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/* Copyright (C) 2000-2020 Free Software Foundation, Inc.
Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
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/>. */
#ifndef _LINUX_S390_SYSDEP_H
#define _LINUX_S390_SYSDEP_H
#include <sysdeps/s390/s390-32/sysdep.h>
#include <sysdeps/unix/sysdep.h>
#include <sysdeps/unix/sysv/linux/s390/sysdep.h>
#include <sysdeps/unix/sysv/linux/sysdep.h>
#include <dl-sysdep.h> /* For RTLD_PRIVATE_ERRNO. */
#include <tls.h>
/* Define __set_errno() for INLINE_SYSCALL macro below. */
#ifndef __ASSEMBLER__
#include <errno.h>
#endif
/* For Linux we can use the system call table in the header file
/usr/include/asm/unistd.h
of the kernel. But these symbols do not follow the SYS_* syntax
so we have to redefine the `SYS_ify' macro here. */
/* in newer 2.1 kernels __NR_syscall is missing so we define it here */
#define __NR_syscall 0
#undef SYS_ify
#define SYS_ify(syscall_name) __NR_##syscall_name
#ifdef __ASSEMBLER__
/* Linux uses a negative return value to indicate syscall errors, unlike
most Unices, which use the condition codes' carry flag.
Since version 2.1 the return value of a system call might be negative
even if the call succeeded. E.g., the `lseek' system call might return
a large offset. Therefore we must not anymore test for < 0, but test
for a real error by making sure the value in gpr2 is a real error
number. Linus said he will make sure that no syscall returns a value
in -1 .. -4095 as a valid result so we can savely test with -4095. */
#undef PSEUDO
#define PSEUDO(name, syscall_name, args) \
.text; \
ENTRY (name) \
DO_CALL (syscall_name, args); \
lhi %r4,-4095 ; \
clr %r2,%r4 ; \
jnl SYSCALL_ERROR_LABEL
#undef PSEUDO_END
#define PSEUDO_END(name) \
SYSCALL_ERROR_HANDLER; \
END (name)
#undef PSEUDO_NOERRNO
#define PSEUDO_NOERRNO(name, syscall_name, args) \
.text; \
ENTRY (name) \
DO_CALL (syscall_name, args)
#undef PSEUDO_END_NOERRNO
#define PSEUDO_END_NOERRNO(name) \
END (name)
#undef PSEUDO_ERRVAL
#define PSEUDO_ERRVAL(name, syscall_name, args) \
.text; \
ENTRY (name) \
DO_CALL (syscall_name, args); \
lcr %r2,%r2
#undef PSEUDO_END_ERRVAL
#define PSEUDO_END_ERRVAL(name) \
END (name)
#ifndef PIC
# define SYSCALL_ERROR_LABEL 0f
# define SYSCALL_ERROR_HANDLER \
0: basr %r1,0; \
1: l %r1,2f-1b(%r1); \
br %r1; \
2: .long syscall_error
#else
# if RTLD_PRIVATE_ERRNO
# define SYSCALL_ERROR_LABEL 0f
# define SYSCALL_ERROR_HANDLER \
0: basr %r1,0; \
1: al %r1,2f-1b(%r1); \
lcr %r2,%r2; \
st %r2,0(%r1); \
lhi %r2,-1; \
br %r14; \
2: .long rtld_errno-1b
# elif defined _LIBC_REENTRANT
# if IS_IN (libc)
# define SYSCALL_ERROR_ERRNO __libc_errno
# else
# define SYSCALL_ERROR_ERRNO errno
# endif
# define SYSCALL_ERROR_LABEL 0f
# define SYSCALL_ERROR_HANDLER \
0: lcr %r0,%r2; \
basr %r1,0; \
1: al %r1,2f-1b(%r1); \
l %r1,SYSCALL_ERROR_ERRNO@gotntpoff(%r1); \
ear %r2,%a0; \
st %r0,0(%r1,%r2); \
lhi %r2,-1; \
br %r14; \
2: .long _GLOBAL_OFFSET_TABLE_-1b
# else
# define SYSCALL_ERROR_LABEL 0f
# define SYSCALL_ERROR_HANDLER \
0: basr %r1,0; \
1: al %r1,2f-1b(%r1); \
l %r1,errno@GOT(%r1); \
lcr %r2,%r2; \
st %r2,0(%r1); \
lhi %r2,-1; \
br %r14; \
2: .long _GLOBAL_OFFSET_TABLE_-1b
# endif /* _LIBC_REENTRANT */
#endif /* PIC */
/* Linux takes system call arguments in registers:
syscall number 1 call-clobbered
arg 1 2 call-clobbered
arg 2 3 call-clobbered
arg 3 4 call-clobbered
arg 4 5 call-clobbered
arg 5 6 call-saved
arg 6 7 call-saved
(Of course a function with say 3 arguments does not have entries for
arguments 4 and 5.)
