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. | |
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> | |
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 |
606576ce | 64 | #ifdef CONFIG_FUNCTION_TRACER |
d61f82d0 SR |
65 | #ifdef CONFIG_DYNAMIC_FTRACE |
66 | ENTRY(mcount) | |
d61f82d0 SR |
67 | retq |
68 | END(mcount) | |
69 | ||
70 | ENTRY(ftrace_caller) | |
60a7ecf4 SR |
71 | cmpl $0, function_trace_stop |
72 | jne ftrace_stub | |
d61f82d0 | 73 | |
d680fe44 | 74 | MCOUNT_SAVE_FRAME |
d61f82d0 SR |
75 | |
76 | movq 0x38(%rsp), %rdi | |
77 | movq 8(%rbp), %rsi | |
395a59d0 | 78 | subq $MCOUNT_INSN_SIZE, %rdi |
d61f82d0 | 79 | |
bc8b2b92 | 80 | GLOBAL(ftrace_call) |
d61f82d0 SR |
81 | call ftrace_stub |
82 | ||
d680fe44 | 83 | MCOUNT_RESTORE_FRAME |
d61f82d0 | 84 | |
48d68b20 | 85 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
bc8b2b92 | 86 | GLOBAL(ftrace_graph_call) |
48d68b20 FW |
87 | jmp ftrace_stub |
88 | #endif | |
d61f82d0 | 89 | |
bc8b2b92 | 90 | GLOBAL(ftrace_stub) |
d61f82d0 SR |
91 | retq |
92 | END(ftrace_caller) | |
93 | ||
94 | #else /* ! CONFIG_DYNAMIC_FTRACE */ | |
16444a8a | 95 | ENTRY(mcount) |
60a7ecf4 SR |
96 | cmpl $0, function_trace_stop |
97 | jne ftrace_stub | |
98 | ||
16444a8a ACM |
99 | cmpq $ftrace_stub, ftrace_trace_function |
100 | jnz trace | |
48d68b20 FW |
101 | |
102 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
103 | cmpq $ftrace_stub, ftrace_graph_return | |
104 | jnz ftrace_graph_caller | |
e49dc19c SR |
105 | |
106 | cmpq $ftrace_graph_entry_stub, ftrace_graph_entry | |
107 | jnz ftrace_graph_caller | |
48d68b20 FW |
108 | #endif |
109 | ||
bc8b2b92 | 110 | GLOBAL(ftrace_stub) |
16444a8a ACM |
111 | retq |
112 | ||
113 | trace: | |
d680fe44 | 114 | MCOUNT_SAVE_FRAME |
16444a8a ACM |
115 | |
116 | movq 0x38(%rsp), %rdi | |
117 | movq 8(%rbp), %rsi | |
395a59d0 | 118 | subq $MCOUNT_INSN_SIZE, %rdi |
16444a8a ACM |
119 | |
120 | call *ftrace_trace_function | |
121 | ||
d680fe44 | 122 | MCOUNT_RESTORE_FRAME |
16444a8a ACM |
123 | |
124 | jmp ftrace_stub | |
125 | END(mcount) | |
d61f82d0 | 126 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
606576ce | 127 | #endif /* CONFIG_FUNCTION_TRACER */ |
16444a8a | 128 | |
48d68b20 FW |
129 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
130 | ENTRY(ftrace_graph_caller) | |
131 | cmpl $0, function_trace_stop | |
132 | jne ftrace_stub | |
133 | ||
d680fe44 | 134 | MCOUNT_SAVE_FRAME |
48d68b20 FW |
135 | |
136 | leaq 8(%rbp), %rdi | |
137 | movq 0x38(%rsp), %rsi | |
71e308a2 | 138 | movq (%rbp), %rdx |
bb4304c7 | 139 | subq $MCOUNT_INSN_SIZE, %rsi |
48d68b20 FW |
140 | |
141 | call prepare_ftrace_return | |
142 | ||
d680fe44 CG |
143 | MCOUNT_RESTORE_FRAME |
144 | ||
48d68b20 FW |
145 | retq |
146 | END(ftrace_graph_caller) | |
147 | ||
bc8b2b92 | 148 | GLOBAL(return_to_handler) |
4818d809 | 149 | subq $24, %rsp |
48d68b20 | 150 | |
e71e99c2 | 151 | /* Save the return values */ |
16444a8a | 152 | movq %rax, (%rsp) |
e71e99c2 | 153 | movq %rdx, 8(%rsp) |
71e308a2 | 154 | movq %rbp, %rdi |
16444a8a | 155 | |
48d68b20 | 156 | call ftrace_return_to_handler |
16444a8a | 157 | |
194ec341 | 158 | movq %rax, %rdi |
e71e99c2 | 159 | movq 8(%rsp), %rdx |
16444a8a | 160 | movq (%rsp), %rax |
194ec341 SR |
161 | addq $24, %rsp |
162 | jmp *%rdi | |
48d68b20 | 163 | #endif |
16444a8a | 164 | |
16444a8a | 165 | |
dc37db4d | 166 | #ifndef CONFIG_PREEMPT |
1da177e4 | 167 | #define retint_kernel retint_restore_args |
0bd7b798 | 168 | #endif |
2601e64d | 169 | |
72fe4858 | 170 | #ifdef CONFIG_PARAVIRT |
2be29982 | 171 | ENTRY(native_usergs_sysret64) |
72fe4858 GOC |
172 | swapgs |
173 | sysretq | |
b3baaa13 | 174 | ENDPROC(native_usergs_sysret64) |
72fe4858 GOC |
175 | #endif /* CONFIG_PARAVIRT */ |
176 | ||
2601e64d IM |
177 | |
178 | .macro TRACE_IRQS_IRETQ offset=ARGOFFSET | |
179 | #ifdef CONFIG_TRACE_IRQFLAGS | |
180 | bt $9,EFLAGS-\offset(%rsp) /* interrupts off? */ | |
181 | jnc 1f | |
182 | TRACE_IRQS_ON | |
183 | 1: | |
184 | #endif | |
185 | .endm | |
186 | ||
1da177e4 | 187 | /* |
0bd7b798 AH |
188 | * C code is not supposed to know about undefined top of stack. Every time |
189 | * a C function with an pt_regs argument is called from the SYSCALL based | |
1da177e4 LT |
190 | * fast path FIXUP_TOP_OF_STACK is needed. |
191 | * RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs | |
192 | * manipulation. | |
0bd7b798 AH |
193 | */ |
194 | ||
195 | /* %rsp:at FRAMEEND */ | |
c002a1e6 | 196 | .macro FIXUP_TOP_OF_STACK tmp offset=0 |
3d1e42a7 | 197 | movq PER_CPU_VAR(old_rsp),\tmp |
c002a1e6 AH |
198 | movq \tmp,RSP+\offset(%rsp) |
199 | movq $__USER_DS,SS+\offset(%rsp) | |
200 | movq $__USER_CS,CS+\offset(%rsp) | |
201 | movq $-1,RCX+\offset(%rsp) | |
202 | movq R11+\offset(%rsp),\tmp /* get eflags */ | |
203 | movq \tmp,EFLAGS+\offset(%rsp) | |
1da177e4 LT |
204 | .endm |
205 | ||
c002a1e6 AH |
206 | .macro RESTORE_TOP_OF_STACK tmp offset=0 |
207 | movq RSP+\offset(%rsp),\tmp | |
3d1e42a7 | 208 | movq \tmp,PER_CPU_VAR(old_rsp) |
c002a1e6 AH |
209 | movq EFLAGS+\offset(%rsp),\tmp |
210 | movq \tmp,R11+\offset(%rsp) | |
1da177e4 LT |
211 | .endm |
212 | ||
213 | .macro FAKE_STACK_FRAME child_rip | |
214 | /* push in order ss, rsp, eflags, cs, rip */ | |
3829ee6b | 215 | xorl %eax, %eax |
e04e0a63 | 216 | pushq $__KERNEL_DS /* ss */ |
1da177e4 | 217 | CFI_ADJUST_CFA_OFFSET 8 |
7effaa88 | 218 | /*CFI_REL_OFFSET ss,0*/ |
1da177e4 LT |
219 | pushq %rax /* rsp */ |
220 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 221 | CFI_REL_OFFSET rsp,0 |
33454539 | 222 | pushq $X86_EFLAGS_IF /* eflags - interrupts on */ |
1da177e4 | 223 | CFI_ADJUST_CFA_OFFSET 8 |
7effaa88 | 224 | /*CFI_REL_OFFSET rflags,0*/ |
1da177e4 LT |
225 | pushq $__KERNEL_CS /* cs */ |
226 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 227 | /*CFI_REL_OFFSET cs,0*/ |
1da177e4 LT |
228 | pushq \child_rip /* rip */ |
229 | CFI_ADJUST_CFA_OFFSET 8 | |
7effaa88 | 230 | CFI_REL_OFFSET rip,0 |
1da177e4 LT |
231 | pushq %rax /* orig rax */ |
232 | CFI_ADJUST_CFA_OFFSET 8 | |
233 | .endm | |
234 | ||
235 | .macro UNFAKE_STACK_FRAME | |
236 | addq $8*6, %rsp | |
237 | CFI_ADJUST_CFA_OFFSET -(6*8) | |
238 | .endm | |
239 | ||
dcd072e2 AH |
240 | /* |
241 | * initial frame state for interrupts (and exceptions without error code) | |
242 | */ | |
243 | .macro EMPTY_FRAME start=1 offset=0 | |
7effaa88 | 244 | .if \start |
dcd072e2 | 245 | CFI_STARTPROC simple |
adf14236 | 246 | CFI_SIGNAL_FRAME |
dcd072e2 | 247 | CFI_DEF_CFA rsp,8+\offset |
7effaa88 | 248 | .else |
