Merge tag 'v4.1-next-soc' of https://github.com/mbgg/linux-mediatek into fixes
[deliverable/linux.git] / arch / x86 / ia32 / ia32entry.S
CommitLineData
1da177e4
LT
1/*
2 * Compatibility mode system call entry point for x86-64.
3 *
4 * Copyright 2000-2002 Andi Kleen, SuSE Labs.
5 */
6
7#include <asm/dwarf2.h>
8#include <asm/calling.h>
e2d5df93 9#include <asm/asm-offsets.h>
1da177e4
LT
10#include <asm/current.h>
11#include <asm/errno.h>
12#include <asm/ia32_unistd.h>
13#include <asm/thread_info.h>
14#include <asm/segment.h>
2601e64d 15#include <asm/irqflags.h>
1ce6f868 16#include <asm/asm.h>
63bcff2a 17#include <asm/smap.h>
1da177e4 18#include <linux/linkage.h>
d7e7528b 19#include <linux/err.h>
1da177e4 20
5cbf1565
RM
21/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
22#include <linux/elf-em.h>
23#define AUDIT_ARCH_I386 (EM_386|__AUDIT_ARCH_LE)
24#define __AUDIT_ARCH_LE 0x40000000
25
26#ifndef CONFIG_AUDITSYSCALL
24e35800
JB
27#define sysexit_audit ia32_ret_from_sys_call
28#define sysretl_audit ia32_ret_from_sys_call
5cbf1565
RM
29#endif
30
ea714547
JO
31 .section .entry.text, "ax"
32
f2db9382
DV
33 /* clobbers %rax */
34 .macro CLEAR_RREGS _r9=rax
1da177e4 35 xorl %eax,%eax
f2db9382
DV
36 movq %rax,R11(%rsp)
37 movq %rax,R10(%rsp)
38 movq %\_r9,R9(%rsp)
39 movq %rax,R8(%rsp)
1da177e4
LT
40 .endm
41
d4d67150
RM
42 /*
43 * Reload arg registers from stack in case ptrace changed them.
44 * We don't reload %eax because syscall_trace_enter() returned
eefdca04
RM
45 * the %rax value we should see. Instead, we just truncate that
46 * value to 32 bits again as we did on entry from user mode.
47 * If it's a new value set by user_regset during entry tracing,
48 * this matches the normal truncation of the user-mode value.
49 * If it's -1 to make us punt the syscall, then (u32)-1 is still
50 * an appropriately invalid value.
d4d67150 51 */
f2db9382 52 .macro LOAD_ARGS32 _r9=0
295286a8 53 .if \_r9
f2db9382 54 movl R9(%rsp),%r9d
295286a8 55 .endif
f2db9382
DV
56 movl RCX(%rsp),%ecx
57 movl RDX(%rsp),%edx
58 movl RSI(%rsp),%esi
59 movl RDI(%rsp),%edi
eefdca04 60 movl %eax,%eax /* zero extension */
176df245
AK
61 .endm
62
2765130b
JB
63 .macro CFI_STARTPROC32 simple
64 CFI_STARTPROC \simple
65 CFI_UNDEFINED r8
66 CFI_UNDEFINED r9
67 CFI_UNDEFINED r10
68 CFI_UNDEFINED r11
69 CFI_UNDEFINED r12
70 CFI_UNDEFINED r13
71 CFI_UNDEFINED r14
72 CFI_UNDEFINED r15
73 .endm
74
2be29982
JF
75#ifdef CONFIG_PARAVIRT
76ENTRY(native_usergs_sysret32)
77 swapgs
78 sysretl
79ENDPROC(native_usergs_sysret32)
80
81ENTRY(native_irq_enable_sysexit)
82 swapgs
83 sti
84 sysexit
85ENDPROC(native_irq_enable_sysexit)
86#endif
87
1da177e4
LT
88/*
89 * 32bit SYSENTER instruction entry.
90 *
b87cf63e
DV
91 * SYSENTER loads ss, rsp, cs, and rip from previously programmed MSRs.
92 * IF and VM in rflags are cleared (IOW: interrupts are off).
93 * SYSENTER does not save anything on the stack,
94 * and does not save old rip (!!!) and rflags.
