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/* Create new context.
Copyright (C) 2005-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <abort-instr.h>
#include "ucontext_i.h"
/* void __makecontext (ucontext_t *ucp, void (*func)(), int argc, ...);
__makecontext sets up a stack and registers for context to run a given
function. The registers are set up like this:
r4-r7: parameters 1 to 4
r8 : uc_link from ucontext structure
pc : (*func) pointer
pr : address of exitcode
r15 : stack pointer for func. */
.text
.align 5
ENTRY(__makecontext)
mov #4, r3
mov.l @(oSS_SP,r4), r1 /* r1 <- ucb->stack_base */
mov.l @(oSS_SIZE,r4), r2 /* r2 <- ucb->stack_size */
add r1, r2 /* r2 <- stack_top */
cmp/gt r3, r6 /* argc > 4? */
bf/s 1f
shlr2 r2 /* r2 <- stack_top / 4 */
sub r6, r2
add r3, r2
1:
shll2 r2 /* r2 <- stack_top - ((argc > 4) ? 4 * (argc - 4) : 0 */
mov #oR15, r0
mov.l @(oLINK,r4), r1
mov.l r2, @(r0,r4) /* ucp->r15 <- r2 */
mov.l r1, @(oR8,r4) /* ucp->r8 <- ucp->uc_link */
mov #oPC, r0
mov.l r5, @(r0,r4) /* ucp->PC <- func */
cmp/pl r6 /* argc > 0? */
bf/s .L1
dt r6
mov.l r7, @(oR4,r4) /* ucp->r4 <- argv[0] */
cmp/pl r6 /* argc > 1? */
bf/s .L1
dt r6
mov.l @(0,r15), r1
mov.l r1, @(oR5,r4) /* ucp->r5 <- argv[1] */
cmp/pl r6 /* argc > 2? */
bf/s .L1
dt r6
mov.l @(4,r15), r1
mov.l r1, @(oR6,r4) /* ucp->r6 <- argv[2] */
cmp/pl r6 /* argc > 3? */
bf/s .L1
dt r6
mov.l @(8,r15), r1
mov.l r1, @(oR7,r4) /* ucp->r7 <- argv[3] */
mov #12,r0
.L0: /* Save remaining argv[] on the stack. */
cmp/pl r6
bf/s .L1
dt r6
mov.l @(r0,r15), r1
mov.l r1, @r2
add #4, r0
bra .L0
add #4, r2
.L1:
#ifdef PIC
mova .Lexitcode, r0
#else
mov.l .L2, r0
#endif
add #oPR, r4
rts
mov.l r0, @r4 /* ucp->pr <- exitcode */
#ifndef PIC
.align 2
.L2:
.long .Lexitcode
#endif
cfi_endproc
.align 5
cfi_startproc
.Lexitcode:
#ifdef PIC
mov.l r12, @-r15
cfi_adjust_cfa_offset (4)
cfi_rel_offset (r12, 0)
mova .Lgot, r0
mov.l .Lgot, r12
add r0, r12
#endif
tst r8, r8 /* ucb->uc_link == NULL? */
bt/s 2f
mov r8, r4 /* r4 <- ucb->uc_link */
mov.l .Lsetcontext, r1
sts.l pr, @-r15
cfi_adjust_cfa_offset (4)
cfi_rel_offset (pr, 0)
#ifdef PIC
bsrf r1
.LPCS0:
nop
#else
jsr @r1
nop
#endif
/* Restore to keep CFI/CFA balanced. */
lds.l @r15+, pr
cfi_adjust_cfa_offset (-4)
cfi_restore (pr)
/* If this returns (which can happen if the syscall fails) we'll exit
the program with the return error value (-1). */
mov r0, r4
2:
mov.l .Lexit, r1
#ifdef PIC
add r12, r1
#endif
jsr @r1
nop
/* The 'exit' call should never return. In case it does cause the
process to terminate. */
ABORT_INSTRUCTION_ASM
.align 2
#ifdef PIC
.Lgot:
.long _GLOBAL_OFFSET_TABLE_
.Lsetcontext:
.long __setcontext@PLT-(.LPCS0+2-(.))
.Lexit:
.long HIDDEN_JUMPTARGET(exit)@GOTOFF
#else
.Lsetcontext:
.long __setcontext
.Lexit:
.long HIDDEN_JUMPTARGET(exit)
#endif
PSEUDO_END(__makecontext)
weak_alias (__makecontext, makecontext)
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