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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/arch/x86_64/entry.S | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs | |
6 | * Copyright (C) 2000 Pavel Machek <pavel@suse.cz> | |
1da177e4 LT |
7 | */ |
8 | ||
9 | /* | |
10 | * entry.S contains the system-call and fault low-level handling routines. | |
11 | * | |
8b4777a4 AL |
12 | * Some of this is documented in Documentation/x86/entry_64.txt |
13 | * | |
1da177e4 LT |
14 | * NOTE: This code handles signal-recognition, which happens every time |
15 | * after an interrupt and after each system call. | |
0bd7b798 AH |
16 | * |
17 | * Normal syscalls and interrupts don't save a full stack frame, this is | |
1da177e4 | 18 | * only done for syscall tracing, signals or fork/exec et.al. |
0bd7b798 AH |
19 | * |
20 | * A note on terminology: | |
21 | * - top of stack: Architecture defined interrupt frame from SS to RIP | |
22 | * at the top of the kernel process stack. | |
0d2eb44f | 23 | * - partial stack frame: partially saved registers up to R11. |
0bd7b798 | 24 | * - full stack frame: Like partial stack frame, but all register saved. |
2e91a17b AK |
25 | * |
26 | * Some macro usage: | |
27 | * - CFI macros are used to generate dwarf2 unwind information for better | |
28 | * backtraces. They don't change any code. | |
29 | * - SAVE_ALL/RESTORE_ALL - Save/restore all registers | |
30 | * - SAVE_ARGS/RESTORE_ARGS - Save/restore registers that C functions modify. | |
31 | * There are unfortunately lots of special cases where some registers | |
32 | * not touched. The macro is a big mess that should be cleaned up. | |
33 | * - SAVE_REST/RESTORE_REST - Handle the registers not saved by SAVE_ARGS. | |
34 | * Gives a full stack frame. | |
35 | * - ENTRY/END Define functions in the symbol table. | |
36 | * - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack | |
37 | * frame that is otherwise undefined after a SYSCALL | |
38 | * - TRACE_IRQ_* - Trace hard interrupt state for lock debugging. | |
39 | * - errorentry/paranoidentry/zeroentry - Define exception entry points. | |
1da177e4 LT |
40 | */ |
41 | ||
1da177e4 LT |
42 | #include <linux/linkage.h> |
43 | #include <asm/segment.h> | |
1da177e4 LT |
44 | #include <asm/cache.h> |
45 | #include <asm/errno.h> | |
46 | #include <asm/dwarf2.h> | |
47 | #include <asm/calling.h> | |
e2d5df93 | 48 | #include <asm/asm-offsets.h> |
1da177e4 LT |
49 | #include <asm/msr.h> |
50 | #include <asm/unistd.h> | |
51 | #include <asm/thread_info.h> | |
52 | #include <asm/hw_irq.h> | |
0341c14d | 53 | #include <asm/page_types.h> |
2601e64d | 54 | #include <asm/irqflags.h> |
72fe4858 | 55 | #include <asm/paravirt.h> |
395a59d0 | 56 | #include <asm/ftrace.h> |
9939ddaf | 57 | #include <asm/percpu.h> |
d7e7528b | 58 | #include <linux/err.h> |
1da177e4 | 59 | |
86a1c34a RM |
60 | /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */ |
61 | #include <linux/elf-em.h> | |
62 | #define AUDIT_ARCH_X86_64 (EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE) | |
63 | #define __AUDIT_ARCH_64BIT 0x80000000 | |
64 | #define __AUDIT_ARCH_LE 0x40000000 | |
65 | ||
1da177e4 | 66 | .code64 |
ea714547 JO |
67 | .section .entry.text, "ax" |
68 | ||
606576ce | 69 | #ifdef CONFIG_FUNCTION_TRACER |
d61f82d0 SR |
70 | #ifdef CONFIG_DYNAMIC_FTRACE |
71 | ENTRY(mcount) | |
d61f82d0 SR |
72 | retq |
73 | END(mcount) | |
74 | ||
75 | ENTRY(ftrace_caller) | |
60a7ecf4 SR |
76 | cmpl $0, function_trace_stop |
77 | jne ftrace_stub | |
d61f82d0 | 78 | |
d680fe44 | 79 | MCOUNT_SAVE_FRAME |
d61f82d0 SR |
80 | |
81 | movq 0x38(%rsp), %rdi | |
82 | movq 8(%rbp), %rsi | |
395a59d0 | 83 | subq $MCOUNT_INSN_SIZE, %rdi |
d61f82d0 | 84 | |
bc8b2b92 | 85 | GLOBAL(ftrace_call) |
d61f82d0 SR |
86 | call ftrace_stub |
87 | ||
d680fe44 | 88 | MCOUNT_RESTORE_FRAME |
d61f82d0 | 89 | |
48d68b20 | 90 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
bc8b2b92 | 91 | GLOBAL(ftrace_graph_call) |
48d68b20 FW |
92 | jmp ftrace_stub |
93 | #endif | |
d61f82d0 | 94 | |
bc8b2b92 | 95 | GLOBAL(ftrace_stub) |
d61f82d0 SR |
96 | retq |
97 | END(ftrace_caller) | |
98 | ||
99 | #else /* ! CONFIG_DYNAMIC_FTRACE */ | |
16444a8a | 100 | ENTRY(mcount) |
60a7ecf4 SR |
101 | cmpl $0, function_trace_stop |
102 | jne ftrace_stub | |
103 | ||
16444a8a ACM |
104 | cmpq $ftrace_stub, ftrace_trace_function |
105 | jnz trace | |
48d68b20 FW |
106 | |
107 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
108 | cmpq $ftrace_stub, ftrace_graph_return | |
109 | jnz ftrace_graph_caller | |
e49dc19c SR |
110 | |
111 | cmpq $ftrace_graph_entry_stub, ftrace_graph_entry | |
112 | jnz ftrace_graph_caller | |
48d68b20 FW |
113 | #endif |
114 | ||
bc8b2b92 | 115 | GLOBAL(ftrace_stub) |
16444a8a ACM |
116 | retq |
117 | ||
118 | trace: | |
d680fe44 | 119 | MCOUNT_SAVE_FRAME |
16444a8a ACM |
120 | |
121 | movq 0x38(%rsp), %rdi | |
122 | movq 8(%rbp), %rsi | |
395a59d0 | 123 | subq $MCOUNT_INSN_SIZE, %rdi |
16444a8a ACM |
124 | |
125 | call *ftrace_trace_function | |
126 | ||
d680fe44 | 127 | MCOUNT_RESTORE_FRAME |
16444a8a ACM |
128 | |
129 | jmp ftrace_stub | |
130 | END(mcount) | |
d61f82d0 | 131 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
606576ce | 132 | #endif /* CONFIG_FUNCTION_TRACER */ |
16444a8a | 133 | |
48d68b20 FW |
134 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
135 | ENTRY(ftrace_graph_caller) | |
136 | cmpl $0, function_trace_stop | |
137 | jne ftrace_stub | |
138 | ||
d680fe44 | 139 | MCOUNT_SAVE_FRAME |
48d68b20 FW |
140 | |
141 | leaq 8(%rbp), %rdi | |
142 | movq 0x38(%rsp), %rsi | |
71e308a2 | 143 | movq (%rbp), %rdx |
bb4304c7 | 144 | subq $MCOUNT_INSN_SIZE, %rsi |
48d68b20 FW |
145 | |
146 | call prepare_ftrace_return | |
147 | ||
d680fe44 CG |
148 | MCOUNT_RESTORE_FRAME |
149 | ||
48d68b20 FW |
150 | retq |
151 | END(ftrace_graph_caller) | |
152 | ||
bc8b2b92 | 153 | GLOBAL(return_to_handler) |
4818d809 | 154 | subq $24, %rsp |
48d68b20 | 155 | |
e71e99c2 | 156 | /* Save the return values */ |
16444a8a | 157 | movq %rax, (%rsp) |
e71e99c2 | 158 | movq %rdx, 8(%rsp) |
71e308a2 | 159 | movq %rbp, %rdi |
16444a8a | 160 | |
48d68b20 | 161 | call ftrace_return_to_handler |
16444a8a | 162 | |
194ec341 | 163 | movq %rax, %rdi |
e71e99c2 | 164 | movq 8(%rsp), %rdx |
16444a8a | 165 | movq (%rsp), %rax |
194ec341 SR |
166 | addq $24, %rsp |
167 | jmp *%rdi | |
48d68b20 | 168 | #endif |
