1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
5 * S I G T R A M P - T A R G E T *
7 * Asm Implementation Include File *
9 * Copyright (C) 2011-2018, Free Software Foundation, Inc. *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. *
18 * As a special exception under Section 7 of GPL version 3, you are granted *
19 * additional permissions described in the GCC Runtime Library Exception, *
20 * version 3.1, as published by the Free Software Foundation. *
22 * In particular, you can freely distribute your programs built with the *
23 * GNAT Pro compiler, including any required library run-time units, using *
24 * any licensing terms of your choosing. See the AdaCore Software License *
27 * GNAT was originally developed by the GNAT team at New York University. *
28 * Extensive contributions were provided by Ada Core Technologies Inc. *
30 ****************************************************************************/
32 /***************************************************************
33 * VxWorks target specific part of the __gnat_sigtramp service *
34 ***************************************************************/
36 /* Note: This target specific part is kept in a separate file to avoid
37 duplication of its code for the vxworks and vxworks-vxsim asm
38 implementation files. */
40 /* ---------------------------
41 -- And now the asm stubs --
42 ---------------------------
44 They all have a common structure with blocks of asm sequences queued one
45 after the others. Typically:
55 asm code to establish frame, setup the cfa reg value,
56 call the real signal handler, ...
61 /*--------------------------------
62 -- Misc constants and helpers --
63 -------------------------------- */
65 /* asm string construction helpers. */
67 #define STR(TEXT) #TEXT
68 /* stringify expanded TEXT, surrounding it with double quotes. */
71 /* stringify E, which will resolve as text but may contain macros
72 still to be expanded. */
74 /* asm (TEXT) outputs <tab>TEXT. These facilitate the output of
80 #define TCR(S) TAB(CR(S))
82 /* REGNO constants, dwarf column numbers for registers of interest. */
90 #define REGNO_GR(N) (N)
92 #define REGNO_PC 67 /* ARG_POINTER_REGNUM */
94 #define FUNCTION "@function"
98 #define REGNO_G_REG_OFFSET(N) (N)
100 #define FUNCTION "%function"
103 #define REGNO_PC_OFFSET 80 /* aka V16, a scratch register */
105 #define REGNO_PC_OFFSET 15 /* PC_REGNUM */
108 /* Mapping of CFI Column, Gcc Regno, Signal context offset for _LP64
111 G0-G30 0-30 0-30 0-30
114 V0-V31 64-95 32-63 N/A
120 /* These are the cfi colunm numbers */
130 #define REGNO_EFLAGS 9
131 #define REGNO_SET_PC 8 /* aka %eip */
133 #define FUNCTION "@function"
135 /* Mapping of CFI Column, Gcc Regno, Signal context offset for 32bit
151 There is no unique numbering for the x86 architecture. It's parameterized
152 by DWARF_FRAME_REGNUM, which is DBX_REGISTER_NUMBER except for Windows, and
153 the latter depends on the platform.
156 #elif defined (__x86_64__)
158 /* These are the cfi colunm numbers */
176 #define REGNO_RPC 16 /* aka %rip */
177 #define REGNO_EFLAGS 49
180 #define FUNCTION "@function"
184 #endif /* REGNO constants */
187 /*------------------------------
188 -- Stub construction blocks --
189 ------------------------------ */
193 Only non-volatile registers are suitable for a CFA base. These are the
194 only ones we can expect to be able retrieve from the unwinding context
195 while walking up the chain, saved by at least the bottom-most exception
196 propagation services. We set a non-volatile register to the value we
197 need in the stub body that follows. */
199 #if defined (__PPC__)
201 /* Use r15 for PPC. Note that r14 is inappropriate here, even though it
202 is non-volatile according to the ABI, because GCC uses it as an extra
203 SCRATCH on SPE targets. */
207 #elif defined (ARMEL)
212 /* Use r8 for ARM. Any of r4-r8 should work. */
220 #elif defined (__x86_64__)
227 #endif /* CFA setup block */
229 #define CFI_DEF_CFA \
230 CR(".cfi_def_cfa " S(CFA_REG) ", 0")
232 /* Register location blocks
233 ------------------------
234 Rules to find registers of interest from the CFA. This should comprise
235 all the non-volatile registers relevant to the interrupted context.
