,RAX-ARGOFFSET(%rsp) | |
528 | jmp ret_from_sys_call | |
529 | ||
86a1c34a RM |
530 | #ifdef CONFIG_AUDITSYSCALL |
531 | /* | |
532 | * Fast path for syscall audit without full syscall trace. | |
533 | * We just call audit_syscall_entry() directly, and then | |
534 | * jump back to the normal fast path. | |
535 | */ | |
536 | auditsys: | |
537 | movq %r10,%r9 /* 6th arg: 4th syscall arg */ | |
538 | movq %rdx,%r8 /* 5th arg: 3rd syscall arg */ | |
539 | movq %rsi,%rcx /* 4th arg: 2nd syscall arg */ | |
540 | movq %rdi,%rdx /* 3rd arg: 1st syscall arg */ | |
541 | movq %rax,%rsi /* 2nd arg: syscall number */ | |
542 | movl $AUDIT_ARCH_X86_64,%edi /* 1st arg: audit arch */ | |
543 | call audit_syscall_entry | |
544 | LOAD_ARGS 0 /* reload call-clobbered registers */ | |
545 | jmp system_call_fastpath | |
546 | ||
547 | /* | |
548 | * Return fast path for syscall audit. Call audit_syscall_exit() | |
549 | * directly and then jump back to the fast path with TIF_SYSCALL_AUDIT | |
550 | * masked off. | |
551 | */ | |
552 | sysret_audit: | |
553 | movq %rax,%rsi /* second arg, syscall return value */ | |
554 | cmpq $0,%rax /* is it < 0? */ | |
555 | setl %al /* 1 if so, 0 if not */ | |
556 | movzbl %al,%edi /* zero-extend that into %edi */ | |
557 | inc %edi /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */ | |
558 | call audit_syscall_exit | |
559 | movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi | |
560 | jmp sysret_check | |
561 | #endif /* CONFIG_AUDITSYSCALL */ | |
562 | ||
1da177e4 | 563 | /* Do syscall tracing */ |
0bd7b798 | 564 | tracesys: |
86a1c34a RM |
565 | #ifdef CONFIG_AUDITSYSCALL |
566 | testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%rcx) | |
567 | jz auditsys | |
568 | #endif | |
1da177e4 | 569 | SAVE_REST |
a31f8dd7 | 570 | movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */ |
1da177e4 LT |
571 | FIXUP_TOP_OF_STACK %rdi |
572 | movq %rsp,%rdi | |
573 | call syscall_trace_enter | |
d4d67150 RM |
574 | /* |
575 | * Reload arg registers from stack in case ptrace changed them. | |
576 | * We don't reload %rax because syscall_trace_enter() returned | |
577 | * the value it wants us to use in the table lookup. | |
578 | */ | |
579 | LOAD_ARGS ARGOFFSET, 1 | |
1da177e4 LT |
580 | RESTORE_REST |
581 | cmpq $__NR_syscall_max,%rax | |
a31f8dd7 | 582 | ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */ |
1da177e4 LT |
583 | movq %r10,%rcx /* fixup for C */ |
584 | call *sys_call_table(,%rax,8) | |
a31f8dd7 | 585 | movq %rax,RAX-ARGOFFSET(%rsp) |
7bf36bbc | 586 | /* Use IRET because user could have changed frame */ |
0bd7b798 AH |
587 | |
588 | /* | |
1da177e4 LT |
589 | * Syscall return path ending with IRET. |
590 | * Has correct top of stack, but partial stack frame. | |
bcddc015 JB |
591 | */ |
592 | .globl int_ret_from_sys_call | |
5cbf1565 | 593 | .globl int_with_check |
bcddc015 | 594 | int_ret_from_sys_call: |
72fe4858 | 595 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 596 | TRACE_IRQS_OFF |
1da177e4 LT |
597 | testl $3,CS-ARGOFFSET(%rsp) |
598 | je retint_restore_args | |
599 | movl $_TIF_ALLWORK_MASK,%edi | |
600 | /* edi: mask to check */ | |
601 | int_with_check: | |
10cd706d | 602 | LOCKDEP_SYS_EXIT_IRQ |
1da177e4 | 603 | GET_THREAD_INFO(%rcx) |
26ccb8a7 | 604 | movl TI_flags(%rcx),%edx |
1da177e4 LT |
605 | andl %edi,%edx |
606 | jnz int_careful | |
26ccb8a7 | 607 | andl $~TS_COMPAT,TI_status(%rcx) |
1da177e4 LT |
608 | jmp retint_swapgs |
609 | ||
610 | /* Either reschedule or signal or syscall exit tracking needed. */ | |
611 | /* First do a reschedule test. */ | |
612 | /* edx: work, edi: workmask */ | |
613 | int_careful: | |
614 | bt $TIF_NEED_RESCHED,%edx | |
615 | jnc int_very_careful | |
2601e64d | 616 | TRACE_IRQS_ON |
72fe4858 | 617 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 618 | pushq %rdi |
7effaa88 | 619 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
620 | call schedule |
621 | popq %rdi | |
7effaa88 | 622 | CFI_ADJUST_CFA_OFFSET -8 |
72fe4858 | 623 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 624 | TRACE_IRQS_OFF |
1da177e4 LT |
625 | jmp int_with_check |
626 | ||
627 | /* handle signals and tracing -- both require a full stack frame */ | |
628 | int_very_careful: | |
2601e64d | 629 | TRACE_IRQS_ON |
72fe4858 | 630 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 631 | SAVE_REST |
0bd7b798 | 632 | /* Check for syscall exit trace */ |
d4d67150 | 633 | testl $_TIF_WORK_SYSCALL_EXIT,%edx |
1da177e4 LT |
634 | jz int_signal |
635 | pushq %rdi | |
7effaa88 | 636 | CFI_ADJUST_CFA_OFFSET 8 |
0bd7b798 | 637 | leaq 8(%rsp),%rdi # &ptregs -> arg1 |
1da177e4 LT |
638 | call syscall_trace_leave |
639 | popq %rdi | |
7effaa88 | 640 | CFI_ADJUST_CFA_OFFSET -8 |
d4d67150 | 641 | andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU),%edi |
1da177e4 | 642 | jmp int_restore_rest |
