/*--------------------------------------------------------------------*/
/*--- Support for doing system calls. syscall-amd64-darwin.S ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Valgrind, a dynamic binary instrumentation
framework.
Copyright (C) 2000-2017 Julian Seward
jseward@acm.org
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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file COPYING.
*/
#include "pub_core_basics_asm.h"
#if defined(VGP_amd64_darwin)
#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 %eip 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 guest_state->guest_RAX. The syscall result
is written back to guest_state->guest_RAX on completion.
Returns 0 if the syscall was successfully called (even if the
syscall itself failed), or a -ve error code if one of the
sigprocmasks failed (there's no way to determine which one
failed).
VG_(fixup_guest_state_after_syscall_interrupted) does the
thread state fixup in the case where we were interrupted by a
signal.
Prototype:
Int ML_(do_syscall_for_client_WRK(
Int syscallno, // rdi
void* guest_state, // rsi
const vki_sigset_t *sysmask, // rdx
const vki_sigset_t *postmask, // rcx
Int sigsetSzB) // r8
Note that sigsetSzB is totally ignored (and irrelevant).
*/
/* from vki_arch.h */
#define VKI_SIG_SETMASK 3
/* DO_SYSCALL MACH|MDEP|UNIX */
#define MACH 1
#define MDEP 2
#define UNIX 3
.macro DO_SYSCALL
/* save callee-saved regs */
pushq %rbp
movq %rsp, %rbp
// stack is now aligned
pushq %rdi // -8(%rbp) syscallno
pushq %rsi // -16(%rbp) guest_state
pushq %rdx // -24(%rbp) sysmask
pushq %rcx // -32(%rbp) postmask
pushq %r8 // -40(%rbp) sigsetSzB
// stack is now aligned
L_$0_1: /* Even though we can't take a signal until the sigprocmask completes,
start the range early.
If rip is in the range [1,2), the syscall hasn't been started yet */
/* Set the signal mask which should be current during the syscall. */
/* GrP fixme signals
DDD: JRS fixme: use __NR___pthread_sigmask, not __NR_rt_sigprocmask
movq $__NR_rt_sigprocmask, %rax // syscall #
movq $VKI_SIG_SETMASK, %rdi // how
movq -24(%rbp), %rsi // sysmask
movq -32(%rbp), %rdx // postmask
movq -40(%rbp), %r10 // sigsetSzB in r10 not rcx
DDD: fixme return address
syscall
jnc 7f // sigprocmask failed
*/
/* OK, that worked. Now do the syscall proper. */
/* 6 register parameters */
movq -16(%rbp), %r11 /* r11 = VexGuestAMD64State * */
movq OFFSET_amd64_RDI(%r11), %rdi
movq OFFSET_amd64_RSI(%r11), %rsi
movq OFFSET_amd64_RDX(%r11), %rdx
movq OFFSET_amd64_RCX(%r11), %r10 /* rcx is passed in r10 instead */
movq OFFSET_amd64_R8(%r11), %r8
movq OFFSET_amd64_R9(%r11), %r9
/* 2 stack parameters plus return address (ignored by syscall) */
movq OFFSET_amd64_RSP(%r11), %r11 /* r11 = simulated RSP */
movq 16(%r11), %rax
pushq %rax
movq 8(%r11), %rax
pushq %rax
/* stack is currently aligned - return address misaligns */
movq 0(%r11), %rax
pushq %rax
/* syscallno */
movq -8(%rbp), %rax
/* If rip==2, then the syscall was either just about
to start, or was interrupted and the kernel was
restarting it. */
L_$0_2: syscall
L_$0_3: /* In the range [3, 4), the syscall result is in %rax,
but hasn't been committed to RAX. */
/* stack contents: 3 words for syscall above, plus our prologue */
setc 0(%rsp) /* stash returned carry flag */
movq -16(%rbp), %r11 /* r11 = VexGuestAMD64State * */
