Commit | Line | Data |
---|---|---|
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. | |
0d2eb44f | 21 | * - partial stack frame: partially saved registers up to 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> | |
0341c14d | 51 | #include <asm/page_types.h> |
2601e64d | 52 | #include <asm/irqflags.h> |
72fe4858 | 53 | #include <asm/paravirt.h> |
395a59d0 | 54 | #include <asm/ftrace.h> |
9939ddaf | 55 | #include <asm/percpu.h> |
1da177e4 | 56 | |
86a1c34a RM |
57 | /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */ |
58 | #include <linux/elf-em.h> | |
59 | #define AUDIT_ARCH_X86_64 (EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE) | |
60 | #define __AUDIT_ARCH_64BIT 0x80000000 | |
61 | #define __AUDIT_ARCH_LE 0x40000000 | |
62 | ||
1da177e4 | 63 | .code64 |
ea714547 JO |
64 | .section .entry.text, "ax" |
65 | ||
606576ce | 66 | #ifdef CONFIG_FUNCTION_TRACER |
d61f82d0 SR |
67 | #ifdef CONFIG_DYNAMIC_FTRACE |
68 | ENTRY(mcount) | |
d61f82d0 SR |
69 | retq |
70 | END(mcount) | |
71 | ||
72 | ENTRY(ftrace_caller) | |
60a7ecf4 SR |
73 | cmpl $0, function_trace_stop |
74 | jne ftrace_stub | |
d61f82d0 | 75 | |
d680fe44 | 76 | MCOUNT_SAVE_FRAME |
d61f82d0 SR |
77 | |
78 | movq 0x38(%rsp), %rdi | |
79 | movq 8(%rbp), %rsi | |
395a59d0 | 80 | subq $MCOUNT_INSN_SIZE, %rdi |
d61f82d0 | 81 | |
bc8b2b92 | 82 | GLOBAL(ftrace_call) |
d61f82d0 SR |
83 | call ftrace_stub |
84 | ||
d680fe44 | 85 | MCOUNT_RESTORE_FRAME |
d61f82d0 | 86 | |
48d68b20 | 87 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
bc8b2b92 | 88 | GLOBAL(ftrace_graph_call) |
48d68b20 FW |
89 | jmp ftrace_stub |
90 | #endif | |
d61f82d0 | 91 | |
bc8b2b92 | 92 | GLOBAL(ftrace_stub) |
d61f82d0 SR |
93 | retq |
94 | END(ftrace_caller) | |
95 | ||
96 | #else /* ! CONFIG_DYNAMIC_FTRACE */ | |
16444a8a | 97 | ENTRY(mcount) |
60a7ecf4 SR |
98 | cmpl $0, function_trace_stop |
99 | jne ftrace_stub | |
100 | ||
16444a8a ACM |
101 | cmpq $ftrace_stub, ftrace_trace_function |
102 | jnz trace | |
48d68b20 FW |
103 | |
104 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
105 | cmpq $ftrace_stub, ftrace_graph_return | |
106 | jnz ftrace_graph_caller | |
e49dc19c SR |
107 | |
108 | cmpq $ftrace_graph_entry_stub, ftrace_graph_entry | |
109 | jnz ftrace_graph_caller | |
48d68b20 FW |
110 | #endif |
111 | ||
bc8b2b92 | 112 | GLOBAL(ftrace_stub) |
16444a8a ACM |
113 | retq |
114 | ||
115 | trace: | |
d680fe44 | 116 | MCOUNT_SAVE_FRAME |
16444a8a ACM |
117 | |
118 | movq 0x38(%rsp), %rdi | |
119 | movq 8(%rbp), %rsi | |
395a59d0 | 120 | subq $MCOUNT_INSN_SIZE, %rdi |
16444a8a ACM |
121 | |
122 | call *ftrace_trace_function | |
123 | ||
d680fe44 | 124 | MCOUNT_RESTORE_FRAME |
16444a8a ACM |
125 | |
126 | jmp ftrace_stub | |
127 | END(mcount) | |
d61f82d0 | 128 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
606576ce | 129 | #endif /* CONFIG_FUNCTION_TRACER */ |
16444a8a | 130 | |
48d68b20 FW |
131 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
132 | ENTRY(ftrace_graph_caller) | |
133 | cmpl $0, function_trace_stop | |
134 | jne ftrace_stub | |
135 | ||
d680fe44 | 136 | MCOUNT_SAVE_FRAME |
48d68b20 FW |
137 | |
138 | leaq 8(%rbp), %rdi | |
139 | movq 0x38(%rsp), %rsi | |
71e308a2 | 140 | movq (%rbp), %rdx |
bb4304c7 | 141 | subq $MCOUNT_INSN_SIZE, %rsi |
48d68b20 FW |
142 | |
143 | call prepare_ftrace_return | |
144 | ||
d680fe44 CG |
145 | MCOUNT_RESTORE_FRAME |
146 | ||
48d68b20 FW |
147 | retq |
148 | END(ftrace_graph_caller) | |
149 | ||
bc8b2b92 | 150 | GLOBAL(return_to_handler) |
4818d809 | 151 | subq $24, %rsp |
48d68b20 | 152 | |
e71e99c2 | 153 | /* Save the return values */ |
16444a8a | 154 | movq %rax, (%rsp) |
e71e99c2 | 155 | movq %rdx, 8(%rsp) |
71e308a2 | 156 | movq %rbp, %rdi |
16444a8a | 157 | |
48d68b20 | 158 | call ftrace_return_to_handler |
16444a8a | 159 | |
194ec341 | 160 | movq %rax, %rdi |
e71e99c2 | 161 | movq 8(%rsp), %rdx |
16444a8a | 162 | movq (%rsp), %rax |
194ec341 SR |
163 | addq $24, %rsp |
164 | jmp *%rdi | |
48d68b20 | 165 | #endif |
16444a8a | 166 | |
16444a8a | 167 | |
dc37db4d | 168 | #ifndef CONFIG_PREEMPT |
1da177e4 | 169 | #define retint_kernel retint_restore_args |
0bd7b798 | 170 | #endif |
2601e64d | 171 | |
72fe4858 | 172 | #ifdef CONFIG_PARAVIRT |
2be29982 | 173 | ENTRY(native_usergs_sysret64) |
72fe4858 GOC |
174 | swapgs |
175 | sysretq | |
b3baaa13 | 176 | ENDPROC(native_usergs_sysret64) |
72fe4858 GOC |
177 | #endif /* CONFIG_PARAVIRT */ |
178 | ||
2601e64d IM |
179 | |
180 | .macro TRACE_IRQS_IRETQ offset=ARGOFFSET | |
181 | #ifdef CONFIG_TRACE_IRQFLAGS | |
182 | bt $9,EFLAGS-\offset(%rsp) /* interrupts off? */ | |
183 | jnc 1f | |
184 | TRACE_IRQS_ON | |
185 | 1: | |
186 | #endif | |
187 | .endm | |
188 | ||
1da177e4 | 189 | /* |
0bd7b798 AH |
190 | * C code is not supposed to know about undefined top of stack. Every time |
191 | * a C function with an pt_regs argument is called from the SYSCALL based | |
1da177e4 LT |
192 | * fast path FIXUP_TOP_OF_STACK is needed. |
193 | * RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs | |
194 | * manipulation. | |
0bd7b798 AH |
195 | */ |
196 | ||
197 | /* %rsp:at FRAMEEND */ | |
c002a1e6 | 198 | .macro FIXUP_TOP_OF_STACK tmp offset=0 |
3d1e42a7 | 199 | movq PER_CPU_VAR(old_rsp),\tmp |
c002a1e6 AH |
200 | movq \tmp,RSP+\offset(%rsp) |
201 | movq $__USER_DS,SS+\offset(%rsp) | |
202 | movq $__USER_CS,CS+\offset(%rsp) | |
203 | movq $-1,RCX+\offset(%rsp) | |
204 | movq R11+\offset(%rsp),\tmp /* get eflags */ | |
205 | movq \tmp,EFLAGS+\offset(%rsp) | |
1da177e4 LT |
206 | .endm |
207 | ||
c002a1e6 AH |
208 | .macro RESTORE_TOP_OF_STACK tmp offset=0 |
209 | movq RSP+\offset(%rsp),\tmp | |
3d1e42a7 | 210 | movq \tmp,PER_CPU_VAR(old_rsp) |
c002a1e6 AH |
211 | movq EFLAGS+\offset(%rsp),\tmp |
212 | movq \tmp,R11+\offset(%rsp) | |
1da177e4 LT |
213 | .endm |
214 | ||
215 | .macro FAKE_STACK_FRAME child_rip | |
216 | /* push in order ss, rsp, eflags, cs, rip */ | |
3829ee6b | 217 | xorl %eax, %eax |
df5d1874 | 218 | pushq_cfi $__KERNEL_DS /* ss */ |
7effaa88 | 219 | /*CFI_REL_OFFSET ss,0*/ |
df5d1874 | 220 | pushq_cfi %rax /* rsp */ |
7effaa88 | 221 | CFI_REL_OFFSET rsp,0 |
df5d1874 | 222 | pushq_cfi $X86_EFLAGS_IF /* eflags - interrupts on */ |
7effaa88 | 223 | /*CFI_REL_OFFSET rflags,0*/ |
df5d1874 | 224 | pushq_cfi $__KERNEL_CS /* cs */ |
7effaa88 | 225 | /*CFI_REL_OFFSET cs,0*/ |
df5d1874 | 226 | pushq_cfi \child_rip /* rip */ |
7effaa88 | 227 | CFI_REL_OFFSET rip,0 |
df5d1874 | 228 | pushq_cfi %rax /* orig rax */ |
1da177e4 LT |
229 | .endm |
230 | ||
231 | .macro UNFAKE_STACK_FRAME | |
232 | addq $8*6, %rsp | |
233 | CFI_ADJUST_CFA_OFFSET -(6*8) | |
234 | .endm | |
235 | ||
dcd072e2 AH |
236 | /* |
237 | * initial frame state for interrupts (and exceptions without error code) | |
238 | */ | |
239 | .macro EMPTY_FRAME start=1 offset=0 | |
7effaa88 | 240 | .if \start |