0bd7b798 | 643 | |
1da177e4 | 644 | int_signal: |
8f4d37ec | 645 | testl $_TIF_DO_NOTIFY_MASK,%edx |
1da177e4 LT |
646 | jz 1f |
647 | movq %rsp,%rdi # &ptregs -> arg1 | |
648 | xorl %esi,%esi # oldset -> arg2 | |
649 | call do_notify_resume | |
eca91e78 | 650 | 1: movl $_TIF_WORK_MASK,%edi |
1da177e4 LT |
651 | int_restore_rest: |
652 | RESTORE_REST | |
72fe4858 | 653 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 654 | TRACE_IRQS_OFF |
1da177e4 LT |
655 | jmp int_with_check |
656 | CFI_ENDPROC | |
bcddc015 | 657 | END(system_call) |
0bd7b798 AH |
658 | |
659 | /* | |
1da177e4 | 660 | * Certain special system calls that need to save a complete full stack frame. |
0bd7b798 | 661 | */ |
1da177e4 | 662 | .macro PTREGSCALL label,func,arg |
c002a1e6 AH |
663 | ENTRY(\label) |
664 | PARTIAL_FRAME 1 8 /* offset 8: return address */ | |
665 | subq $REST_SKIP, %rsp | |
666 | CFI_ADJUST_CFA_OFFSET REST_SKIP | |
667 | call save_rest | |
668 | DEFAULT_FRAME 0 8 /* offset 8: return address */ | |
669 | leaq 8(%rsp), \arg /* pt_regs pointer */ | |
670 | call \func | |
671 | jmp ptregscall_common | |
672 | CFI_ENDPROC | |
4b787e0b | 673 | END(\label) |
1da177e4 LT |
674 | .endm |
675 | ||
676 | PTREGSCALL stub_clone, sys_clone, %r8 | |
677 | PTREGSCALL stub_fork, sys_fork, %rdi | |
678 | PTREGSCALL stub_vfork, sys_vfork, %rdi | |
1da177e4 LT |
679 | PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx |
680 | PTREGSCALL stub_iopl, sys_iopl, %rsi | |
681 | ||
682 | ENTRY(ptregscall_common) | |
c002a1e6 AH |
683 | DEFAULT_FRAME 1 8 /* offset 8: return address */ |
684 | RESTORE_TOP_OF_STACK %r11, 8 | |
685 | movq_cfi_restore R15+8, r15 | |
686 | movq_cfi_restore R14+8, r14 | |
687 | movq_cfi_restore R13+8, r13 | |
688 | movq_cfi_restore R12+8, r12 | |
689 | movq_cfi_restore RBP+8, rbp | |
690 | movq_cfi_restore RBX+8, rbx | |
691 | ret $REST_SKIP /* pop extended registers */ | |
1da177e4 | 692 | CFI_ENDPROC |
4b787e0b | 693 | END(ptregscall_common) |
0bd7b798 | 694 | |
1da177e4 LT |
695 | ENTRY(stub_execve) |
696 | CFI_STARTPROC | |
697 | popq %r11 | |
7effaa88 JB |
698 | CFI_ADJUST_CFA_OFFSET -8 |
699 | CFI_REGISTER rip, r11 | |
1da177e4 | 700 | SAVE_REST |
1da177e4 | 701 | FIXUP_TOP_OF_STACK %r11 |
5d119b2c | 702 | movq %rsp, %rcx |
1da177e4 | 703 | call sys_execve |
1da177e4 | 704 | RESTORE_TOP_OF_STACK %r11 |
1da177e4 LT |
705 | movq %rax,RAX(%rsp) |
706 | RESTORE_REST | |
707 | jmp int_ret_from_sys_call | |
708 | CFI_ENDPROC | |
4b787e0b | 709 | END(stub_execve) |
0bd7b798 | 710 | |
1da177e4 LT |
711 | /* |
712 | * sigreturn is special because it needs to restore all registers on return. | |
713 | * This cannot be done with SYSRET, so use the IRET return path instead. | |
0bd7b798 | 714 | */ |
1da177e4 LT |
715 | ENTRY(stub_rt_sigreturn) |
716 | CFI_STARTPROC | |
7effaa88 JB |
717 | addq $8, %rsp |
718 | CFI_ADJUST_CFA_OFFSET -8 | |
1da177e4 LT |
719 | SAVE_REST |
720 | movq %rsp,%rdi | |
721 | FIXUP_TOP_OF_STACK %r11 | |
722 | call sys_rt_sigreturn | |
723 | movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer | |
724 | RESTORE_REST | |
725 | jmp int_ret_from_sys_call | |
726 | CFI_ENDPROC | |
4b787e0b | 727 | END(stub_rt_sigreturn) |
1da177e4 | 728 | |
939b7871 PA |
729 | /* |
730 | * Build the entry stubs and pointer table with some assembler magic. | |
731 | * We pack 7 stubs into a single 32-byte chunk, which will fit in a | |
732 | * single cache line on all modern x86 implementations. | |
733 | */ | |
734 | .section .init.rodata,"a" | |
735 | ENTRY(interrupt) | |
736 | .text | |
737 | .p2align 5 | |
738 | .p2align CONFIG_X86_L1_CACHE_SHIFT | |
739 | ENTRY(irq_entries_start) | |
740 | INTR_FRAME | |
741 | vector=FIRST_EXTERNAL_VECTOR | |
742 | .rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7 | |
743 | .balign 32 | |
744 | .rept 7 | |
745 | .if vector < NR_VECTORS | |
8665596e | 746 | .if vector <> FIRST_EXTERNAL_VECTOR |
939b7871 PA |
747 | CFI_ADJUST_CFA_OFFSET -8 |
748 | .endif | |
749 | 1: pushq $(~vector+0x80) /* Note: always in signed byte range */ | |
750 | CFI_ADJUST_CFA_OFFSET 8 | |
8665596e | 751 | .if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6 |
939b7871 PA |
752 | jmp 2f |
753 | .endif | |
754 | .previous | |
755 | .quad 1b | |
756 | .text | |
757 | vector=vector+1 | |
758 | .endif | |
759 | .endr | |
760 | 2: jmp common_interrupt | |
761 | .endr | |
762 | CFI_ENDPROC | |
763 | END(irq_entries_start) | |
764 | ||
765 | .previous | |
766 | END(interrupt) | |
767 | .previous | |
768 | ||
d99015b1 | 769 | /* |
1da177e4 LT |
770 | * Interrupt entry/exit. |
771 | * | |
772 | * Interrupt entry points save only callee clobbered registers in fast path. | |
d99015b1 AH |
773 | * |
774 | * Entry runs with interrupts off. | |
775 | */ | |
1da177e4 | 776 | |
722024db | 777 | /* 0(%rsp): ~(interrupt number) */ |
1da177e4 | 778 | .macro interrupt func |