237 Note that we include r1 in this set, unlike the libgcc unwinding
238 fallbacks. This is useful for fallbacks to allow the use of r1 in CFI
239 expressions and the absence of rule for r1 gets compensated by using the
240 target CFA instead. We don't need the expression facility here and
241 setup a fake CFA to allow very simple offset expressions, so having a
242 rule for r1 is the proper thing to do. We for sure have observed
243 crashes in some cases without it. */
245 #if defined (__PPC__)
247 #define COMMON_CFI(REG) \
248 ".cfi_offset " S(REGNO_##REG) "," S(REG_SET_##REG)
250 #define CFI_COMMON_REGS \
251 CR("# CFI for common registers\n") \
252 TCR(COMMON_CFI(GR(0))) \
253 TCR(COMMON_CFI(GR(1))) \
254 TCR(COMMON_CFI(GR(2))) \
255 TCR(COMMON_CFI(GR(3))) \
256 TCR(COMMON_CFI(GR(4))) \
257 TCR(COMMON_CFI(GR(5))) \
258 TCR(COMMON_CFI(GR(6))) \
259 TCR(COMMON_CFI(GR(7))) \
260 TCR(COMMON_CFI(GR(8))) \
261 TCR(COMMON_CFI(GR(9))) \
262 TCR(COMMON_CFI(GR(10))) \
263 TCR(COMMON_CFI(GR(11))) \
264 TCR(COMMON_CFI(GR(12))) \
265 TCR(COMMON_CFI(GR(13))) \
266 TCR(COMMON_CFI(GR(14))) \
267 TCR(COMMON_CFI(GR(15))) \
268 TCR(COMMON_CFI(GR(16))) \
269 TCR(COMMON_CFI(GR(17))) \
270 TCR(COMMON_CFI(GR(18))) \
271 TCR(COMMON_CFI(GR(19))) \
272 TCR(COMMON_CFI(GR(20))) \
273 TCR(COMMON_CFI(GR(21))) \
274 TCR(COMMON_CFI(GR(22))) \
275 TCR(COMMON_CFI(GR(23))) \
276 TCR(COMMON_CFI(GR(24))) \
277 TCR(COMMON_CFI(GR(25))) \
278 TCR(COMMON_CFI(GR(26))) \
279 TCR(COMMON_CFI(GR(27))) \
280 TCR(COMMON_CFI(GR(28))) \
281 TCR(COMMON_CFI(GR(29))) \
282 TCR(COMMON_CFI(GR(30))) \
283 TCR(COMMON_CFI(GR(31))) \
284 TCR(COMMON_CFI(LR)) \
285 TCR(COMMON_CFI(CR)) \
286 TCR(COMMON_CFI(CTR)) \
287 TCR(COMMON_CFI(XER)) \
288 TCR(COMMON_CFI(PC)) \
289 TCR(".cfi_return_column " S(REGNO_PC))
291 /* Trampoline body block
292 --------------------- */
294 #if !defined (__PPC64__)
295 #define SIGTRAMP_BODY \
297 TCR("# Allocate frame and save the non-volatile") \
298 TCR("# registers we're going to modify") \
299 TCR("stwu %r1,-16(%r1)") \
301 TCR("stw %r0,20(%r1)") \
302 TCR("stw %r" S(CFA_REG) ",8(%r1)") \
304 TCR("# Setup CFA_REG = context, which we'll retrieve as our CFA value") \
305 TCR("mr %r" S(CFA_REG) ", %r7") \
307 TCR("# Call the real handler. The signo, siginfo and sigcontext") \
308 TCR("# arguments are the same as those we received in r3, r4 and r5") \
312 TCR("# Restore our callee-saved items, release our frame and return") \
313 TCR("lwz %r" S(CFA_REG) ",8(%r1)") \
314 TCR("lwz %r0,20(%r1)") \
317 TCR("addi %r1,%r1,16") \
320 #define SIGTRAMP_BODY \