95 *
1da177e4 96 * Arguments:
b87cf63e
DV
97 * eax system call number
98 * ebx arg1
99 * ecx arg2
100 * edx arg3
101 * esi arg4
102 * edi arg5
103 * ebp user stack
104 * 0(%ebp) arg6
105 *
1da177e4 106 * This is purely a fast path. For anything complicated we use the int 0x80
b87cf63e 107 * path below. We set up a complete hardware stack frame to share code
1da177e4 108 * with the int 0x80 path.
b87cf63e 109 */
1da177e4 110ENTRY(ia32_sysenter_target)
2765130b 111 CFI_STARTPROC32 simple
adf14236 112 CFI_SIGNAL_FRAME
7effaa88
JB
113 CFI_DEF_CFA rsp,0
114 CFI_REGISTER rsp,rbp
a232e3d5 115
2601e64d 116 /*
a232e3d5
DV
117 * Interrupts are off on entry.
118 * We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON,
119 * it is too small to ever cause noticeable irq latency.
2601e64d 120 */
a232e3d5
DV
121 SWAPGS_UNSAFE_STACK
122 movq PER_CPU_VAR(cpu_tss + TSS_sp0), %rsp
66804154 123 ENABLE_INTERRUPTS(CLBR_NONE)
a232e3d5 124
4ee8ec17
DV
125 /* Zero-extending 32-bit regs, do not remove */
126 movl %ebp, %ebp
127 movl %eax, %eax
128
4c9c0e91 129 movl ASM_THREAD_INFO(TI_sysenter_return, %rsp, 0), %r10d
7effaa88 130 CFI_REGISTER rip,r10
4c9c0e91
DV
131
132 /* Construct struct pt_regs on stack */
133 pushq_cfi $__USER32_DS /* pt_regs->ss */
134 pushq_cfi %rbp /* pt_regs->sp */
135 CFI_REL_OFFSET rsp,0
136 pushfq_cfi /* pt_regs->flags */
137 pushq_cfi $__USER32_CS /* pt_regs->cs */
138 pushq_cfi %r10 /* pt_regs->ip = thread_info->sysenter_return */
139 CFI_REL_OFFSET rip,0
140 pushq_cfi_reg rax /* pt_regs->orig_ax */
141 pushq_cfi_reg rdi /* pt_regs->di */
142 pushq_cfi_reg rsi /* pt_regs->si */
143 pushq_cfi_reg rdx /* pt_regs->dx */
144 pushq_cfi_reg rcx /* pt_regs->cx */
145 pushq_cfi_reg rax /* pt_regs->ax */
1da177e4 146 cld
4c9c0e91
DV
147 sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */
148 CFI_ADJUST_CFA_OFFSET 10*8
149
b87cf63e
DV
150 /*
151 * no need to do an access_ok check here because rbp has been
152 * 32bit zero extended
153 */
63bcff2a 154 ASM_STAC
295286a8 1551: movl (%rbp),%ebp
1ce6f868 156 _ASM_EXTABLE(1b,ia32_badarg)
63bcff2a 157 ASM_CLAC
8c7aa698
AL
158
159 /*
160 * Sysenter doesn't filter flags, so we need to clear NT
161 * ourselves. To save a few cycles, we can check whether
162 * NT was set instead of doing an unconditional popfq.
163 */
f2db9382 164 testl $X86_EFLAGS_NT,EFLAGS(%rsp)
8c7aa698
AL
165 jnz sysenter_fix_flags
166sysenter_flags_fixed:
167
dca5b52a
IM
168 orl $TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS)
169 testl $_TIF_WORK_SYSCALL_ENTRY, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
7effaa88 170 CFI_REMEMBER_STATE
1da177e4 171 jnz sysenter_tracesys
36d001c7 172 cmpq $(IA32_NR_syscalls-1),%rax
67d53ea5 173 ja ia32_badsys
d4d67150 174sysenter_do_call:
14f6e953
DV
175 /* 32bit syscall -> 64bit C ABI argument conversion */
176 movl %edi,%r8d /* arg5 */
177 movl %ebp,%r9d /* arg6 */
178 xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */
179 movl %ebx,%edi /* arg1 */
180 movl %edx,%edx /* arg3 (zero extension) */
5cbf1565 181sysenter_dispatch:
1da177e4 182 call *ia32_sys_call_table(,%rax,8)
f2db9382 183 movq %rax,RAX(%rsp)
66804154 184 DISABLE_INTERRUPTS(CLBR_NONE)
2601e64d 185 TRACE_IRQS_OFF
dca5b52a 186 testl $_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
5cbf1565
RM
187 jnz sysexit_audit
188sysexit_from_sys_call:
4214a16b
AL
189 /*
190 * NB: SYSEXIT is not obviously safe for 64-bit kernels -- an
191 * NMI between STI and SYSEXIT has poorly specified behavior,
192 * and and NMI followed by an IRQ with usergs is fatal. So
193 * we just pretend we're using SYSEXIT but we really use
194 * SYSRETL instead.