16444a8a | 169 | |
16444a8a | 170 | |
dc37db4d | 171 | #ifndef CONFIG_PREEMPT |
1da177e4 | 172 | #define retint_kernel retint_restore_args |
0bd7b798 | 173 | #endif |
2601e64d | 174 | |
72fe4858 | 175 | #ifdef CONFIG_PARAVIRT |
2be29982 | 176 | ENTRY(native_usergs_sysret64) |
72fe4858 GOC |
177 | swapgs |
178 | sysretq | |
b3baaa13 | 179 | ENDPROC(native_usergs_sysret64) |
72fe4858 GOC |
180 | #endif /* CONFIG_PARAVIRT */ |
181 | ||
2601e64d IM |
182 | |
183 | .macro TRACE_IRQS_IRETQ offset=ARGOFFSET | |
184 | #ifdef CONFIG_TRACE_IRQFLAGS | |
185 | bt $9,EFLAGS-\offset(%rsp) /* interrupts off? */ | |
186 | jnc 1f | |
187 | TRACE_IRQS_ON | |
188 | 1: | |
189 | #endif | |
190 | .endm | |
191 | ||
1da177e4 | 192 | /* |
0bd7b798 AH |
193 | * C code is not supposed to know about undefined top of stack. Every time |
194 | * a C function with an pt_regs argument is called from the SYSCALL based | |
1da177e4 LT |
195 | * fast path FIXUP_TOP_OF_STACK is needed. |
196 | * RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs | |
197 | * manipulation. | |
0bd7b798 AH |
198 | */ |
199 | ||
200 | /* %rsp:at FRAMEEND */ | |
c002a1e6 | 201 | .macro FIXUP_TOP_OF_STACK tmp offset=0 |
3d1e42a7 | 202 | movq PER_CPU_VAR(old_rsp),\tmp |
c002a1e6 AH |
203 | movq \tmp,RSP+\offset(%rsp) |
204 | movq $__USER_DS,SS+\offset(%rsp) | |
205 | movq $__USER_CS,CS+\offset(%rsp) | |
206 | movq $-1,RCX+\offset(%rsp) | |
207 | movq R11+\offset(%rsp),\tmp /* get eflags */ | |
208 | movq \tmp,EFLAGS+\offset(%rsp) | |
1da177e4 LT |
209 | .endm |
210 | ||
c002a1e6 AH |
211 | .macro RESTORE_TOP_OF_STACK tmp offset=0 |
212 | movq RSP+\offset(%rsp),\tmp | |
3d1e42a7 | 213 | movq \tmp,PER_CPU_VAR(old_rsp) |
c002a1e6 AH |
214 | movq EFLAGS+\offset(%rsp),\tmp |
215 | movq \tmp,R11+\offset(%rsp) | |
1da177e4 LT |
216 | .endm |
217 | ||
218 | .macro FAKE_STACK_FRAME child_rip | |
219 | /* push in order ss, rsp, eflags, cs, rip */ | |
3829ee6b | 220 | xorl %eax, %eax |
df5d1874 | 221 | pushq_cfi $__KERNEL_DS /* ss */ |
7effaa88 | 222 | /*CFI_REL_OFFSET ss,0*/ |
df5d1874 | 223 | pushq_cfi %rax /* rsp */ |
7effaa88 | 224 | CFI_REL_OFFSET rsp,0 |
1cf8343f | 225 | pushq_cfi $(X86_EFLAGS_IF|X86_EFLAGS_BIT1) /* eflags - interrupts on */ |
7effaa88 | 226 | /*CFI_REL_OFFSET rflags,0*/ |
df5d1874 | 227 | pushq_cfi $__KERNEL_CS /* cs */ |
7effaa88 | 228 | /*CFI_REL_OFFSET cs,0*/ |
df5d1874 | 229 | pushq_cfi \child_rip /* rip */ |
7effaa88 | 230 | CFI_REL_OFFSET rip,0 |
df5d1874 | 231 | pushq_cfi %rax /* orig rax */ |
1da177e4 LT |
232 | .endm |
233 | ||
234 | .macro UNFAKE_STACK_FRAME | |
235 | addq $8*6, %rsp | |
236 | CFI_ADJUST_CFA_OFFSET -(6*8) | |
237 | .endm | |
238 | ||
dcd072e2 AH |
239 | /* |
240 | * initial frame state for interrupts (and exceptions without error code) | |
241 | */ | |
242 | .macro EMPTY_FRAME start=1 offset=0 | |
7effaa88 | 243 | .if \start |
dcd072e2 | 244 | CFI_STARTPROC simple |
adf14236 | 245 | CFI_SIGNAL_FRAME |
dcd072e2 | 246 | CFI_DEF_CFA rsp,8+\offset |
7effaa88 | 247 | .else |
dcd072e2 | 248 | CFI_DEF_CFA_OFFSET 8+\offset |
7effaa88 | 249 | .endif |
1da177e4 | 250 | .endm |
d99015b1 AH |
251 | |
252 | /* | |
dcd072e2 | 253 | * initial frame state for interrupts (and exceptions without error code) |
d99015b1 | 254 | */ |
dcd072e2 | 255 | .macro INTR_FRAME start=1 offset=0 |
e8a0e276 IM |
256 | EMPTY_FRAME \start, SS+8+\offset-RIP |
257 | /*CFI_REL_OFFSET ss, SS+\offset-RIP*/ | |
258 | CFI_REL_OFFSET rsp, RSP+\offset-RIP | |
259 | /*CFI_REL_OFFSET rflags, EFLAGS+\offset-RIP*/ | |
260 | /*CFI_REL_OFFSET cs, CS+\offset-RIP*/ | |
261 | CFI_REL_OFFSET rip, RIP+\offset-RIP | |
d99015b1 AH |
262 | .endm |
263 | ||
d99015b1 AH |
264 | /* |
265 | * initial frame state for exceptions with error code (and interrupts | |
266 | * with vector already pushed) | |
267 | */ | |
dcd072e2 | 268 | .macro XCPT_FRAME start=1 offset=0 |
e8a0e276 | 269 | INTR_FRAME \start, RIP+\offset-ORIG_RAX |
dcd072e2 AH |
270 | /*CFI_REL_OFFSET orig_rax, ORIG_RAX-ORIG_RAX*/ |
271 | .endm | |
272 | ||
273 | /* | |
274 | * frame that enables calling into C. | |
275 | */ | |
276 | .macro PARTIAL_FRAME start=1 offset=0 | |
e8a0e276 IM |
277 | XCPT_FRAME \start, ORIG_RAX+\offset-ARGOFFSET |
278 | CFI_REL_OFFSET rdi, RDI+\offset-ARGOFFSET | |
279 | CFI_REL_OFFSET rsi, RSI+\offset-ARGOFFSET | |
280 | CFI_REL_OFFSET rdx, RDX+\offset-ARGOFFSET | |
281 | CFI_REL_OFFSET rcx, RCX+\offset-ARGOFFSET | |
282 | CFI_REL_OFFSET rax, RAX+\offset-ARGOFFSET | |
283 | CFI_REL_OFFSET r8, R8+\offset-ARGOFFSET | |
284 | CFI_REL_OFFSET r9, R9+\offset-ARGOFFSET | |
285 | CFI_REL_OFFSET r10, R10+\offset-ARGOFFSET | |
286 | CFI_REL_OFFSET r11, R11+\offset-ARGOFFSET | |
dcd072e2 AH |
287 | .endm |
288 | ||
289 | /* | |
290 | * frame that enables passing a complete pt_regs to a C function. | |
291 | */ | |
292 | .macro DEFAULT_FRAME start=1 offset=0 | |
e8a0e276 | 293 | PARTIAL_FRAME \start, R11+\offset-R15 |
dcd072e2 AH |
294 | CFI_REL_OFFSET rbx, RBX+\offset |
295 | CFI_REL_OFFSET rbp, RBP+\offset | |
296 | CFI_REL_OFFSET r12, R12+\offset | |
297 | CFI_REL_OFFSET r13, R13+\offset | |
298 | CFI_REL_OFFSET r14, R14+\offset | |
299 | CFI_REL_OFFSET r15, R15+\offset | |
300 | .endm | |
d99015b1 AH |
301 | |
302 | /* save partial stack frame */ | |
1871853f | 303 | .macro SAVE_ARGS_IRQ |
d99015b1 | 304 | cld |
1871853f FW |
305 | /* start from rbp in pt_regs and jump over */ |
306 | movq_cfi rdi, RDI-RBP | |
307 | movq_cfi rsi, RSI-RBP | |
308 | movq_cfi rdx, RDX-RBP | |
309 | movq_cfi rcx, RCX-RBP | |
310 | movq_cfi rax, RAX-RBP | |
311 | movq_cfi r8, R8-RBP | |
312 | movq_cfi r9, R9-RBP | |
313 | movq_cfi r10, R10-RBP | |
314 | movq_cfi r11, R11-RBP | |
315 | ||
a2bbe750 FW |
316 | /* Save rbp so that we can unwind from get_irq_regs() */ |
317 | movq_cfi rbp, 0 | |
318 | ||
319 | /* Save previous stack value */ | |
320 | movq %rsp, %rsi | |
3b99a3ef FW |
321 | |
322 | leaq -RBP(%rsp),%rdi /* arg1 for handler */ | |
d99015b1 AH |
323 | testl $3, CS(%rdi) |
324 | je 1f | |
325 | SWAPGS | |
326 | /* | |
56895530 | 327 | * irq_count is used to check if a CPU is already on an interrupt stack |
d99015b1 AH |
328 | * or not. While this is essentially redundant with preempt_count it is |
329 | * a little cheaper to use a separate counter in the PDA (short of | |
330 | * moving irq_enter into assembly, which would be too much work) | |
331 | */ | |