movq %rax, OFFSET_amd64_RAX(%r11) /* save back to RAX */
movq %rdx, OFFSET_amd64_RDX(%r11) /* save back to RDX */
.if $0 == UNIX
/* save carry flag to VEX */
xor %rax, %rax
movb 0(%rsp), %al
movq %rax, %rdi /* arg1 = new flag */
movq %r11, %rsi /* arg2 = vex state */
addq $$24, %rsp /* remove syscall parameters */
call _LibVEX_GuestAMD64_put_rflag_c
.else
addq $$24, %rsp /* remove syscall parameters*/
.endif
L_$0_4: /* Re-block signals. If eip is in [4,5), then the syscall
is complete and we needn't worry about it. */
/* GrP fixme signals
DDD: JRS fixme: use __NR___pthread_sigmask, not __NR_rt_sigprocmask
PUSH_di_si_dx_cx_8
movq $__NR_rt_sigprocmask, %rax // syscall #
movq $VKI_SIG_SETMASK, %rdi // how
movq %rcx, %rsi // postmask
xorq %rdx, %rdx // NULL
movq %r8, %r10 // sigsetSzB
DDD: fixme return address
syscall
POP_di_si_dx_cx_8
jnc 7f // sigprocmask failed
*/
L_$0_5: /* now safe from signals */
movq $$0, %rax /* SUCCESS */
movq %rbp, %rsp
popq %rbp
ret
/* GrP fixme signals
L_$0_7: // failure: return 0x8000 | error code
DDD: fixme return value
movq %rbp, %rsp
popq %rbp
ret
*/
.endmacro
.globl ML_(do_syscall_for_client_unix_WRK)
ML_(do_syscall_for_client_unix_WRK):
DO_SYSCALL UNIX
.globl ML_(do_syscall_for_client_mach_WRK)
ML_(do_syscall_for_client_mach_WRK):
DO_SYSCALL MACH
.globl ML_(do_syscall_for_client_mdep_WRK)
ML_(do_syscall_for_client_mdep_WRK):
DO_SYSCALL MDEP
.data
/* export the ranges so that
VG_(fixup_guest_state_after_syscall_interrupted) can do the
right thing */
/* eg MK_L_SCLASS_N(UNIX,99) produces L_3_99
since UNIX is #defined to 3 at the top of this file */
#define FOO(scclass,labelno) L_##scclass##_##labelno
#define MK_L_SCCLASS_N(scclass,labelno) FOO(scclass,labelno)
.globl ML_(blksys_setup_MACH)
.globl ML_(blksys_restart_MACH)
.globl ML_(blksys_complete_MACH)
.globl ML_(blksys_committed_MACH)
.globl ML_(blksys_finished_MACH)
ML_(blksys_setup_MACH): .quad MK_L_SCCLASS_N(MACH,1)
ML_(blksys_restart_MACH): .quad MK_L_SCCLASS_N(MACH,2)
ML_(blksys_complete_MACH): .quad MK_L_SCCLASS_N(MACH,3)
ML_(blksys_committed_MACH): .quad MK_L_SCCLASS_N(MACH,4)
ML_(blksys_finished_MACH): .quad MK_L_SCCLASS_N(MACH,5)
.globl ML_(blksys_setup_MDEP)
.globl ML_(blksys_restart_MDEP)
.globl ML_(blksys_complete_MDEP)
.globl ML_(blksys_committed_MDEP)
.globl ML_(blksys_finished_MDEP)
ML_(blksys_setup_MDEP): .quad MK_L_SCCLASS_N(MDEP,1)
ML_(blksys_restart_MDEP): .quad MK_L_SCCLASS_N(MDEP,2)
ML_(blksys_complete_MDEP): .quad MK_L_SCCLASS_N(MDEP,3)
ML_(blksys_committed_MDEP): .quad MK_L_SCCLASS_N(MDEP,4)
ML_(blksys_finished_MDEP): .quad MK_L_SCCLASS_N(MDEP,5)
.globl ML_(blksys_setup_UNIX)
.globl ML_(blksys_restart_UNIX)
.globl ML_(blksys_complete_UNIX)
.globl ML_(blksys_committed_UNIX)
.globl ML_(blksys_finished_UNIX)
ML_(blksys_setup_UNIX): .quad MK_L_SCCLASS_N(UNIX,1)
ML_(blksys_restart_UNIX): .quad MK_L_SCCLASS_N(UNIX,2)
ML_(blksys_complete_UNIX): .quad MK_L_SCCLASS_N(UNIX,3)
ML_(blksys_committed_UNIX): .quad MK_L_SCCLASS_N(UNIX,4)
ML_(blksys_finished_UNIX): .quad MK_L_SCCLASS_N(UNIX,5)
#endif // defined(VGP_amd64_darwin)
/* Let the linker know we don't need an executable stack */
MARK_STACK_NO_EXEC
/*--------------------------------------------------------------------*/
/*--- end ---*/
/*--------------------------------------------------------------------*/