d99015b1 AH |
779 | subq $10*8, %rsp |
780 | CFI_ADJUST_CFA_OFFSET 10*8 | |
781 | call save_args | |
dcd072e2 | 782 | PARTIAL_FRAME 0 |
1da177e4 LT |
783 | call \func |
784 | .endm | |
785 | ||
722024db AH |
786 | /* |
787 | * The interrupt stubs push (~vector+0x80) onto the stack and | |
788 | * then jump to common_interrupt. | |
789 | */ | |
939b7871 PA |
790 | .p2align CONFIG_X86_L1_CACHE_SHIFT |
791 | common_interrupt: | |
7effaa88 | 792 | XCPT_FRAME |
722024db | 793 | addq $-0x80,(%rsp) /* Adjust vector to [-256,-1] range */ |
1da177e4 LT |
794 | interrupt do_IRQ |
795 | /* 0(%rsp): oldrsp-ARGOFFSET */ | |
7effaa88 | 796 | ret_from_intr: |
72fe4858 | 797 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 798 | TRACE_IRQS_OFF |
3829ee6b | 799 | decl %gs:pda_irqcount |
1de9c3f6 | 800 | leaveq |
7effaa88 | 801 | CFI_DEF_CFA_REGISTER rsp |
1de9c3f6 | 802 | CFI_ADJUST_CFA_OFFSET -8 |
7effaa88 | 803 | exit_intr: |
1da177e4 LT |
804 | GET_THREAD_INFO(%rcx) |
805 | testl $3,CS-ARGOFFSET(%rsp) | |
806 | je retint_kernel | |
0bd7b798 | 807 | |
1da177e4 LT |
808 | /* Interrupt came from user space */ |
809 | /* | |
810 | * Has a correct top of stack, but a partial stack frame | |
811 | * %rcx: thread info. Interrupts off. | |
0bd7b798 | 812 | */ |
1da177e4 LT |
813 | retint_with_reschedule: |
814 | movl $_TIF_WORK_MASK,%edi | |
7effaa88 | 815 | retint_check: |
10cd706d | 816 | LOCKDEP_SYS_EXIT_IRQ |
26ccb8a7 | 817 | movl TI_flags(%rcx),%edx |
1da177e4 | 818 | andl %edi,%edx |
7effaa88 | 819 | CFI_REMEMBER_STATE |
1da177e4 | 820 | jnz retint_careful |
10cd706d PZ |
821 | |
822 | retint_swapgs: /* return to user-space */ | |
2601e64d IM |
823 | /* |
824 | * The iretq could re-enable interrupts: | |
825 | */ | |
72fe4858 | 826 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d | 827 | TRACE_IRQS_IRETQ |
72fe4858 | 828 | SWAPGS |
2601e64d IM |
829 | jmp restore_args |
830 | ||
10cd706d | 831 | retint_restore_args: /* return to kernel space */ |
72fe4858 | 832 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d IM |
833 | /* |
834 | * The iretq could re-enable interrupts: | |
835 | */ | |
836 | TRACE_IRQS_IRETQ | |
837 | restore_args: | |
3701d863 IM |
838 | RESTORE_ARGS 0,8,0 |
839 | ||
f7f3d791 | 840 | irq_return: |
72fe4858 | 841 | INTERRUPT_RETURN |
3701d863 IM |
842 | |
843 | .section __ex_table, "a" | |
844 | .quad irq_return, bad_iret | |
845 | .previous | |
846 | ||
847 | #ifdef CONFIG_PARAVIRT | |
72fe4858 | 848 | ENTRY(native_iret) |
1da177e4 LT |
849 | iretq |
850 | ||
851 | .section __ex_table,"a" | |
72fe4858 | 852 | .quad native_iret, bad_iret |
1da177e4 | 853 | .previous |
3701d863 IM |
854 | #endif |
855 | ||
1da177e4 | 856 | .section .fixup,"ax" |
1da177e4 | 857 | bad_iret: |
3aa4b37d RM |
858 | /* |
859 | * The iret traps when the %cs or %ss being restored is bogus. | |
860 | * We've lost the original trap vector and error code. | |
861 | * #GPF is the most likely one to get for an invalid selector. | |
862 | * So pretend we completed the iret and took the #GPF in user mode. | |
863 | * | |
864 | * We are now running with the kernel GS after exception recovery. | |
865 | * But error_entry expects us to have user GS to match the user %cs, | |
866 | * so swap back. | |
867 | */ | |
868 | pushq $0 | |
869 | ||
870 | SWAPGS | |
871 | jmp general_protection | |
872 | ||
72fe4858 GOC |
873 | .previous |
874 | ||
7effaa88 | 875 | /* edi: workmask, edx: work */ |
1da177e4 | 876 | retint_careful: |
7effaa88 | 877 | CFI_RESTORE_STATE |
1da177e4 LT |
878 | bt $TIF_NEED_RESCHED,%edx |
879 | jnc retint_signal | |
2601e64d | 880 | TRACE_IRQS_ON |
72fe4858 | 881 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 882 | pushq %rdi |
7effaa88 | 883 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 | 884 | call schedule |
0bd7b798 | 885 | popq %rdi |
7effaa88 | 886 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 | 887 | GET_THREAD_INFO(%rcx) |
72fe4858 | 888 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 889 | TRACE_IRQS_OFF |
1da177e4 | 890 | jmp retint_check |
0bd7b798 | 891 | |
1da177e4 | 892 | retint_signal: |
8f4d37ec | 893 | testl $_TIF_DO_NOTIFY_MASK,%edx |
10ffdbb8 | 894 | jz retint_swapgs |
2601e64d | 895 | TRACE_IRQS_ON |
72fe4858 | 896 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 897 | SAVE_REST |
0bd7b798 | 898 | movq $-1,ORIG_RAX(%rsp) |
3829ee6b | 899 | xorl %esi,%esi # oldset |
1da177e4 LT |
900 | movq %rsp,%rdi # &pt_regs |
901 | call do_notify_resume | |
902 | RESTORE_REST | |
72fe4858 | 903 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 904 | TRACE_IRQS_OFF |
be9e6870 | 905 | GET_THREAD_INFO(%rcx) |
eca91e78 | 906 | jmp retint_with_reschedule |
1da177e4 LT |
907 | |
908 | #ifdef CONFIG_PREEMPT | |
909 | /* Returning to kernel space. Check if we need preemption */ | |
910 | /* rcx: threadinfo. interrupts off. */ | |