56895530 | 332 | 1: incl PER_CPU_VAR(irq_count) |
d99015b1 | 333 | jne 2f |
26f80bd6 | 334 | mov PER_CPU_VAR(irq_stack_ptr),%rsp |
eab9e613 | 335 | CFI_DEF_CFA_REGISTER rsi |
a2bbe750 FW |
336 | |
337 | 2: /* Store previous stack value */ | |
338 | pushq %rsi | |
eab9e613 JB |
339 | CFI_ESCAPE 0x0f /* DW_CFA_def_cfa_expression */, 6, \ |
340 | 0x77 /* DW_OP_breg7 */, 0, \ | |
341 | 0x06 /* DW_OP_deref */, \ | |
342 | 0x08 /* DW_OP_const1u */, SS+8-RBP, \ | |
343 | 0x22 /* DW_OP_plus */ | |
a2bbe750 FW |
344 | /* We entered an interrupt context - irqs are off: */ |
345 | TRACE_IRQS_OFF | |
1871853f | 346 | .endm |
d99015b1 | 347 | |
c002a1e6 AH |
348 | ENTRY(save_rest) |
349 | PARTIAL_FRAME 1 REST_SKIP+8 | |
350 | movq 5*8+16(%rsp), %r11 /* save return address */ | |
351 | movq_cfi rbx, RBX+16 | |
352 | movq_cfi rbp, RBP+16 | |
353 | movq_cfi r12, R12+16 | |
354 | movq_cfi r13, R13+16 | |
355 | movq_cfi r14, R14+16 | |
356 | movq_cfi r15, R15+16 | |
357 | movq %r11, 8(%rsp) /* return address */ | |
358 | FIXUP_TOP_OF_STACK %r11, 16 | |
359 | ret | |
360 | CFI_ENDPROC | |
361 | END(save_rest) | |
362 | ||
e2f6bc25 | 363 | /* save complete stack frame */ |
c2810188 | 364 | .pushsection .kprobes.text, "ax" |
e2f6bc25 AH |
365 | ENTRY(save_paranoid) |
366 | XCPT_FRAME 1 RDI+8 | |
367 | cld | |
368 | movq_cfi rdi, RDI+8 | |
369 | movq_cfi rsi, RSI+8 | |
370 | movq_cfi rdx, RDX+8 | |
371 | movq_cfi rcx, RCX+8 | |
372 | movq_cfi rax, RAX+8 | |
373 | movq_cfi r8, R8+8 | |
374 | movq_cfi r9, R9+8 | |
375 | movq_cfi r10, R10+8 | |
376 | movq_cfi r11, R11+8 | |
377 | movq_cfi rbx, RBX+8 | |
378 | movq_cfi rbp, RBP+8 | |
379 | movq_cfi r12, R12+8 | |
380 | movq_cfi r13, R13+8 | |
381 | movq_cfi r14, R14+8 | |
382 | movq_cfi r15, R15+8 | |
383 | movl $1,%ebx | |
384 | movl $MSR_GS_BASE,%ecx | |
385 | rdmsr | |
386 | testl %edx,%edx | |
387 | js 1f /* negative -> in kernel */ | |
388 | SWAPGS | |
389 | xorl %ebx,%ebx | |
390 | 1: ret | |
391 | CFI_ENDPROC | |
392 | END(save_paranoid) | |
c2810188 | 393 | .popsection |
e2f6bc25 | 394 | |
1da177e4 | 395 | /* |
5b3eec0c IM |
396 | * A newly forked process directly context switches into this address. |
397 | * | |
398 | * rdi: prev task we switched from | |
0bd7b798 | 399 | */ |
1da177e4 | 400 | ENTRY(ret_from_fork) |
dcd072e2 | 401 | DEFAULT_FRAME |
5b3eec0c | 402 | |
7106a5ab BL |
403 | LOCK ; btr $TIF_FORK,TI_flags(%r8) |
404 | ||
df5d1874 JB |
405 | pushq_cfi kernel_eflags(%rip) |
406 | popfq_cfi # reset kernel eflags | |
5b3eec0c IM |
407 | |
408 | call schedule_tail # rdi: 'prev' task parameter | |
409 | ||
1da177e4 | 410 | GET_THREAD_INFO(%rcx) |
5b3eec0c | 411 | |
1da177e4 | 412 | RESTORE_REST |
5b3eec0c IM |
413 | |
414 | testl $3, CS-ARGOFFSET(%rsp) # from kernel_thread? | |
70ea6855 | 415 | jz retint_restore_args |
5b3eec0c IM |
416 | |
417 | testl $_TIF_IA32, TI_flags(%rcx) # 32-bit compat task needs IRET | |
1da177e4 | 418 | jnz int_ret_from_sys_call |
5b3eec0c | 419 | |
c002a1e6 | 420 | RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET |
5b3eec0c IM |
421 | jmp ret_from_sys_call # go to the SYSRET fastpath |
422 | ||
1da177e4 | 423 | CFI_ENDPROC |
4b787e0b | 424 | END(ret_from_fork) |
1da177e4 LT |
425 | |
426 | /* | |
0d2eb44f | 427 | * System call entry. Up to 6 arguments in registers are supported. |
1da177e4 LT |
428 | * |
429 | * SYSCALL does not save anything on the stack and does not change the | |
430 | * stack pointer. | |
431 | */ | |
0bd7b798 | 432 | |
1da177e4 | 433 | /* |
0bd7b798 | 434 | * Register setup: |
1da177e4 LT |
435 | * rax system call number |
436 | * rdi arg0 | |
0bd7b798 | 437 | * rcx return address for syscall/sysret, C arg3 |
1da177e4 | 438 | * rsi arg1 |
0bd7b798 | 439 | * rdx arg2 |
1da177e4 LT |
440 | * r10 arg3 (--> moved to rcx for C) |
441 | * r8 arg4 | |
442 | * r9 arg5 | |
443 | * r11 eflags for syscall/sysret, temporary for C | |
0bd7b798 AH |
444 | * r12-r15,rbp,rbx saved by C code, not touched. |
445 | * | |
1da177e4 LT |
446 | * Interrupts are off on entry. |
447 | * Only called from user space. | |
448 | * | |
449 | * XXX if we had a free scratch register we could save the RSP into the stack frame | |
450 | * and report it properly in ps. Unfortunately we haven't. | |
7bf36bbc AK |
451 | * |
452 | * When user can change the frames always force IRET. That is because | |
453 | * it deals with uncanonical addresses better. SYSRET has trouble | |
454 | * with them due to bugs in both AMD and Intel CPUs. | |
0bd7b798 | 455 | */ |
1da177e4 LT |
456 | |
457 | ENTRY(system_call) | |
7effaa88 | 458 | CFI_STARTPROC simple |
adf14236 | 459 | CFI_SIGNAL_FRAME |
9af45651 | 460 | CFI_DEF_CFA rsp,KERNEL_STACK_OFFSET |
7effaa88 JB |
461 | CFI_REGISTER rip,rcx |
462 | /*CFI_REGISTER rflags,r11*/ | |
72fe4858 GOC |
463 | SWAPGS_UNSAFE_STACK |
464 | /* | |
465 | * A hypervisor implementation might want to use a label | |
466 | * after the swapgs, so that it can do the swapgs | |
467 | * for the guest and jump here on syscall. | |
468 | */ | |
f6b2bc84 | 469 | GLOBAL(system_call_after_swapgs) |
72fe4858 | 470 | |
3d1e42a7 | 471 | movq %rsp,PER_CPU_VAR(old_rsp) |
9af45651 | 472 | movq PER_CPU_VAR(kernel_stack),%rsp |
2601e64d IM |
473 | /* |
474 | * No need to follow this irqs off/on section - it's straight | |
475 | * and short: | |
476 | */ | |
72fe4858 | 477 | ENABLE_INTERRUPTS(CLBR_NONE) |
cac0e0a7 | 478 | SAVE_ARGS 8,0 |
0bd7b798 | 479 | movq %rax,ORIG_RAX-ARGOFFSET(%rsp) |
7effaa88 JB |
480 | movq %rcx,RIP-ARGOFFSET(%rsp) |
481 | CFI_REL_OFFSET rip,RIP-ARGOFFSET | |
46db09d3 | 482 | testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) |
1da177e4 | 483 | jnz tracesys |
86a1c34a | 484 | system_call_fastpath: |
1da177e4 LT |
485 | cmpq $__NR_syscall_max,%rax |
486 | ja badsys | |
487 | movq %r10,%rcx | |
488 | call *sys_call_table(,%rax,8) # XXX: rip relative | |
489 | movq %rax,RAX-ARGOFFSET(%rsp) | |
490 | /* | |
491 | * Syscall return path ending with SYSRET (fast path) | |
0bd7b798 AH |
492 | * Has incomplete stack frame and undefined top of stack. |
493 | */ | |
1da177e4 | 494 | ret_from_sys_call: |
11b854b2 | 495 | movl $_TIF_ALLWORK_MASK,%edi |
1da177e4 | 496 | /* edi: flagmask */ |
0bd7b798 | 497 | sysret_check: |
10cd706d | 498 | LOCKDEP_SYS_EXIT |
72fe4858 | 499 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 500 | TRACE_IRQS_OFF |
