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/*--------------------------------------------------------------------*/
/*--- Support for doing system calls. syscall-nanomips-linux.S ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Valgrind, a dynamic binary instrumentation
framework.
Copyright (C) 2017-2018 RT-RK
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
The GNU General Public License is contained in the file COPYING.
*/
#include "pub_core_basics_asm.h"
#if defined(VGP_nanomips_linux)
#include "pub_core_vkiscnums_asm.h"
#include "libvex_guest_offsets.h"
/*----------------------------------------------------------------*/
/*
Perform a syscall for the client. This will run a syscall
with the client's specific per-thread signal mask.
The structure of this function is such that, if the syscall is
interrupted by a signal, we can determine exactly what
execution state we were in with respect to the execution of
the syscall by examining the value of IP in the signal
handler. This means that we can always do the appropriate
thing to precisely emulate the kernel's signal/syscall
interactions.
The syscall number is taken from the argument, even though it
should also be in regs->v0. The syscall result is written
back to regs->v0 on completion.
Returns 0 if the syscall was successfully called (even if the
syscall itself failed), or a nonzero error code in the lowest
8 bits if one of the sigprocmasks failed (there's no way to
determine which one failed). And there's no obvious way to
recover from that either, but nevertheless we want to know.
VG_(fixup_guest_state_after_syscall_interrupted) does the
thread state fixup in the case where we were interrupted by a
signal.
Prototype:
UWord ML_(do_syscall_for_client_WRK)(
Int syscallno, // a0
void* guest_state, // a1
const vki_sigset_t *sysmask, // a2
const vki_sigset_t *postmask, // a3
Int nsigwords) // a4
*/
/* from vki_arch.h */
#define VKI_SIG_SETMASK 2
.globl ML_(do_syscall_for_client_WRK)
ML_(do_syscall_for_client_WRK):
save 32, $a0-$a4
1: li $t4, __NR_rt_sigprocmask
li $a0, VKI_SIG_SETMASK
move $a1, $a2 # sysmask
move $a2, $a3 # postmask
move $a3, $a4 # nsigwords
syscall[32]
bnezc $a0, 5f # error
lw $t4, 28($sp) # t4 = syscallno
lw $t0, 24($sp) # t0 = &guest_state
lw $a0, OFFSET_mips32_r4($t0)
lw $a1, OFFSET_mips32_r5($t0)
lw $a2, OFFSET_mips32_r6($t0)
lw $a3, OFFSET_mips32_r7($t0)
lw $a4, OFFSET_mips32_r8($t0)
lw $a5, OFFSET_mips32_r9($t0)
lw $a6, OFFSET_mips32_r10($t0)
lw $a7, OFFSET_mips32_r11($t0)
2: syscall[32]
3: lw $t0, 24($sp) # t0 = &guest_state
sw $a0, OFFSET_mips32_r4($t0)
4: li $t4, __NR_rt_sigprocmask
li $a0, VKI_SIG_SETMASK
lw $a1, 16($sp)
li $a2, 0
lw $a3, 12($sp)
syscall[32]
bnezc $a0, 5f # error
li $a0, 0
bc 6f
5: #error, return 0x8000
lui $a0, 0x00008
6: addu $sp, $sp, 32
jrc $ra
.section .rodata
/* export the ranges so that
VG_(fixup_guest_state_after_syscall_interrupted) can do the
right thing */
.globl ML_(blksys_setup)
.globl ML_(blksys_restart)
.globl ML_(blksys_complete)
.globl ML_(blksys_committed)
.globl ML_(blksys_finished)
ML_(blksys_setup): .long 1b
ML_(blksys_restart): .long 2b
ML_(blksys_complete): .long 3b
ML_(blksys_committed): .long 4b
ML_(blksys_finished): .long 6b
#endif
/* Let the linker know we don't need an executable stack */
MARK_STACK_NO_EXEC
/*--------------------------------------------------------------------*/
/*--- end syscall-nanomips-linux.S ---*/
/*--------------------------------------------------------------------*/
|