b06babac | 911 | ENTRY(retint_kernel) |
26ccb8a7 | 912 | cmpl $0,TI_preempt_count(%rcx) |
1da177e4 | 913 | jnz retint_restore_args |
26ccb8a7 | 914 | bt $TIF_NEED_RESCHED,TI_flags(%rcx) |
1da177e4 LT |
915 | jnc retint_restore_args |
916 | bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */ | |
917 | jnc retint_restore_args | |
918 | call preempt_schedule_irq | |
919 | jmp exit_intr | |
0bd7b798 | 920 | #endif |
4b787e0b | 921 | |
1da177e4 | 922 | CFI_ENDPROC |
4b787e0b | 923 | END(common_interrupt) |
0bd7b798 | 924 | |
1da177e4 LT |
925 | /* |
926 | * APIC interrupts. | |
0bd7b798 | 927 | */ |
322648d1 AH |
928 | .macro apicinterrupt num sym do_sym |
929 | ENTRY(\sym) | |
7effaa88 | 930 | INTR_FRAME |
19eadf98 | 931 | pushq $~(\num) |
7effaa88 | 932 | CFI_ADJUST_CFA_OFFSET 8 |
322648d1 | 933 | interrupt \do_sym |
1da177e4 LT |
934 | jmp ret_from_intr |
935 | CFI_ENDPROC | |
322648d1 AH |
936 | END(\sym) |
937 | .endm | |
1da177e4 | 938 | |
322648d1 AH |
939 | #ifdef CONFIG_SMP |
940 | apicinterrupt IRQ_MOVE_CLEANUP_VECTOR \ | |
941 | irq_move_cleanup_interrupt smp_irq_move_cleanup_interrupt | |
942 | #endif | |
1da177e4 | 943 | |
5ae3a139 | 944 | apicinterrupt UV_BAU_MESSAGE \ |
322648d1 AH |
945 | uv_bau_message_intr1 uv_bau_message_interrupt |
946 | apicinterrupt LOCAL_TIMER_VECTOR \ | |
947 | apic_timer_interrupt smp_apic_timer_interrupt | |
89b831ef | 948 | |
0bd7b798 | 949 | #ifdef CONFIG_SMP |
322648d1 AH |
950 | apicinterrupt INVALIDATE_TLB_VECTOR_START+0 \ |
951 | invalidate_interrupt0 smp_invalidate_interrupt | |
952 | apicinterrupt INVALIDATE_TLB_VECTOR_START+1 \ | |
953 | invalidate_interrupt1 smp_invalidate_interrupt | |
954 | apicinterrupt INVALIDATE_TLB_VECTOR_START+2 \ | |
955 | invalidate_interrupt2 smp_invalidate_interrupt | |
956 | apicinterrupt INVALIDATE_TLB_VECTOR_START+3 \ | |
957 | invalidate_interrupt3 smp_invalidate_interrupt | |
958 | apicinterrupt INVALIDATE_TLB_VECTOR_START+4 \ | |
959 | invalidate_interrupt4 smp_invalidate_interrupt | |
960 | apicinterrupt INVALIDATE_TLB_VECTOR_START+5 \ | |
961 | invalidate_interrupt5 smp_invalidate_interrupt | |
962 | apicinterrupt INVALIDATE_TLB_VECTOR_START+6 \ | |
963 | invalidate_interrupt6 smp_invalidate_interrupt | |
964 | apicinterrupt INVALIDATE_TLB_VECTOR_START+7 \ | |
965 | invalidate_interrupt7 smp_invalidate_interrupt | |
1da177e4 LT |
966 | #endif |
967 | ||
322648d1 AH |
968 | apicinterrupt THRESHOLD_APIC_VECTOR \ |
969 | threshold_interrupt mce_threshold_interrupt | |
970 | apicinterrupt THERMAL_APIC_VECTOR \ | |
971 | thermal_interrupt smp_thermal_interrupt | |
1812924b | 972 | |
322648d1 AH |
973 | #ifdef CONFIG_SMP |
974 | apicinterrupt CALL_FUNCTION_SINGLE_VECTOR \ | |
975 | call_function_single_interrupt smp_call_function_single_interrupt | |
976 | apicinterrupt CALL_FUNCTION_VECTOR \ | |
977 | call_function_interrupt smp_call_function_interrupt | |
978 | apicinterrupt RESCHEDULE_VECTOR \ | |
979 | reschedule_interrupt smp_reschedule_interrupt | |
980 | #endif | |
1da177e4 | 981 | |
322648d1 AH |
982 | apicinterrupt ERROR_APIC_VECTOR \ |
983 | error_interrupt smp_error_interrupt | |
984 | apicinterrupt SPURIOUS_APIC_VECTOR \ | |
985 | spurious_interrupt smp_spurious_interrupt | |
0bd7b798 | 986 | |
241771ef IM |
987 | #ifdef CONFIG_PERF_COUNTERS |
988 | apicinterrupt LOCAL_PERF_VECTOR \ | |
989 | perf_counter_interrupt smp_perf_counter_interrupt | |
990 | #endif | |
991 | ||
1da177e4 LT |
992 | /* |
993 | * Exception entry points. | |
0bd7b798 | 994 | */ |
322648d1 AH |
995 | .macro zeroentry sym do_sym |
996 | ENTRY(\sym) | |
7effaa88 | 997 | INTR_FRAME |
fab58420 | 998 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
14ae22ba | 999 | pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */ |
d99015b1 AH |
1000 | subq $15*8,%rsp |
1001 | CFI_ADJUST_CFA_OFFSET 15*8 | |
1002 | call error_entry | |
dcd072e2 | 1003 | DEFAULT_FRAME 0 |
d99015b1 AH |
1004 | movq %rsp,%rdi /* pt_regs pointer */ |
1005 | xorl %esi,%esi /* no error code */ | |
322648d1 | 1006 | call \do_sym |
d99015b1 | 1007 | jmp error_exit /* %ebx: no swapgs flag */ |
7effaa88 | 1008 | CFI_ENDPROC |
322648d1 AH |
1009 | END(\sym) |
1010 | .endm | |
1da177e4 | 1011 | |
322648d1 | 1012 | .macro paranoidzeroentry sym do_sym |
ddeb8f21 | 1013 | ENTRY(\sym) |
b8b1d08b AH |
1014 | INTR_FRAME |
1015 | PARAVIRT_ADJUST_EXCEPTION_FRAME | |
1016 | pushq $-1 /* ORIG_RAX: no syscall to restart */ | |
1017 | CFI_ADJUST_CFA_OFFSET 8 | |
1018 | subq $15*8, %rsp | |
1019 | call save_paranoid | |
1020 | TRACE_IRQS_OFF | |
1021 | movq %rsp,%rdi /* pt_regs pointer */ | |
1022 | xorl %esi,%esi /* no error code */ | |
322648d1 | 1023 | call \do_sym |
b8b1d08b AH |
1024 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1025 | CFI_ENDPROC | |
ddeb8f21 | 1026 | END(\sym) |
322648d1 | 1027 | .endm |
b8b1d08b | 1028 | |