46db09d3 | 501 | movl TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET),%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 |
838feb47 | 511 | RESTORE_ARGS 1,-ARG_SKIP,0 |
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. | |
b05d8447 | 552 | * We just call __audit_syscall_entry() directly, and then |
86a1c34a RM |
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 */ | |
b05d8447 | 562 | call __audit_syscall_entry |
86a1c34a RM |
563 | LOAD_ARGS 0 /* reload call-clobbered registers */ |
564 | jmp system_call_fastpath | |
565 | ||
566 | /* | |
d7e7528b | 567 | * Return fast path for syscall audit. Call __audit_syscall_exit() |
86a1c34a RM |
568 | * directly and then jump back to the fast path with TIF_SYSCALL_AUDIT |
569 | * masked off. | |
570 | */ | |
571 | sysret_audit: | |
03275591 | 572 | movq RAX-ARGOFFSET(%rsp),%rsi /* second arg, syscall return value */ |
d7e7528b EP |
573 | cmpq $-MAX_ERRNO,%rsi /* is it < -MAX_ERRNO? */ |
574 | setbe %al /* 1 if so, 0 if not */ | |
86a1c34a | 575 | movzbl %al,%edi /* zero-extend that into %edi */ |
d7e7528b | 576 | call __audit_syscall_exit |
86a1c34a RM |
577 | movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi |
578 | jmp sysret_check | |
579 | #endif /* CONFIG_AUDITSYSCALL */ | |
580 | ||
1da177e4 | 581 | /* Do syscall tracing */ |
0bd7b798 | 582 | tracesys: |
86a1c34a | 583 | #ifdef CONFIG_AUDITSYSCALL |
46db09d3 | 584 | testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) |
86a1c34a RM |
585 | jz auditsys |
586 | #endif | |
1da177e4 | 587 | SAVE_REST |
a31f8dd7 | 588 | movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */ |
1da177e4 LT |
589 | FIXUP_TOP_OF_STACK %rdi |
590 | movq %rsp,%rdi | |
591 | call syscall_trace_enter | |
d4d67150 RM |
592 | /* |
593 | * Reload arg registers from stack in case ptrace changed them. | |
594 | * We don't reload %rax because syscall_trace_enter() returned | |
595 | * the value it wants us to use in the table lookup. | |
596 | */ | |
597 | LOAD_ARGS ARGOFFSET, 1 | |
1da177e4 LT |
598 | RESTORE_REST |
599 | cmpq $__NR_syscall_max,%rax | |
a31f8dd7 | 600 | ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */ |
1da177e4 LT |
601 | movq %r10,%rcx /* fixup for C */ |
602 | call *sys_call_table(,%rax,8) | |
a31f8dd7 | 603 | movq %rax,RAX-ARGOFFSET(%rsp) |
7bf36bbc | 604 | /* Use IRET because user could have changed frame */ |
0bd7b798 AH |
605 | |
606 | /* | |
1da177e4 LT |
607 | * Syscall return path ending with IRET. |
608 | * Has correct top of stack, but partial stack frame. | |
bcddc015 | 609 | */ |
bc8b2b92 | 610 | GLOBAL(int_ret_from_sys_call) |
72fe4858 | 611 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 612 | TRACE_IRQS_OFF |
1da177e4 LT |
613 | movl $_TIF_ALLWORK_MASK,%edi |
614 | /* edi: mask to check */ | |
bc8b2b92 | 615 | GLOBAL(int_with_check) |
10cd706d | 616 | LOCKDEP_SYS_EXIT_IRQ |
1da177e4 | 617 | GET_THREAD_INFO(%rcx) |
26ccb8a7 | 618 | movl TI_flags(%rcx),%edx |
1da177e4 LT |
619 | andl %edi,%edx |
620 | jnz int_careful | |
26ccb8a7 | 621 | andl $~TS_COMPAT,TI_status(%rcx) |
1da177e4 LT |
622 | jmp retint_swapgs |
623 | ||
624 | /* Either reschedule or signal or syscall exit tracking needed. */ | |
625 | /* First do a reschedule test. */ | |
626 | /* edx: work, edi: workmask */ | |
627 | int_careful: | |
628 | bt $TIF_NEED_RESCHED,%edx | |
629 | jnc int_very_careful | |
2601e64d | 630 | TRACE_IRQS_ON |
72fe4858 | 631 | ENABLE_INTERRUPTS(CLBR_NONE) |
df5d1874 | 632 | pushq_cfi %rdi |
1da177e4 | 633 | call schedule |
df5d1874 | 634 | popq_cfi %rdi |
72fe4858 | 635 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 636 | TRACE_IRQS_OFF |
1da177e4 LT |
637 | jmp int_with_check |
638 | ||
639 | /* handle signals and tracing -- both require a full stack frame */ | |
640 | int_very_careful: | |
2601e64d | 641 | TRACE_IRQS_ON |
72fe4858 | 642 | ENABLE_INTERRUPTS(CLBR_NONE) |
b60e714d | 643 | int_check_syscall_exit_work: |
1da177e4 | 644 | SAVE_REST |
0bd7b798 | 645 | /* Check for syscall exit trace */ |
d4d67150 | 646 | testl $_TIF_WORK_SYSCALL_EXIT,%edx |
1da177e4 | 647 | jz int_signal |
df5d1874 | 648 | pushq_cfi %rdi |
0bd7b798 | 649 | leaq 8(%rsp),%rdi # &ptregs -> arg1 |
1da177e4 | 650 | call syscall_trace_leave |
df5d1874 | 651 | popq_cfi %rdi |
d4d67150 | 652 | andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU),%edi |
1da177e4 | 653 | jmp int_restore_rest |
0bd7b798 | 654 | |
1da177e4 | 655 | int_signal: |
8f4d37ec | 656 | testl $_TIF_DO_NOTIFY_MASK,%edx |
1da177e4 LT |
657 | jz 1f |
658 | movq %rsp,%rdi # &ptregs -> arg1 | |
659 | xorl %esi,%esi # oldset -> arg2 | |
660 | call do_notify_resume | |
eca91e78 | 661 | 1: movl $_TIF_WORK_MASK,%edi |
1da177e4 LT |
662 | int_restore_rest: |
663 | RESTORE_REST | |
72fe4858 | 664 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 665 | TRACE_IRQS_OFF |
1da177e4 LT |
666 | jmp int_with_check |
667 | CFI_ENDPROC | |
bcddc015 | 668 | END(system_call) |
0bd7b798 AH |
669 | |
670 | /* | |
1da177e4 | 671 | * Certain special system calls that need to save a complete full stack frame. |
0bd7b798 | 672 | */ |
1da177e4 | 673 | .macro PTREGSCALL label,func,arg |
c002a1e6 AH |
674 | ENTRY(\label) |
675 | PARTIAL_FRAME 1 8 /* offset 8: return address */ | |
676 | subq $REST_SKIP, %rsp | |
677 | CFI_ADJUST_CFA_OFFSET REST_SKIP | |
678 | call save_rest | |
679 | DEFAULT_FRAME 0 8 /* offset 8: return address */ | |
680 | leaq 8(%rsp), \arg /* pt_regs pointer */ | |
681 | call \func | |
682 | jmp ptregscall_common | |
683 | CFI_ENDPROC | |
4b787e0b | 684 | END(\label) |
1da177e4 LT |
685 | .endm |
686 | ||
687 | PTREGSCALL stub_clone, sys_clone, %r8 | |
688 | PTREGSCALL stub_fork, sys_fork, %rdi | |
689 | PTREGSCALL stub_vfork, sys_vfork, %rdi | |
1da177e4 LT |
690 | PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx |
691 | PTREGSCALL stub_iopl, sys_iopl, %rsi | |
692 | ||
693 | ENTRY(ptregscall_common) | |
c002a1e6 AH |
694 | DEFAULT_FRAME 1 8 /* offset 8: return address */ |
695 | RESTORE_TOP_OF_STACK %r11, 8 | |
696 | movq_cfi_restore R15+8, r15 | |
697 | movq_cfi_restore R14+8, r14 | |
698 | movq_cfi_restore R13+8, r13 | |
699 | movq_cfi_restore R12+8, r12 | |
700 | movq_cfi_restore RBP+8, rbp | |
701 | movq_cfi_restore RBX+8, rbx | |
702 | ret $REST_SKIP /* pop extended registers */ | |
1da177e4 | 703 | CFI_ENDPROC |
4b787e0b | 704 | END(ptregscall_common) |
0bd7b798 | 705 | |
1da177e4 LT |
706 | ENTRY(stub_execve) |