dcd072e2 | 241 | CFI_STARTPROC simple |
adf14236 | 242 | CFI_SIGNAL_FRAME |
dcd072e2 | 243 | CFI_DEF_CFA rsp,8+\offset |
7effaa88 | 244 | .else |
dcd072e2 | 245 | CFI_DEF_CFA_OFFSET 8+\offset |
7effaa88 | 246 | .endif |
1da177e4 | 247 | .endm |
d99015b1 AH |
248 | |
249 | /* | |
dcd072e2 | 250 | * initial frame state for interrupts (and exceptions without error code) |
d99015b1 | 251 | */ |
dcd072e2 | 252 | .macro INTR_FRAME start=1 offset=0 |
e8a0e276 IM |
253 | EMPTY_FRAME \start, SS+8+\offset-RIP |
254 | /*CFI_REL_OFFSET ss, SS+\offset-RIP*/ | |
255 | CFI_REL_OFFSET rsp, RSP+\offset-RIP | |
256 | /*CFI_REL_OFFSET rflags, EFLAGS+\offset-RIP*/ | |
257 | /*CFI_REL_OFFSET cs, CS+\offset-RIP*/ | |
258 | CFI_REL_OFFSET rip, RIP+\offset-RIP | |
d99015b1 AH |
259 | .endm |
260 | ||
d99015b1 AH |
261 | /* |
262 | * initial frame state for exceptions with error code (and interrupts | |
263 | * with vector already pushed) | |
264 | */ | |
dcd072e2 | 265 | .macro XCPT_FRAME start=1 offset=0 |
e8a0e276 | 266 | INTR_FRAME \start, RIP+\offset-ORIG_RAX |
dcd072e2 AH |
267 | /*CFI_REL_OFFSET orig_rax, ORIG_RAX-ORIG_RAX*/ |
268 | .endm | |
269 | ||
270 | /* | |
271 | * frame that enables calling into C. | |
272 | */ | |
273 | .macro PARTIAL_FRAME start=1 offset=0 | |
e8a0e276 IM |
274 | XCPT_FRAME \start, ORIG_RAX+\offset-ARGOFFSET |
275 | CFI_REL_OFFSET rdi, RDI+\offset-ARGOFFSET | |
276 | CFI_REL_OFFSET rsi, RSI+\offset-ARGOFFSET | |
277 | CFI_REL_OFFSET rdx, RDX+\offset-ARGOFFSET | |
278 | CFI_REL_OFFSET rcx, RCX+\offset-ARGOFFSET | |
279 | CFI_REL_OFFSET rax, RAX+\offset-ARGOFFSET | |
280 | CFI_REL_OFFSET r8, R8+\offset-ARGOFFSET | |
281 | CFI_REL_OFFSET r9, R9+\offset-ARGOFFSET | |
282 | CFI_REL_OFFSET r10, R10+\offset-ARGOFFSET | |
283 | CFI_REL_OFFSET r11, R11+\offset-ARGOFFSET | |
dcd072e2 AH |
284 | .endm |
285 | ||
286 | /* | |
287 | * frame that enables passing a complete pt_regs to a C function. | |
288 | */ | |
289 | .macro DEFAULT_FRAME start=1 offset=0 | |
e8a0e276 | 290 | PARTIAL_FRAME \start, R11+\offset-R15 |
dcd072e2 AH |
291 | CFI_REL_OFFSET rbx, RBX+\offset |
292 | CFI_REL_OFFSET rbp, RBP+\offset | |
293 | CFI_REL_OFFSET r12, R12+\offset | |
294 | CFI_REL_OFFSET r13, R13+\offset | |
295 | CFI_REL_OFFSET r14, R14+\offset | |
296 | CFI_REL_OFFSET r15, R15+\offset | |
297 | .endm | |
d99015b1 AH |
298 | |
299 | /* save partial stack frame */ | |
de31ec8a | 300 | .pushsection .kprobes.text, "ax" |
d99015b1 AH |
301 | ENTRY(save_args) |
302 | XCPT_FRAME | |
303 | cld | |
625dbc3b FW |
304 | /* |
305 | * start from rbp in pt_regs and jump over | |
306 | * return address. | |
307 | */ | |
308 | movq_cfi rdi, RDI+8-RBP | |
309 | movq_cfi rsi, RSI+8-RBP | |
310 | movq_cfi rdx, RDX+8-RBP | |
311 | movq_cfi rcx, RCX+8-RBP | |
312 | movq_cfi rax, RAX+8-RBP | |
313 | movq_cfi r8, R8+8-RBP | |
314 | movq_cfi r9, R9+8-RBP | |
315 | movq_cfi r10, R10+8-RBP | |
316 | movq_cfi r11, R11+8-RBP | |
317 | ||
318 | leaq -RBP+8(%rsp),%rdi /* arg1 for handler */ | |
14ae22ba | 319 | movq_cfi rbp, 8 /* push %rbp */ |
d99015b1 AH |
320 | leaq 8(%rsp), %rbp /* mov %rsp, %ebp */ |
321 | testl $3, CS(%rdi) | |
322 | je 1f | |
323 | SWAPGS | |
324 | /* | |
56895530 | 325 | * irq_count is used to check if a CPU is already on an interrupt stack |
d99015b1 AH |
326 | * or not. While this is essentially redundant with preempt_count it is |
327 | * a little cheaper to use a separate counter in the PDA (short of | |
328 | * moving irq_enter into assembly, which would be too much work) | |
329 | */ | |
56895530 | 330 | 1: incl PER_CPU_VAR(irq_count) |
d99015b1 | 331 | jne 2f |
14ae22ba | 332 | popq_cfi %rax /* move return address... */ |
26f80bd6 | 333 | mov PER_CPU_VAR(irq_stack_ptr),%rsp |
dcd072e2 | 334 | EMPTY_FRAME 0 |
a67798cd | 335 | pushq_cfi %rbp /* backlink for unwinder */ |
14ae22ba | 336 | pushq_cfi %rax /* ... to the new stack */ |
d99015b1 AH |
337 | /* |
338 | * We entered an interrupt context - irqs are off: | |
339 | */ | |
340 | 2: TRACE_IRQS_OFF | |
341 | ret | |
342 | CFI_ENDPROC | |
343 | END(save_args) | |
de31ec8a | 344 | .popsection |
d99015b1 | 345 | |
c002a1e6 AH |
346 | ENTRY(save_rest) |
347 | PARTIAL_FRAME 1 REST_SKIP+8 | |
348 | movq 5*8+16(%rsp), %r11 /* save return address */ | |
349 | movq_cfi rbx, RBX+16 | |
350 | movq_cfi rbp, RBP+16 | |
351 | movq_cfi r12, R12+16 | |
352 | movq_cfi r13, R13+16 | |
353 | movq_cfi r14, R14+16 | |
354 | movq_cfi r15, R15+16 | |
355 | movq %r11, 8(%rsp) /* return address */ | |
356 | FIXUP_TOP_OF_STACK %r11, 16 | |
357 | ret | |
358 | CFI_ENDPROC | |
359 | END(save_rest) | |
360 | ||
e2f6bc25 | 361 | /* save complete stack frame */ |
c2810188 | 362 | .pushsection .kprobes.text, "ax" |
e2f6bc25 AH |
363 | ENTRY(save_paranoid) |
364 | XCPT_FRAME 1 RDI+8 | |
365 | cld | |
366 | movq_cfi rdi, RDI+8 | |
367 | movq_cfi rsi, RSI+8 | |
368 | movq_cfi rdx, RDX+8 | |
369 | movq_cfi rcx, RCX+8 | |
370 | movq_cfi rax, RAX+8 | |
371 | movq_cfi r8, R8+8 | |
372 | movq_cfi r9, R9+8 | |
373 | movq_cfi r10, R10+8 | |
374 | movq_cfi r11, R11+8 | |
375 | movq_cfi rbx, RBX+8 | |
376 | movq_cfi rbp, RBP+8 | |
377 | movq_cfi r12, R12+8 | |
378 | movq_cfi r13, R13+8 | |
379 | movq_cfi r14, R14+8 | |
380 | movq_cfi r15, R15+8 | |
381 | movl $1,%ebx | |
382 | movl $MSR_GS_BASE,%ecx | |
383 | rdmsr | |
384 | testl %edx,%edx | |
385 | js 1f /* negative -> in kernel */ | |
386 | SWAPGS | |
387 | xorl %ebx,%ebx | |
388 | 1: ret | |
389 | CFI_ENDPROC | |
390 | END(save_paranoid) | |
c2810188 | 391 | .popsection |
e2f6bc25 | 392 | |
1da177e4 | 393 | /* |
5b3eec0c IM |
394 | * A newly forked process directly context switches into this address. |
395 | * | |
396 | * rdi: prev task we switched from | |
0bd7b798 | 397 | */ |
1da177e4 | 398 | ENTRY(ret_from_fork) |
dcd072e2 | 399 | DEFAULT_FRAME |
5b3eec0c | 400 | |
7106a5ab BL |
401 | LOCK ; btr $TIF_FORK,TI_flags(%r8) |
402 | ||
df5d1874 JB |
403 | pushq_cfi kernel_eflags(%rip) |
404 | popfq_cfi # reset kernel eflags | |
5b3eec0c IM |
405 | |
406 | call schedule_tail # rdi: 'prev' task parameter | |
407 | ||
1da177e4 | 408 | GET_THREAD_INFO(%rcx) |
5b3eec0c | 409 | |
1da177e4 | 410 | RESTORE_REST |
5b3eec0c IM |
411 | |
412 | testl $3, CS-ARGOFFSET(%rsp) # from kernel_thread? | |
1da177e4 | 413 | je int_ret_from_sys_call |
5b3eec0c IM |
414 | |
415 | testl $_TIF_IA32, TI_flags(%rcx) # 32-bit compat task needs IRET | |
1da177e4 | 416 | jnz int_ret_from_sys_call |
5b3eec0c | 417 | |
c002a1e6 | 418 | RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET |
5b3eec0c IM |
419 | jmp ret_from_sys_call # go to the SYSRET fastpath |
420 | ||
1da177e4 | 421 | CFI_ENDPROC |
4b787e0b | 422 | END(ret_from_fork) |
1da177e4 LT |
423 | |
424 | /* | |
0d2eb44f | 425 | * System call entry. Up to 6 arguments in registers are supported. |
1da177e4 LT |
426 | * |
427 | * SYSCALL does not save anything on the stack and does not change the | |