323 TCR("addis 2,12,.TOC.-0@ha") \
324 TCR("addi 2,2,.TOC.-0@l") \
325 TCR(".localentry __gnat_sigtramp_common,.-__gnat_sigtramp_common") \
326 TCR("# Allocate frame and save the non-volatile") \
327 TCR("# registers we're going to modify") \
329 TCR("std %r0,16(%r1)") \
330 TCR("stdu %r1,-32(%r1)") \
331 TCR("std %r2,24(%r1)") \
332 TCR("std %r" S(CFA_REG) ",8(%r1)") \
334 TCR("# Setup CFA_REG = context, which we'll retrieve as our CFA value") \
335 TCR("mr %r" S(CFA_REG) ", %r7") \
337 TCR("# Call the real handler. The signo, siginfo and sigcontext") \
338 TCR("# arguments are the same as those we received in r3, r4 and r5") \
343 TCR("# Restore our callee-saved items, release our frame and return") \
344 TCR("ld %r" S(CFA_REG) ",8(%r1)") \
345 TCR("ld %r2,24(%r1)") \
346 TCR("addi %r1,%r1,32") \
347 TCR("ld %r0,16(%r1)") \
352 #elif defined (ARMEL)
354 #define COMMON_CFI(REG) \
355 ".cfi_offset " S(REGNO_##REG) "," S(REG_SET_##REG)
358 #define CFI_COMMON_REGS \
359 CR("# CFI for common registers\n") \
360 TCR(COMMON_CFI(G_REG_OFFSET(0))) \
361 TCR(COMMON_CFI(G_REG_OFFSET(1))) \
362 TCR(COMMON_CFI(G_REG_OFFSET(2))) \
363 TCR(COMMON_CFI(G_REG_OFFSET(3))) \
364 TCR(COMMON_CFI(G_REG_OFFSET(4))) \
365 TCR(COMMON_CFI(G_REG_OFFSET(5))) \
366 TCR(COMMON_CFI(G_REG_OFFSET(6))) \
367 TCR(COMMON_CFI(G_REG_OFFSET(7))) \
368 TCR(COMMON_CFI(G_REG_OFFSET(8))) \
369 TCR(COMMON_CFI(G_REG_OFFSET(9))) \
370 TCR(COMMON_CFI(G_REG_OFFSET(10))) \
371 TCR(COMMON_CFI(G_REG_OFFSET(11))) \
372 TCR(COMMON_CFI(G_REG_OFFSET(12))) \
373 TCR(COMMON_CFI(G_REG_OFFSET(13))) \
374 TCR(COMMON_CFI(G_REG_OFFSET(14))) \
375 TCR(COMMON_CFI(G_REG_OFFSET(15))) \
376 TCR(COMMON_CFI(G_REG_OFFSET(16))) \
377 TCR(COMMON_CFI(G_REG_OFFSET(17))) \
378 TCR(COMMON_CFI(G_REG_OFFSET(18))) \
379 TCR(COMMON_CFI(G_REG_OFFSET(19))) \
380 TCR(COMMON_CFI(G_REG_OFFSET(20))) \
381 TCR(COMMON_CFI(G_REG_OFFSET(21))) \
382 TCR(COMMON_CFI(G_REG_OFFSET(22))) \
383 TCR(COMMON_CFI(G_REG_OFFSET(23))) \
384 TCR(COMMON_CFI(G_REG_OFFSET(24))) \
385 TCR(COMMON_CFI(G_REG_OFFSET(25))) \
386 TCR(COMMON_CFI(G_REG_OFFSET(26))) \
387 TCR(COMMON_CFI(G_REG_OFFSET(27))) \
388 TCR(COMMON_CFI(G_REG_OFFSET(28))) \
389 TCR(COMMON_CFI(G_REG_OFFSET(29))) \
390 TCR(COMMON_CFI(G_REG_OFFSET(30))) \
391 TCR(COMMON_CFI(G_REG_OFFSET(31))) \
392 TCR(COMMON_CFI(PC_OFFSET)) \
393 TCR(".cfi_return_column " S(REGNO_PC_OFFSET))
395 #define CFI_COMMON_REGS \
396 CR("# CFI for common registers\n") \
397 TCR(COMMON_CFI(G_REG_OFFSET(0))) \
398 TCR(COMMON_CFI(G_REG_OFFSET(1))) \
399 TCR(COMMON_CFI(G_REG_OFFSET(2))) \