dcd072e2 | 249 | CFI_DEF_CFA_OFFSET 8+\offset |
7effaa88 | 250 | .endif |
1da177e4 | 251 | .endm |
d99015b1 AH |
252 | |
253 | /* | |
dcd072e2 | 254 | * initial frame state for interrupts (and exceptions without error code) |
d99015b1 | 255 | */ |
dcd072e2 | 256 | .macro INTR_FRAME start=1 offset=0 |
e8a0e276 IM |
257 | EMPTY_FRAME \start, SS+8+\offset-RIP |
258 | /*CFI_REL_OFFSET ss, SS+\offset-RIP*/ | |
259 | CFI_REL_OFFSET rsp, RSP+\offset-RIP | |
260 | /*CFI_REL_OFFSET rflags, EFLAGS+\offset-RIP*/ | |
261 | /*CFI_REL_OFFSET cs, CS+\offset-RIP*/ | |
262 | CFI_REL_OFFSET rip, RIP+\offset-RIP | |
d99015b1 AH |
263 | .endm |
264 | ||
d99015b1 AH |
265 | /* |
266 | * initial frame state for exceptions with error code (and interrupts | |
267 | * with vector already pushed) | |
268 | */ | |
dcd072e2 | 269 | .macro XCPT_FRAME start=1 offset=0 |
e8a0e276 | 270 | INTR_FRAME \start, RIP+\offset-ORIG_RAX |
dcd072e2 AH |
271 | /*CFI_REL_OFFSET orig_rax, ORIG_RAX-ORIG_RAX*/ |
272 | .endm | |
273 | ||
274 | /* | |
275 | * frame that enables calling into C. | |
276 | */ | |
277 | .macro PARTIAL_FRAME start=1 offset=0 | |
e8a0e276 IM |
278 | XCPT_FRAME \start, ORIG_RAX+\offset-ARGOFFSET |
279 | CFI_REL_OFFSET rdi, RDI+\offset-ARGOFFSET | |
280 | CFI_REL_OFFSET rsi, RSI+\offset-ARGOFFSET | |
281 | CFI_REL_OFFSET rdx, RDX+\offset-ARGOFFSET | |
282 | CFI_REL_OFFSET rcx, RCX+\offset-ARGOFFSET | |
283 | CFI_REL_OFFSET rax, RAX+\offset-ARGOFFSET | |
284 | CFI_REL_OFFSET r8, R8+\offset-ARGOFFSET | |
285 | CFI_REL_OFFSET r9, R9+\offset-ARGOFFSET | |
286 | CFI_REL_OFFSET r10, R10+\offset-ARGOFFSET | |
287 | CFI_REL_OFFSET r11, R11+\offset-ARGOFFSET | |
dcd072e2 AH |
288 | .endm |
289 | ||
290 | /* | |
291 | * frame that enables passing a complete pt_regs to a C function. | |
292 | */ | |
293 | .macro DEFAULT_FRAME start=1 offset=0 | |
e8a0e276 | 294 | PARTIAL_FRAME \start, R11+\offset-R15 |
dcd072e2 AH |
295 | CFI_REL_OFFSET rbx, RBX+\offset |
296 | CFI_REL_OFFSET rbp, RBP+\offset | |
297 | CFI_REL_OFFSET r12, R12+\offset | |
298 | CFI_REL_OFFSET r13, R13+\offset | |
299 | CFI_REL_OFFSET r14, R14+\offset | |
300 | CFI_REL_OFFSET r15, R15+\offset | |
301 | .endm | |
d99015b1 AH |
302 | |
303 | /* save partial stack frame */ | |
304 | ENTRY(save_args) | |
305 | XCPT_FRAME | |
306 | cld | |
14ae22ba IM |
307 | movq_cfi rdi, RDI+16-ARGOFFSET |
308 | movq_cfi rsi, RSI+16-ARGOFFSET | |
309 | movq_cfi rdx, RDX+16-ARGOFFSET | |
310 | movq_cfi rcx, RCX+16-ARGOFFSET | |
311 | movq_cfi rax, RAX+16-ARGOFFSET | |
312 | movq_cfi r8, R8+16-ARGOFFSET | |
313 | movq_cfi r9, R9+16-ARGOFFSET | |
314 | movq_cfi r10, R10+16-ARGOFFSET | |
315 | movq_cfi r11, R11+16-ARGOFFSET | |
316 | ||
d99015b1 | 317 | leaq -ARGOFFSET+16(%rsp),%rdi /* arg1 for handler */ |
14ae22ba | 318 | movq_cfi rbp, 8 /* push %rbp */ |
d99015b1 AH |
319 | leaq 8(%rsp), %rbp /* mov %rsp, %ebp */ |
320 | testl $3, CS(%rdi) | |
321 | je 1f | |
322 | SWAPGS | |
323 | /* | |
56895530 | 324 | * irq_count is used to check if a CPU is already on an interrupt stack |
d99015b1 AH |
325 | * or not. While this is essentially redundant with preempt_count it is |
326 | * a little cheaper to use a separate counter in the PDA (short of | |
327 | * moving irq_enter into assembly, which would be too much work) | |
328 | */ | |
56895530 | 329 | 1: incl PER_CPU_VAR(irq_count) |
d99015b1 | 330 | jne 2f |
14ae22ba | 331 | popq_cfi %rax /* move return address... */ |
26f80bd6 | 332 | mov PER_CPU_VAR(irq_stack_ptr),%rsp |
dcd072e2 | 333 | EMPTY_FRAME 0 |
a67798cd | 334 | pushq_cfi %rbp /* backlink for unwinder */ |
14ae22ba | 335 | pushq_cfi %rax /* ... to the new stack */ |
d99015b1 AH |
336 | /* |
337 | * We entered an interrupt context - irqs are off: | |
338 | */ | |
339 | 2: TRACE_IRQS_OFF | |
340 | ret | |
341 | CFI_ENDPROC | |
342 | END(save_args) | |
343 | ||
c002a1e6 AH |
344 | ENTRY(save_rest) |
345 | PARTIAL_FRAME 1 REST_SKIP+8 | |
346 | movq 5*8+16(%rsp), %r11 /* save return address */ | |
347 | movq_cfi rbx, RBX+16 | |
348 | movq_cfi rbp, RBP+16 | |
349 | movq_cfi r12, R12+16 | |
350 | movq_cfi r13, R13+16 | |
351 | movq_cfi r14, R14+16 | |
352 | movq_cfi r15, R15+16 | |
353 | movq %r11, 8(%rsp) /* return address */ | |
354 | FIXUP_TOP_OF_STACK %r11, 16 | |
355 | ret | |
356 | CFI_ENDPROC | |
357 | END(save_rest) | |
358 | ||
e2f6bc25 | 359 | /* save complete stack frame */ |
c2810188 | 360 | .pushsection .kprobes.text, "ax" |
e2f6bc25 AH |
361 | ENTRY(save_paranoid) |
362 | XCPT_FRAME 1 RDI+8 | |
363 | cld | |
364 | movq_cfi rdi, RDI+8 | |
365 | movq_cfi rsi, RSI+8 | |
366 | movq_cfi rdx, RDX+8 | |
367 | movq_cfi rcx, RCX+8 | |
368 | movq_cfi rax, RAX+8 | |
369 | movq_cfi r8, R8+8 | |
370 | movq_cfi r9, R9+8 | |
371 | movq_cfi r10, R10+8 | |
372 | movq_cfi r11, R11+8 | |
373 | movq_cfi rbx, RBX+8 | |
374 | movq_cfi rbp, RBP+8 | |
375 | movq_cfi r12, R12+8 | |
376 | movq_cfi r13, R13+8 | |
377 | movq_cfi r14, R14+8 | |
378 | movq_cfi r15, R15+8 | |
379 | movl $1,%ebx | |
380 | movl $MSR_GS_BASE,%ecx | |
381 | rdmsr | |
382 | testl %edx,%edx | |
383 | js 1f /* negative -> in kernel */ | |
384 | SWAPGS | |
385 | xorl %ebx,%ebx | |
386 | 1: ret | |
387 | CFI_ENDPROC | |
388 | END(save_paranoid) | |
c2810188 | 389 | .popsection |
e2f6bc25 | 390 | |
1da177e4 | 391 | /* |
5b3eec0c IM |
392 | * A newly forked process directly context switches into this address. |
393 | * | |
394 | * rdi: prev task we switched from | |
0bd7b798 | 395 | */ |
1da177e4 | 396 | ENTRY(ret_from_fork) |
dcd072e2 | 397 | DEFAULT_FRAME |
5b3eec0c | 398 | |
7106a5ab BL |
399 | LOCK ; btr $TIF_FORK,TI_flags(%r8) |
400 | ||
658fdbef | 401 | push kernel_eflags(%rip) |
e0a5a5d9 | 402 | CFI_ADJUST_CFA_OFFSET 8 |
5b3eec0c | 403 | popf # reset kernel eflags |
e0a5a5d9 | 404 | CFI_ADJUST_CFA_OFFSET -8 |
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 | /* | |
425 | * System call entry. Upto 6 arguments in registers are supported. | |
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) |
1da177e4 | 524 | pushq %rdi |
7effaa88 | 525 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
526 | call schedule |
527 | popq %rdi | |
7effaa88 | 528 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 LT |
529 | jmp sysret_check |
530 | ||
0bd7b798 | 531 | /* Handle a signal */ |
1da177e4 | 532 | sysret_signal: |
2601e64d | 533 | TRACE_IRQS_ON |
72fe4858 | 534 | ENABLE_INTERRUPTS(CLBR_NONE) |
86a1c34a RM |
535 | #ifdef CONFIG_AUDITSYSCALL |
536 | bt $TIF_SYSCALL_AUDIT,%edx | |
537 | jc sysret_audit | |
538 | #endif | |
b60e714d RM |
539 | /* |
540 | * We have a signal, or exit tracing or single-step. | |
