arch: add s390x port

pull/10/head
William Pitcock 2018-02-15 05:54:17 +00:00
parent f0741bc7a0
commit a76df6b81a
6 changed files with 203 additions and 0 deletions

8
arch/s390x/defs.h Normal file
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#ifndef __ARCH_S390X_DEFS_H
#define __ARCH_S390X_DEFS_H
#define OFFSET_GREGS (56)
#define OFFSET_AREGS (184)
#define OFFSET_FPREGS (248)
#endif

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arch/s390x/getcontext.S Normal file
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/*
* Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* This software is provided 'as is' and without any warranty, express or
* implied. In no event shall the authors be liable for any damages arising
* from the use of this software.
*/
#include "defs.h"
.globl __getcontext;
__getcontext:
lgr %r1, %r2 /* use %r1 as our working register */
la %r2, 0 /* we will return 0 */
stam %a0, %a15, OFFSET_AREGS(%r1) /* store access registers */
stmg %r0, %r15, OFFSET_GREGS(%r1) /* store general-purpose registers */
br %r14 /* return to where we came from */
.weak getcontext;
getcontext = __getcontext;

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arch/s390x/makecontext.c Normal file
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/*
* Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* This software is provided 'as is' and without any warranty, express or
* implied. In no event shall the authors be liable for any damages arising
* from the use of this software.
*/
#define _GNU_SOURCE
#include <stddef.h>
#include <stdarg.h>
#include <signal.h>
#include <string.h>
#include <stdint.h>
#include "defs.h"
extern void __start_context(void);
extern int __setcontext(const ucontext_t *ucp);
void
__makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
{
greg_t *sp, *argp;
va_list va;
int i;
unsigned int stack_args;
stack_args = argc > 5 ? argc - 5 : 0;
sp = (greg_t *) ((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
sp -= stack_args; // maybe +1
sp = (greg_t *) (((uintptr_t) sp & -16L));
ucp->uc_mcontext.gregs[7] = (uintptr_t) func;
ucp->uc_mcontext.gregs[8] = (uintptr_t) ucp->uc_link;
ucp->uc_mcontext.gregs[9] = (uintptr_t) &__setcontext;
ucp->uc_mcontext.gregs[14] = (uintptr_t) &__start_context;
argp = sp;
va_start(va, argc);
for (i = 0; i < argc; i++)
switch (i)
{
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
ucp->uc_mcontext.gregs[i + 2] = va_arg (va, greg_t);
break;
default:
*argp++ = va_arg (va, greg_t);
break;
}
va_end(va);
/* make room for backchain / register save area */
sp -= 20;
*sp = 0;
/* set up %r15 as sp */
ucp->uc_mcontext.gregs[15] = (uintptr_t) sp;
}
extern __typeof(__makecontext) makecontext __attribute__((weak, __alias__("__makecontext")));

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arch/s390x/setcontext.S Normal file
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/*
* Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* This software is provided 'as is' and without any warranty, express or
* implied. In no event shall the authors be liable for any damages arising
* from the use of this software.
*/
#include "defs.h"
.globl __setcontext;
__setcontext:
lgr %r1, %r2 /* use %r1 as our working register */
lam %a2, %a15, OFFSET_AREGS+8(%r1) /* load access registers, but skip %a0 and %a1 which are for TLS */
lmg %r0, %r15, OFFSET_GREGS(%r1) /* store general-purpose registers */
br %r14 /* return to new link register address */
.weak setcontext;
setcontext = __setcontext;

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arch/s390x/startcontext.S Normal file
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/*
* Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* This software is provided 'as is' and without any warranty, express or
* implied. In no event shall the authors be liable for any damages arising
* from the use of this software.
*/
#include "defs.h"
.globl __start_context;
__start_context:
basr %r14, %r7 /* run function pointer (%r7) and return here */
ltgr %r8, %r8 /* check to see if uc_link (%r8) is null */
jz no_linked_context /* if we have no linked context, prepare to exit */
lgr %r2, %r8 /* copy the uc_link structure address to %r2 */
br %r9 /* call setcontext */
no_linked_context:
la %r2, 0 /* return 0 */
brasl %r14, exit@plt /* call exit */
j .+2 /* crash if exit returns */

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arch/s390x/swapcontext.S Normal file
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/*
* Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* This software is provided 'as is' and without any warranty, express or
* implied. In no event shall the authors be liable for any damages arising
* from the use of this software.
*/
#include "defs.h"
.globl __swapcontext;
__swapcontext:
lgr %r1, %r2 /* use %r1 to save current context to */
lgr %r0, %r3 /* use %r0 for source context */
stam %a0, %a15, OFFSET_AREGS(%r1) /* store access registers */
stmg %r0, %r15, OFFSET_GREGS(%r1) /* store general-purpose registers */
lgr %r2, %r0 /* swap %r0 to %r2 (XXX: figure out why it hates loading from %r0) */
lam %a2, %a15, OFFSET_AREGS+8(%r2) /* load access registers, but skip %a0 and %a1 which are for TLS */
lmg %r0, %r15, OFFSET_GREGS(%r2) /* load general-purpose registers */
br %r14 /* return to new link register address */
.weak swapcontext;
swapcontext = __swapcontext;