707 | CFI_STARTPROC | |
e6b04b6b JB |
708 | addq $8, %rsp |
709 | PARTIAL_FRAME 0 | |
1da177e4 | 710 | SAVE_REST |
1da177e4 | 711 | FIXUP_TOP_OF_STACK %r11 |
5d119b2c | 712 | movq %rsp, %rcx |
1da177e4 | 713 | call sys_execve |
1da177e4 | 714 | RESTORE_TOP_OF_STACK %r11 |
1da177e4 LT |
715 | movq %rax,RAX(%rsp) |
716 | RESTORE_REST | |
717 | jmp int_ret_from_sys_call | |
718 | CFI_ENDPROC | |
4b787e0b | 719 | END(stub_execve) |
0bd7b798 | 720 | |
1da177e4 LT |
721 | /* |
722 | * sigreturn is special because it needs to restore all registers on return. | |
723 | * This cannot be done with SYSRET, so use the IRET return path instead. | |
0bd7b798 | 724 | */ |
1da177e4 LT |
725 | ENTRY(stub_rt_sigreturn) |
726 | CFI_STARTPROC | |
7effaa88 | 727 | addq $8, %rsp |
e6b04b6b | 728 | PARTIAL_FRAME 0 |
1da177e4 LT |
729 | SAVE_REST |
730 | movq %rsp,%rdi | |
731 | FIXUP_TOP_OF_STACK %r11 | |
732 | call sys_rt_sigreturn | |
733 | movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer | |
734 | RESTORE_REST | |
735 | jmp int_ret_from_sys_call | |
736 | CFI_ENDPROC | |
4b787e0b | 737 | END(stub_rt_sigreturn) |
1da177e4 | 738 | |
939b7871 PA |
739 | /* |
740 | * Build the entry stubs and pointer table with some assembler magic. | |
741 | * We pack 7 stubs into a single 32-byte chunk, which will fit in a | |
742 | * single cache line on all modern x86 implementations. | |
743 | */ | |
744 | .section .init.rodata,"a" | |
745 | ENTRY(interrupt) | |
ea714547 | 746 | .section .entry.text |
939b7871 PA |
747 | .p2align 5 |
748 | .p2align CONFIG_X86_L1_CACHE_SHIFT | |
749 | ENTRY(irq_entries_start) | |
750 | INTR_FRAME | |
751 | vector=FIRST_EXTERNAL_VECTOR | |
752 | .rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7 | |
753 | .balign 32 | |
754 | .rept 7 | |
755 | .if vector < NR_VECTORS | |
8665596e | 756 | .if vector <> FIRST_EXTERNAL_VECTOR |
939b7871 PA |
757 | CFI_ADJUST_CFA_OFFSET -8 |
758 | .endif | |
df5d1874 | 759 | 1: pushq_cfi $(~vector+0x80) /* Note: always in signed byte range */ |
8665596e | 760 | .if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6 |
939b7871 PA |
761 | jmp 2f |
762 | .endif | |
763 | .previous | |
764 | .quad 1b | |
ea714547 | 765 | .section .entry.text |
939b7871 PA |
766 | vector=vector+1 |
767 | .endif | |
768 | .endr | |
769 | 2: jmp common_interrupt | |
770 | .endr | |
771 | CFI_ENDPROC | |
772 | END(irq_entries_start) | |
773 | ||
774 | .previous | |
775 | END(interrupt) | |
776 | .previous | |
777 | ||
d99015b1 | 778 | /* |
1da177e4 LT |
779 | * Interrupt entry/exit. |
780 | * | |
781 | * Interrupt entry points save only callee clobbered registers in fast path. | |
d99015b1 AH |
782 | * |
783 | * Entry runs with interrupts off. | |
784 | */ | |
1da177e4 | 785 | |
722024db | 786 | /* 0(%rsp): ~(interrupt number) */ |
1da177e4 | 787 | .macro interrupt func |
625dbc3b FW |
788 | /* reserve pt_regs for scratch regs and rbp */ |
789 | subq $ORIG_RAX-RBP, %rsp | |
790 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-RBP | |
1871853f | 791 | SAVE_ARGS_IRQ |
1da177e4 LT |
792 | call \func |
793 | .endm | |
794 | ||
8222d718 MH |
795 | /* |
796 | * Interrupt entry/exit should be protected against kprobes | |
797 | */ | |
798 | .pushsection .kprobes.text, "ax" | |
722024db AH |
799 | /* |
800 | * The interrupt stubs push (~vector+0x80) onto the stack and | |
801 | * then jump to common_interrupt. | |
802 | */ | |
939b7871 PA |
803 | .p2align CONFIG_X86_L1_CACHE_SHIFT |
804 | common_interrupt: | |
7effaa88 | 805 | XCPT_FRAME |
722024db | 806 | addq $-0x80,(%rsp) /* Adjust vector to [-256,-1] range */ |
1da177e4 | 807 | interrupt do_IRQ |
3d1e42a7 | 808 | /* 0(%rsp): old_rsp-ARGOFFSET */ |
7effaa88 | 809 | ret_from_intr: |
72fe4858 | 810 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 811 | TRACE_IRQS_OFF |
56895530 | 812 | decl PER_CPU_VAR(irq_count) |
625dbc3b | 813 | |
a2bbe750 FW |
814 | /* Restore saved previous stack */ |
815 | popq %rsi | |
eab9e613 JB |
816 | CFI_DEF_CFA_REGISTER rsi |
817 | leaq ARGOFFSET-RBP(%rsi), %rsp | |
7effaa88 | 818 | CFI_DEF_CFA_REGISTER rsp |
eab9e613 | 819 | CFI_ADJUST_CFA_OFFSET RBP-ARGOFFSET |
625dbc3b | 820 | |
7effaa88 | 821 | exit_intr: |
1da177e4 LT |
822 | GET_THREAD_INFO(%rcx) |
823 | testl $3,CS-ARGOFFSET(%rsp) | |
824 | je retint_kernel | |
0bd7b798 | 825 | |
1da177e4 LT |
826 | /* Interrupt came from user space */ |
827 | /* | |
828 | * Has a correct top of stack, but a partial stack frame | |
829 | * %rcx: thread info. Interrupts off. | |
0bd7b798 | 830 | */ |
1da177e4 LT |
831 | retint_with_reschedule: |
832 | movl $_TIF_WORK_MASK,%edi | |
7effaa88 | 833 | retint_check: |
10cd706d | 834 | LOCKDEP_SYS_EXIT_IRQ |
26ccb8a7 | 835 | movl TI_flags(%rcx),%edx |
1da177e4 | 836 | andl %edi,%edx |
7effaa88 | 837 | CFI_REMEMBER_STATE |
1da177e4 | 838 | jnz retint_careful |
10cd706d PZ |
839 | |
840 | retint_swapgs: /* return to user-space */ | |
2601e64d IM |
841 | /* |
842 | * The iretq could re-enable interrupts: | |
843 | */ | |
72fe4858 | 844 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d | 845 | TRACE_IRQS_IRETQ |
72fe4858 | 846 | SWAPGS |
2601e64d IM |
847 | jmp restore_args |
848 | ||
10cd706d | 849 | retint_restore_args: /* return to kernel space */ |
72fe4858 | 850 | DISABLE_INTERRUPTS(CLBR_ANY) |
2601e64d IM |
851 | /* |
852 | * The iretq could re-enable interrupts: | |
853 | */ | |
854 | TRACE_IRQS_IRETQ | |
855 | restore_args: | |
838feb47 | 856 | RESTORE_ARGS 1,8,1 |
3701d863 | 857 | |
f7f3d791 | 858 | irq_return: |
72fe4858 | 859 | INTERRUPT_RETURN |
3701d863 IM |
860 | |
861 | .section __ex_table, "a" | |
862 | .quad irq_return, bad_iret | |
863 | .previous | |
864 | ||
865 | #ifdef CONFIG_PARAVIRT | |
72fe4858 | 866 | ENTRY(native_iret) |
1da177e4 LT |
867 | iretq |
868 | ||
869 | .section __ex_table,"a" | |
72fe4858 | 870 | .quad native_iret, bad_iret |
1da177e4 | 871 | .previous |
3701d863 IM |
872 | #endif |
873 | ||
1da177e4 | 874 | .section .fixup,"ax" |
1da177e4 | 875 | bad_iret: |
3aa4b37d RM |
876 | /* |
877 | * The iret traps when the %cs or %ss being restored is bogus. | |
878 | * We've lost the original trap vector and error code. | |
879 | * #GPF is the most likely one to get for an invalid selector. | |
880 | * So pretend we completed the iret and took the #GPF in user mode. | |
881 | * | |
882 | * We are now running with the kernel GS after exception recovery. | |