541 | * These all wind up with the iret return path anyway, | |
542 | * so just join that path right now. | |
543 | */ | |
544 | FIXUP_TOP_OF_STACK %r11, -ARGOFFSET | |
545 | jmp int_check_syscall_exit_work | |
0bd7b798 | 546 | |
7effaa88 JB |
547 | badsys: |
548 | movq $-ENOSYS,RAX-ARGOFFSET(%rsp) | |
549 | jmp ret_from_sys_call | |
550 | ||
86a1c34a RM |
551 | #ifdef CONFIG_AUDITSYSCALL |
552 | /* | |
553 | * Fast path for syscall audit without full syscall trace. | |
554 | * We just call audit_syscall_entry() directly, and then | |
555 | * jump back to the normal fast path. | |
556 | */ | |
557 | auditsys: | |
558 | movq %r10,%r9 /* 6th arg: 4th syscall arg */ | |
559 | movq %rdx,%r8 /* 5th arg: 3rd syscall arg */ | |
560 | movq %rsi,%rcx /* 4th arg: 2nd syscall arg */ | |
561 | movq %rdi,%rdx /* 3rd arg: 1st syscall arg */ | |
562 | movq %rax,%rsi /* 2nd arg: syscall number */ | |
563 | movl $AUDIT_ARCH_X86_64,%edi /* 1st arg: audit arch */ | |
564 | call audit_syscall_entry | |
565 | LOAD_ARGS 0 /* reload call-clobbered registers */ | |
566 | jmp system_call_fastpath | |
567 | ||
568 | /* | |
569 | * Return fast path for syscall audit. Call audit_syscall_exit() | |
570 | * directly and then jump back to the fast path with TIF_SYSCALL_AUDIT | |
571 | * masked off. | |
572 | */ | |
573 | sysret_audit: | |
03275591 RM |
574 | movq RAX-ARGOFFSET(%rsp),%rsi /* second arg, syscall return value */ |
575 | cmpq $0,%rsi /* is it < 0? */ | |
86a1c34a RM |
576 | setl %al /* 1 if so, 0 if not */ |
577 | movzbl %al,%edi /* zero-extend that into %edi */ | |
578 | inc %edi /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */ | |
579 | call audit_syscall_exit | |
580 | movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi | |
581 | jmp sysret_check | |
582 | #endif /* CONFIG_AUDITSYSCALL */ | |
583 | ||
1da177e4 | 584 | /* Do syscall tracing */ |
0bd7b798 | 585 | tracesys: |
86a1c34a RM |
586 | #ifdef CONFIG_AUDITSYSCALL |
587 | testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%rcx) | |
588 | jz auditsys | |
589 | #endif | |
1da177e4 | 590 | SAVE_REST |
a31f8dd7 | 591 | movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */ |
1da177e4 LT |
592 | FIXUP_TOP_OF_STACK %rdi |
593 | movq %rsp,%rdi | |
594 | call syscall_trace_enter | |
d4d67150 RM |
595 | /* |
596 | * Reload arg registers from stack in case ptrace changed them. | |
597 | * We don't reload %rax because syscall_trace_enter() returned | |
598 | * the value it wants us to use in the table lookup. | |
599 | */ | |
600 | LOAD_ARGS ARGOFFSET, 1 | |
1da177e4 LT |
601 | RESTORE_REST |
602 | cmpq $__NR_syscall_max,%rax | |
a31f8dd7 | 603 | ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */ |
1da177e4 LT |
604 | movq %r10,%rcx /* fixup for C */ |
605 | call *sys_call_table(,%rax,8) | |
a31f8dd7 | 606 | movq %rax,RAX-ARGOFFSET(%rsp) |
7bf36bbc | 607 | /* Use IRET because user could have changed frame */ |
0bd7b798 AH |
608 | |
609 | /* | |
1da177e4 LT |
610 | * Syscall return path ending with IRET. |
611 | * Has correct top of stack, but partial stack frame. | |
bcddc015 | 612 | */ |
bc8b2b92 | 613 | GLOBAL(int_ret_from_sys_call) |
72fe4858 | 614 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 615 | TRACE_IRQS_OFF |
1da177e4 LT |
616 | testl $3,CS-ARGOFFSET(%rsp) |
617 | je retint_restore_args | |
618 | movl $_TIF_ALLWORK_MASK,%edi | |
619 | /* edi: mask to check */ | |
bc8b2b92 | 620 | GLOBAL(int_with_check) |
10cd706d | 621 | LOCKDEP_SYS_EXIT_IRQ |
1da177e4 | 622 | GET_THREAD_INFO(%rcx) |
26ccb8a7 | 623 | movl TI_flags(%rcx),%edx |
1da177e4 LT |
624 | andl %edi,%edx |
625 | jnz int_careful | |
26ccb8a7 | 626 | andl $~TS_COMPAT,TI_status(%rcx) |
1da177e4 LT |
627 | jmp retint_swapgs |
628 | ||
629 | /* Either reschedule or signal or syscall exit tracking needed. */ | |
630 | /* First do a reschedule test. */ | |
631 | /* edx: work, edi: workmask */ | |
632 | int_careful: | |
633 | bt $TIF_NEED_RESCHED,%edx | |
634 | jnc int_very_careful | |
2601e64d | 635 | TRACE_IRQS_ON |
72fe4858 | 636 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 637 | pushq %rdi |
7effaa88 | 638 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 LT |
639 | call schedule |
640 | popq %rdi | |
7effaa88 | 641 | CFI_ADJUST_CFA_OFFSET -8 |
72fe4858 | 642 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 643 | TRACE_IRQS_OFF |
1da177e4 LT |
644 | jmp int_with_check |
645 | ||
646 | /* handle signals and tracing -- both require a full stack frame */ | |
647 | int_very_careful: | |
2601e64d | 648 | TRACE_IRQS_ON |
72fe4858 | 649 | ENABLE_INTERRUPTS(CLBR_NONE) |
b60e714d | 650 | int_check_syscall_exit_work: |
1da177e4 | 651 | SAVE_REST |
0bd7b798 | 652 | /* Check for syscall exit trace */ |
d4d67150 | 653 | testl $_TIF_WORK_SYSCALL_EXIT,%edx |
1da177e4 LT |
654 | jz int_signal |
655 | pushq %rdi | |
7effaa88 | 656 | CFI_ADJUST_CFA_OFFSET 8 |
0bd7b798 | 657 | leaq 8(%rsp),%rdi # &ptregs -> arg1 |
1da177e4 LT |
658 | call syscall_trace_leave |
659 | popq %rdi | |
7effaa88 | 660 | CFI_ADJUST_CFA_OFFSET -8 |
d4d67150 | 661 | andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU),%edi |
1da177e4 | 662 | jmp int_restore_rest |
0bd7b798 | 663 | |
1da177e4 | 664 | int_signal: |
8f4d37ec | 665 | testl $_TIF_DO_NOTIFY_MASK,%edx |
1da177e4 LT |
666 | jz 1f |
667 | movq %rsp,%rdi # &ptregs -> arg1 | |
668 | xorl %esi,%esi # oldset -> arg2 | |
669 | call do_notify_resume | |
eca91e78 | 670 | 1: movl $_TIF_WORK_MASK,%edi |
1da177e4 LT |
671 | int_restore_rest: |
672 | RESTORE_REST | |
72fe4858 | 673 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 674 | TRACE_IRQS_OFF |
1da177e4 LT |
675 | jmp int_with_check |
676 | CFI_ENDPROC | |
bcddc015 | 677 | END(system_call) |
0bd7b798 AH |
678 | |
679 | /* | |
1da177e4 | 680 | * Certain special system calls that need to save a complete full stack frame. |
0bd7b798 | 681 | */ |
1da177e4 | 682 | .macro PTREGSCALL label,func,arg |
c002a1e6 AH |
683 | ENTRY(\label) |
684 | PARTIAL_FRAME 1 8 /* offset 8: return address */ | |
685 | subq $REST_SKIP, %rsp | |
686 | CFI_ADJUST_CFA_OFFSET REST_SKIP | |
687 | call save_rest | |
688 | DEFAULT_FRAME 0 8 /* offset 8: return address */ | |
689 | leaq 8(%rsp), \arg /* pt_regs pointer */ | |
690 | call \func | |
691 | jmp ptregscall_common | |
692 | CFI_ENDPROC | |
4b787e0b | 693 | END(\label) |
1da177e4 LT |
694 | .endm |
695 | ||
696 | PTREGSCALL stub_clone, sys_clone, %r8 | |
697 | PTREGSCALL stub_fork, sys_fork, %rdi | |
698 | PTREGSCALL stub_vfork, sys_vfork, %rdi | |
1da177e4 LT |
699 | PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx |
700 | PTREGSCALL stub_iopl, sys_iopl, %rsi | |
701 | ||
702 | ENTRY(ptregscall_common) | |
c002a1e6 AH |
703 | DEFAULT_FRAME 1 8 /* offset 8: return address */ |
704 | RESTORE_TOP_OF_STACK %r11, 8 | |
705 | movq_cfi_restore R15+8, r15 | |
706 | movq_cfi_restore R14+8, r14 | |
707 | movq_cfi_restore R13+8, r13 | |
708 | movq_cfi_restore R12+8, r12 | |
709 | movq_cfi_restore RBP+8, rbp | |
710 | movq_cfi_restore RBX+8, rbx | |
711 | ret $REST_SKIP /* pop extended registers */ | |
1da177e4 | 712 | CFI_ENDPROC |
4b787e0b | 713 | END(ptregscall_common) |
0bd7b798 | 714 | |
1da177e4 LT |
715 | ENTRY(stub_execve) |
716 | CFI_STARTPROC | |
717 | popq %r11 | |
7effaa88 JB |
718 | CFI_ADJUST_CFA_OFFSET -8 |
719 | CFI_REGISTER rip, r11 | |
1da177e4 | 720 | SAVE_REST |
1da177e4 | 721 | FIXUP_TOP_OF_STACK %r11 |
5d119b2c | 722 | movq %rsp, %rcx |
1da177e4 | 723 | call sys_execve |
1da177e4 | 724 | RESTORE_TOP_OF_STACK %r11 |
1da177e4 LT |
725 | movq %rax,RAX(%rsp) |
726 | RESTORE_REST | |
727 | jmp int_ret_from_sys_call | |
728 | CFI_ENDPROC | |
4b787e0b | 729 | END(stub_execve) |
0bd7b798 | 730 | |
1da177e4 LT |
731 | /* |
732 | * sigreturn is special because it needs to restore all registers on return. | |
733 | * This cannot be done with SYSRET, so use the IRET return path instead. | |
0bd7b798 | 734 | */ |
1da177e4 LT |
735 | ENTRY(stub_rt_sigreturn) |
736 | CFI_STARTPROC | |
7effaa88 JB |
737 | addq $8, %rsp |
738 | CFI_ADJUST_CFA_OFFSET -8 | |
1da177e4 LT |
739 | SAVE_REST |
740 | movq %rsp,%rdi | |
741 | FIXUP_TOP_OF_STACK %r11 | |
742 | call sys_rt_sigreturn | |
743 | movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer | |
744 | RESTORE_REST | |
745 | jmp int_ret_from_sys_call | |
746 | CFI_ENDPROC | |
4b787e0b | 747 | END(stub_rt_sigreturn) |
1da177e4 | 748 | |
939b7871 PA |
749 | /* |
750 | * Build the entry stubs and pointer table with some assembler magic. | |
751 | * We pack 7 stubs into a single 32-byte chunk, which will fit in a | |
752 | * single cache line on all modern x86 implementations. | |
753 | */ | |
754 | .section .init.rodata,"a" | |
755 | ENTRY(interrupt) | |
756 | .text | |
757 | .p2align 5 | |
758 | .p2align CONFIG_X86_L1_CACHE_SHIFT | |
759 | ENTRY(irq_entries_start) | |
760 | INTR_FRAME | |
761 | vector=FIRST_EXTERNAL_VECTOR | |
762 | .rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7 | |
763 | .balign 32 | |
764 | .rept 7 | |
765 | .if vector < NR_VECTORS | |
8665596e | 766 | .if vector <> FIRST_EXTERNAL_VECTOR |
939b7871 PA |
767 | CFI_ADJUST_CFA_OFFSET -8 |
768 | .endif | |
769 | 1: pushq $(~vector+0x80) /* Note: always in signed byte range */ | |
770 | CFI_ADJUST_CFA_OFFSET 8 | |
8665596e | 771 | .if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6 |
939b7871 PA |
772 | jmp 2f |
773 | .endif | |
774 | .previous | |
775 | .quad 1b | |
776 | .text | |
777 | vector=vector+1 | |
778 | .endif | |
779 | .endr | |
780 | 2: jmp common_interrupt | |
781 | .endr | |
782 | CFI_ENDPROC | |
783 | END(irq_entries_start) | |
784 | ||
785 | .previous | |
786 | END(interrupt) | |
787 | .previous | |
788 | ||
d99015b1 | 789 | /* |
1da177e4 LT |
790 | * Interrupt entry/exit. |
791 | * | |
792 | * Interrupt entry points save only callee clobbered registers in fast path. | |
d99015b1 AH |
793 | * |
794 | * Entry runs with interrupts off. | |
795 | */ | |
1da177e4 | 796 | |
722024db | 797 | /* 0(%rsp): ~(interrupt number) */ |
1da177e4 | 798 | .macro interrupt func |
d99015b1 AH |
799 | subq $10*8, %rsp |
800 | CFI_ADJUST_CFA_OFFSET 10*8 | |
801 | call save_args | |
dcd072e2 | 802 | PARTIAL_FRAME 0 |
1da177e4 LT |
803 | call \func |
804 | .endm | |
805 | ||
8222d718 MH |
806 | /* |
807 | * Interrupt entry/exit should be protected against kprobes | |
808 | */ | |
809 | .pushsection .kprobes.text, "ax" | |
722024db AH |
810 | /* |
811 | * The interrupt stubs push (~vector+0x80) onto the stack and | |
812 | * then jump to common_interrupt. | |
813 | */ | |
939b7871 PA |
814 | .p2align CONFIG_X86_L1_CACHE_SHIFT |
815 | common_interrupt: | |
7effaa88 | 816 | XCPT_FRAME |
722024db | 817 | addq $-0x80,(%rsp) /* Adjust vector to [-256,-1] range */ |
1da177e4 | 818 | interrupt do_IRQ |
3d1e42a7 | 819 | /* 0(%rsp): old_rsp-ARGOFFSET */ |
7effaa88 | 820 | ret_from_intr: |
72fe4858 | 821 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 822 | TRACE_IRQS_OFF |
56895530 | 823 | decl PER_CPU_VAR(irq_count) |
1de9c3f6 | 824 | leaveq |
7effaa88 | 825 | CFI_DEF_CFA_REGISTER rsp |
1de9c3f6 | 826 | CFI_ADJUST_CFA_OFFSET -8 |
7effaa88 | 827 | exit_intr: |
1da177e4 LT |
828 | GET_THREAD_INFO(%rcx) |
829 | testl $3,CS-ARGOFFSET(%rsp) | |
830 | je retint_kernel | |
0bd7b798 | 831 | |
1da177e4 LT |
832 | /* Interrupt came from user space */ |
833 | /* | |
834 | * Has a correct top of stack, but a partial stack frame | |
835 | * %rcx: thread info. Interrupts off. | |
0bd7b798 | 836 | */ |
1da177e4 LT |
837 | retint_with_reschedule: |
838 | movl $_TIF_WORK_MASK,%edi | |
7effaa88 | 839 | retint_check: |
10cd706d | 840 | LOCKDEP_SYS_EXIT_IRQ |
26ccb8a7 | 841 | movl TI_flags(%rcx),%edx |
1da177e4 | 842 | andl %edi,%edx |
7effaa88 | 843 | CFI_REMEMBER_STATE |
1da177e4 | 844 | jnz retint_careful |
10cd706d PZ |
845 | |
846 | retint_swapgs: /* return to user-space */ | |
2601e64d IM |
847 | /* |
848 | * The iretq could re-enable interrupts: | |
849 | */ | |
72fe4858 | 850 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d | 851 | TRACE_IRQS_IRETQ |
72fe4858 | 852 | SWAPGS |
2601e64d IM |
853 | jmp restore_args |
854 | ||
10cd706d | 855 | retint_restore_args: /* return to kernel space */ |
72fe4858 | 856 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d IM |
857 | /* |
858 | * The iretq could re-enable interrupts: | |
859 | */ | |
860 | TRACE_IRQS_IRETQ | |
861 | restore_args: | |
3701d863 IM |
862 | RESTORE_ARGS 0,8,0 |
863 | ||
f7f3d791 | 864 | irq_return: |
72fe4858 | 865 | INTERRUPT_RETURN |
3701d863 IM |
866 | |
867 | .section __ex_table, "a" | |
868 | .quad irq_return, bad_iret | |
869 | .previous | |
870 | ||
871 | #ifdef CONFIG_PARAVIRT | |
72fe4858 | 872 | ENTRY(native_iret) |
1da177e4 LT |
873 | iretq |
874 | ||
875 | .section __ex_table,"a" | |
72fe4858 | 876 | .quad native_iret, bad_iret |
1da177e4 | 877 | .previous |
3701d863 IM |
878 | #endif |
879 | ||
1da177e4 | 880 | .section .fixup,"ax" |
1da177e4 | 881 | bad_iret: |
3aa4b37d RM |
882 | /* |
883 | * The iret traps when the %cs or %ss being restored is bogus. | |
884 | * We've lost the original trap vector and error code. | |
885 | * #GPF is the most likely one to get for an invalid selector. | |