428 | * stack pointer. | |
429 | */ | |
0bd7b798 | 430 | |
1da177e4 | 431 | /* |
0bd7b798 | 432 | * Register setup: |
1da177e4 LT |
433 | * rax system call number |
434 | * rdi arg0 | |
0bd7b798 | 435 | * rcx return address for syscall/sysret, C arg3 |
1da177e4 | 436 | * rsi arg1 |
0bd7b798 | 437 | * rdx arg2 |
1da177e4 LT |
438 | * r10 arg3 (--> moved to rcx for C) |
439 | * r8 arg4 | |
440 | * r9 arg5 | |
441 | * r11 eflags for syscall/sysret, temporary for C | |
0bd7b798 AH |
442 | * r12-r15,rbp,rbx saved by C code, not touched. |
443 | * | |
1da177e4 LT |
444 | * Interrupts are off on entry. |
445 | * Only called from user space. | |
446 | * | |
447 | * XXX if we had a free scratch register we could save the RSP into the stack frame | |
448 | * and report it properly in ps. Unfortunately we haven't. | |
7bf36bbc AK |
449 | * |
450 | * When user can change the frames always force IRET. That is because | |
451 | * it deals with uncanonical addresses better. SYSRET has trouble | |
452 | * with them due to bugs in both AMD and Intel CPUs. | |
0bd7b798 | 453 | */ |
1da177e4 LT |
454 | |
455 | ENTRY(system_call) | |
7effaa88 | 456 | CFI_STARTPROC simple |
adf14236 | 457 | CFI_SIGNAL_FRAME |
9af45651 | 458 | CFI_DEF_CFA rsp,KERNEL_STACK_OFFSET |
7effaa88 JB |
459 | CFI_REGISTER rip,rcx |
460 | /*CFI_REGISTER rflags,r11*/ | |
72fe4858 GOC |
461 | SWAPGS_UNSAFE_STACK |
462 | /* | |
463 | * A hypervisor implementation might want to use a label | |
464 | * after the swapgs, so that it can do the swapgs | |
465 | * for the guest and jump here on syscall. | |
466 | */ | |
467 | ENTRY(system_call_after_swapgs) | |
468 | ||
3d1e42a7 | 469 | movq %rsp,PER_CPU_VAR(old_rsp) |
9af45651 | 470 | movq PER_CPU_VAR(kernel_stack),%rsp |
2601e64d IM |
471 | /* |
472 | * No need to follow this irqs off/on section - it's straight | |
473 | * and short: | |
474 | */ | |
72fe4858 | 475 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 476 | SAVE_ARGS 8,1 |
0bd7b798 | 477 | movq %rax,ORIG_RAX-ARGOFFSET(%rsp) |
7effaa88 JB |
478 | movq %rcx,RIP-ARGOFFSET(%rsp) |
479 | CFI_REL_OFFSET rip,RIP-ARGOFFSET | |
1da177e4 | 480 | GET_THREAD_INFO(%rcx) |
d4d67150 | 481 | testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%rcx) |
1da177e4 | 482 | jnz tracesys |
86a1c34a | 483 | system_call_fastpath: |
1da177e4 LT |
484 | cmpq $__NR_syscall_max,%rax |
485 | ja badsys | |
486 | movq %r10,%rcx | |
487 | call *sys_call_table(,%rax,8) # XXX: rip relative | |
488 | movq %rax,RAX-ARGOFFSET(%rsp) | |
489 | /* | |
490 | * Syscall return path ending with SYSRET (fast path) | |
0bd7b798 AH |
491 | * Has incomplete stack frame and undefined top of stack. |
492 | */ | |
1da177e4 | 493 | ret_from_sys_call: |
11b854b2 | 494 | movl $_TIF_ALLWORK_MASK,%edi |
1da177e4 | 495 | /* edi: flagmask */ |
0bd7b798 | 496 | sysret_check: |
10cd706d | 497 | LOCKDEP_SYS_EXIT |
1da177e4 | 498 | GET_THREAD_INFO(%rcx) |
72fe4858 | 499 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 500 | TRACE_IRQS_OFF |
26ccb8a7 | 501 | movl TI_flags(%rcx),%edx |
1da177e4 | 502 | andl %edi,%edx |
0bd7b798 | 503 | jnz sysret_careful |
bcddc015 | 504 | CFI_REMEMBER_STATE |
2601e64d IM |
505 | /* |
506 | * sysretq will re-enable interrupts: | |
507 | */ | |
508 | TRACE_IRQS_ON | |
1da177e4 | 509 | movq RIP-ARGOFFSET(%rsp),%rcx |
7effaa88 | 510 | CFI_REGISTER rip,rcx |
1da177e4 | 511 | RESTORE_ARGS 0,-ARG_SKIP,1 |
7effaa88 | 512 | /*CFI_REGISTER rflags,r11*/ |
3d1e42a7 | 513 | movq PER_CPU_VAR(old_rsp), %rsp |
2be29982 | 514 | USERGS_SYSRET64 |
1da177e4 | 515 | |
bcddc015 | 516 | CFI_RESTORE_STATE |
1da177e4 | 517 | /* Handle reschedules */ |
0bd7b798 | 518 | /* edx: work, edi: workmask */ |
1da177e4 LT |
519 | sysret_careful: |
520 | bt $TIF_NEED_RESCHED,%edx | |
521 | jnc sysret_signal | |
2601e64d | 522 | TRACE_IRQS_ON |
72fe4858 | 523 | ENABLE_INTERRUPTS(CLBR_NONE) |
df5d1874 | 524 | pushq_cfi %rdi |
1da177e4 | 525 | call schedule |
df5d1874 | 526 | popq_cfi %rdi |
1da177e4 LT |
527 | jmp sysret_check |
528 | ||
0bd7b798 | 529 | /* Handle a signal */ |
1da177e4 | 530 | sysret_signal: |
2601e64d | 531 | TRACE_IRQS_ON |
72fe4858 | 532 | ENABLE_INTERRUPTS(CLBR_NONE) |
86a1c34a RM |
533 | #ifdef CONFIG_AUDITSYSCALL |
534 | bt $TIF_SYSCALL_AUDIT,%edx | |
535 | jc sysret_audit | |
536 | #endif | |
b60e714d RM |
537 | /* |
538 | * We have a signal, or exit tracing or single-step. | |
539 | * These all wind up with the iret return path anyway, | |
540 | * so just join that path right now. | |
541 | */ | |
542 | FIXUP_TOP_OF_STACK %r11, -ARGOFFSET | |
543 | jmp int_check_syscall_exit_work | |
0bd7b798 | 544 | |
7effaa88 JB |
545 | badsys: |
546 | movq $-ENOSYS,RAX-ARGOFFSET(%rsp) | |
547 | jmp ret_from_sys_call | |
548 | ||
86a1c34a RM |
549 | #ifdef CONFIG_AUDITSYSCALL |
550 | /* | |
551 | * Fast path for syscall audit without full syscall trace. | |
552 | * We just call audit_syscall_entry() directly, and then | |
553 | * jump back to the normal fast path. | |
554 | */ | |
555 | auditsys: | |
556 | movq %r10,%r9 /* 6th arg: 4th syscall arg */ | |
557 | movq %rdx,%r8 /* 5th arg: 3rd syscall arg */ | |
558 | movq %rsi,%rcx /* 4th arg: 2nd syscall arg */ | |
559 | movq %rdi,%rdx /* 3rd arg: 1st syscall arg */ | |
560 | movq %rax,%rsi /* 2nd arg: syscall number */ | |
561 | movl $AUDIT_ARCH_X86_64,%edi /* 1st arg: audit arch */ | |
562 | call audit_syscall_entry | |
563 | LOAD_ARGS 0 /* reload call-clobbered registers */ | |
564 | jmp system_call_fastpath | |
565 | ||
566 | /* | |
567 | * Return fast path for syscall audit. Call audit_syscall_exit() | |
568 | * directly and then jump back to the fast path with TIF_SYSCALL_AUDIT | |
569 | * masked off. | |
570 | */ | |
571 | sysret_audit: | |
03275591 RM |
572 | movq RAX-ARGOFFSET(%rsp),%rsi /* second arg, syscall return value */ |
573 | cmpq $0,%rsi /* is it < 0? */ | |
86a1c34a RM |
574 | setl %al /* 1 if so, 0 if not */ |
575 | movzbl %al,%edi /* zero-extend that into %edi */ | |
576 | inc %edi /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */ | |
577 | call audit_syscall_exit | |
578 | movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi | |
579 | jmp sysret_check | |
580 | #endif /* CONFIG_AUDITSYSCALL */ | |
581 | ||
1da177e4 | 582 | /* Do syscall tracing */ |
0bd7b798 | 583 | tracesys: |
86a1c34a RM |
584 | #ifdef CONFIG_AUDITSYSCALL |
585 | testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%rcx) | |
586 | jz auditsys | |
587 | #endif | |
1da177e4 | 588 | SAVE_REST |
a31f8dd7 | 589 | movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */ |
1da177e4 LT |
590 | FIXUP_TOP_OF_STACK %rdi |
591 | movq %rsp,%rdi | |
592 | call syscall_trace_enter | |
d4d67150 RM |
593 | /* |
594 | * Reload arg registers from stack in case ptrace changed them. | |
595 | * We don't reload %rax because syscall_trace_enter() returned | |