883 | * But error_entry expects us to have user GS to match the user %cs, | |
884 | * so swap back. | |
885 | */ | |
886 | pushq $0 | |
887 | ||
888 | SWAPGS | |
889 | jmp general_protection | |
890 | ||
72fe4858 GOC |
891 | .previous |
892 | ||
7effaa88 | 893 | /* edi: workmask, edx: work */ |
1da177e4 | 894 | retint_careful: |
7effaa88 | 895 | CFI_RESTORE_STATE |
1da177e4 LT |
896 | bt $TIF_NEED_RESCHED,%edx |
897 | jnc retint_signal | |
2601e64d | 898 | TRACE_IRQS_ON |
72fe4858 | 899 | ENABLE_INTERRUPTS(CLBR_NONE) |
df5d1874 | 900 | pushq_cfi %rdi |
1da177e4 | 901 | call schedule |
df5d1874 | 902 | popq_cfi %rdi |
1da177e4 | 903 | GET_THREAD_INFO(%rcx) |
72fe4858 | 904 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 905 | TRACE_IRQS_OFF |
1da177e4 | 906 | jmp retint_check |
0bd7b798 | 907 | |
1da177e4 | 908 | retint_signal: |
8f4d37ec | 909 | testl $_TIF_DO_NOTIFY_MASK,%edx |
10ffdbb8 | 910 | jz retint_swapgs |
2601e64d | 911 | TRACE_IRQS_ON |
72fe4858 | 912 | ENABLE_INTERRUPTS(CLBR_NONE) |
1da177e4 | 913 | SAVE_REST |
0bd7b798 | 914 | movq $-1,ORIG_RAX(%rsp) |
3829ee6b | 915 | xorl %esi,%esi # oldset |
1da177e4 LT |
916 | movq %rsp,%rdi # &pt_regs |
917 | call do_notify_resume | |
918 | RESTORE_REST | |
72fe4858 | 919 | DISABLE_INTERRUPTS(CLBR_NONE) |
2601e64d | 920 | TRACE_IRQS_OFF |
be9e6870 | 921 | GET_THREAD_INFO(%rcx) |
eca91e78 | 922 | jmp retint_with_reschedule |
1da177e4 LT |
923 | |
924 | #ifdef CONFIG_PREEMPT | |
925 | /* Returning to kernel space. Check if we need preemption */ | |
926 | /* rcx: threadinfo. interrupts off. */ | |
b06babac | 927 | ENTRY(retint_kernel) |
26ccb8a7 | 928 | cmpl $0,TI_preempt_count(%rcx) |
1da177e4 | 929 | jnz retint_restore_args |
26ccb8a7 | 930 | bt $TIF_NEED_RESCHED,TI_flags(%rcx) |
1da177e4 LT |
931 | jnc retint_restore_args |
932 | bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */ | |
933 | jnc retint_restore_args | |
934 | call preempt_schedule_irq | |
935 | jmp exit_intr | |
0bd7b798 | 936 | #endif |
4b787e0b | 937 | |
1da177e4 | 938 | CFI_ENDPROC |
4b787e0b | 939 | END(common_interrupt) |
8222d718 MH |
940 | /* |
941 | * End of kprobes section | |
942 | */ | |
943 | .popsection | |
0bd7b798 | 944 | |
1da177e4 LT |
945 | /* |
946 | * APIC interrupts. | |
0bd7b798 | 947 | */ |
322648d1 AH |
948 | .macro apicinterrupt num sym do_sym |
949 | ENTRY(\sym) | |
7effaa88 | 950 | INTR_FRAME |
df5d1874 | 951 | pushq_cfi $~(\num) |
39e95433 | 952 | .Lcommon_\sym: |
322648d1 | 953 | interrupt \do_sym |
1da177e4 LT |
954 | jmp ret_from_intr |
955 | CFI_ENDPROC | |
322648d1 AH |
956 | END(\sym) |
957 | .endm | |
1da177e4 | 958 | |
322648d1 AH |
959 | #ifdef CONFIG_SMP |
960 | apicinterrupt IRQ_MOVE_CLEANUP_VECTOR \ | |
961 | irq_move_cleanup_interrupt smp_irq_move_cleanup_interrupt | |
4ef702c1 AK |
962 | apicinterrupt REBOOT_VECTOR \ |
963 | reboot_interrupt smp_reboot_interrupt | |
322648d1 | 964 | #endif |
1da177e4 | 965 | |
03b48632 | 966 | #ifdef CONFIG_X86_UV |
5ae3a139 | 967 | apicinterrupt UV_BAU_MESSAGE \ |
322648d1 | 968 | uv_bau_message_intr1 uv_bau_message_interrupt |
03b48632 | 969 | #endif |
322648d1 AH |
970 | apicinterrupt LOCAL_TIMER_VECTOR \ |
971 | apic_timer_interrupt smp_apic_timer_interrupt | |
4a4de9c7 DS |
972 | apicinterrupt X86_PLATFORM_IPI_VECTOR \ |
973 | x86_platform_ipi smp_x86_platform_ipi | |
89b831ef | 974 | |
0bd7b798 | 975 | #ifdef CONFIG_SMP |
39e95433 JB |
976 | ALIGN |
977 | INTR_FRAME | |
978 | .irp idx,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15, \ | |
3a09fb45 SL |
979 | 16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 |
980 | .if NUM_INVALIDATE_TLB_VECTORS > \idx | |
39e95433 JB |
981 | ENTRY(invalidate_interrupt\idx) |
982 | pushq_cfi $~(INVALIDATE_TLB_VECTOR_START+\idx) | |
983 | jmp .Lcommon_invalidate_interrupt0 | |
984 | CFI_ADJUST_CFA_OFFSET -8 | |
985 | END(invalidate_interrupt\idx) | |
3a09fb45 | 986 | .endif |
3234282f | 987 | .endr |
39e95433 JB |
988 | CFI_ENDPROC |
989 | apicinterrupt INVALIDATE_TLB_VECTOR_START, \ | |
990 | invalidate_interrupt0, smp_invalidate_interrupt | |
1da177e4 LT |
991 | #endif |
992 | ||
322648d1 | 993 | apicinterrupt THRESHOLD_APIC_VECTOR \ |
7856f6cc | 994 | threshold_interrupt smp_threshold_interrupt |
322648d1 AH |
995 | apicinterrupt THERMAL_APIC_VECTOR \ |
996 | thermal_interrupt smp_thermal_interrupt | |
1812924b | 997 | |
322648d1 AH |
998 | #ifdef CONFIG_SMP |
999 | apicinterrupt CALL_FUNCTION_SINGLE_VECTOR \ | |
1000 | call_function_single_interrupt smp_call_function_single_interrupt | |
1001 | apicinterrupt CALL_FUNCTION_VECTOR \ | |
1002 | call_function_interrupt smp_call_function_interrupt | |
1003 | apicinterrupt RESCHEDULE_VECTOR \ | |
1004 | reschedule_interrupt smp_reschedule_interrupt | |
1005 | #endif | |
1da177e4 | 1006 | |
322648d1 AH |
1007 | apicinterrupt ERROR_APIC_VECTOR \ |
1008 | error_interrupt smp_error_interrupt | |
1009 | apicinterrupt SPURIOUS_APIC_VECTOR \ | |
1010 | spurious_interrupt smp_spurious_interrupt | |
0bd7b798 | 1011 | |
e360adbe PZ |
1012 | #ifdef CONFIG_IRQ_WORK |
1013 | apicinterrupt IRQ_WORK_VECTOR \ | |
1014 | irq_work_interrupt smp_irq_work_interrupt | |
241771ef IM |
1015 | #endif |
1016 | ||
1da177e4 LT |
1017 | /* |
1018 | * Exception entry points. | |
0bd7b798 | 1019 | */ |
322648d1 AH |
1020 | .macro zeroentry sym do_sym |
1021 | ENTRY(\sym) | |
7effaa88 | 1022 | INTR_FRAME |
fab58420 | 1023 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
14ae22ba | 1024 | pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */ |
b1cccb1b JB |
1025 | subq $ORIG_RAX-R15, %rsp |
1026 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
d99015b1 | 1027 | call error_entry |
dcd072e2 | 1028 | DEFAULT_FRAME 0 |
d99015b1 AH |
1029 | movq %rsp,%rdi /* pt_regs pointer */ |
1030 | xorl %esi,%esi /* no error code */ | |
322648d1 | 1031 | call \do_sym |
d99015b1 | 1032 | jmp error_exit /* %ebx: no swapgs flag */ |
7effaa88 | 1033 | CFI_ENDPROC |
322648d1 AH |
1034 | END(\sym) |
1035 | .endm | |
1da177e4 | 1036 | |
322648d1 | 1037 | .macro paranoidzeroentry sym do_sym |
ddeb8f21 | 1038 | ENTRY(\sym) |
b8b1d08b AH |
1039 | INTR_FRAME |
1040 | PARAVIRT_ADJUST_EXCEPTION_FRAME | |
b1cccb1b JB |
1041 | pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */ |
1042 | subq $ORIG_RAX-R15, %rsp | |
1043 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
b8b1d08b AH |
1044 | call save_paranoid |