886 | * So pretend we completed the iret and took the #GPF in user mode. | |
887 | * | |
888 | * We are now running with the kernel GS after exception recovery. | |
889 | * But error_entry expects us to have user GS to match the user %cs, | |
890 | * so swap back. | |
891 | */ | |
892 | pushq $0 | |
893 | ||
894 | SWAPGS | |
895 | jmp general_protection | |
896 | ||
72fe4858 GOC |
897 | .previous |
898 | ||
7effaa88 | 899 | /* edi: workmask, edx: work */ |
1da177e4 | 900 | retint_careful: |
7effaa88 | 901 | CFI_RESTORE_STATE |
1da177e4 LT |
902 | bt $TIF_NEED_RESCHED,%edx |
903 | jnc retint_signal | |
2601e64d | 904 | TRACE_IRQS_ON |
72fe4858 | 905 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 906 | pushq %rdi |
7effaa88 | 907 | CFI_ADJUST_CFA_OFFSET 8 |
1da177e4 | 908 | call schedule |
0bd7b798 | 909 | popq %rdi |
7effaa88 | 910 | CFI_ADJUST_CFA_OFFSET -8 |
1da177e4 | 911 | GET_THREAD_INFO(%rcx) |
72fe4858 | 912 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 913 | TRACE_IRQS_OFF |
1da177e4 | 914 | jmp retint_check |
0bd7b798 | 915 | |
1da177e4 | 916 | retint_signal: |
8f4d37ec | 917 | testl $_TIF_DO_NOTIFY_MASK,%edx |
10ffdbb8 | 918 | jz retint_swapgs |
2601e64d | 919 | TRACE_IRQS_ON |
72fe4858 | 920 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 921 | SAVE_REST |
0bd7b798 | 922 | movq $-1,ORIG_RAX(%rsp) |
3829ee6b | 923 | xorl %esi,%esi # oldset |
1da177e4 LT |
924 | movq %rsp,%rdi # &pt_regs |
925 | call do_notify_resume | |
926 | RESTORE_REST | |
72fe4858 | 927 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 928 | TRACE_IRQS_OFF |
be9e6870 | 929 | GET_THREAD_INFO(%rcx) |
eca91e78 | 930 | jmp retint_with_reschedule |
1da177e4 LT |
931 | |
932 | #ifdef CONFIG_PREEMPT | |
933 | /* Returning to kernel space. Check if we need preemption */ | |
934 | /* rcx: threadinfo. interrupts off. */ | |
b06babac | 935 | ENTRY(retint_kernel) |
26ccb8a7 | 936 | cmpl $0,TI_preempt_count(%rcx) |
1da177e4 | 937 | jnz retint_restore_args |
26ccb8a7 | 938 | bt $TIF_NEED_RESCHED,TI_flags(%rcx) |
1da177e4 LT |
939 | jnc retint_restore_args |
940 | bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */ | |
941 | jnc retint_restore_args | |
942 | call preempt_schedule_irq | |
943 | jmp exit_intr | |
0bd7b798 | 944 | #endif |
4b787e0b | 945 | |
1da177e4 | 946 | CFI_ENDPROC |
4b787e0b | 947 | END(common_interrupt) |
8222d718 MH |
948 | /* |
949 | * End of kprobes section | |
950 | */ | |
951 | .popsection | |
0bd7b798 | 952 | |
1da177e4 LT |
953 | /* |
954 | * APIC interrupts. | |
0bd7b798 | 955 | */ |
322648d1 AH |
956 | .macro apicinterrupt num sym do_sym |
957 | ENTRY(\sym) | |
7effaa88 | 958 | INTR_FRAME |
19eadf98 | 959 | pushq $~(\num) |
7effaa88 | 960 | CFI_ADJUST_CFA_OFFSET 8 |
322648d1 | 961 | interrupt \do_sym |
1da177e4 LT |
962 | jmp ret_from_intr |
963 | CFI_ENDPROC | |
322648d1 AH |
964 | END(\sym) |
965 | .endm | |
1da177e4 | 966 | |
322648d1 AH |
967 | #ifdef CONFIG_SMP |
968 | apicinterrupt IRQ_MOVE_CLEANUP_VECTOR \ | |
969 | irq_move_cleanup_interrupt smp_irq_move_cleanup_interrupt | |
4ef702c1 AK |
970 | apicinterrupt REBOOT_VECTOR \ |
971 | reboot_interrupt smp_reboot_interrupt | |
322648d1 | 972 | #endif |
1da177e4 | 973 | |
03b48632 | 974 | #ifdef CONFIG_X86_UV |
5ae3a139 | 975 | apicinterrupt UV_BAU_MESSAGE \ |
322648d1 | 976 | uv_bau_message_intr1 uv_bau_message_interrupt |
03b48632 | 977 | #endif |
322648d1 AH |
978 | apicinterrupt LOCAL_TIMER_VECTOR \ |
979 | apic_timer_interrupt smp_apic_timer_interrupt | |
4a4de9c7 DS |
980 | apicinterrupt X86_PLATFORM_IPI_VECTOR \ |
981 | x86_platform_ipi smp_x86_platform_ipi | |
89b831ef | 982 | |
0bd7b798 | 983 | #ifdef CONFIG_SMP |
322648d1 AH |
984 | apicinterrupt INVALIDATE_TLB_VECTOR_START+0 \ |
985 | invalidate_interrupt0 smp_invalidate_interrupt | |
986 | apicinterrupt INVALIDATE_TLB_VECTOR_START+1 \ | |
987 | invalidate_interrupt1 smp_invalidate_interrupt | |
988 | apicinterrupt INVALIDATE_TLB_VECTOR_START+2 \ | |
989 | invalidate_interrupt2 smp_invalidate_interrupt | |
990 | apicinterrupt INVALIDATE_TLB_VECTOR_START+3 \ | |
991 | invalidate_interrupt3 smp_invalidate_interrupt | |
992 | apicinterrupt INVALIDATE_TLB_VECTOR_START+4 \ | |
993 | invalidate_interrupt4 smp_invalidate_interrupt | |
994 | apicinterrupt INVALIDATE_TLB_VECTOR_START+5 \ | |
995 | invalidate_interrupt5 smp_invalidate_interrupt | |
996 | apicinterrupt INVALIDATE_TLB_VECTOR_START+6 \ | |
997 | invalidate_interrupt6 smp_invalidate_interrupt | |
998 | apicinterrupt INVALIDATE_TLB_VECTOR_START+7 \ | |
999 | invalidate_interrupt7 smp_invalidate_interrupt | |
1da177e4 LT |
1000 | #endif |
1001 | ||
322648d1 | 1002 | apicinterrupt THRESHOLD_APIC_VECTOR \ |
7856f6cc | 1003 | threshold_interrupt smp_threshold_interrupt |
322648d1 AH |
1004 | apicinterrupt THERMAL_APIC_VECTOR \ |
1005 | thermal_interrupt smp_thermal_interrupt | |
1812924b | 1006 | |
ccc3c319 AK |
1007 | #ifdef CONFIG_X86_MCE |
1008 | apicinterrupt MCE_SELF_VECTOR \ | |
1009 | mce_self_interrupt smp_mce_self_interrupt | |
1010 | #endif | |
1011 | ||
322648d1 AH |
1012 | #ifdef CONFIG_SMP |
1013 | apicinterrupt CALL_FUNCTION_SINGLE_VECTOR \ | |
1014 | call_function_single_interrupt smp_call_function_single_interrupt | |
1015 | apicinterrupt CALL_FUNCTION_VECTOR \ | |
1016 | call_function_interrupt smp_call_function_interrupt | |
1017 | apicinterrupt RESCHEDULE_VECTOR \ | |
1018 | reschedule_interrupt smp_reschedule_interrupt | |
1019 | #endif | |
1da177e4 | 1020 | |
322648d1 AH |
1021 | apicinterrupt ERROR_APIC_VECTOR \ |
1022 | error_interrupt smp_error_interrupt | |
1023 | apicinterrupt SPURIOUS_APIC_VECTOR \ | |
1024 | spurious_interrupt smp_spurious_interrupt | |
0bd7b798 | 1025 | |
cdd6c482 | 1026 | #ifdef CONFIG_PERF_EVENTS |
b6276f35 PZ |
1027 | apicinterrupt LOCAL_PENDING_VECTOR \ |
1028 | perf_pending_interrupt smp_perf_pending_interrupt | |
241771ef IM |
1029 | #endif |
1030 | ||
1da177e4 LT |
1031 | /* |
1032 | * Exception entry points. | |
0bd7b798 | 1033 | */ |
322648d1 AH |
1034 | .macro zeroentry sym do_sym |
1035 | ENTRY(\sym) | |
7effaa88 | 1036 | INTR_FRAME |
fab58420 | 1037 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
14ae22ba | 1038 | pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */ |
d99015b1 AH |
1039 | subq $15*8,%rsp |
1040 | CFI_ADJUST_CFA_OFFSET 15*8 | |
1041 | call error_entry | |
dcd072e2 | 1042 | DEFAULT_FRAME 0 |
d99015b1 AH |
1043 | movq %rsp,%rdi /* pt_regs pointer */ |
1044 | xorl %esi,%esi /* no error code */ | |
322648d1 | 1045 | call \do_sym |