195 *
196 * This code path is still called 'sysexit' because it pairs
197 * with 'sysenter' and it uses the SYSENTER calling convention.
198 */
dca5b52a 199 andl $~TS_COMPAT,ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS)
4214a16b
AL
200 movl RIP(%rsp),%ecx /* User %eip */
201 CFI_REGISTER rip,rcx
76f5df43 202 RESTORE_RSI_RDI
4214a16b 203 xorl %edx,%edx /* avoid info leaks */
24e35800
JB
204 xorq %r8,%r8
205 xorq %r9,%r9
206 xorq %r10,%r10
4214a16b 207 movl EFLAGS(%rsp),%r11d /* User eflags */
7effaa88 208 /*CFI_RESTORE rflags*/
2601e64d 209 TRACE_IRQS_ON
4214a16b
AL
210
211 /*
212 * SYSRETL works even on Intel CPUs. Use it in preference to SYSEXIT,
213 * since it avoids a dicey window with interrupts enabled.
214 */
215 movl RSP(%rsp),%esp
216
b87cf63e 217 /*
4214a16b
AL
218 * USERGS_SYSRET32 does:
219 * gsbase = user's gs base
220 * eip = ecx
221 * rflags = r11
222 * cs = __USER32_CS
223 * ss = __USER_DS
224 *
225 * The prologue set RIP(%rsp) to VDSO32_SYSENTER_RETURN, which does:
226 *
227 * pop %ebp
228 * pop %edx
229 * pop %ecx
230 *
231 * Therefore, we invoke SYSRETL with EDX and R8-R10 zeroed to
232 * avoid info leaks. R11 ends up with VDSO32_SYSENTER_RETURN's
233 * address (already known to user code), and R12-R15 are
234 * callee-saved and therefore don't contain any interesting
235 * kernel data.
b87cf63e 236 */
4214a16b 237 USERGS_SYSRET32
1da177e4 238
8c7aa698
AL
239 CFI_RESTORE_STATE
240
5cbf1565
RM
241#ifdef CONFIG_AUDITSYSCALL
242 .macro auditsys_entry_common
b4f0d375
RGB
243 movl %esi,%r8d /* 5th arg: 4th syscall arg */
244 movl %ecx,%r9d /*swap with edx*/
245 movl %edx,%ecx /* 4th arg: 3rd syscall arg */
246 movl %r9d,%edx /* 3rd arg: 2nd syscall arg */
247 movl %ebx,%esi /* 2nd arg: 1st syscall arg */
248 movl %eax,%edi /* 1st arg: syscall number */
b05d8447 249 call __audit_syscall_entry
f2db9382 250 movl RAX(%rsp),%eax /* reload syscall number */
36d001c7 251 cmpq $(IA32_NR_syscalls-1),%rax
5cbf1565
RM
252 ja ia32_badsys
253 movl %ebx,%edi /* reload 1st syscall arg */
f2db9382
DV
254 movl RCX(%rsp),%esi /* reload 2nd syscall arg */
255 movl RDX(%rsp),%edx /* reload 3rd syscall arg */
256 movl RSI(%rsp),%ecx /* reload 4th syscall arg */
257 movl RDI(%rsp),%r8d /* reload 5th syscall arg */
5cbf1565
RM
258 .endm
259
81766741 260 .macro auditsys_exit exit
dca5b52a 261 testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
24e35800 262 jnz ia32_ret_from_sys_call
5cbf1565 263 TRACE_IRQS_ON
40a1ef95 264 ENABLE_INTERRUPTS(CLBR_NONE)
5cbf1565 265 movl %eax,%esi /* second arg, syscall return value */
d7e7528b 266 cmpl $-MAX_ERRNO,%eax /* is it an error ? */
f031cd25
EP
267 jbe 1f
268 movslq %eax, %rsi /* if error sign extend to 64 bits */
2691: setbe %al /* 1 if error, 0 if not */
5cbf1565 270 movzbl %al,%edi /* zero-extend that into %edi */
d7e7528b 271 call __audit_syscall_exit
f2db9382 272 movq RAX(%rsp),%rax /* reload syscall return value */
5cbf1565 273 movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi
40a1ef95 274 DISABLE_INTERRUPTS(CLBR_NONE)
5cbf1565 275 TRACE_IRQS_OFF
dca5b52a 276 testl %edi, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
24e35800 277 jz \exit
f2db9382 278 CLEAR_RREGS
24e35800 279 jmp int_with_check
5cbf1565
RM
280 .endm
281
282sysenter_auditsys:
5cbf1565
RM
283 auditsys_entry_common
284 movl %ebp,%r9d /* reload 6th syscall arg */
285 jmp sysenter_dispatch
286
287sysexit_audit:
288 auditsys_exit sysexit_from_sys_call
289#endif
290
8c7aa698
AL
291sysenter_fix_flags:
292 pushq_cfi $(X86_EFLAGS_IF|X86_EFLAGS_FIXED)
293 popfq_cfi
294 jmp sysenter_flags_fixed
295
5cbf1565 296sysenter_tracesys:
5cbf1565 297#ifdef CONFIG_AUDITSYSCALL
dca5b52a 298 testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
5cbf1565
RM
299 jz sysenter_auditsys
300#endif
76f5df43 301 SAVE_EXTRA_REGS
1da177e4 302 CLEAR_RREGS
48ee679a 303 movq $-ENOSYS,RAX(%rsp)/* ptrace can change this for a bad syscall */
1da177e4
LT
304 movq %rsp,%rdi /* &pt_regs -> arg1 */
305 call syscall_trace_enter
f2db9382 306 LOAD_ARGS32 /* reload args from stack in case ptrace changed it */
76f5df43 307 RESTORE_EXTRA_REGS
36d001c7 308 cmpq $(IA32_NR_syscalls-1),%rax
48ee679a 309 ja int_ret_from_sys_call /* sysenter_tracesys has set RAX(%rsp) */
1da177e4
LT
310 jmp sysenter_do_call
311 CFI_ENDPROC
4b787e0b 312ENDPROC(ia32_sysenter_target)
1da177e4
LT
313
314/*
315 * 32bit SYSCALL instruction entry.
316 *
b87cf63e
DV
317 * 32bit SYSCALL saves rip to rcx, clears rflags.RF, then saves rflags to r11,
318 * then loads new ss, cs, and rip from previously programmed MSRs.
319 * rflags gets masked by a value from another MSR (so CLD and CLAC
320 * are not needed). SYSCALL does not save anything on the stack
321 * and does not change rsp.
322 *
323 * Note: rflags saving+masking-with-MSR happens only in Long mode
324 * (in legacy 32bit mode, IF, RF and VM bits are cleared and that's it).
325 * Don't get confused: rflags saving+masking depends on Long Mode Active bit
326 * (EFER.LMA=1), NOT on bitness of userspace where SYSCALL executes
327 * or target CS descriptor's L bit (SYSCALL does not read segment descriptors).
328 *
1da177e4 329 * Arguments:
b87cf63e
DV
330 * eax system call number
331 * ecx return address
332 * ebx arg1
333 * ebp arg2 (note: not saved in the stack frame, should not be touched)
334 * edx arg3
335 * esi arg4
336 * edi arg5
337 * esp user stack
338 * 0(%esp) arg6
339 *
1da177e4 340 * This is purely a fast path. For anything complicated we use the int 0x80
b87cf63e
DV
341 * path below. We set up a complete hardware stack frame to share code
342 * with the int 0x80 path.
343 */
1da177e4 344ENTRY(ia32_cstar_target)
2765130b 345 CFI_STARTPROC32 simple
adf14236 346 CFI_SIGNAL_FRAME
ef593260 347 CFI_DEF_CFA rsp,0
7effaa88
JB
348 CFI_REGISTER rip,rcx
349 /*CFI_REGISTER rflags,r11*/
a232e3d5
DV
350
351 /*
352 * Interrupts are off on entry.
353 * We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON,
354 * it is too small to ever cause noticeable irq latency.