400 TCR(COMMON_CFI(G_REG_OFFSET(3))) \
401 TCR(COMMON_CFI(G_REG_OFFSET(4))) \
402 TCR(COMMON_CFI(G_REG_OFFSET(5))) \
403 TCR(COMMON_CFI(G_REG_OFFSET(6))) \
404 TCR(COMMON_CFI(G_REG_OFFSET(7))) \
405 TCR(COMMON_CFI(G_REG_OFFSET(8))) \
406 TCR(COMMON_CFI(G_REG_OFFSET(9))) \
407 TCR(COMMON_CFI(G_REG_OFFSET(10))) \
408 TCR(COMMON_CFI(G_REG_OFFSET(11))) \
409 TCR(COMMON_CFI(G_REG_OFFSET(12))) \
410 TCR(COMMON_CFI(G_REG_OFFSET(13))) \
411 TCR(COMMON_CFI(G_REG_OFFSET(14))) \
412 TCR(COMMON_CFI(PC_OFFSET)) \
413 TCR(".cfi_return_column " S(REGNO_PC_OFFSET))
416 /* Trampoline body block
417 --------------------- */
419 #define SIGTRAMP_BODY \
421 TCR("# Allocate the frame (16bytes aligned) and push FP and LR") \
422 TCR("stp x29, x30, [sp, #-32]!") \
423 TCR("add x29, sp, 0") \
424 TCR("# Store register used to hold the CFA on stack (pro forma)") \
425 TCR("str x" S(CFA_REG) ", [sp, 16]") \
426 TCR("# Set the CFA reg from the 5th arg") \
427 TCR("mov x" S(CFA_REG) ", x4") \
428 TCR("# Call the handler") \
430 TCR("# Release our frame and return (should never get here!).") \
431 TCR("ldr x" S(CFA_REG) ", [sp, 16]") \
432 TCR("ldp x29, x30, [sp], 32") \
435 #define SIGTRAMP_BODY \
437 TCR("# Allocate frame and save the non-volatile") \
438 TCR("# registers we're going to modify") \
440 TCR("stmfd sp!, {r"S(CFA_REG)", fp, ip, lr, pc}") \
441 TCR("# Setup CFA_REG = context, which we'll retrieve as our CFA value") \
442 TCR("ldr r"S(CFA_REG)", [ip]") \
444 TCR("# Call the real handler. The signo, siginfo and sigcontext") \
445 TCR("# arguments are the same as those we received in r0, r1 and r2") \
446 TCR("sub fp, ip, #4") \
448 TCR("# Restore our callee-saved items, release our frame and return") \
449 TCR("ldmfd sp, {r"S(CFA_REG)", fp, sp, pc}")
454 #if CPU == SIMNT || CPU == SIMPENTIUM || CPU == SIMLINUX
455 #define COMMON_CFI(REG) \
456 ".cfi_offset " S(REGNO_##REG) "," S(REG_SET_##REG)
458 #define COMMON_CFI(REG) \
459 ".cfi_offset " S(REGNO_##REG) "," S(REG_##REG)
462 #define PC_CFI(REG) \
463 ".cfi_offset " S(REGNO_##REG) "," S(REG_##REG)
465 #define CFI_COMMON_REGS \
466 CR("# CFI for common registers\n") \
467 TCR(COMMON_CFI(EDI)) \
468 TCR(COMMON_CFI(ESI)) \
469 TCR(COMMON_CFI(EBP)) \
470 TCR(COMMON_CFI(ESP)) \
471 TCR(COMMON_CFI(EBX)) \
472 TCR(COMMON_CFI(EDX)) \
473 TCR(COMMON_CFI(ECX)) \
474 TCR(COMMON_CFI(EAX)) \
475 TCR(COMMON_CFI(EFLAGS)) \
476 TCR(PC_CFI(SET_PC)) \
477 TCR(".cfi_return_column " S(REGNO_SET_PC))
479 /* Trampoline body block
480 --------------------- */
482 #define SIGTRAMP_BODY \