322648d1 | 1029 | .macro paranoidzeroentry_ist sym do_sym ist |
ddeb8f21 | 1030 | ENTRY(\sym) |
9f1e87ea | 1031 | INTR_FRAME |
b8b1d08b AH |
1032 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1033 | pushq $-1 /* ORIG_RAX: no syscall to restart */ | |
1034 | CFI_ADJUST_CFA_OFFSET 8 | |
1035 | subq $15*8, %rsp | |
1036 | call save_paranoid | |
1037 | TRACE_IRQS_OFF | |
1038 | movq %rsp,%rdi /* pt_regs pointer */ | |
1039 | xorl %esi,%esi /* no error code */ | |
1040 | movq %gs:pda_data_offset, %rbp | |
1041 | subq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) | |
322648d1 | 1042 | call \do_sym |
b8b1d08b AH |
1043 | addq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) |
1044 | jmp paranoid_exit /* %ebx: no swapgs flag */ | |
1045 | CFI_ENDPROC | |
ddeb8f21 | 1046 | END(\sym) |
322648d1 | 1047 | .endm |
b8b1d08b | 1048 | |
ddeb8f21 | 1049 | .macro errorentry sym do_sym |
322648d1 | 1050 | ENTRY(\sym) |
7effaa88 | 1051 | XCPT_FRAME |
fab58420 | 1052 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
d99015b1 AH |
1053 | subq $15*8,%rsp |
1054 | CFI_ADJUST_CFA_OFFSET 15*8 | |
1055 | call error_entry | |
dcd072e2 | 1056 | DEFAULT_FRAME 0 |
d99015b1 AH |
1057 | movq %rsp,%rdi /* pt_regs pointer */ |
1058 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
1059 | movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */ | |
322648d1 | 1060 | call \do_sym |
d99015b1 | 1061 | jmp error_exit /* %ebx: no swapgs flag */ |
7effaa88 | 1062 | CFI_ENDPROC |
322648d1 | 1063 | END(\sym) |
322648d1 | 1064 | .endm |
1da177e4 LT |
1065 | |
1066 | /* error code is on the stack already */ | |
ddeb8f21 | 1067 | .macro paranoiderrorentry sym do_sym |
322648d1 | 1068 | ENTRY(\sym) |
b8b1d08b AH |
1069 | XCPT_FRAME |
1070 | PARAVIRT_ADJUST_EXCEPTION_FRAME | |
1071 | subq $15*8,%rsp | |
e2f6bc25 AH |
1072 | CFI_ADJUST_CFA_OFFSET 15*8 |
1073 | call save_paranoid | |
1074 | DEFAULT_FRAME 0 | |
7e61a793 | 1075 | TRACE_IRQS_OFF |
b8b1d08b AH |
1076 | movq %rsp,%rdi /* pt_regs pointer */ |
1077 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
1078 | movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */ | |
322648d1 | 1079 | call \do_sym |
b8b1d08b AH |
1080 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1081 | CFI_ENDPROC | |
322648d1 | 1082 | END(\sym) |
322648d1 AH |
1083 | .endm |
1084 | ||
1085 | zeroentry divide_error do_divide_error | |
322648d1 AH |
1086 | zeroentry overflow do_overflow |
1087 | zeroentry bounds do_bounds | |
1088 | zeroentry invalid_op do_invalid_op | |
1089 | zeroentry device_not_available do_device_not_available | |
ddeb8f21 | 1090 | paranoiderrorentry double_fault do_double_fault |
322648d1 AH |
1091 | zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun |
1092 | errorentry invalid_TSS do_invalid_TSS | |
1093 | errorentry segment_not_present do_segment_not_present | |
322648d1 AH |
1094 | zeroentry spurious_interrupt_bug do_spurious_interrupt_bug |
1095 | zeroentry coprocessor_error do_coprocessor_error | |
1096 | errorentry alignment_check do_alignment_check | |
322648d1 | 1097 | zeroentry simd_coprocessor_error do_simd_coprocessor_error |
2601e64d | 1098 | |
9f1e87ea CG |
1099 | /* Reload gs selector with exception handling */ |
1100 | /* edi: new selector */ | |
9f9d489a | 1101 | ENTRY(native_load_gs_index) |
7effaa88 | 1102 | CFI_STARTPROC |
1da177e4 | 1103 | pushf |
7effaa88 | 1104 | CFI_ADJUST_CFA_OFFSET 8 |
72fe4858 | 1105 | DISABLE_INTERRUPTS(CLBR_ANY | ~(CLBR_RDI)) |
9f1e87ea | 1106 | SWAPGS |
0bd7b798 | 1107 | gs_change: |
9f1e87ea | 1108 | movl %edi,%gs |
1da177e4 | 1109 | 2: mfence /* workaround */ |
72fe4858 | 1110 | SWAPGS |
9f1e87ea | 1111 | popf |
7effaa88 | 1112 | CFI_ADJUST_CFA_OFFSET -8 |
9f1e87ea | 1113 | ret |
7effaa88 | 1114 | CFI_ENDPROC |
6efdcfaf | 1115 | END(native_load_gs_index) |
0bd7b798 | 1116 | |
9f1e87ea CG |
1117 | .section __ex_table,"a" |
1118 | .align 8 | |
1119 | .quad gs_change,bad_gs | |
1120 | .previous | |
1121 | .section .fixup,"ax" | |
1da177e4 | 1122 | /* running with kernelgs */ |
0bd7b798 | 1123 | bad_gs: |
72fe4858 | 1124 | SWAPGS /* switch back to user gs */ |
1da177e4 | 1125 | xorl %eax,%eax |
9f1e87ea CG |
1126 | movl %eax,%gs |
1127 | jmp 2b | |
1128 | .previous | |
0bd7b798 | 1129 | |
1da177e4 LT |
1130 | /* |
1131 | * Create a kernel thread. | |
1132 | * | |
1133 | * C extern interface: | |
1134 | * extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
1135 | * | |
1136 | * asm input arguments: | |
1137 | * rdi: fn, rsi: arg, rdx: flags | |
1138 | */ | |
1139 | ENTRY(kernel_thread) | |
1140 | CFI_STARTPROC | |
1141 | FAKE_STACK_FRAME $child_rip | |
1142 | SAVE_ALL | |
1143 | ||
1144 | # rdi: flags, rsi: usp, rdx: will be &pt_regs | |
1145 | movq %rdx,%rdi | |
1146 | orq kernel_thread_flags(%rip),%rdi | |
1147 | movq $-1, %rsi | |
1148 | movq %rsp, %rdx | |
1149 | ||
1150 | xorl %r8d,%r8d | |