355 */
457da70e 356 SWAPGS_UNSAFE_STACK
1da177e4 357 movl %esp,%r8d
7effaa88 358 CFI_REGISTER rsp,r8
9af45651 359 movq PER_CPU_VAR(kernel_stack),%rsp
66804154 360 ENABLE_INTERRUPTS(CLBR_NONE)
a232e3d5 361
4ee8ec17
DV
362 /* Zero-extending 32-bit regs, do not remove */
363 movl %eax,%eax
364
4c9c0e91
DV
365 /* Construct struct pt_regs on stack */
366 pushq_cfi $__USER32_DS /* pt_regs->ss */
367 pushq_cfi %r8 /* pt_regs->sp */
368 CFI_REL_OFFSET rsp,0
369 pushq_cfi %r11 /* pt_regs->flags */
370 pushq_cfi $__USER32_CS /* pt_regs->cs */
371 pushq_cfi %rcx /* pt_regs->ip */
372 CFI_REL_OFFSET rip,0
373 pushq_cfi_reg rax /* pt_regs->orig_ax */
374 pushq_cfi_reg rdi /* pt_regs->di */
375 pushq_cfi_reg rsi /* pt_regs->si */
376 pushq_cfi_reg rdx /* pt_regs->dx */
377 pushq_cfi_reg rbp /* pt_regs->cx */
1da177e4 378 movl %ebp,%ecx
4c9c0e91
DV
379 pushq_cfi_reg rax /* pt_regs->ax */
380 sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */
381 CFI_ADJUST_CFA_OFFSET 10*8
382
b87cf63e
DV
383 /*
384 * no need to do an access_ok check here because r8 has been
385 * 32bit zero extended
386 */
63bcff2a 387 ASM_STAC
1da177e4 3881: movl (%r8),%r9d
a3e859fe 389 _ASM_EXTABLE(1b,ia32_badarg)
63bcff2a 390 ASM_CLAC
dca5b52a
IM
391 orl $TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS)
392 testl $_TIF_WORK_SYSCALL_ENTRY, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
7effaa88 393 CFI_REMEMBER_STATE
1da177e4 394 jnz cstar_tracesys
36d001c7 395 cmpq $IA32_NR_syscalls-1,%rax
67d53ea5 396 ja ia32_badsys
295286a8 397cstar_do_call:
14f6e953
DV
398 /* 32bit syscall -> 64bit C ABI argument conversion */
399 movl %edi,%r8d /* arg5 */
400 /* r9 already loaded */ /* arg6 */
401 xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */
402 movl %ebx,%edi /* arg1 */
403 movl %edx,%edx /* arg3 (zero extension) */
5cbf1565 404cstar_dispatch:
1da177e4 405 call *ia32_sys_call_table(,%rax,8)
f2db9382 406 movq %rax,RAX(%rsp)
66804154 407 DISABLE_INTERRUPTS(CLBR_NONE)
2601e64d 408 TRACE_IRQS_OFF
dca5b52a 409 testl $_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
5cbf1565
RM
410 jnz sysretl_audit
411sysretl_from_sys_call:
dca5b52a 412 andl $~TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS)
76f5df43 413 RESTORE_RSI_RDI_RDX
f2db9382 414 movl RIP(%rsp),%ecx
7effaa88 415 CFI_REGISTER rip,rcx
f2db9382 416 movl EFLAGS(%rsp),%r11d
7effaa88 417 /*CFI_REGISTER rflags,r11*/
24e35800
JB
418 xorq %r10,%r10
419 xorq %r9,%r9
420 xorq %r8,%r8
2601e64d 421 TRACE_IRQS_ON
f2db9382 422 movl RSP(%rsp),%esp
7effaa88 423 CFI_RESTORE rsp
b87cf63e
DV
424 /*
425 * 64bit->32bit SYSRET restores eip from ecx,
426 * eflags from r11 (but RF and VM bits are forced to 0),
427 * cs and ss are loaded from MSRs.
428 * (Note: 32bit->32bit SYSRET is different: since r11
429 * does not exist, it merely sets eflags.IF=1).