484 TCR("# Allocate frame and save the non-volatile") \
485 TCR("# registers we're going to modify") \
487 TCR("movl %esp, %ebp") \
489 TCR("subl $24, %esp") \
490 TCR("# Setup CFA_REG = context, which we'll retrieve as our CFA value") \
491 TCR("movl 24(%ebp), %edi") \
492 TCR("# Call the real handler. The signo, siginfo and sigcontext") \
493 TCR("# arguments are the same as those we received") \
494 TCR("movl 16(%ebp), %eax") \
495 TCR("movl %eax, 8(%esp)") \
496 TCR("movl 12(%ebp), %eax") \
497 TCR("movl %eax, 4(%esp)") \
498 TCR("movl 8(%ebp), %eax") \
499 TCR("movl %eax, (%esp)") \
500 TCR("call *20(%ebp)") \
501 TCR("# Restore our callee-saved items, release our frame and return") \
506 #elif defined (__x86_64__)
508 #define COMMON_CFI(REG) \
509 ".cfi_offset " S(REGNO_##REG) "," S(REG_##REG)
511 #define CFI_COMMON_REGS \
512 CR("# CFI for common registers\n") \
513 TCR(COMMON_CFI(R15)) \
514 TCR(COMMON_CFI(R14)) \
515 TCR(COMMON_CFI(R13)) \
516 TCR(COMMON_CFI(R12)) \
517 TCR(COMMON_CFI(R11)) \
518 TCR(COMMON_CFI(R10)) \
519 TCR(COMMON_CFI(R9)) \
520 TCR(COMMON_CFI(R8)) \
521 TCR(COMMON_CFI(RDI)) \
522 TCR(COMMON_CFI(RSI)) \
523 TCR(COMMON_CFI(RBP)) \
524 TCR(COMMON_CFI(RSP)) \
525 TCR(COMMON_CFI(RBX)) \
526 TCR(COMMON_CFI(RDX)) \
527 TCR(COMMON_CFI(RCX)) \
528 TCR(COMMON_CFI(RAX)) \
529 TCR(COMMON_CFI(RPC)) \
530 TCR(".cfi_return_column " S(REGNO_RPC))
532 /* Trampoline body block
533 --------------------- */
535 #define SIGTRAMP_BODY \
537 TCR("# Allocate frame and save the non-volatile") \
538 TCR("# registers we're going to modify") \
539 TCR("subq $8, %rsp") \
540 TCR("# Setup CFA_REG = context, which we'll retrieve as our CFA value") \
541 TCR("movq %r8, %r15") \
542 TCR("# Call the real handler. The signo, siginfo and sigcontext") \
543 TCR("# arguments are the same as those we received") \
545 TCR("# This part should never be executed") \
546 TCR("addq $8, %rsp") \
551 #endif /* CFI_COMMON_REGS and SIGTRAMP_BODY */
553 /* Symbol definition block
554 ----------------------- */
557 #define FUNC_ALIGN TCR(".p2align 4,,15")
562 #define SIGTRAMP_START(SYM) \
563 CR("# " S(SYM) " cfi trampoline") \
564 TCR(".type " S(SYM) ", "FUNCTION) \
568 TCR(".cfi_startproc") \
569 TCR(".cfi_signal_frame")
571 /* Symbol termination block
572 ------------------------ */
574 #define SIGTRAMP_END(SYM) \
576 TCR(".size " S(SYM) ", .-" S(SYM))
578 /*----------------------------
579 -- And now, the real code --
580 ---------------------------- */
582 /* Text section start. The compiler isn't aware of that switch. */