596 | * the value it wants us to use in the table lookup. | |
597 | */ | |
598 | LOAD_ARGS ARGOFFSET, 1 | |
1da177e4 LT |
599 | RESTORE_REST |
600 | cmpq $__NR_syscall_max,%rax | |
a31f8dd7 | 601 | ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */ |
1da177e4 LT |
602 | movq %r10,%rcx /* fixup for C */ |
603 | call *sys_call_table(,%rax,8) | |
a31f8dd7 | 604 | movq %rax,RAX-ARGOFFSET(%rsp) |
7bf36bbc | 605 | /* Use IRET because user could have changed frame */ |
0bd7b798 AH |
606 | |
607 | /* | |
1da177e4 LT |
608 | * Syscall return path ending with IRET. |
609 | * Has correct top of stack, but partial stack frame. | |
bcddc015 | 610 | */ |
bc8b2b92 | 611 | GLOBAL(int_ret_from_sys_call) |
72fe4858 | 612 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 613 | TRACE_IRQS_OFF |
1da177e4 LT |
614 | testl $3,CS-ARGOFFSET(%rsp) |
615 | je retint_restore_args | |
616 | movl $_TIF_ALLWORK_MASK,%edi | |
617 | /* edi: mask to check */ | |
bc8b2b92 | 618 | GLOBAL(int_with_check) |
10cd706d | 619 | LOCKDEP_SYS_EXIT_IRQ |
1da177e4 | 620 | GET_THREAD_INFO(%rcx) |
26ccb8a7 | 621 | movl TI_flags(%rcx),%edx |
1da177e4 LT |
622 | andl %edi,%edx |
623 | jnz int_careful | |
26ccb8a7 | 624 | andl $~TS_COMPAT,TI_status(%rcx) |
1da177e4 LT |
625 | jmp retint_swapgs |
626 | ||
627 | /* Either reschedule or signal or syscall exit tracking needed. */ | |
628 | /* First do a reschedule test. */ | |
629 | /* edx: work, edi: workmask */ | |
630 | int_careful: | |
631 | bt $TIF_NEED_RESCHED,%edx | |
632 | jnc int_very_careful | |
2601e64d | 633 | TRACE_IRQS_ON |
72fe4858 | 634 | ENABLE_INTERRUPTS(CLBR_NONE) |
df5d1874 | 635 | pushq_cfi %rdi |
1da177e4 | 636 | call schedule |
df5d1874 | 637 | popq_cfi %rdi |
72fe4858 | 638 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 639 | TRACE_IRQS_OFF |
1da177e4 LT |
640 | jmp int_with_check |
641 | ||
642 | /* handle signals and tracing -- both require a full stack frame */ | |
643 | int_very_careful: | |
2601e64d | 644 | TRACE_IRQS_ON |
72fe4858 | 645 | ENABLE_INTERRUPTS(CLBR_NONE) |
b60e714d | 646 | int_check_syscall_exit_work: |
1da177e4 | 647 | SAVE_REST |
0bd7b798 | 648 | /* Check for syscall exit trace */ |
d4d67150 | 649 | testl $_TIF_WORK_SYSCALL_EXIT,%edx |
1da177e4 | 650 | jz int_signal |
df5d1874 | 651 | pushq_cfi %rdi |
0bd7b798 | 652 | leaq 8(%rsp),%rdi # &ptregs -> arg1 |
1da177e4 | 653 | call syscall_trace_leave |
df5d1874 | 654 | popq_cfi %rdi |
d4d67150 | 655 | andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU),%edi |
1da177e4 | 656 | jmp int_restore_rest |
0bd7b798 | 657 | |
1da177e4 | 658 | int_signal: |
8f4d37ec | 659 | testl $_TIF_DO_NOTIFY_MASK,%edx |
1da177e4 LT |
660 | jz 1f |
661 | movq %rsp,%rdi # &ptregs -> arg1 | |
662 | xorl %esi,%esi # oldset -> arg2 | |
663 | call do_notify_resume | |
eca91e78 | 664 | 1: movl $_TIF_WORK_MASK,%edi |
1da177e4 LT |
665 | int_restore_rest: |
666 | RESTORE_REST | |
72fe4858 | 667 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 668 | TRACE_IRQS_OFF |
1da177e4 LT |
669 | jmp int_with_check |
670 | CFI_ENDPROC | |
bcddc015 | 671 | END(system_call) |
0bd7b798 AH |
672 | |
673 | /* | |
1da177e4 | 674 | * Certain special system calls that need to save a complete full stack frame. |
0bd7b798 | 675 | */ |
1da177e4 | 676 | .macro PTREGSCALL label,func,arg |
c002a1e6 AH |
677 | ENTRY(\label) |
678 | PARTIAL_FRAME 1 8 /* offset 8: return address */ | |
679 | subq $REST_SKIP, %rsp | |
680 | CFI_ADJUST_CFA_OFFSET REST_SKIP | |
681 | call save_rest | |
682 | DEFAULT_FRAME 0 8 /* offset 8: return address */ | |
683 | leaq 8(%rsp), \arg /* pt_regs pointer */ | |
684 | call \func | |
685 | jmp ptregscall_common | |
686 | CFI_ENDPROC | |
4b787e0b | 687 | END(\label) |
1da177e4 LT |
688 | .endm |
689 | ||
690 | PTREGSCALL stub_clone, sys_clone, %r8 | |
691 | PTREGSCALL stub_fork, sys_fork, %rdi | |
692 | PTREGSCALL stub_vfork, sys_vfork, %rdi | |
1da177e4 LT |
693 | PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx |
694 | PTREGSCALL stub_iopl, sys_iopl, %rsi | |
695 | ||
696 | ENTRY(ptregscall_common) | |
c002a1e6 AH |
697 | DEFAULT_FRAME 1 8 /* offset 8: return address */ |
698 | RESTORE_TOP_OF_STACK %r11, 8 | |
699 | movq_cfi_restore R15+8, r15 | |
700 | movq_cfi_restore R14+8, r14 | |
701 | movq_cfi_restore R13+8, r13 | |
702 | movq_cfi_restore R12+8, r12 | |
703 | movq_cfi_restore RBP+8, rbp | |
704 | movq_cfi_restore RBX+8, rbx | |
705 | ret $REST_SKIP /* pop extended registers */ | |
1da177e4 | 706 | CFI_ENDPROC |
4b787e0b | 707 | END(ptregscall_common) |
0bd7b798 | 708 | |
1da177e4 LT |
709 | ENTRY(stub_execve) |
710 | CFI_STARTPROC | |
e6b04b6b JB |
711 | addq $8, %rsp |
712 | PARTIAL_FRAME 0 | |
1da177e4 | 713 | SAVE_REST |
1da177e4 | 714 | FIXUP_TOP_OF_STACK %r11 |
5d119b2c | 715 | movq %rsp, %rcx |
1da177e4 | 716 | call sys_execve |
1da177e4 | 717 | RESTORE_TOP_OF_STACK %r11 |
1da177e4 LT |
718 | movq %rax,RAX(%rsp) |
719 | RESTORE_REST | |
720 | jmp int_ret_from_sys_call | |
721 | CFI_ENDPROC | |
4b787e0b | 722 | END(stub_execve) |
0bd7b798 | 723 | |
1da177e4 LT |
724 | /* |
725 | * sigreturn is special because it needs to restore all registers on return. | |
726 | * This cannot be done with SYSRET, so use the IRET return path instead. | |
0bd7b798 | 727 | */ |
1da177e4 LT |
728 | ENTRY(stub_rt_sigreturn) |
729 | CFI_STARTPROC | |
7effaa88 | 730 | addq $8, %rsp |
e6b04b6b | 731 | PARTIAL_FRAME 0 |
1da177e4 LT |
732 | SAVE_REST |
733 | movq %rsp,%rdi | |
734 | FIXUP_TOP_OF_STACK %r11 | |
735 | call sys_rt_sigreturn | |
736 | movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer | |
737 | RESTORE_REST | |
738 | jmp int_ret_from_sys_call | |
739 | CFI_ENDPROC | |
4b787e0b | 740 | END(stub_rt_sigreturn) |
1da177e4 | 741 | |
939b7871 PA |
742 | /* |
743 | * Build the entry stubs and pointer table with some assembler magic. | |
744 | * We pack 7 stubs into a single 32-byte chunk, which will fit in a | |
745 | * single cache line on all modern x86 implementations. | |
746 | */ | |
747 | .section .init.rodata,"a" | |
748 | ENTRY(interrupt) | |
ea714547 | 749 | .section .entry.text |
939b7871 PA |
750 | .p2align 5 |
751 | .p2align CONFIG_X86_L1_CACHE_SHIFT | |
752 | ENTRY(irq_entries_start) | |
753 | INTR_FRAME | |
754 | vector=FIRST_EXTERNAL_VECTOR | |
755 | .rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7 | |
756 | .balign 32 | |
757 | .rept 7 | |
758 | .if vector < NR_VECTORS | |
8665596e | 759 | .if vector <> FIRST_EXTERNAL_VECTOR |
939b7871 PA |
760 | CFI_ADJUST_CFA_OFFSET -8 |
761 | .endif | |
df5d1874 | 762 | 1: pushq_cfi $(~vector+0x80) /* Note: always in signed byte range */ |
8665596e | 763 | .if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6 |
939b7871 PA |
764 | jmp 2f |
765 | .endif | |
766 | .previous | |
767 | .quad 1b | |
ea714547 | 768 | .section .entry.text |
939b7871 PA |
769 | vector=vector+1 |
770 | .endif | |
771 | .endr | |
772 | 2: jmp common_interrupt | |