1151 | xorl %r9d,%r9d | |
0bd7b798 | 1152 | |
1da177e4 LT |
1153 | # clone now |
1154 | call do_fork | |
1155 | movq %rax,RAX(%rsp) | |
1156 | xorl %edi,%edi | |
1157 | ||
1158 | /* | |
1159 | * It isn't worth to check for reschedule here, | |
1160 | * so internally to the x86_64 port you can rely on kernel_thread() | |
1161 | * not to reschedule the child before returning, this avoids the need | |
1162 | * of hacks for example to fork off the per-CPU idle tasks. | |
9f1e87ea | 1163 | * [Hopefully no generic code relies on the reschedule -AK] |
1da177e4 LT |
1164 | */ |
1165 | RESTORE_ALL | |
1166 | UNFAKE_STACK_FRAME | |
1167 | ret | |
1168 | CFI_ENDPROC | |
6efdcfaf | 1169 | END(kernel_thread) |
0bd7b798 | 1170 | |
c2c631e3 | 1171 | ENTRY(child_rip) |
c05991ed AK |
1172 | pushq $0 # fake return address |
1173 | CFI_STARTPROC | |
1da177e4 LT |
1174 | /* |
1175 | * Here we are in the child and the registers are set as they were | |
1176 | * at kernel_thread() invocation in the parent. | |
1177 | */ | |
1178 | movq %rdi, %rax | |
1179 | movq %rsi, %rdi | |
1180 | call *%rax | |
1181 | # exit | |
1c5b5cfd | 1182 | mov %eax, %edi |
1da177e4 | 1183 | call do_exit |
5f5db591 | 1184 | ud2 # padding for call trace |
c05991ed | 1185 | CFI_ENDPROC |
6efdcfaf | 1186 | END(child_rip) |
1da177e4 LT |
1187 | |
1188 | /* | |
1189 | * execve(). This function needs to use IRET, not SYSRET, to set up all state properly. | |
1190 | * | |
1191 | * C extern interface: | |
1192 | * extern long execve(char *name, char **argv, char **envp) | |
1193 | * | |
1194 | * asm input arguments: | |
1195 | * rdi: name, rsi: argv, rdx: envp | |
1196 | * | |
1197 | * We want to fallback into: | |
5d119b2c | 1198 | * extern long sys_execve(char *name, char **argv,char **envp, struct pt_regs *regs) |
1da177e4 LT |
1199 | * |
1200 | * do_sys_execve asm fallback arguments: | |
5d119b2c | 1201 | * rdi: name, rsi: argv, rdx: envp, rcx: fake frame on the stack |
1da177e4 | 1202 | */ |
3db03b4a | 1203 | ENTRY(kernel_execve) |
1da177e4 LT |
1204 | CFI_STARTPROC |
1205 | FAKE_STACK_FRAME $0 | |
0bd7b798 | 1206 | SAVE_ALL |
5d119b2c | 1207 | movq %rsp,%rcx |
1da177e4 | 1208 | call sys_execve |
0bd7b798 | 1209 | movq %rax, RAX(%rsp) |
1da177e4 LT |
1210 | RESTORE_REST |
1211 | testq %rax,%rax | |
1212 | je int_ret_from_sys_call | |
1213 | RESTORE_ARGS | |
1214 | UNFAKE_STACK_FRAME | |
1215 | ret | |
1216 | CFI_ENDPROC | |
6efdcfaf | 1217 | END(kernel_execve) |
1da177e4 | 1218 | |
2699500b | 1219 | /* Call softirq on interrupt stack. Interrupts are off. */ |
ed6b676c | 1220 | ENTRY(call_softirq) |
7effaa88 | 1221 | CFI_STARTPROC |
2699500b AK |
1222 | push %rbp |
1223 | CFI_ADJUST_CFA_OFFSET 8 | |
1224 | CFI_REL_OFFSET rbp,0 | |
1225 | mov %rsp,%rbp | |
1226 | CFI_DEF_CFA_REGISTER rbp | |
ed6b676c | 1227 | incl %gs:pda_irqcount |
2699500b AK |
1228 | cmove %gs:pda_irqstackptr,%rsp |
1229 | push %rbp # backlink for old unwinder | |
ed6b676c | 1230 | call __do_softirq |
2699500b | 1231 | leaveq |
7effaa88 | 1232 | CFI_DEF_CFA_REGISTER rsp |
2699500b | 1233 | CFI_ADJUST_CFA_OFFSET -8 |
ed6b676c | 1234 | decl %gs:pda_irqcount |
ed6b676c | 1235 | ret |
7effaa88 | 1236 | CFI_ENDPROC |
6efdcfaf | 1237 | END(call_softirq) |
75154f40 | 1238 | |
3d75e1b8 | 1239 | #ifdef CONFIG_XEN |
322648d1 | 1240 | zeroentry xen_hypervisor_callback xen_do_hypervisor_callback |
3d75e1b8 JF |
1241 | |
1242 | /* | |
9f1e87ea CG |
1243 | * A note on the "critical region" in our callback handler. |
1244 | * We want to avoid stacking callback handlers due to events occurring | |
1245 | * during handling of the last event. To do this, we keep events disabled | |
1246 | * until we've done all processing. HOWEVER, we must enable events before | |
1247 | * popping the stack frame (can't be done atomically) and so it would still | |
1248 | * be possible to get enough handler activations to overflow the stack. | |
1249 | * Although unlikely, bugs of that kind are hard to track down, so we'd | |
1250 | * like to avoid the possibility. | |
1251 | * So, on entry to the handler we detect whether we interrupted an | |
1252 | * existing activation in its critical region -- if so, we pop the current | |
1253 | * activation and restart the handler using the previous one. | |
1254 | */ | |
3d75e1b8 JF |
1255 | ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs) |
1256 | CFI_STARTPROC | |
9f1e87ea CG |
1257 | /* |
1258 | * Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will | |
1259 | * see the correct pointer to the pt_regs | |
1260 | */ | |
3d75e1b8 JF |
1261 | movq %rdi, %rsp # we don't return, adjust the stack frame |
1262 | CFI_ENDPROC | |
dcd072e2 | 1263 | DEFAULT_FRAME |
3d75e1b8 JF |
1264 | 11: incl %gs:pda_irqcount |
1265 | movq %rsp,%rbp | |
1266 | CFI_DEF_CFA_REGISTER rbp | |
1267 | cmovzq %gs:pda_irqstackptr,%rsp | |
1268 | pushq %rbp # backlink for old unwinder | |