1045 | TRACE_IRQS_OFF | |
1046 | movq %rsp,%rdi /* pt_regs pointer */ | |
1047 | xorl %esi,%esi /* no error code */ | |
322648d1 | 1048 | call \do_sym |
b8b1d08b AH |
1049 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1050 | CFI_ENDPROC | |
ddeb8f21 | 1051 | END(\sym) |
322648d1 | 1052 | .endm |
b8b1d08b | 1053 | |
c15a5958 | 1054 | #define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8) |
322648d1 | 1055 | .macro paranoidzeroentry_ist sym do_sym ist |
ddeb8f21 | 1056 | ENTRY(\sym) |
9f1e87ea | 1057 | INTR_FRAME |
b8b1d08b | 1058 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
b1cccb1b JB |
1059 | pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */ |
1060 | subq $ORIG_RAX-R15, %rsp | |
1061 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
b8b1d08b AH |
1062 | call save_paranoid |
1063 | TRACE_IRQS_OFF | |
1064 | movq %rsp,%rdi /* pt_regs pointer */ | |
1065 | xorl %esi,%esi /* no error code */ | |
c15a5958 | 1066 | subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist) |
322648d1 | 1067 | call \do_sym |
c15a5958 | 1068 | addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist) |
b8b1d08b AH |
1069 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1070 | CFI_ENDPROC | |
ddeb8f21 | 1071 | END(\sym) |
322648d1 | 1072 | .endm |
b8b1d08b | 1073 | |
ddeb8f21 | 1074 | .macro errorentry sym do_sym |
322648d1 | 1075 | ENTRY(\sym) |
7effaa88 | 1076 | XCPT_FRAME |
fab58420 | 1077 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
b1cccb1b JB |
1078 | subq $ORIG_RAX-R15, %rsp |
1079 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
d99015b1 | 1080 | call error_entry |
dcd072e2 | 1081 | DEFAULT_FRAME 0 |
d99015b1 AH |
1082 | movq %rsp,%rdi /* pt_regs pointer */ |
1083 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
1084 | movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */ | |
322648d1 | 1085 | call \do_sym |
d99015b1 | 1086 | jmp error_exit /* %ebx: no swapgs flag */ |
7effaa88 | 1087 | CFI_ENDPROC |
322648d1 | 1088 | END(\sym) |
322648d1 | 1089 | .endm |
1da177e4 LT |
1090 | |
1091 | /* error code is on the stack already */ | |
ddeb8f21 | 1092 | .macro paranoiderrorentry sym do_sym |
322648d1 | 1093 | ENTRY(\sym) |
b8b1d08b AH |
1094 | XCPT_FRAME |
1095 | PARAVIRT_ADJUST_EXCEPTION_FRAME | |
b1cccb1b JB |
1096 | subq $ORIG_RAX-R15, %rsp |
1097 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
e2f6bc25 AH |
1098 | call save_paranoid |
1099 | DEFAULT_FRAME 0 | |
7e61a793 | 1100 | TRACE_IRQS_OFF |
b8b1d08b AH |
1101 | movq %rsp,%rdi /* pt_regs pointer */ |
1102 | movq ORIG_RAX(%rsp),%rsi /* get error code */ | |
1103 | movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */ | |
322648d1 | 1104 | call \do_sym |
b8b1d08b AH |
1105 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1106 | CFI_ENDPROC | |
322648d1 | 1107 | END(\sym) |
322648d1 AH |
1108 | .endm |
1109 | ||
1110 | zeroentry divide_error do_divide_error | |
322648d1 AH |
1111 | zeroentry overflow do_overflow |
1112 | zeroentry bounds do_bounds | |
1113 | zeroentry invalid_op do_invalid_op | |
1114 | zeroentry device_not_available do_device_not_available | |
ddeb8f21 | 1115 | paranoiderrorentry double_fault do_double_fault |
322648d1 AH |
1116 | zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun |
1117 | errorentry invalid_TSS do_invalid_TSS | |
1118 | errorentry segment_not_present do_segment_not_present | |
322648d1 AH |
1119 | zeroentry spurious_interrupt_bug do_spurious_interrupt_bug |
1120 | zeroentry coprocessor_error do_coprocessor_error | |
1121 | errorentry alignment_check do_alignment_check | |
322648d1 | 1122 | zeroentry simd_coprocessor_error do_simd_coprocessor_error |
5cec93c2 | 1123 | |
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 | ||
3f3c8b8c SR |
1483 | /* |
1484 | * Test if a given stack is an NMI stack or not. | |
1485 | */ | |
1486 | .macro test_in_nmi reg stack nmi_ret normal_ret | |
1487 | cmpq %\reg, \stack | |
1488 | ja \normal_ret | |
1489 | subq $EXCEPTION_STKSZ, %\reg | |
1490 | cmpq %\reg, \stack | |
1491 | jb \normal_ret | |
1492 | jmp \nmi_ret | |
1493 | .endm | |
ddeb8f21 AH |
1494 | |
1495 | /* runs on exception stack */ | |
1496 | ENTRY(nmi) | |
1497 | INTR_FRAME | |
1498 | PARAVIRT_ADJUST_EXCEPTION_FRAME | |
3f3c8b8c SR |
1499 | /* |
1500 | * We allow breakpoints in NMIs. If a breakpoint occurs, then | |
1501 | * the iretq it performs will take us out of NMI context. | |
1502 | * This means that we can have nested NMIs where the next | |
1503 | * NMI is using the top of the stack of the previous NMI. We | |
1504 | * can't let it execute because the nested NMI will corrupt the | |
1505 | * stack of the previous NMI. NMI handlers are not re-entrant | |
1506 | * anyway. | |
1507 | * | |
1508 | * To handle this case we do the following: | |
1509 | * Check the a special location on the stack that contains | |
1510 | * a variable that is set when NMIs are executing. | |
1511 | * The interrupted task's stack is also checked to see if it | |
1512 | * is an NMI stack. | |
1513 | * If the variable is not set and the stack is not the NMI | |
1514 | * stack then: | |
1515 | * o Set the special variable on the stack | |
1516 | * o Copy the interrupt frame into a "saved" location on the stack | |
1517 | * o Copy the interrupt frame into a "copy" location on the stack | |
1518 | * o Continue processing the NMI | |
1519 | * If the variable is set or the previous stack is the NMI stack: | |
1520 | * o Modify the "copy" location to jump to the repeate_nmi | |
1521 | * o return back to the first NMI | |
1522 | * | |
1523 | * Now on exit of the first NMI, we first clear the stack variable | |
1524 | * The NMI stack will tell any nested NMIs at that point that it is | |
1525 | * nested. Then we pop the stack normally with iret, and if there was | |
1526 | * a nested NMI that updated the copy interrupt stack frame, a | |
1527 | * jump will be made to the repeat_nmi code that will handle the second | |
1528 | * NMI. | |
1529 | */ | |
1530 | ||
1531 | /* Use %rdx as out temp variable throughout */ | |
1532 | pushq_cfi %rdx | |
62610913 | 1533 | CFI_REL_OFFSET rdx, 0 |
3f3c8b8c | 1534 | |
45d5a168 SR |
1535 | /* |
1536 | * If %cs was not the kernel segment, then the NMI triggered in user | |
1537 | * space, which means it is definitely not nested. | |
1538 | */ | |
a38449ef | 1539 | cmpl $__KERNEL_CS, 16(%rsp) |
45d5a168 SR |