773 | .endr | |
774 | CFI_ENDPROC | |
775 | END(irq_entries_start) | |
776 | ||
777 | .previous | |
778 | END(interrupt) | |
779 | .previous | |
780 | ||
d99015b1 | 781 | /* |
1da177e4 LT |
782 | * Interrupt entry/exit. |
783 | * | |
784 | * Interrupt entry points save only callee clobbered registers in fast path. | |
d99015b1 AH |
785 | * |
786 | * Entry runs with interrupts off. | |
787 | */ | |
1da177e4 | 788 | |
722024db | 789 | /* 0(%rsp): ~(interrupt number) */ |
1da177e4 | 790 | .macro interrupt func |
625dbc3b FW |
791 | /* reserve pt_regs for scratch regs and rbp */ |
792 | subq $ORIG_RAX-RBP, %rsp | |
793 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-RBP | |
d99015b1 | 794 | call save_args |
dcd072e2 | 795 | PARTIAL_FRAME 0 |
1da177e4 LT |
796 | call \func |
797 | .endm | |
798 | ||
8222d718 MH |
799 | /* |
800 | * Interrupt entry/exit should be protected against kprobes | |
801 | */ | |
802 | .pushsection .kprobes.text, "ax" | |
722024db AH |
803 | /* |
804 | * The interrupt stubs push (~vector+0x80) onto the stack and | |
805 | * then jump to common_interrupt. | |
806 | */ | |
939b7871 PA |
807 | .p2align CONFIG_X86_L1_CACHE_SHIFT |
808 | common_interrupt: | |
7effaa88 | 809 | XCPT_FRAME |
722024db | 810 | addq $-0x80,(%rsp) /* Adjust vector to [-256,-1] range */ |
1da177e4 | 811 | interrupt do_IRQ |
3d1e42a7 | 812 | /* 0(%rsp): old_rsp-ARGOFFSET */ |
7effaa88 | 813 | ret_from_intr: |
72fe4858 | 814 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 815 | TRACE_IRQS_OFF |
56895530 | 816 | decl PER_CPU_VAR(irq_count) |
1de9c3f6 | 817 | leaveq |
625dbc3b | 818 | |
df5d1874 | 819 | CFI_RESTORE rbp |
7effaa88 | 820 | CFI_DEF_CFA_REGISTER rsp |
1de9c3f6 | 821 | CFI_ADJUST_CFA_OFFSET -8 |
625dbc3b FW |
822 | |
823 | /* we did not save rbx, restore only from ARGOFFSET */ | |
824 | addq $8, %rsp | |
825 | CFI_ADJUST_CFA_OFFSET -8 | |
7effaa88 | 826 | exit_intr: |
1da177e4 LT |
827 | GET_THREAD_INFO(%rcx) |
828 | testl $3,CS-ARGOFFSET(%rsp) | |
829 | je retint_kernel | |
0bd7b798 | 830 | |
1da177e4 LT |
831 | /* Interrupt came from user space */ |
832 | /* | |
833 | * Has a correct top of stack, but a partial stack frame | |
834 | * %rcx: thread info. Interrupts off. | |
0bd7b798 | 835 | */ |
1da177e4 LT |
836 | retint_with_reschedule: |
837 | movl $_TIF_WORK_MASK,%edi | |
7effaa88 | 838 | retint_check: |
10cd706d | 839 | LOCKDEP_SYS_EXIT_IRQ |
26ccb8a7 | 840 | movl TI_flags(%rcx),%edx |
1da177e4 | 841 | andl %edi,%edx |
7effaa88 | 842 | CFI_REMEMBER_STATE |
1da177e4 | 843 | jnz retint_careful |
10cd706d PZ |
844 | |
845 | retint_swapgs: /* return to user-space */ | |
2601e64d IM |
846 | /* |
847 | * The iretq could re-enable interrupts: | |
848 | */ | |
72fe4858 | 849 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d | 850 | TRACE_IRQS_IRETQ |
72fe4858 | 851 | SWAPGS |
2601e64d IM |
852 | jmp restore_args |
853 | ||
10cd706d | 854 | retint_restore_args: /* return to kernel space */ |
72fe4858 | 855 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d IM |
856 | /* |
857 | * The iretq could re-enable interrupts: | |
858 | */ | |
859 | TRACE_IRQS_IRETQ | |
860 | restore_args: | |
3701d863 IM |
861 | RESTORE_ARGS 0,8,0 |
862 | ||
f7f3d791 | 863 | irq_return: |
72fe4858 | 864 | INTERRUPT_RETURN |
3701d863 IM |
865 | |
866 | .section __ex_table, "a" | |
867 | .quad irq_return, bad_iret | |
868 | .previous | |
869 | ||
870 | #ifdef CONFIG_PARAVIRT | |
72fe4858 | 871 | ENTRY(native_iret) |
1da177e4 LT |
872 | iretq |
873 | ||
874 | .section __ex_table,"a" | |
72fe4858 | 875 | .quad native_iret, bad_iret |
1da177e4 | 876 | .previous |
3701d863 IM |
877 | #endif |
878 | ||
1da177e4 | 879 | .section .fixup,"ax" |
1da177e4 | 880 | bad_iret: |
3aa4b37d RM |
881 | /* |
882 | * The iret traps when the %cs or %ss being restored is bogus. | |
883 | * We've lost the original trap vector and error code. | |
884 | * #GPF is the most likely one to get for an invalid selector. | |
885 | * So pretend we completed the iret and took the #GPF in user mode. | |
886 | * | |
887 | * We are now running with the kernel GS after exception recovery. | |
888 | * But error_entry expects us to have user GS to match the user %cs, | |
889 | * so swap back. | |
890 | */ | |
891 | pushq $0 | |
892 | ||
893 | SWAPGS | |
894 | jmp general_protection | |
895 | ||
72fe4858 GOC |
896 | .previous |
897 | ||
7effaa88 | 898 | /* edi: workmask, edx: work */ |
1da177e4 | 899 | retint_careful: |
7effaa88 | 900 | CFI_RESTORE_STATE |
1da177e4 LT |
901 | bt $TIF_NEED_RESCHED,%edx |
902 | jnc retint_signal | |
2601e64d | 903 | TRACE_IRQS_ON |
72fe4858 | 904 | ENABLE_INTERRUPTS(CLBR_NONE) |
df5d1874 | 905 | pushq_cfi %rdi |
1da177e4 | 906 | call schedule |
df5d1874 | 907 | popq_cfi %rdi |
1da177e4 | 908 | GET_THREAD_INFO(%rcx) |
72fe4858 | 909 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 910 | TRACE_IRQS_OFF |
1da177e4 | 911 | jmp retint_check |
0bd7b798 | 912 | |
1da177e4 | 913 | retint_signal: |
8f4d37ec | 914 | testl $_TIF_DO_NOTIFY_MASK,%edx |
10ffdbb8 | 915 | jz retint_swapgs |
2601e64d | 916 | TRACE_IRQS_ON |
72fe4858 | 917 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 918 | SAVE_REST |
0bd7b798 | 919 | movq $-1,ORIG_RAX(%rsp) |
3829ee6b | 920 | xorl %esi,%esi # oldset |
1da177e4 LT |
921 | movq %rsp,%rdi # &pt_regs |
922 | call do_notify_resume | |
923 | RESTORE_REST | |
72fe4858 | 924 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 925 | TRACE_IRQS_OFF |
be9e6870 | 926 | GET_THREAD_INFO(%rcx) |
eca91e78 | 927 | jmp retint_with_reschedule |
1da177e4 LT |
928 | |
929 | #ifdef CONFIG_PREEMPT | |
930 | /* Returning to kernel space. Check if we need preemption */ | |
931 | /* rcx: threadinfo. interrupts off. */ | |
b06babac | 932 | ENTRY(retint_kernel) |
26ccb8a7 | 933 | cmpl $0,TI_preempt_count(%rcx) |
1da177e4 | 934 | jnz retint_restore_args |
26ccb8a7 | 935 | bt $TIF_NEED_RESCHED,TI_flags(%rcx) |
1da177e4 LT |
936 | jnc retint_restore_args |
937 | bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */ | |
938 | jnc retint_restore_args | |
939 | call preempt_schedule_irq | |
940 | jmp exit_intr | |
0bd7b798 | 941 | #endif |
4b787e0b | 942 | |
1da177e4 | 943 | CFI_ENDPROC |
4b787e0b | 944 | END(common_interrupt) |
8222d718 MH |
945 | /* |
946 | * End of kprobes section | |
947 | */ | |
948 | .popsection | |
0bd7b798 | 949 | |
1da177e4 LT |
950 | /* |
951 | * APIC interrupts. | |
0bd7b798 | 952 | */ |
322648d1 AH |
953 | .macro apicinterrupt num sym do_sym |
954 | ENTRY(\sym) | |
7effaa88 | 955 | INTR_FRAME |
df5d1874 | 956 | pushq_cfi $~(\num) |
322648d1 | 957 | interrupt \do_sym |
1da177e4 LT |
958 | jmp ret_from_intr |
959 | CFI_ENDPROC | |
322648d1 AH |
960 | END(\sym) |
961 | .endm | |
1da177e4 | 962 | |
322648d1 AH |
963 | #ifdef CONFIG_SMP |
964 | apicinterrupt IRQ_MOVE_CLEANUP_VECTOR \ | |
965 | irq_move_cleanup_interrupt smp_irq_move_cleanup_interrupt | |