d99015b1 | 1046 | jmp error_exit /* %ebx: no swapgs flag */ |
7effaa88 | 1047 | CFI_ENDPROC |
322648d1 AH |
1048 | END(\sym) |
1049 | .endm | |
1da177e4 | 1050 | |
322648d1 | 1051 | .macro paranoidzeroentry sym do_sym |
ddeb8f21 | 1052 | ENTRY(\sym) |
b8b1d08b AH |
1053 | INTR_FRAME |
1054 | PARAVIRT_ADJUST_EXCEPTION_FRAME | |
1055 | pushq $-1 /* ORIG_RAX: no syscall to restart */ | |
1056 | CFI_ADJUST_CFA_OFFSET 8 | |
1057 | subq $15*8, %rsp | |
1058 | call save_paranoid | |
1059 | TRACE_IRQS_OFF | |
1060 | movq %rsp,%rdi /* pt_regs pointer */ | |
1061 | xorl %esi,%esi /* no error code */ | |
322648d1 | 1062 | call \do_sym |
b8b1d08b AH |
1063 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1064 | CFI_ENDPROC | |
ddeb8f21 | 1065 | END(\sym) |
322648d1 | 1066 | .endm |
b8b1d08b | 1067 | |
c15a5958 | 1068 | #define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8) |
322648d1 | 1069 | .macro paranoidzeroentry_ist sym do_sym ist |
ddeb8f21 | 1070 | ENTRY(\sym) |
9f1e87ea | 1071 | INTR_FRAME |
b8b1d08b AH |
1072 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1073 | pushq $-1 /* ORIG_RAX: no syscall to restart */ | |
1074 | CFI_ADJUST_CFA_OFFSET 8 | |
1075 | subq $15*8, %rsp | |
1076 | call save_paranoid | |
1077 | TRACE_IRQS_OFF | |
1078 | movq %rsp,%rdi /* pt_regs pointer */ | |
1079 | xorl %esi,%esi /* no error code */ | |
c15a5958 | 1080 | subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist) |
322648d1 | 1081 | call \do_sym |
c15a5958 | 1082 | addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist) |
b8b1d08b AH |
1083 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1084 | CFI_ENDPROC | |
ddeb8f21 | 1085 | END(\sym) |
322648d1 | 1086 | .endm |
b8b1d08b | 1087 | |
ddeb8f21 | 1088 | .macro errorentry sym do_sym |
322648d1 | 1089 | ENTRY(\sym) |
7effaa88 | 1090 | XCPT_FRAME |
fab58420 | 1091 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
d99015b1 AH |
1092 | subq $15*8,%rsp |
1093 | CFI_ADJUST_CFA_OFFSET 15*8 | |
1094 | call error_entry | |
dcd072e2 | 1095 | DEFAULT_FRAME 0 |
d99015b1 AH |
1096 | movq %rsp,%rdi /* pt_regs pointer */ |
1097 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
1098 | movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */ | |
322648d1 | 1099 | call \do_sym |
d99015b1 | 1100 | jmp error_exit /* %ebx: no swapgs flag */ |
7effaa88 | 1101 | CFI_ENDPROC |
322648d1 | 1102 | END(\sym) |
322648d1 | 1103 | .endm |
1da177e4 LT |
1104 | |
1105 | /* error code is on the stack already */ | |
ddeb8f21 | 1106 | .macro paranoiderrorentry sym do_sym |
322648d1 | 1107 | ENTRY(\sym) |
b8b1d08b AH |
1108 | XCPT_FRAME |
1109 | PARAVIRT_ADJUST_EXCEPTION_FRAME | |
1110 | subq $15*8,%rsp | |
e2f6bc25 AH |
1111 | CFI_ADJUST_CFA_OFFSET 15*8 |
1112 | call save_paranoid | |
1113 | DEFAULT_FRAME 0 | |
7e61a793 | 1114 | TRACE_IRQS_OFF |
b8b1d08b AH |
1115 | movq %rsp,%rdi /* pt_regs pointer */ |
1116 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
1117 | movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */ | |
322648d1 | 1118 | call \do_sym |
b8b1d08b AH |
1119 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1120 | CFI_ENDPROC | |
322648d1 | 1121 | END(\sym) |
322648d1 AH |
1122 | .endm |
1123 | ||
1124 | zeroentry divide_error do_divide_error | |
322648d1 AH |
1125 | zeroentry overflow do_overflow |
1126 | zeroentry bounds do_bounds | |
1127 | zeroentry invalid_op do_invalid_op | |
1128 | zeroentry device_not_available do_device_not_available | |
ddeb8f21 | 1129 | paranoiderrorentry double_fault do_double_fault |
322648d1 AH |
1130 | zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun |
1131 | errorentry invalid_TSS do_invalid_TSS | |
1132 | errorentry segment_not_present do_segment_not_present | |
322648d1 AH |
1133 | zeroentry spurious_interrupt_bug do_spurious_interrupt_bug |
1134 | zeroentry coprocessor_error do_coprocessor_error | |
1135 | errorentry alignment_check do_alignment_check | |
322648d1 | 1136 | zeroentry simd_coprocessor_error do_simd_coprocessor_error |
2601e64d | 1137 | |
9f1e87ea CG |
1138 | /* Reload gs selector with exception handling */ |
1139 | /* edi: new selector */ | |
9f9d489a | 1140 | ENTRY(native_load_gs_index) |
7effaa88 | 1141 | CFI_STARTPROC |
1da177e4 | 1142 | pushf |
7effaa88 | 1143 | CFI_ADJUST_CFA_OFFSET 8 |
b8aa287f | 1144 | DISABLE_INTERRUPTS(CLBR_ANY & ~CLBR_RDI) |
9f1e87ea | 1145 | SWAPGS |
0bd7b798 | 1146 | gs_change: |
9f1e87ea | 1147 | movl %edi,%gs |
1da177e4 | 1148 | 2: mfence /* workaround */ |
72fe4858 | 1149 | SWAPGS |
9f1e87ea | 1150 | popf |
7effaa88 | 1151 | CFI_ADJUST_CFA_OFFSET -8 |
9f1e87ea | 1152 | ret |
7effaa88 | 1153 | CFI_ENDPROC |
6efdcfaf | 1154 | END(native_load_gs_index) |
0bd7b798 | 1155 | |
9f1e87ea CG |
1156 | .section __ex_table,"a" |
1157 | .align 8 | |
1158 | .quad gs_change,bad_gs | |
1159 | .previous | |
1160 | .section .fixup,"ax" | |
1da177e4 | 1161 | /* running with kernelgs */ |
0bd7b798 | 1162 | bad_gs: |
72fe4858 | 1163 | SWAPGS /* switch back to user gs */ |
1da177e4 | 1164 | xorl %eax,%eax |
9f1e87ea CG |
1165 | movl %eax,%gs |
1166 | jmp 2b | |
1167 | .previous | |
0bd7b798 | 1168 | |
3bd95dfb | 1169 | ENTRY(kernel_thread_helper) |
c05991ed AK |
1170 | pushq $0 # fake return address |
1171 | CFI_STARTPROC | |
1da177e4 LT |
1172 | /* |
1173 | * Here we are in the child and the registers are set as they were | |
1174 | * at kernel_thread() invocation in the parent. | |
1175 | */ | |
3bd95dfb | 1176 | call *%rsi |
1da177e4 | 1177 | # exit |
1c5b5cfd | 1178 | mov %eax, %edi |
1da177e4 | 1179 | call do_exit |
5f5db591 | 1180 | ud2 # padding for call trace |
c05991ed | 1181 | CFI_ENDPROC |
3bd95dfb | 1182 | END(kernel_thread_helper) |
1da177e4 LT |
1183 | |
1184 | /* | |
1185 | * execve(). This function needs to use IRET, not SYSRET, to set up all state properly. | |
1186 | * | |
1187 | * C extern interface: | |
1188 | * extern long execve(char *name, char **argv, char **envp) | |
1189 | * | |
1190 | * asm input arguments: | |
1191 | * rdi: name, rsi: argv, rdx: envp | |
1192 | * | |
1193 | * We want to fallback into: | |
5d119b2c | 1194 | * extern long sys_execve(char *name, char **argv,char **envp, struct pt_regs *regs) |
1da177e4 LT |
1195 | * |
1196 | * do_sys_execve asm fallback arguments: | |
5d119b2c | 1197 | * rdi: name, rsi: argv, rdx: envp, rcx: fake frame on the stack |
1da177e4 | 1198 | */ |
3db03b4a | 1199 | ENTRY(kernel_execve) |
1da177e4 LT |
1200 | CFI_STARTPROC |
1201 | FAKE_STACK_FRAME $0 | |
0bd7b798 | 1202 | SAVE_ALL |
5d119b2c | 1203 | movq %rsp,%rcx |
1da177e4 | 1204 | call sys_execve |
0bd7b798 | 1205 | movq %rax, RAX(%rsp) |