1269 | call xen_evtchn_do_upcall | |
1270 | popq %rsp | |
1271 | CFI_DEF_CFA_REGISTER rsp | |
1272 | decl %gs:pda_irqcount | |
1273 | jmp error_exit | |
1274 | CFI_ENDPROC | |
1275 | END(do_hypervisor_callback) | |
1276 | ||
1277 | /* | |
9f1e87ea CG |
1278 | * Hypervisor uses this for application faults while it executes. |
1279 | * We get here for two reasons: | |
1280 | * 1. Fault while reloading DS, ES, FS or GS | |
1281 | * 2. Fault while executing IRET | |
1282 | * Category 1 we do not need to fix up as Xen has already reloaded all segment | |
1283 | * registers that could be reloaded and zeroed the others. | |
1284 | * Category 2 we fix up by killing the current process. We cannot use the | |
1285 | * normal Linux return path in this case because if we use the IRET hypercall | |
1286 | * to pop the stack frame we end up in an infinite loop of failsafe callbacks. | |
1287 | * We distinguish between categories by comparing each saved segment register | |
1288 | * with its current contents: any discrepancy means we in category 1. | |
1289 | */ | |
3d75e1b8 | 1290 | ENTRY(xen_failsafe_callback) |
dcd072e2 AH |
1291 | INTR_FRAME 1 (6*8) |
1292 | /*CFI_REL_OFFSET gs,GS*/ | |
1293 | /*CFI_REL_OFFSET fs,FS*/ | |
1294 | /*CFI_REL_OFFSET es,ES*/ | |
1295 | /*CFI_REL_OFFSET ds,DS*/ | |
1296 | CFI_REL_OFFSET r11,8 | |
1297 | CFI_REL_OFFSET rcx,0 | |
3d75e1b8 JF |
1298 | movw %ds,%cx |
1299 | cmpw %cx,0x10(%rsp) | |
1300 | CFI_REMEMBER_STATE | |
1301 | jne 1f | |
1302 | movw %es,%cx | |
1303 | cmpw %cx,0x18(%rsp) | |
1304 | jne 1f | |
1305 | movw %fs,%cx | |
1306 | cmpw %cx,0x20(%rsp) | |
1307 | jne 1f | |
1308 | movw %gs,%cx | |
1309 | cmpw %cx,0x28(%rsp) | |
1310 | jne 1f | |
1311 | /* All segments match their saved values => Category 2 (Bad IRET). */ | |
1312 | movq (%rsp),%rcx | |
1313 | CFI_RESTORE rcx | |
1314 | movq 8(%rsp),%r11 | |
1315 | CFI_RESTORE r11 | |
1316 | addq $0x30,%rsp | |
1317 | CFI_ADJUST_CFA_OFFSET -0x30 | |
14ae22ba IM |
1318 | pushq_cfi $0 /* RIP */ |
1319 | pushq_cfi %r11 | |
1320 | pushq_cfi %rcx | |
4a5c3e77 | 1321 | jmp general_protection |
3d75e1b8 JF |
1322 | CFI_RESTORE_STATE |
1323 | 1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */ | |
1324 | movq (%rsp),%rcx | |
1325 | CFI_RESTORE rcx | |
1326 | movq 8(%rsp),%r11 | |
1327 | CFI_RESTORE r11 | |
1328 | addq $0x30,%rsp | |
1329 | CFI_ADJUST_CFA_OFFSET -0x30 | |
14ae22ba | 1330 | pushq_cfi $0 |
3d75e1b8 JF |
1331 | SAVE_ALL |
1332 | jmp error_exit | |
1333 | CFI_ENDPROC | |
3d75e1b8 JF |
1334 | END(xen_failsafe_callback) |
1335 | ||
1336 | #endif /* CONFIG_XEN */ | |
ddeb8f21 AH |
1337 | |
1338 | /* | |
1339 | * Some functions should be protected against kprobes | |
1340 | */ | |
1341 | .pushsection .kprobes.text, "ax" | |
1342 | ||
1343 | paranoidzeroentry_ist debug do_debug DEBUG_STACK | |
1344 | paranoidzeroentry_ist int3 do_int3 DEBUG_STACK | |
1345 | paranoiderrorentry stack_segment do_stack_segment | |
1346 | errorentry general_protection do_general_protection | |
1347 | errorentry page_fault do_page_fault | |
1348 | #ifdef CONFIG_X86_MCE | |
1349 | paranoidzeroentry machine_check do_machine_check | |
1350 | #endif | |
1351 | ||
1352 | /* | |
9f1e87ea CG |
1353 | * "Paranoid" exit path from exception stack. |
1354 | * Paranoid because this is used by NMIs and cannot take | |
ddeb8f21 AH |
1355 | * any kernel state for granted. |
1356 | * We don't do kernel preemption checks here, because only | |
1357 | * NMI should be common and it does not enable IRQs and | |
1358 | * cannot get reschedule ticks. | |
1359 | * | |
1360 | * "trace" is 0 for the NMI handler only, because irq-tracing | |
1361 | * is fundamentally NMI-unsafe. (we cannot change the soft and | |
1362 | * hard flags at once, atomically) | |
1363 | */ | |
1364 | ||
1365 | /* ebx: no swapgs flag */ | |
1366 | ENTRY(paranoid_exit) | |
1367 | INTR_FRAME | |
1368 | DISABLE_INTERRUPTS(CLBR_NONE) | |
1369 | TRACE_IRQS_OFF | |
1370 | testl %ebx,%ebx /* swapgs needed? */ | |
1371 | jnz paranoid_restore | |
1372 | testl $3,CS(%rsp) | |
1373 | jnz paranoid_userspace | |
1374 | paranoid_swapgs: | |
1375 | TRACE_IRQS_IRETQ 0 | |
1376 | SWAPGS_UNSAFE_STACK | |
1377 | paranoid_restore: | |
1378 | RESTORE_ALL 8 | |
1379 | jmp irq_return | |
1380 | paranoid_userspace: | |
1381 | GET_THREAD_INFO(%rcx) | |
1382 | movl TI_flags(%rcx),%ebx | |
1383 | andl $_TIF_WORK_MASK,%ebx | |
1384 | jz paranoid_swapgs | |
1385 | movq %rsp,%rdi /* &pt_regs */ | |
1386 | call sync_regs | |
1387 | movq %rax,%rsp /* switch stack for scheduling */ | |
1388 | testl $_TIF_NEED_RESCHED,%ebx | |
1389 | jnz paranoid_schedule | |
1390 | movl %ebx,%edx /* arg3: thread flags */ | |
1391 | TRACE_IRQS_ON | |
1392 | ENABLE_INTERRUPTS(CLBR_NONE) | |
1393 | xorl %esi,%esi /* arg2: oldset */ | |
1394 | movq %rsp,%rdi /* arg1: &pt_regs */ | |
1395 | call do_notify_resume | |