4ef702c1 AK |
966 | apicinterrupt REBOOT_VECTOR \ |
967 | reboot_interrupt smp_reboot_interrupt | |
322648d1 | 968 | #endif |
1da177e4 | 969 | |
03b48632 | 970 | #ifdef CONFIG_X86_UV |
5ae3a139 | 971 | apicinterrupt UV_BAU_MESSAGE \ |
322648d1 | 972 | uv_bau_message_intr1 uv_bau_message_interrupt |
03b48632 | 973 | #endif |
322648d1 AH |
974 | apicinterrupt LOCAL_TIMER_VECTOR \ |
975 | apic_timer_interrupt smp_apic_timer_interrupt | |
4a4de9c7 DS |
976 | apicinterrupt X86_PLATFORM_IPI_VECTOR \ |
977 | x86_platform_ipi smp_x86_platform_ipi | |
89b831ef | 978 | |
0bd7b798 | 979 | #ifdef CONFIG_SMP |
3a09fb45 SL |
980 | .irp idx,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15, \ |
981 | 16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 | |
982 | .if NUM_INVALIDATE_TLB_VECTORS > \idx | |
3234282f JB |
983 | apicinterrupt (INVALIDATE_TLB_VECTOR_START)+\idx \ |
984 | invalidate_interrupt\idx smp_invalidate_interrupt | |
3a09fb45 | 985 | .endif |
3234282f | 986 | .endr |
1da177e4 LT |
987 | #endif |
988 | ||
322648d1 | 989 | apicinterrupt THRESHOLD_APIC_VECTOR \ |
7856f6cc | 990 | threshold_interrupt smp_threshold_interrupt |
322648d1 AH |
991 | apicinterrupt THERMAL_APIC_VECTOR \ |
992 | thermal_interrupt smp_thermal_interrupt | |
1812924b | 993 | |
ccc3c319 AK |
994 | #ifdef CONFIG_X86_MCE |
995 | apicinterrupt MCE_SELF_VECTOR \ | |
996 | mce_self_interrupt smp_mce_self_interrupt | |
997 | #endif | |
998 | ||
322648d1 AH |
999 | #ifdef CONFIG_SMP |
1000 | apicinterrupt CALL_FUNCTION_SINGLE_VECTOR \ | |
1001 | call_function_single_interrupt smp_call_function_single_interrupt | |
1002 | apicinterrupt CALL_FUNCTION_VECTOR \ | |
1003 | call_function_interrupt smp_call_function_interrupt | |
1004 | apicinterrupt RESCHEDULE_VECTOR \ | |
1005 | reschedule_interrupt smp_reschedule_interrupt | |
1006 | #endif | |
1da177e4 | 1007 | |
322648d1 AH |
1008 | apicinterrupt ERROR_APIC_VECTOR \ |
1009 | error_interrupt smp_error_interrupt | |
1010 | apicinterrupt SPURIOUS_APIC_VECTOR \ | |
1011 | spurious_interrupt smp_spurious_interrupt | |
0bd7b798 | 1012 | |
e360adbe PZ |
1013 | #ifdef CONFIG_IRQ_WORK |
1014 | apicinterrupt IRQ_WORK_VECTOR \ | |
1015 | irq_work_interrupt smp_irq_work_interrupt | |
241771ef IM |
1016 | #endif |
1017 | ||
1da177e4 LT |
1018 | /* |
1019 | * Exception entry points. | |
0bd7b798 | 1020 | */ |
322648d1 AH |
1021 | .macro zeroentry sym do_sym |
1022 | ENTRY(\sym) | |
7effaa88 | 1023 | INTR_FRAME |
fab58420 | 1024 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
14ae22ba | 1025 | pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */ |
b1cccb1b JB |
1026 | subq $ORIG_RAX-R15, %rsp |
1027 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
d99015b1 | 1028 | call error_entry |
dcd072e2 | 1029 | DEFAULT_FRAME 0 |
d99015b1 AH |
1030 | movq %rsp,%rdi /* pt_regs pointer */ |
1031 | xorl %esi,%esi /* no error code */ | |
322648d1 | 1032 | call \do_sym |
d99015b1 | 1033 | jmp error_exit /* %ebx: no swapgs flag */ |
7effaa88 | 1034 | CFI_ENDPROC |
322648d1 AH |
1035 | END(\sym) |
1036 | .endm | |
1da177e4 | 1037 | |
322648d1 | 1038 | .macro paranoidzeroentry sym do_sym |
ddeb8f21 | 1039 | ENTRY(\sym) |
b8b1d08b AH |
1040 | INTR_FRAME |
1041 | PARAVIRT_ADJUST_EXCEPTION_FRAME | |
b1cccb1b JB |
1042 | pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */ |
1043 | subq $ORIG_RAX-R15, %rsp | |
1044 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
b8b1d08b AH |
1045 | call save_paranoid |
1046 | TRACE_IRQS_OFF | |
1047 | movq %rsp,%rdi /* pt_regs pointer */ | |
1048 | xorl %esi,%esi /* no error code */ | |
322648d1 | 1049 | call \do_sym |
b8b1d08b AH |
1050 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1051 | CFI_ENDPROC | |
ddeb8f21 | 1052 | END(\sym) |
322648d1 | 1053 | .endm |
b8b1d08b | 1054 | |
c15a5958 | 1055 | #define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8) |
322648d1 | 1056 | .macro paranoidzeroentry_ist sym do_sym ist |
ddeb8f21 | 1057 | ENTRY(\sym) |
9f1e87ea | 1058 | INTR_FRAME |
b8b1d08b | 1059 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
b1cccb1b JB |
1060 | pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */ |
1061 | subq $ORIG_RAX-R15, %rsp | |
1062 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
b8b1d08b AH |
1063 | call save_paranoid |
1064 | TRACE_IRQS_OFF | |
1065 | movq %rsp,%rdi /* pt_regs pointer */ | |
1066 | xorl %esi,%esi /* no error code */ | |
c15a5958 | 1067 | subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist) |
322648d1 | 1068 | call \do_sym |
c15a5958 | 1069 | addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist) |
b8b1d08b AH |
1070 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1071 | CFI_ENDPROC | |
ddeb8f21 | 1072 | END(\sym) |
322648d1 | 1073 | .endm |
b8b1d08b | 1074 | |
ddeb8f21 | 1075 | .macro errorentry sym do_sym |
322648d1 | 1076 | ENTRY(\sym) |
7effaa88 | 1077 | XCPT_FRAME |
fab58420 | 1078 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
b1cccb1b JB |
1079 | subq $ORIG_RAX-R15, %rsp |
1080 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
d99015b1 | 1081 | call error_entry |
dcd072e2 | 1082 | DEFAULT_FRAME 0 |
d99015b1 AH |
1083 | movq %rsp,%rdi /* pt_regs pointer */ |
1084 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
1085 | movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */ | |
322648d1 | 1086 | call \do_sym |
d99015b1 | 1087 | jmp error_exit /* %ebx: no swapgs flag */ |
7effaa88 | 1088 | CFI_ENDPROC |
322648d1 | 1089 | END(\sym) |
322648d1 | 1090 | .endm |
1da177e4 LT |
1091 | |
1092 | /* error code is on the stack already */ | |
ddeb8f21 | 1093 | .macro paranoiderrorentry sym do_sym |
322648d1 | 1094 | ENTRY(\sym) |
b8b1d08b AH |
1095 | XCPT_FRAME |
1096 | PARAVIRT_ADJUST_EXCEPTION_FRAME | |
b1cccb1b JB |
1097 | subq $ORIG_RAX-R15, %rsp |
1098 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
e2f6bc25 AH |
1099 | call save_paranoid |
1100 | DEFAULT_FRAME 0 | |
7e61a793 | 1101 | TRACE_IRQS_OFF |
b8b1d08b AH |
1102 | movq %rsp,%rdi /* pt_regs pointer */ |
1103 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
1104 | movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */ | |
322648d1 | 1105 | call \do_sym |
b8b1d08b AH |
1106 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1107 | CFI_ENDPROC | |
322648d1 | 1108 | END(\sym) |
322648d1 AH |
1109 | .endm |
1110 | ||
1111 | zeroentry divide_error do_divide_error | |
322648d1 AH |
1112 | zeroentry overflow do_overflow |
1113 | zeroentry bounds do_bounds | |
1114 | zeroentry invalid_op do_invalid_op | |
1115 | zeroentry device_not_available do_device_not_available | |
ddeb8f21 | 1116 | paranoiderrorentry double_fault do_double_fault |
322648d1 AH |
1117 | zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun |
1118 | errorentry invalid_TSS do_invalid_TSS | |
1119 | errorentry segment_not_present do_segment_not_present | |