1da177e4 LT |
1206 | RESTORE_REST |
1207 | testq %rax,%rax | |
1208 | je int_ret_from_sys_call | |
1209 | RESTORE_ARGS | |
1210 | UNFAKE_STACK_FRAME | |
1211 | ret | |
1212 | CFI_ENDPROC | |
6efdcfaf | 1213 | END(kernel_execve) |
1da177e4 | 1214 | |
2699500b | 1215 | /* Call softirq on interrupt stack. Interrupts are off. */ |
ed6b676c | 1216 | ENTRY(call_softirq) |
7effaa88 | 1217 | CFI_STARTPROC |
2699500b AK |
1218 | push %rbp |
1219 | CFI_ADJUST_CFA_OFFSET 8 | |
1220 | CFI_REL_OFFSET rbp,0 | |
1221 | mov %rsp,%rbp | |
1222 | CFI_DEF_CFA_REGISTER rbp | |
56895530 | 1223 | incl PER_CPU_VAR(irq_count) |
26f80bd6 | 1224 | cmove PER_CPU_VAR(irq_stack_ptr),%rsp |
2699500b | 1225 | push %rbp # backlink for old unwinder |
ed6b676c | 1226 | call __do_softirq |
2699500b | 1227 | leaveq |
7effaa88 | 1228 | CFI_DEF_CFA_REGISTER rsp |
2699500b | 1229 | CFI_ADJUST_CFA_OFFSET -8 |
56895530 | 1230 | decl PER_CPU_VAR(irq_count) |
ed6b676c | 1231 | ret |
7effaa88 | 1232 | CFI_ENDPROC |
6efdcfaf | 1233 | END(call_softirq) |
75154f40 | 1234 | |
3d75e1b8 | 1235 | #ifdef CONFIG_XEN |
322648d1 | 1236 | zeroentry xen_hypervisor_callback xen_do_hypervisor_callback |
3d75e1b8 JF |
1237 | |
1238 | /* | |
9f1e87ea CG |
1239 | * A note on the "critical region" in our callback handler. |
1240 | * We want to avoid stacking callback handlers due to events occurring | |
1241 | * during handling of the last event. To do this, we keep events disabled | |
1242 | * until we've done all processing. HOWEVER, we must enable events before | |
1243 | * popping the stack frame (can't be done atomically) and so it would still | |
1244 | * be possible to get enough handler activations to overflow the stack. | |
1245 | * Although unlikely, bugs of that kind are hard to track down, so we'd | |
1246 | * like to avoid the possibility. | |
1247 | * So, on entry to the handler we detect whether we interrupted an | |
1248 | * existing activation in its critical region -- if so, we pop the current | |
1249 | * activation and restart the handler using the previous one. | |
1250 | */ | |
3d75e1b8 JF |
1251 | ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs) |
1252 | CFI_STARTPROC | |
9f1e87ea CG |
1253 | /* |
1254 | * Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will | |
1255 | * see the correct pointer to the pt_regs | |
1256 | */ | |
3d75e1b8 JF |
1257 | movq %rdi, %rsp # we don't return, adjust the stack frame |
1258 | CFI_ENDPROC | |
dcd072e2 | 1259 | DEFAULT_FRAME |
56895530 | 1260 | 11: incl PER_CPU_VAR(irq_count) |
3d75e1b8 JF |
1261 | movq %rsp,%rbp |
1262 | CFI_DEF_CFA_REGISTER rbp | |
26f80bd6 | 1263 | cmovzq PER_CPU_VAR(irq_stack_ptr),%rsp |
3d75e1b8 JF |
1264 | pushq %rbp # backlink for old unwinder |
1265 | call xen_evtchn_do_upcall | |
1266 | popq %rsp | |
1267 | CFI_DEF_CFA_REGISTER rsp | |
56895530 | 1268 | decl PER_CPU_VAR(irq_count) |
3d75e1b8 JF |
1269 | jmp error_exit |
1270 | CFI_ENDPROC | |
1271 | END(do_hypervisor_callback) | |
1272 | ||
1273 | /* | |
9f1e87ea CG |
1274 | * Hypervisor uses this for application faults while it executes. |
1275 | * We get here for two reasons: | |
1276 | * 1. Fault while reloading DS, ES, FS or GS | |
1277 | * 2. Fault while executing IRET | |
1278 | * Category 1 we do not need to fix up as Xen has already reloaded all segment | |
1279 | * registers that could be reloaded and zeroed the others. | |
1280 | * Category 2 we fix up by killing the current process. We cannot use the | |
1281 | * normal Linux return path in this case because if we use the IRET hypercall | |
1282 | * to pop the stack frame we end up in an infinite loop of failsafe callbacks. | |
1283 | * We distinguish between categories by comparing each saved segment register | |
1284 | * with its current contents: any discrepancy means we in category 1. | |
1285 | */ | |
3d75e1b8 | 1286 | ENTRY(xen_failsafe_callback) |
dcd072e2 AH |
1287 | INTR_FRAME 1 (6*8) |
1288 | /*CFI_REL_OFFSET gs,GS*/ | |
1289 | /*CFI_REL_OFFSET fs,FS*/ | |
1290 | /*CFI_REL_OFFSET es,ES*/ | |
1291 | /*CFI_REL_OFFSET ds,DS*/ | |
1292 | CFI_REL_OFFSET r11,8 | |
1293 | CFI_REL_OFFSET rcx,0 | |
3d75e1b8 JF |
1294 | movw %ds,%cx |
1295 | cmpw %cx,0x10(%rsp) | |
1296 | CFI_REMEMBER_STATE | |
1297 | jne 1f | |
1298 | movw %es,%cx | |
1299 | cmpw %cx,0x18(%rsp) | |
1300 | jne 1f | |
1301 | movw %fs,%cx | |
1302 | cmpw %cx,0x20(%rsp) | |
1303 | jne 1f | |
1304 | movw %gs,%cx | |
1305 | cmpw %cx,0x28(%rsp) | |
1306 | jne 1f | |
1307 | /* All segments match their saved values => Category 2 (Bad IRET). */ | |
1308 | movq (%rsp),%rcx | |
1309 | CFI_RESTORE rcx | |
1310 | movq 8(%rsp),%r11 | |
1311 | CFI_RESTORE r11 | |
1312 | addq $0x30,%rsp | |
1313 | CFI_ADJUST_CFA_OFFSET -0x30 | |
14ae22ba IM |
1314 | pushq_cfi $0 /* RIP */ |
1315 | pushq_cfi %r11 | |
1316 | pushq_cfi %rcx | |
4a5c3e77 | 1317 | jmp general_protection |
3d75e1b8 JF |
1318 | CFI_RESTORE_STATE |
1319 | 1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */ | |
1320 | movq (%rsp),%rcx | |
1321 | CFI_RESTORE rcx | |
1322 | movq 8(%rsp),%r11 | |
1323 | CFI_RESTORE r11 | |
1324 | addq $0x30,%rsp | |
1325 | CFI_ADJUST_CFA_OFFSET -0x30 | |
14ae22ba | 1326 | pushq_cfi $0 |
3d75e1b8 JF |
1327 | SAVE_ALL |
1328 | jmp error_exit | |
1329 | CFI_ENDPROC | |
3d75e1b8 JF |
1330 | END(xen_failsafe_callback) |
1331 | ||
38e20b07 SY |
1332 | apicinterrupt XEN_HVM_EVTCHN_CALLBACK \ |
1333 | xen_hvm_callback_vector xen_evtchn_do_upcall | |
1334 | ||
3d75e1b8 | 1335 | #endif /* CONFIG_XEN */ |
ddeb8f21 AH |
1336 | |
1337 | /* | |
1338 | * Some functions should be protected against kprobes | |
1339 | */ | |
1340 | .pushsection .kprobes.text, "ax" | |
1341 | ||
1342 | paranoidzeroentry_ist debug do_debug DEBUG_STACK | |
1343 | paranoidzeroentry_ist int3 do_int3 DEBUG_STACK | |
1344 | paranoiderrorentry stack_segment do_stack_segment | |
6cac5a92 JF |
1345 | #ifdef CONFIG_XEN |
1346 | zeroentry xen_debug do_debug | |
1347 | zeroentry xen_int3 do_int3 | |
1348 | errorentry xen_stack_segment do_stack_segment | |
1349 | #endif | |
ddeb8f21 AH |
1350 | errorentry general_protection do_general_protection |
1351 | errorentry page_fault do_page_fault | |
1352 | #ifdef CONFIG_X86_MCE | |
5d727926 | 1353 | paranoidzeroentry machine_check *machine_check_vector(%rip) |
ddeb8f21 AH |
1354 | #endif |
1355 | ||
1356 | /* | |
9f1e87ea CG |
1357 | * "Paranoid" exit path from exception stack. |
1358 | * Paranoid because this is used by NMIs and cannot take | |
ddeb8f21 AH |
1359 | * any kernel state for granted. |
1360 | * We don't do kernel preemption checks here, because only | |