1396 | DISABLE_INTERRUPTS(CLBR_NONE) | |
1397 | TRACE_IRQS_OFF | |
1398 | jmp paranoid_userspace | |
1399 | paranoid_schedule: | |
1400 | TRACE_IRQS_ON | |
1401 | ENABLE_INTERRUPTS(CLBR_ANY) | |
1402 | call schedule | |
1403 | DISABLE_INTERRUPTS(CLBR_ANY) | |
1404 | TRACE_IRQS_OFF | |
1405 | jmp paranoid_userspace | |
1406 | CFI_ENDPROC | |
1407 | END(paranoid_exit) | |
1408 | ||
1409 | /* | |
1410 | * Exception entry point. This expects an error code/orig_rax on the stack. | |
1411 | * returns in "no swapgs flag" in %ebx. | |
1412 | */ | |
1413 | ENTRY(error_entry) | |
1414 | XCPT_FRAME | |
1415 | CFI_ADJUST_CFA_OFFSET 15*8 | |
1416 | /* oldrax contains error code */ | |
1417 | cld | |
1418 | movq_cfi rdi, RDI+8 | |
1419 | movq_cfi rsi, RSI+8 | |
1420 | movq_cfi rdx, RDX+8 | |
1421 | movq_cfi rcx, RCX+8 | |
1422 | movq_cfi rax, RAX+8 | |
1423 | movq_cfi r8, R8+8 | |
1424 | movq_cfi r9, R9+8 | |
1425 | movq_cfi r10, R10+8 | |
1426 | movq_cfi r11, R11+8 | |
1427 | movq_cfi rbx, RBX+8 | |
1428 | movq_cfi rbp, RBP+8 | |
1429 | movq_cfi r12, R12+8 | |
1430 | movq_cfi r13, R13+8 | |
1431 | movq_cfi r14, R14+8 | |
1432 | movq_cfi r15, R15+8 | |
1433 | xorl %ebx,%ebx | |
1434 | testl $3,CS+8(%rsp) | |
1435 | je error_kernelspace | |
1436 | error_swapgs: | |
1437 | SWAPGS | |
1438 | error_sti: | |
1439 | TRACE_IRQS_OFF | |
1440 | ret | |
1441 | CFI_ENDPROC | |
1442 | ||
1443 | /* | |
1444 | * There are two places in the kernel that can potentially fault with | |
1445 | * usergs. Handle them here. The exception handlers after iret run with | |
1446 | * kernel gs again, so don't set the user space flag. B stepping K8s | |
1447 | * sometimes report an truncated RIP for IRET exceptions returning to | |
1448 | * compat mode. Check for these here too. | |
1449 | */ | |
1450 | error_kernelspace: | |
1451 | incl %ebx | |
1452 | leaq irq_return(%rip),%rcx | |
1453 | cmpq %rcx,RIP+8(%rsp) | |
1454 | je error_swapgs | |
1455 | movl %ecx,%ecx /* zero extend */ | |
1456 | cmpq %rcx,RIP+8(%rsp) | |
1457 | je error_swapgs | |
1458 | cmpq $gs_change,RIP+8(%rsp) | |
9f1e87ea | 1459 | je error_swapgs |
ddeb8f21 AH |
1460 | jmp error_sti |
1461 | END(error_entry) | |
1462 | ||
1463 | ||
1464 | /* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */ | |
1465 | ENTRY(error_exit) | |
1466 | DEFAULT_FRAME | |
1467 | movl %ebx,%eax | |
1468 | RESTORE_REST | |
1469 | DISABLE_INTERRUPTS(CLBR_NONE) | |
1470 | TRACE_IRQS_OFF | |
1471 | GET_THREAD_INFO(%rcx) | |
1472 | testl %eax,%eax | |
1473 | jne retint_kernel | |
1474 | LOCKDEP_SYS_EXIT_IRQ | |
1475 | movl TI_flags(%rcx),%edx | |
1476 | movl $_TIF_WORK_MASK,%edi | |
1477 | andl %edi,%edx | |
1478 | jnz retint_careful | |
1479 | jmp retint_swapgs | |
1480 | CFI_ENDPROC | |
1481 | END(error_exit) | |
1482 | ||
1483 | ||
1484 | /* runs on exception stack */ | |
1485 | ENTRY(nmi) | |
1486 | INTR_FRAME | |
1487 | PARAVIRT_ADJUST_EXCEPTION_FRAME | |
1488 | pushq_cfi $-1 | |
1489 | subq $15*8, %rsp | |
1490 | CFI_ADJUST_CFA_OFFSET 15*8 | |
1491 | call save_paranoid | |
1492 | DEFAULT_FRAME 0 | |
1493 | /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */ | |
1494 | movq %rsp,%rdi | |
1495 | movq $-1,%rsi | |
1496 | call do_nmi | |
1497 | #ifdef CONFIG_TRACE_IRQFLAGS | |
1498 | /* paranoidexit; without TRACE_IRQS_OFF */ | |
1499 | /* ebx: no swapgs flag */ | |
1500 | DISABLE_INTERRUPTS(CLBR_NONE) | |
1501 | testl %ebx,%ebx /* swapgs needed? */ | |
1502 | jnz nmi_restore | |
1503 | testl $3,CS(%rsp) | |
1504 | jnz nmi_userspace | |
1505 | nmi_swapgs: | |
1506 | SWAPGS_UNSAFE_STACK | |
1507 | nmi_restore: | |
1508 | RESTORE_ALL 8 | |
1509 | jmp irq_return | |
1510 | nmi_userspace: | |
1511 | GET_THREAD_INFO(%rcx) | |
1512 | movl TI_flags(%rcx),%ebx | |
1513 | andl $_TIF_WORK_MASK,%ebx | |
1514 | jz nmi_swapgs | |
1515 | movq %rsp,%rdi /* &pt_regs */ | |
1516 | call sync_regs | |
1517 | movq %rax,%rsp /* switch stack for scheduling */ | |
1518 | testl $_TIF_NEED_RESCHED,%ebx | |
1519 | jnz nmi_schedule | |
1520 | movl %ebx,%edx /* arg3: thread flags */ | |
1521 | ENABLE_INTERRUPTS(CLBR_NONE) | |
1522 | xorl %esi,%esi /* arg2: oldset */ | |
1523 | movq %rsp,%rdi /* arg1: &pt_regs */ | |
1524 | call do_notify_resume | |
1525 | DISABLE_INTERRUPTS(CLBR_NONE) | |
1526 | jmp nmi_userspace | |
1527 | nmi_schedule: | |
1528 | ENABLE_INTERRUPTS(CLBR_ANY) | |
1529 | call schedule | |
1530 | DISABLE_INTERRUPTS(CLBR_ANY) | |
1531 | jmp nmi_userspace | |
1532 | CFI_ENDPROC | |
1533 | #else | |
1534 | jmp paranoid_exit | |
9f1e87ea | 1535 | CFI_ENDPROC |
ddeb8f21 AH |
1536 | #endif |
1537 | END(nmi) | |
1538 | ||
1539 | ENTRY(ignore_sysret) | |
1540 | CFI_STARTPROC | |
1541 | mov $-ENOSYS,%eax | |
1542 | sysret | |
1543 | CFI_ENDPROC | |
1544 | END(ignore_sysret) | |
1545 | ||
1546 | /* | |
1547 | * End of kprobes section | |
1548 | */ | |
1549 | .popsection |