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/* Set current context.
Copyright (C) 2015-2024 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 "ucontext_i.h"
/* int setcontext (const ucontext_t *ucp) */
.text
ENTRY(__setcontext)
ldw r5, UCONTEXT_FLAGS(r4)
movi r6, 1
bne r5, r6, .Lsigreturn
mov r10, r4
/* Restore signal mask. */
/* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, NULL, _NSIG8) */
movi r7, _NSIG8
addi r5, r4, UCONTEXT_SIGMASK
mov r6, zero
movi r4, SIG_SETMASK
movi r2, SYS_ify (rt_sigprocmask)
trap
bne r7, zero, SYSCALL_ERROR_LABEL
/* Restore argument registers, for the makecontext() case. */
ldw r4, (UCONTEXT_MCONTEXT + 4*4)(r10)
ldw r5, (UCONTEXT_MCONTEXT + 5*4)(r10)
ldw r6, (UCONTEXT_MCONTEXT + 6*4)(r10)
ldw r7, (UCONTEXT_MCONTEXT + 7*4)(r10)
ldw r16, (UCONTEXT_MCONTEXT + 16*4)(r10)
ldw r17, (UCONTEXT_MCONTEXT + 17*4)(r10)
ldw r18, (UCONTEXT_MCONTEXT + 18*4)(r10)
ldw r19, (UCONTEXT_MCONTEXT + 19*4)(r10)
ldw r20, (UCONTEXT_MCONTEXT + 20*4)(r10)
ldw r21, (UCONTEXT_MCONTEXT + 21*4)(r10)
ldw r22, (UCONTEXT_MCONTEXT + 22*4)(r10)
ldw ra, (UCONTEXT_MCONTEXT + 24*4)(r10)
ldw fp, (UCONTEXT_MCONTEXT + 25*4)(r10)
ldw gp, (UCONTEXT_MCONTEXT + 26*4)(r10)
/* Load address to continue execution. */
ldw r3, (UCONTEXT_MCONTEXT + 28*4)(r10)
ldw sp, (UCONTEXT_MCONTEXT + 29*4)(r10)
mov r2, zero
jmp r3
.Lsigreturn:
addi sp, sp, -RT_SIGFRAME_SIZE
cfi_adjust_cfa_offset (RT_SIGFRAME_SIZE)
addi r2, sp, RT_SIGFRAME_UCONTEXT
movi r3, UCONTEXT_SIZE-4
1:
add r6, r4, r3
ldw r5, 0(r6)
add r7, r2, r3
addi r3, r3, -4
stw r5, 0(r7)
bgt r3, zero, 1b
movi r2, SYS_ify (rt_sigreturn)
trap
addi sp, sp, RT_SIGFRAME_SIZE
cfi_adjust_cfa_offset (-RT_SIGFRAME_SIZE)
br SYSCALL_ERROR_LABEL
PSEUDO_END (__setcontext)
weak_alias (__setcontext, setcontext)
/* We add an NOP here to separate between __setcontext/__startcontext.
The wanted behavior that happens is: when unwinding from a function
called inside a makecontext() context, FDE lookup will use
'&__startcontext - 1', then returns NULL for no FDE found,
and immediately ends the unwind, in a normal fashion.
If this NOP word does not exist, FDE lookup just repeatedly finds
__setcontext's FDE in an infinite loop, due to the convention of
using 'address - 1' for FDE lookup. Modifying/deleting the below
__startcontext's FDE has no help on this. */
nop
ENTRY(__startcontext)
mov r4, r16
bne r4, zero, __setcontext
/* If uc_link == zero, call exit. */
#ifdef PIC
nextpc r22
1: movhi r8, %hiadj(_gp_got - 1b)
addi r8, r8, %lo(_gp_got - 1b)
add r22, r22, r8
ldw r8, %call(HIDDEN_JUMPTARGET(exit))(r22)
jmp r8
#else
jmpi exit
#endif
END(__startcontext)
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