1361 | * NMI should be common and it does not enable IRQs and | |
1362 | * cannot get reschedule ticks. | |
1363 | * | |
1364 | * "trace" is 0 for the NMI handler only, because irq-tracing | |
1365 | * is fundamentally NMI-unsafe. (we cannot change the soft and | |
1366 | * hard flags at once, atomically) | |
1367 | */ | |
1368 | ||
1369 | /* ebx: no swapgs flag */ | |
1370 | ENTRY(paranoid_exit) | |
1371 | INTR_FRAME | |
1372 | DISABLE_INTERRUPTS(CLBR_NONE) | |
1373 | TRACE_IRQS_OFF | |
1374 | testl %ebx,%ebx /* swapgs needed? */ | |
1375 | jnz paranoid_restore | |
1376 | testl $3,CS(%rsp) | |
1377 | jnz paranoid_userspace | |
1378 | paranoid_swapgs: | |
1379 | TRACE_IRQS_IRETQ 0 | |
1380 | SWAPGS_UNSAFE_STACK | |
0300e7f1 SR |
1381 | RESTORE_ALL 8 |
1382 | jmp irq_return | |
ddeb8f21 | 1383 | paranoid_restore: |
0300e7f1 | 1384 | TRACE_IRQS_IRETQ 0 |
ddeb8f21 AH |
1385 | RESTORE_ALL 8 |
1386 | jmp irq_return | |
1387 | paranoid_userspace: | |
1388 | GET_THREAD_INFO(%rcx) | |
1389 | movl TI_flags(%rcx),%ebx | |
1390 | andl $_TIF_WORK_MASK,%ebx | |
1391 | jz paranoid_swapgs | |
1392 | movq %rsp,%rdi /* &pt_regs */ | |
1393 | call sync_regs | |
1394 | movq %rax,%rsp /* switch stack for scheduling */ | |
1395 | testl $_TIF_NEED_RESCHED,%ebx | |
1396 | jnz paranoid_schedule | |
1397 | movl %ebx,%edx /* arg3: thread flags */ | |
1398 | TRACE_IRQS_ON | |
1399 | ENABLE_INTERRUPTS(CLBR_NONE) | |
1400 | xorl %esi,%esi /* arg2: oldset */ | |
1401 | movq %rsp,%rdi /* arg1: &pt_regs */ | |
1402 | call do_notify_resume | |
1403 | DISABLE_INTERRUPTS(CLBR_NONE) | |
1404 | TRACE_IRQS_OFF | |
1405 | jmp paranoid_userspace | |
1406 | paranoid_schedule: | |
1407 | TRACE_IRQS_ON | |
1408 | ENABLE_INTERRUPTS(CLBR_ANY) | |
1409 | call schedule | |
1410 | DISABLE_INTERRUPTS(CLBR_ANY) | |
1411 | TRACE_IRQS_OFF | |
1412 | jmp paranoid_userspace | |
1413 | CFI_ENDPROC | |
1414 | END(paranoid_exit) | |
1415 | ||
1416 | /* | |
1417 | * Exception entry point. This expects an error code/orig_rax on the stack. | |
1418 | * returns in "no swapgs flag" in %ebx. | |
1419 | */ | |
1420 | ENTRY(error_entry) | |
1421 | XCPT_FRAME | |
1422 | CFI_ADJUST_CFA_OFFSET 15*8 | |
1423 | /* oldrax contains error code */ | |
1424 | cld | |
1425 | movq_cfi rdi, RDI+8 | |
1426 | movq_cfi rsi, RSI+8 | |
1427 | movq_cfi rdx, RDX+8 | |
1428 | movq_cfi rcx, RCX+8 | |
1429 | movq_cfi rax, RAX+8 | |
1430 | movq_cfi r8, R8+8 | |
1431 | movq_cfi r9, R9+8 | |
1432 | movq_cfi r10, R10+8 | |
1433 | movq_cfi r11, R11+8 | |
1434 | movq_cfi rbx, RBX+8 | |
1435 | movq_cfi rbp, RBP+8 | |
1436 | movq_cfi r12, R12+8 | |
1437 | movq_cfi r13, R13+8 | |
1438 | movq_cfi r14, R14+8 | |
1439 | movq_cfi r15, R15+8 | |
1440 | xorl %ebx,%ebx | |
1441 | testl $3,CS+8(%rsp) | |
1442 | je error_kernelspace | |
1443 | error_swapgs: | |
1444 | SWAPGS | |
1445 | error_sti: | |
1446 | TRACE_IRQS_OFF | |
1447 | ret | |
1448 | CFI_ENDPROC | |
1449 | ||
1450 | /* | |
1451 | * There are two places in the kernel that can potentially fault with | |
1452 | * usergs. Handle them here. The exception handlers after iret run with | |
1453 | * kernel gs again, so don't set the user space flag. B stepping K8s | |
1454 | * sometimes report an truncated RIP for IRET exceptions returning to | |
1455 | * compat mode. Check for these here too. | |
1456 | */ | |
1457 | error_kernelspace: | |
1458 | incl %ebx | |
1459 | leaq irq_return(%rip),%rcx | |
1460 | cmpq %rcx,RIP+8(%rsp) | |
1461 | je error_swapgs | |
ae24ffe5 BG |
1462 | movl %ecx,%eax /* zero extend */ |
1463 | cmpq %rax,RIP+8(%rsp) | |
1464 | je bstep_iret | |
ddeb8f21 | 1465 | cmpq $gs_change,RIP+8(%rsp) |
9f1e87ea | 1466 | je error_swapgs |
ddeb8f21 | 1467 | jmp error_sti |
ae24ffe5 BG |
1468 | |
1469 | bstep_iret: | |
1470 | /* Fix truncated RIP */ | |
1471 | movq %rcx,RIP+8(%rsp) | |
97829de5 | 1472 | jmp error_swapgs |
ddeb8f21 AH |
1473 | END(error_entry) |
1474 | ||
1475 | ||
1476 | /* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */ | |
1477 | ENTRY(error_exit) | |
1478 | DEFAULT_FRAME | |
1479 | movl %ebx,%eax | |
1480 | RESTORE_REST | |
1481 | DISABLE_INTERRUPTS(CLBR_NONE) | |
1482 | TRACE_IRQS_OFF | |
1483 | GET_THREAD_INFO(%rcx) | |
1484 | testl %eax,%eax | |
1485 | jne retint_kernel | |
1486 | LOCKDEP_SYS_EXIT_IRQ | |
1487 | movl TI_flags(%rcx),%edx | |
1488 | movl $_TIF_WORK_MASK,%edi | |
1489 | andl %edi,%edx | |
1490 | jnz retint_careful | |
1491 | jmp retint_swapgs | |
1492 | CFI_ENDPROC | |
1493 | END(error_exit) | |
1494 | ||
1495 | ||
1496 | /* runs on exception stack */ | |
1497 | ENTRY(nmi) | |
1498 | INTR_FRAME | |
1499 | PARAVIRT_ADJUST_EXCEPTION_FRAME | |
1500 | pushq_cfi $-1 | |
1501 | subq $15*8, %rsp | |
1502 | CFI_ADJUST_CFA_OFFSET 15*8 | |
1503 | call save_paranoid | |
1504 | DEFAULT_FRAME 0 | |
1505 | /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */ | |
1506 | movq %rsp,%rdi | |
1507 | movq $-1,%rsi | |
1508 | call do_nmi | |
1509 | #ifdef CONFIG_TRACE_IRQFLAGS | |
1510 | /* paranoidexit; without TRACE_IRQS_OFF */ | |
1511 | /* ebx: no swapgs flag */ | |
1512 | DISABLE_INTERRUPTS(CLBR_NONE) | |
1513 | testl %ebx,%ebx /* swapgs needed? */ | |
1514 | jnz nmi_restore | |
1515 | testl $3,CS(%rsp) | |
1516 | jnz nmi_userspace | |
1517 | nmi_swapgs: | |
1518 | SWAPGS_UNSAFE_STACK | |
1519 | nmi_restore: | |
1520 | RESTORE_ALL 8 | |
1521 | jmp irq_return | |
1522 | nmi_userspace: | |
1523 | GET_THREAD_INFO(%rcx) | |
1524 | movl TI_flags(%rcx),%ebx | |
1525 | andl $_TIF_WORK_MASK,%ebx | |
1526 | jz nmi_swapgs | |
1527 | movq %rsp,%rdi /* &pt_regs */ | |
1528 | call sync_regs | |
1529 | movq %rax,%rsp /* switch stack for scheduling */ | |
1530 | testl $_TIF_NEED_RESCHED,%ebx | |
1531 | jnz nmi_schedule | |
1532 | movl %ebx,%edx /* arg3: thread flags */ | |
1533 | ENABLE_INTERRUPTS(CLBR_NONE) | |
1534 | xorl %esi,%esi /* arg2: oldset */ | |
1535 | movq %rsp,%rdi /* arg1: &pt_regs */ | |
1536 | call do_notify_resume | |
1537 | DISABLE_INTERRUPTS(CLBR_NONE) | |
1538 | jmp nmi_userspace | |
1539 | nmi_schedule: | |
1540 | ENABLE_INTERRUPTS(CLBR_ANY) | |
1541 | call schedule | |
1542 | DISABLE_INTERRUPTS(CLBR_ANY) | |
1543 | jmp nmi_userspace | |
1544 | CFI_ENDPROC | |
1545 | #else | |
1546 | jmp paranoid_exit | |
9f1e87ea | 1547 | CFI_ENDPROC |
ddeb8f21 AH |
1548 | #endif |
1549 | END(nmi) | |
1550 | ||
1551 | ENTRY(ignore_sysret) | |
1552 | CFI_STARTPROC | |
1553 | mov $-ENOSYS,%eax | |
1554 | sysret | |
1555 | CFI_ENDPROC | |
1556 | END(ignore_sysret) | |
1557 | ||
1558 | /* | |
1559 | * End of kprobes section | |
1560 | */ | |
1561 | .popsection |