322648d1 AH |
1120 | zeroentry spurious_interrupt_bug do_spurious_interrupt_bug |
1121 | zeroentry coprocessor_error do_coprocessor_error | |
1122 | errorentry alignment_check do_alignment_check | |
322648d1 | 1123 | zeroentry simd_coprocessor_error do_simd_coprocessor_error |
2601e64d | 1124 | |
9f1e87ea CG |
1125 | /* Reload gs selector with exception handling */ |
1126 | /* edi: new selector */ | |
9f9d489a | 1127 | ENTRY(native_load_gs_index) |
7effaa88 | 1128 | CFI_STARTPROC |
df5d1874 | 1129 | pushfq_cfi |
b8aa287f | 1130 | DISABLE_INTERRUPTS(CLBR_ANY & ~CLBR_RDI) |
9f1e87ea | 1131 | SWAPGS |
0bd7b798 | 1132 | gs_change: |
9f1e87ea | 1133 | movl %edi,%gs |
1da177e4 | 1134 | 2: mfence /* workaround */ |
72fe4858 | 1135 | SWAPGS |
df5d1874 | 1136 | popfq_cfi |
9f1e87ea | 1137 | ret |
7effaa88 | 1138 | CFI_ENDPROC |
6efdcfaf | 1139 | END(native_load_gs_index) |
0bd7b798 | 1140 | |
9f1e87ea CG |
1141 | .section __ex_table,"a" |
1142 | .align 8 | |
1143 | .quad gs_change,bad_gs | |
1144 | .previous | |
1145 | .section .fixup,"ax" | |
1da177e4 | 1146 | /* running with kernelgs */ |
0bd7b798 | 1147 | bad_gs: |
72fe4858 | 1148 | SWAPGS /* switch back to user gs */ |
1da177e4 | 1149 | xorl %eax,%eax |
9f1e87ea CG |
1150 | movl %eax,%gs |
1151 | jmp 2b | |
1152 | .previous | |
0bd7b798 | 1153 | |
3bd95dfb | 1154 | ENTRY(kernel_thread_helper) |
c05991ed AK |
1155 | pushq $0 # fake return address |
1156 | CFI_STARTPROC | |
1da177e4 LT |
1157 | /* |
1158 | * Here we are in the child and the registers are set as they were | |
1159 | * at kernel_thread() invocation in the parent. | |
1160 | */ | |
3bd95dfb | 1161 | call *%rsi |
1da177e4 | 1162 | # exit |
1c5b5cfd | 1163 | mov %eax, %edi |
1da177e4 | 1164 | call do_exit |
5f5db591 | 1165 | ud2 # padding for call trace |
c05991ed | 1166 | CFI_ENDPROC |
3bd95dfb | 1167 | END(kernel_thread_helper) |
1da177e4 LT |
1168 | |
1169 | /* | |
1170 | * execve(). This function needs to use IRET, not SYSRET, to set up all state properly. | |
1171 | * | |
1172 | * C extern interface: | |
c7887325 | 1173 | * extern long execve(const char *name, char **argv, char **envp) |
1da177e4 LT |
1174 | * |
1175 | * asm input arguments: | |
1176 | * rdi: name, rsi: argv, rdx: envp | |
1177 | * | |
1178 | * We want to fallback into: | |
c7887325 | 1179 | * extern long sys_execve(const char *name, char **argv,char **envp, struct pt_regs *regs) |
1da177e4 LT |
1180 | * |
1181 | * do_sys_execve asm fallback arguments: | |
5d119b2c | 1182 | * rdi: name, rsi: argv, rdx: envp, rcx: fake frame on the stack |
1da177e4 | 1183 | */ |
3db03b4a | 1184 | ENTRY(kernel_execve) |
1da177e4 LT |
1185 | CFI_STARTPROC |
1186 | FAKE_STACK_FRAME $0 | |
0bd7b798 | 1187 | SAVE_ALL |
5d119b2c | 1188 | movq %rsp,%rcx |
1da177e4 | 1189 | call sys_execve |
0bd7b798 | 1190 | movq %rax, RAX(%rsp) |
1da177e4 LT |
1191 | RESTORE_REST |
1192 | testq %rax,%rax | |
1193 | je int_ret_from_sys_call | |
1194 | RESTORE_ARGS | |
1195 | UNFAKE_STACK_FRAME | |
1196 | ret | |
1197 | CFI_ENDPROC | |
6efdcfaf | 1198 | END(kernel_execve) |
1da177e4 | 1199 | |
2699500b | 1200 | /* Call softirq on interrupt stack. Interrupts are off. */ |
ed6b676c | 1201 | ENTRY(call_softirq) |
7effaa88 | 1202 | CFI_STARTPROC |
df5d1874 | 1203 | pushq_cfi %rbp |
2699500b AK |
1204 | CFI_REL_OFFSET rbp,0 |
1205 | mov %rsp,%rbp | |
1206 | CFI_DEF_CFA_REGISTER rbp | |
56895530 | 1207 | incl PER_CPU_VAR(irq_count) |
26f80bd6 | 1208 | cmove PER_CPU_VAR(irq_stack_ptr),%rsp |
2699500b | 1209 | push %rbp # backlink for old unwinder |
ed6b676c | 1210 | call __do_softirq |
2699500b | 1211 | leaveq |
df5d1874 | 1212 | CFI_RESTORE rbp |
7effaa88 | 1213 | CFI_DEF_CFA_REGISTER rsp |
2699500b | 1214 | CFI_ADJUST_CFA_OFFSET -8 |
56895530 | 1215 | decl PER_CPU_VAR(irq_count) |
ed6b676c | 1216 | ret |
7effaa88 | 1217 | CFI_ENDPROC |
6efdcfaf | 1218 | END(call_softirq) |
75154f40 | 1219 | |
3d75e1b8 | 1220 | #ifdef CONFIG_XEN |
322648d1 | 1221 | zeroentry xen_hypervisor_callback xen_do_hypervisor_callback |
3d75e1b8 JF |
1222 | |
1223 | /* | |
9f1e87ea CG |
1224 | * A note on the "critical region" in our callback handler. |
1225 | * We want to avoid stacking callback handlers due to events occurring | |
1226 | * during handling of the last event. To do this, we keep events disabled | |
1227 | * until we've done all processing. HOWEVER, we must enable events before | |
1228 | * popping the stack frame (can't be done atomically) and so it would still | |
1229 | * be possible to get enough handler activations to overflow the stack. | |
1230 | * Although unlikely, bugs of that kind are hard to track down, so we'd | |
1231 | * like to avoid the possibility. | |
1232 | * So, on entry to the handler we detect whether we interrupted an | |
1233 | * existing activation in its critical region -- if so, we pop the current | |
1234 | * activation and restart the handler using the previous one. | |
1235 | */ | |
3d75e1b8 JF |
1236 | ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs) |
1237 | CFI_STARTPROC | |
9f1e87ea CG |
1238 | /* |
1239 | * Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will | |
1240 | * see the correct pointer to the pt_regs | |
1241 | */ | |
3d75e1b8 JF |
1242 | movq %rdi, %rsp # we don't return, adjust the stack frame |
1243 | CFI_ENDPROC | |
dcd072e2 | 1244 | DEFAULT_FRAME |
56895530 | 1245 | 11: incl PER_CPU_VAR(irq_count) |
3d75e1b8 JF |
1246 | movq %rsp,%rbp |
1247 | CFI_DEF_CFA_REGISTER rbp | |
26f80bd6 | 1248 | cmovzq PER_CPU_VAR(irq_stack_ptr),%rsp |
3d75e1b8 JF |
1249 | pushq %rbp # backlink for old unwinder |
1250 | call xen_evtchn_do_upcall | |
1251 | popq %rsp | |
1252 | CFI_DEF_CFA_REGISTER rsp | |
56895530 | 1253 | decl PER_CPU_VAR(irq_count) |
3d75e1b8 JF |
1254 | jmp error_exit |
1255 | CFI_ENDPROC | |
371c394a | 1256 | END(xen_do_hypervisor_callback) |
3d75e1b8 JF |
1257 | |
1258 | /* | |
9f1e87ea CG |
1259 | * Hypervisor uses this for application faults while it executes. |
1260 | * We get here for two reasons: | |
1261 | * 1. Fault while reloading DS, ES, FS or GS | |
1262 | * 2. Fault while executing IRET | |
1263 | * Category 1 we do not need to fix up as Xen has already reloaded all segment | |
1264 | * registers that could be reloaded and zeroed the others. | |
1265 | * Category 2 we fix up by killing the current process. We cannot use the | |
1266 | * normal Linux return path in this case because if we use the IRET hypercall | |
1267 | * to pop the stack frame we end up in an infinite loop of failsafe callbacks. | |
1268 | * We distinguish between categories by comparing each saved segment register | |
1269 | * with its current contents: any discrepancy means we in category 1. | |
1270 | */ | |
3d75e1b8 | 1271 | ENTRY(xen_failsafe_callback) |
dcd072e2 AH |
1272 | INTR_FRAME 1 (6*8) |
1273 | /*CFI_REL_OFFSET gs,GS*/ | |
1274 | /*CFI_REL_OFFSET fs,FS*/ | |
