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/*--- Support for doing system calls. syscall-s390x-linux.S ---*/
This file is part of Valgrind, a dynamic binary instrumentation
Copyright IBM Corp. 2010-2013
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
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.
/* Contributed by Christian Borntraeger */
#include "pub_core_basics_asm.h"
#include "pub_core_vkiscnums_asm.h"
#include "libvex_guest_offsets.h"
#if defined(VGA_s390x)
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 NIP in the signal
handler. This means that we can always do the appropriate
thing to precisely emulate the kernel's signal/syscall
The syscall number is taken from the argument, since the syscall
number can be encoded in the svc instruction itself.
The syscall result is written back to guest register r2.
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
UWord ML_(do_syscall_for_client_WRK)(
Int syscallno, // r2
void* guest_state, // r3
const vki_sigset_t *sysmask, // r4
const vki_sigset_t *postmask, // r5
Int nsigwords) // r6
/* from vki_arch.h */
#define SP_SAVE 16
#define SP_R2 SP_SAVE + 0*8
#define SP_R3 SP_SAVE + 1*8
#define SP_R4 SP_SAVE + 2*8
#define SP_R5 SP_SAVE + 3*8
#define SP_R6 SP_SAVE + 4*8
#define SP_R7 SP_SAVE + 5*8
#define SP_R8 SP_SAVE + 6*8
#define SP_R9 SP_SAVE + 7*8
.align 4
.globl ML_(do_syscall_for_client_WRK)
1: /* Even though we can't take a signal until the sigprocmask completes,
start the range early.
If IA is in the range [1,2), the syscall hasn't been started yet */
/* Set the signal mask which should be current during the syscall. */
/* Save and restore all the parameters and all the registers that
we clobber (r6-r9) */
stmg %r2,%r9, SP_R2(%r15)
lghi %r2, VKI_SIG_SETMASK /* how */
lgr %r3, %r4 /* sysmask */
lgr %r4, %r5 /* postmask */
lgr %r5, %r6 /* nsigwords */
svc __NR_rt_sigprocmask
cghi %r2, 0x0
jne 7f /* sigprocmask failed */
/* OK, that worked. Now do the syscall proper. */
lg %r9, SP_R3(%r15) /* guest state --> r9 */
lg %r2, OFFSET_s390x_r2(%r9) /* guest r2 --> real r2 */
lg %r3, OFFSET_s390x_r3(%r9) /* guest r3 --> real r3 */
lg %r4, OFFSET_s390x_r4(%r9) /* guest r4 --> real r4 */
lg %r5, OFFSET_s390x_r5(%r9) /* guest r5 --> real r5 */
lg %r6, OFFSET_s390x_r6(%r9) /* guest r6 --> real r6 */
lg %r7, OFFSET_s390x_r7(%r9) /* guest r7 --> real r7 */
lg %r1, SP_R2(%r15) /* syscallno -> r1 */
2: svc 0
stg %r2, OFFSET_s390x_r2(%r9)
4: /* Re-block signals. If IA is in [4,5), then the syscall
is complete and we needn't worry about it. */
lghi %r2, VKI_SIG_SETMASK /* how */
lg %r3, SP_R5(%r15) /* postmask */
lghi %r4, 0x0 /* NULL */
lg %r5, SP_R6(%r15) /* nsigwords */
svc __NR_rt_sigprocmask
cghi %r2, 0x0
jne 7f /* sigprocmask failed */
5: /* Everyting ok. Return 0 and restore the call-saved
registers, that we have clobbered */
lghi %r2, 0x0
lmg %r6,%r9, SP_R6(%r15)
br %r14
7: /* Some problem. Return 0x8000 | error and restore the call-saved
registers we have clobbered. */
nill %r2, 0x7fff
oill %r2, 0x8000
lmg %r6,%r9, SP_R6(%r15)
br %r14
.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)
/* The compiler can assume that 8 byte data elements are aligned on 8 byte */
.align 8
ML_(blksys_setup): .quad 1b
ML_(blksys_restart): .quad 2b
ML_(blksys_complete): .quad 3b
ML_(blksys_committed): .quad 4b
ML_(blksys_finished): .quad 5b
/* Let the linker know we don't need an executable stack */
.section .note.GNU-stack,"",@progbits
#endif /* VGA_s390x */
/*--- end ---*/