1540 | jne first_nmi |
1541 | ||
3f3c8b8c SR |
1542 | /* |
1543 | * Check the special variable on the stack to see if NMIs are | |
1544 | * executing. | |
1545 | */ | |
a38449ef | 1546 | cmpl $1, -8(%rsp) |
3f3c8b8c SR |
1547 | je nested_nmi |
1548 | ||
1549 | /* | |
1550 | * Now test if the previous stack was an NMI stack. | |
1551 | * We need the double check. We check the NMI stack to satisfy the | |
1552 | * race when the first NMI clears the variable before returning. | |
1553 | * We check the variable because the first NMI could be in a | |
1554 | * breakpoint routine using a breakpoint stack. | |
1555 | */ | |
1556 | lea 6*8(%rsp), %rdx | |
1557 | test_in_nmi rdx, 4*8(%rsp), nested_nmi, first_nmi | |
62610913 | 1558 | CFI_REMEMBER_STATE |
3f3c8b8c SR |
1559 | |
1560 | nested_nmi: | |
1561 | /* | |
1562 | * Do nothing if we interrupted the fixup in repeat_nmi. | |
1563 | * It's about to repeat the NMI handler, so we are fine | |
1564 | * with ignoring this one. | |
1565 | */ | |
1566 | movq $repeat_nmi, %rdx | |
1567 | cmpq 8(%rsp), %rdx | |
1568 | ja 1f | |
1569 | movq $end_repeat_nmi, %rdx | |
1570 | cmpq 8(%rsp), %rdx | |
1571 | ja nested_nmi_out | |
1572 | ||
1573 | 1: | |
1574 | /* Set up the interrupted NMIs stack to jump to repeat_nmi */ | |
1575 | leaq -6*8(%rsp), %rdx | |
1576 | movq %rdx, %rsp | |
1577 | CFI_ADJUST_CFA_OFFSET 6*8 | |
1578 | pushq_cfi $__KERNEL_DS | |
1579 | pushq_cfi %rdx | |
1580 | pushfq_cfi | |
1581 | pushq_cfi $__KERNEL_CS | |
1582 | pushq_cfi $repeat_nmi | |
1583 | ||
1584 | /* Put stack back */ | |
1585 | addq $(11*8), %rsp | |
1586 | CFI_ADJUST_CFA_OFFSET -11*8 | |
1587 | ||
1588 | nested_nmi_out: | |
1589 | popq_cfi %rdx | |
62610913 | 1590 | CFI_RESTORE rdx |
3f3c8b8c SR |
1591 | |
1592 | /* No need to check faults here */ | |
1593 | INTERRUPT_RETURN | |
1594 | ||
62610913 | 1595 | CFI_RESTORE_STATE |
3f3c8b8c SR |
1596 | first_nmi: |
1597 | /* | |
1598 | * Because nested NMIs will use the pushed location that we | |
1599 | * stored in rdx, we must keep that space available. | |
1600 | * Here's what our stack frame will look like: | |
1601 | * +-------------------------+ | |
1602 | * | original SS | | |
1603 | * | original Return RSP | | |
1604 | * | original RFLAGS | | |
1605 | * | original CS | | |
1606 | * | original RIP | | |
1607 | * +-------------------------+ | |
1608 | * | temp storage for rdx | | |
1609 | * +-------------------------+ | |
1610 | * | NMI executing variable | | |
1611 | * +-------------------------+ | |
1612 | * | Saved SS | | |
1613 | * | Saved Return RSP | | |
1614 | * | Saved RFLAGS | | |
1615 | * | Saved CS | | |
1616 | * | Saved RIP | | |
1617 | * +-------------------------+ | |
1618 | * | copied SS | | |
1619 | * | copied Return RSP | | |
1620 | * | copied RFLAGS | | |
1621 | * | copied CS | | |
1622 | * | copied RIP | | |
1623 | * +-------------------------+ | |
1624 | * | pt_regs | | |
1625 | * +-------------------------+ | |
1626 | * | |
1627 | * The saved RIP is used to fix up the copied RIP that a nested | |
1628 | * NMI may zero out. The original stack frame and the temp storage | |
1629 | * is also used by nested NMIs and can not be trusted on exit. | |
1630 | */ | |
62610913 JB |
1631 | /* Do not pop rdx, nested NMIs will corrupt it */ |
1632 | movq (%rsp), %rdx | |
1633 | CFI_RESTORE rdx | |
1634 | ||
3f3c8b8c SR |
1635 | /* Set the NMI executing variable on the stack. */ |
1636 | pushq_cfi $1 | |
1637 | ||
1638 | /* Copy the stack frame to the Saved frame */ | |
1639 | .rept 5 | |
1640 | pushq_cfi 6*8(%rsp) | |
1641 | .endr | |
62610913 JB |
1642 | CFI_DEF_CFA_OFFSET SS+8-RIP |
1643 | ||
1644 | /* | |
1645 | * If there was a nested NMI, the first NMI's iret will return | |
1646 | * here. But NMIs are still enabled and we can take another | |
1647 | * nested NMI. The nested NMI checks the interrupted RIP to see | |
1648 | * if it is between repeat_nmi and end_repeat_nmi, and if so | |
1649 | * it will just return, as we are about to repeat an NMI anyway. | |
1650 | * This makes it safe to copy to the stack frame that a nested | |
1651 | * NMI will update. | |
1652 | */ | |
1653 | repeat_nmi: | |
1654 | /* | |
1655 | * Update the stack variable to say we are still in NMI (the update | |
1656 | * is benign for the non-repeat case, where 1 was pushed just above | |
1657 | * to this very stack slot). | |
1658 | */ | |
1659 | movq $1, 5*8(%rsp) | |
3f3c8b8c SR |
1660 | |
1661 | /* Make another copy, this one may be modified by nested NMIs */ | |
1662 | .rept 5 | |
1663 | pushq_cfi 4*8(%rsp) | |
1664 | .endr | |
62610913 JB |
1665 | CFI_DEF_CFA_OFFSET SS+8-RIP |
1666 | end_repeat_nmi: | |
3f3c8b8c SR |
1667 | |
1668 | /* | |
1669 | * Everything below this point can be preempted by a nested | |
1670 | * NMI if the first NMI took an exception. Repeated NMIs | |
1671 | * caused by an exception and nested NMI will start here, and | |
1672 | * can still be preempted by another NMI. | |
1673 | */ | |
1fd466ef | 1674 | pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */ |
b1cccb1b JB |
1675 | subq $ORIG_RAX-R15, %rsp |
1676 | CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 | |
1fd466ef SR |
1677 | /* |
1678 | * Use save_paranoid to handle SWAPGS, but no need to use paranoid_exit | |
1679 | * as we should not be calling schedule in NMI context. | |
1680 | * Even with normal interrupts enabled. An NMI should not be | |
1681 | * setting NEED_RESCHED or anything that normal interrupts and | |
1682 | * exceptions might do. | |
1683 | */ | |
ddeb8f21 AH |
1684 | call save_paranoid |
1685 | DEFAULT_FRAME 0 | |
1686 | /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */ | |
1687 | movq %rsp,%rdi | |
1688 | movq $-1,%rsi | |
1689 | call do_nmi | |
ddeb8f21 AH |
1690 | testl %ebx,%ebx /* swapgs needed? */ |
1691 | jnz nmi_restore | |
ddeb8f21 AH |
1692 | nmi_swapgs: |
1693 | SWAPGS_UNSAFE_STACK | |
1694 | nmi_restore: | |
1695 | RESTORE_ALL 8 | |
3f3c8b8c SR |
1696 | /* Clear the NMI executing stack variable */ |
1697 | movq $0, 10*8(%rsp) | |
ddeb8f21 | 1698 | jmp irq_return |
9f1e87ea | 1699 | CFI_ENDPROC |
ddeb8f21 AH |
1700 | END(nmi) |
1701 | ||
1702 | ENTRY(ignore_sysret) | |
1703 | CFI_STARTPROC | |
1704 | mov $-ENOSYS,%eax | |
1705 | sysret | |
1706 | CFI_ENDPROC | |
1707 | END(ignore_sysret) | |
1708 | ||
1709 | /* | |
1710 | * End of kprobes section | |
1711 | */ | |
1712 | .popsection |