1275 | /*CFI_REL_OFFSET es,ES*/ | |
1276 | /*CFI_REL_OFFSET ds,DS*/ | |
1277 | CFI_REL_OFFSET r11,8 | |
1278 | CFI_REL_OFFSET rcx,0 | |
3d75e1b8 JF |
1279 | movw %ds,%cx |
1280 | cmpw %cx,0x10(%rsp) | |
1281 | CFI_REMEMBER_STATE | |
1282 | jne 1f | |
1283 | movw %es,%cx | |
1284 | cmpw %cx,0x18(%rsp) | |
1285 | jne 1f | |
1286 | movw %fs,%cx | |
1287 | cmpw %cx,0x20(%rsp) | |
1288 | jne 1f | |
1289 | movw %gs,%cx | |
1290 | cmpw %cx,0x28(%rsp) | |
1291 | jne 1f | |
1292 | /* All segments match their saved values => Category 2 (Bad IRET). */ | |
1293 | movq (%rsp),%rcx | |
1294 | CFI_RESTORE rcx | |
1295 | movq 8(%rsp),%r11 | |
1296 | CFI_RESTORE r11 | |
1297 | addq $0x30,%rsp | |
1298 | CFI_ADJUST_CFA_OFFSET -0x30 | |
14ae22ba IM |
1299 | pushq_cfi $0 /* RIP */ |
1300 | pushq_cfi %r11 | |
1301 | pushq_cfi %rcx | |
4a5c3e77 | 1302 | jmp general_protection |
3d75e1b8 JF |
1303 | CFI_RESTORE_STATE |
1304 | 1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */ | |
1305 | movq (%rsp),%rcx | |
1306 | CFI_RESTORE rcx | |
1307 | movq 8(%rsp),%r11 | |
1308 | CFI_RESTORE r11 | |
1309 | addq $0x30,%rsp | |
1310 | CFI_ADJUST_CFA_OFFSET -0x30 | |
14ae22ba | 1311 | pushq_cfi $0 |
3d75e1b8 JF |
1312 | SAVE_ALL |
1313 | jmp error_exit | |
1314 | CFI_ENDPROC | |
3d75e1b8 JF |
1315 | END(xen_failsafe_callback) |
1316 | ||
38e20b07 SY |
1317 | apicinterrupt XEN_HVM_EVTCHN_CALLBACK \ |
1318 | xen_hvm_callback_vector xen_evtchn_do_upcall | |
1319 | ||
3d75e1b8 | 1320 | #endif /* CONFIG_XEN */ |
ddeb8f21 AH |
1321 | |
1322 | /* | |
1323 | * Some functions should be protected against kprobes | |
1324 | */ | |
1325 | .pushsection .kprobes.text, "ax" | |
1326 | ||
1327 | paranoidzeroentry_ist debug do_debug DEBUG_STACK | |
1328 | paranoidzeroentry_ist int3 do_int3 DEBUG_STACK | |
1329 | paranoiderrorentry stack_segment do_stack_segment | |
6cac5a92 JF |
1330 | #ifdef CONFIG_XEN |
1331 | zeroentry xen_debug do_debug | |
1332 | zeroentry xen_int3 do_int3 | |
1333 | errorentry xen_stack_segment do_stack_segment | |
1334 | #endif | |
ddeb8f21 AH |
1335 | errorentry general_protection do_general_protection |
1336 | errorentry page_fault do_page_fault | |
631bc487 GN |
1337 | #ifdef CONFIG_KVM_GUEST |
1338 | errorentry async_page_fault do_async_page_fault | |
1339 | #endif | |
ddeb8f21 | 1340 | #ifdef CONFIG_X86_MCE |
5d727926 | 1341 | paranoidzeroentry machine_check *machine_check_vector(%rip) |
ddeb8f21 AH |
1342 | #endif |
1343 | ||
1344 | /* | |
9f1e87ea CG |
1345 | * "Paranoid" exit path from exception stack. |
1346 | * Paranoid because this is used by NMIs and cannot take | |
ddeb8f21 AH |
1347 | * any kernel state for granted. |
1348 | * We don't do kernel preemption checks here, because only | |
1349 | * NMI should be common and it does not enable IRQs and | |
1350 | * cannot get reschedule ticks. | |
1351 | * | |
1352 | * "trace" is 0 for the NMI handler only, because irq-tracing | |
1353 | * is fundamentally NMI-unsafe. (we cannot change the soft and | |
1354 | * hard flags at once, atomically) | |
1355 | */ | |
1356 | ||
1357 | /* ebx: no swapgs flag */ | |
1358 | ENTRY(paranoid_exit) | |
1f130a78 | 1359 | DEFAULT_FRAME |
ddeb8f21 AH |
1360 | DISABLE_INTERRUPTS(CLBR_NONE) |
1361 | TRACE_IRQS_OFF | |
1362 | testl %ebx,%ebx /* swapgs needed? */ | |
1363 | jnz paranoid_restore | |
1364 | testl $3,CS(%rsp) | |
1365 | jnz paranoid_userspace | |
1366 | paranoid_swapgs: | |
1367 | TRACE_IRQS_IRETQ 0 | |
1368 | SWAPGS_UNSAFE_STACK | |
0300e7f1 SR |
1369 | RESTORE_ALL 8 |
1370 | jmp irq_return | |
ddeb8f21 | 1371 | paranoid_restore: |
0300e7f1 | 1372 | TRACE_IRQS_IRETQ 0 |
ddeb8f21 AH |
1373 | RESTORE_ALL 8 |
1374 | jmp irq_return | |
1375 | paranoid_userspace: | |
1376 | GET_THREAD_INFO(%rcx) | |
1377 | movl TI_flags(%rcx),%ebx | |
1378 | andl $_TIF_WORK_MASK,%ebx | |
1379 | jz paranoid_swapgs | |
1380 | movq %rsp,%rdi /* &pt_regs */ | |
1381 | call sync_regs | |
1382 | movq %rax,%rsp /* switch stack for scheduling */ | |
1383 | testl $_TIF_NEED_RESCHED,%ebx | |
1384 | jnz paranoid_schedule | |
1385 | movl %ebx,%edx /* arg3: thread flags */ | |
1386 | TRACE_IRQS_ON | |
1387 | ENABLE_INTERRUPTS(CLBR_NONE) | |
1388 | xorl %esi,%esi /* arg2: oldset */ | |
1389 | movq %rsp,%rdi /* arg1: &pt_regs */ | |
1390 | call do_notify_resume | |
1391 | DISABLE_INTERRUPTS(CLBR_NONE) | |
1392 | TRACE_IRQS_OFF | |
1393 | jmp paranoid_userspace | |
1394 | paranoid_schedule: | |
1395 | TRACE_IRQS_ON | |
1396 | ENABLE_INTERRUPTS(CLBR_ANY) | |
1397 | call schedule | |
1398 | DISABLE_INTERRUPTS(CLBR_ANY) | |
1399 | TRACE_IRQS_OFF | |
1400 | jmp paranoid_userspace | |
1401 | CFI_ENDPROC | |
1402 | END(paranoid_exit) | |
1403 | ||
1404 | /* | |
1405 | * Exception entry point. This expects an error code/orig_rax on the stack. | |
1406 | * returns in "no swapgs flag" in %ebx. | |
1407 | */ | |
1408 | ENTRY(error_entry) | |
1409 | XCPT_FRAME | |
1410 | CFI_ADJUST_CFA_OFFSET 15*8 | |
1411 | /* oldrax contains error code */ | |
1412 | cld | |
1413 | movq_cfi rdi, RDI+8 | |
1414 | movq_cfi rsi, RSI+8 | |
1415 | movq_cfi rdx, RDX+8 | |
1416 | movq_cfi rcx, RCX+8 | |
1417 | movq_cfi rax, RAX+8 | |
1418 | movq_cfi r8, R8+8 | |
1419 | movq_cfi r9, R9+8 | |
1420 | movq_cfi r10, R10+8 | |
1421 | movq_cfi r11, R11+8 | |
1422 | movq_cfi rbx, RBX+8 | |
1423 | movq_cfi rbp, RBP+8 | |
1424 | movq_cfi r12, R12+8 | |
1425 | movq_cfi r13, R13+8 | |
1426 | movq_cfi r14, R14+8 | |
1427 | movq_cfi r15, R15+8 | |
1428 | xorl %ebx,%ebx | |
1429 | testl $3,CS+8(%rsp) | |
1430 | je error_kernelspace | |
1431 | error_swapgs: | |
1432 | SWAPGS | |
1433 | error_sti: | |
1434 | TRACE_IRQS_OFF | |
1435 | ret | |
ddeb8f21 AH |
1436 | |
1437 | /* | |
1438 | * There are two places in the kernel that can potentially fault with | |
1439 | * usergs. Handle them here. The exception handlers after iret run with | |
1440 | * kernel gs again, so don't set the user space flag. B stepping K8s | |
1441 | * sometimes report an truncated RIP for IRET exceptions returning to | |
1442 | * compat mode. Check for these here too. | |
1443 | */ | |
1444 | error_kernelspace: | |
1445 | incl %ebx | |
1446 | leaq irq_return(%rip),%rcx | |
1447 | cmpq %rcx,RIP+8(%rsp) | |
1448 | je error_swapgs | |
ae24ffe5 BG |
1449 | movl %ecx,%eax /* zero extend */ |
1450 | cmpq %rax,RIP+8(%rsp) | |
1451 | je bstep_iret | |
ddeb8f21 | 1452 | cmpq $gs_change,RIP+8(%rsp) |
9f1e87ea | 1453 | je error_swapgs |
ddeb8f21 | 1454 | jmp error_sti |
ae24ffe5 BG |
1455 | |
1456 | bstep_iret: | |
1457 | /* Fix truncated RIP */ | |
1458 | movq %rcx,RIP+8(%rsp) | |
97829de5 | 1459 | jmp error_swapgs |
e6b04b6b | 1460 | CFI_ENDPROC |
ddeb8f21 AH |
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 | |
b1cccb1b JB |
1489 | subq $ORIG_RAX-R15, %rsp |
1490 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
ddeb8f21 AH |
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 |