61f01dd9
AL
430 *
431 * NB: On AMD CPUs with the X86_BUG_SYSRET_SS_ATTRS bug, the ss
432 * descriptor is not reinitialized. This means that we must
433 * avoid SYSRET with SS == NULL, which could happen if we schedule,
434 * exit the kernel, and re-enter using an interrupt vector. (All
435 * interrupt entries on x86_64 set SS to NULL.) We prevent that
436 * from happening by reloading SS in __switch_to.
b87cf63e 437 */
2be29982 438 USERGS_SYSRET32
b87cf63e 439
5cbf1565
RM
440#ifdef CONFIG_AUDITSYSCALL
441cstar_auditsys:
7effaa88 442 CFI_RESTORE_STATE
f2db9382 443 movl %r9d,R9(%rsp) /* register to be clobbered by call */
5cbf1565 444 auditsys_entry_common
f2db9382 445 movl R9(%rsp),%r9d /* reload 6th syscall arg */
5cbf1565
RM
446 jmp cstar_dispatch
447
448sysretl_audit:
81766741 449 auditsys_exit sysretl_from_sys_call
5cbf1565
RM
450#endif
451
452cstar_tracesys:
453#ifdef CONFIG_AUDITSYSCALL
dca5b52a 454 testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
5cbf1565
RM
455 jz cstar_auditsys
456#endif
ecd744ee 457 xchgl %r9d,%ebp
76f5df43 458 SAVE_EXTRA_REGS
f2db9382 459 CLEAR_RREGS r9
48ee679a 460 movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
1da177e4
LT
461 movq %rsp,%rdi /* &pt_regs -> arg1 */
462 call syscall_trace_enter
f2db9382 463 LOAD_ARGS32 1 /* reload args from stack in case ptrace changed it */
76f5df43 464 RESTORE_EXTRA_REGS
ecd744ee 465 xchgl %ebp,%r9d
36d001c7 466 cmpq $(IA32_NR_syscalls-1),%rax
48ee679a 467 ja int_ret_from_sys_call /* cstar_tracesys has set RAX(%rsp) */
1da177e4 468 jmp cstar_do_call
4b787e0b 469END(ia32_cstar_target)
1da177e4
LT
470
471ia32_badarg:
63bcff2a 472 ASM_CLAC
1da177e4
LT
473 movq $-EFAULT,%rax
474 jmp ia32_sysret
475 CFI_ENDPROC
476
b87cf63e
DV
477/*
478 * Emulated IA32 system calls via int 0x80.
1da177e4 479 *
b87cf63e
DV
480 * Arguments:
481 * eax system call number
482 * ebx arg1
483 * ecx arg2
484 * edx arg3
485 * esi arg4
486 * edi arg5
487 * ebp arg6 (note: not saved in the stack frame, should not be touched)
1da177e4
LT
488 *
489 * Notes:
b87cf63e
DV
490 * Uses the same stack frame as the x86-64 version.
491 * All registers except eax must be saved (but ptrace may violate that).
1da177e4
LT
492 * Arguments are zero extended. For system calls that want sign extension and
493 * take long arguments a wrapper is needed. Most calls can just be called
494 * directly.
b87cf63e
DV
495 * Assumes it is only called from user space and entered with interrupts off.
496 */
1da177e4
LT
497
498ENTRY(ia32_syscall)
cdc1793e 499 CFI_STARTPROC32 simple
adf14236 500 CFI_SIGNAL_FRAME
a232e3d5
DV
501 CFI_DEF_CFA rsp,5*8
502 /*CFI_REL_OFFSET ss,4*8 */
503 CFI_REL_OFFSET rsp,3*8
504 /*CFI_REL_OFFSET rflags,2*8 */
505 /*CFI_REL_OFFSET cs,1*8 */
506 CFI_REL_OFFSET rip,0*8
507
2601e64d 508 /*
a232e3d5
DV
509 * Interrupts are off on entry.
510 * We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON,
511 * it is too small to ever cause noticeable irq latency.
2601e64d 512 */
a232e3d5
DV
513 PARAVIRT_ADJUST_EXCEPTION_FRAME
514 SWAPGS
66804154 515 ENABLE_INTERRUPTS(CLBR_NONE)
a232e3d5 516
4ee8ec17
DV
517 /* Zero-extending 32-bit regs, do not remove */
518 movl %eax,%eax
519
4c9c0e91
DV
520 /* Construct struct pt_regs on stack (iret frame is already on stack) */
521 pushq_cfi_reg rax /* pt_regs->orig_ax */
522 pushq_cfi_reg rdi /* pt_regs->di */
523 pushq_cfi_reg rsi /* pt_regs->si */
524 pushq_cfi_reg rdx /* pt_regs->dx */
525 pushq_cfi_reg rcx /* pt_regs->cx */
526 pushq_cfi_reg rax /* pt_regs->ax */
1da177e4 527 cld
4c9c0e91
DV
528 sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */
529 CFI_ADJUST_CFA_OFFSET 10*8
530
dca5b52a
IM
531 orl $TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS)
532 testl $_TIF_WORK_SYSCALL_ENTRY, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
1da177e4 533 jnz ia32_tracesys
36d001c7 534 cmpq $(IA32_NR_syscalls-1),%rax
c09249f8
RM
535 ja ia32_badsys
536ia32_do_call:
14f6e953
DV
537 /* 32bit syscall -> 64bit C ABI argument conversion */
538 movl %edi,%r8d /* arg5 */
539 movl %ebp,%r9d /* arg6 */
540 xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */
541 movl %ebx,%edi /* arg1 */
542 movl %edx,%edx /* arg3 (zero extension) */
1da177e4
LT
543 call *ia32_sys_call_table(,%rax,8) # xxx: rip relative
544ia32_sysret:
f2db9382 545 movq %rax,RAX(%rsp)
24e35800 546ia32_ret_from_sys_call:
f2db9382 547 CLEAR_RREGS
76f5df43 548 jmp int_ret_from_sys_call
1da177e4 549
76f5df43
DV
550ia32_tracesys:
551 SAVE_EXTRA_REGS
cdc1793e 552 CLEAR_RREGS
8ab32bb8 553 movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
1da177e4
LT
554 movq %rsp,%rdi /* &pt_regs -> arg1 */
555 call syscall_trace_enter
f2db9382 556 LOAD_ARGS32 /* reload args from stack in case ptrace changed it */
76f5df43 557 RESTORE_EXTRA_REGS
36d001c7 558 cmpq $(IA32_NR_syscalls-1),%rax
c09249f8
RM
559 ja int_ret_from_sys_call /* ia32_tracesys has set RAX(%rsp) */
560 jmp ia32_do_call
4b787e0b 561END(ia32_syscall)
1da177e4
LT
562
563ia32_badsys:
f2db9382 564 movq $0,ORIG_RAX(%rsp)
24e35800
JB
565 movq $-ENOSYS,%rax
566 jmp ia32_sysret
1da177e4 567
1da177e4
LT
568 CFI_ENDPROC
569
d2475b8f 570 .macro PTREGSCALL label, func
f6b2bc84
JB
571 ALIGN
572GLOBAL(\label)
1da177e4 573 leaq \func(%rip),%rax
1da177e4
LT
574 jmp ia32_ptregs_common
575 .endm
576
2765130b 577 CFI_STARTPROC32
7effaa88 578
3fe26fa3
AV
579 PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
580 PTREGSCALL stub32_sigreturn, sys32_sigreturn
3fe26fa3
AV
581 PTREGSCALL stub32_fork, sys_fork
582 PTREGSCALL stub32_vfork, sys_vfork
1da177e4 583
1d4b4b29
AV
584 ALIGN
585GLOBAL(stub32_clone)
586 leaq sys_clone(%rip),%rax
587 mov %r8, %rcx
588 jmp ia32_ptregs_common
589
f6b2bc84
JB
590 ALIGN
591ia32_ptregs_common:
2765130b
JB
592 CFI_ENDPROC
593 CFI_STARTPROC32 simple
adf14236 594 CFI_SIGNAL_FRAME
b3ab90b3 595 CFI_DEF_CFA rsp,SIZEOF_PTREGS
f2db9382
DV
596 CFI_REL_OFFSET rax,RAX
597 CFI_REL_OFFSET rcx,RCX
598 CFI_REL_OFFSET rdx,RDX
599 CFI_REL_OFFSET rsi,RSI
600 CFI_REL_OFFSET rdi,RDI
601 CFI_REL_OFFSET rip,RIP
602/* CFI_REL_OFFSET cs,CS*/
603/* CFI_REL_OFFSET rflags,EFLAGS*/
604 CFI_REL_OFFSET rsp,RSP
605/* CFI_REL_OFFSET ss,SS*/
76f5df43 606 SAVE_EXTRA_REGS 8
1da177e4 607 call *%rax
76f5df43
DV
608 RESTORE_EXTRA_REGS 8
609 ret
1da177e4 610 CFI_ENDPROC
4b787e0b 611END(ia32_ptregs_common)
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