For system calls with 6 parameters a stack operation is required
to load the 6th parameter to register 7. Call saved register 7 is
moved to register 0 and back to avoid an additional stack frame.
*/
#define DO_CALL(syscall, args) \
.if args > 5; \
lr %r0,%r7; \
l %r7,96(%r15); \
.endif; \
.if SYS_ify (syscall) < 256; \
svc SYS_ify (syscall); \
.else; \
lhi %r1,SYS_ify (syscall); \
svc 0; \
.endif; \
.if args > 5; \
lr %r7,%r0; \
.endif
#define ret \
br 14
#define ret_NOERRNO \
br 14
#define ret_ERRVAL \
br 14
#endif /* __ASSEMBLER__ */
#undef INLINE_SYSCALL
#define INLINE_SYSCALL(name, nr, args...) \
({ \
unsigned int _ret = INTERNAL_SYSCALL (name, , nr, args); \
if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (_ret, ))) \
{ \
__set_errno (INTERNAL_SYSCALL_ERRNO (_ret, )); \
_ret = 0xffffffff; \
} \
(int) _ret; })
#undef INTERNAL_SYSCALL_DECL
#define INTERNAL_SYSCALL_DECL(err) do { } while (0)
#undef INTERNAL_SYSCALL_DIRECT
#define INTERNAL_SYSCALL_DIRECT(name, err, nr, args...) \
({ \
DECLARGS_##nr(args) \
register int _ret __asm__("2"); \
__asm__ __volatile__ ( \
"svc %b1\n\t" \
: "=d" (_ret) \
: "i" (__NR_##name) ASMFMT_##nr \
: "memory" ); \
_ret; })
#undef INTERNAL_SYSCALL_SVC0
#define INTERNAL_SYSCALL_SVC0(name, err, nr, args...) \
({ \
DECLARGS_##nr(args) \
register unsigned long _nr __asm__("1") = (unsigned long)(__NR_##name); \
register int _ret __asm__("2"); \
__asm__ __volatile__ ( \
"svc 0\n\t" \
: "=d" (_ret) \
: "d" (_nr) ASMFMT_##nr \
: "memory" ); \
_ret; })
#undef INTERNAL_SYSCALL_NCS
#define INTERNAL_SYSCALL_NCS(no, err, nr, args...) \
({ \
DECLARGS_##nr(args) \
register unsigned long _nr __asm__("1") = (unsigned long)(no); \
register int _ret __asm__("2"); \
__asm__ __volatile__ ( \
"svc 0\n\t" \
: "=d" (_ret) \
: "d" (_nr) ASMFMT_##nr \
: "memory" ); \
_ret; })
#undef INTERNAL_SYSCALL
#define INTERNAL_SYSCALL(name, err, nr, args...) \
(((__NR_##name) < 256) \
? INTERNAL_SYSCALL_DIRECT(name, err, nr, args) \
: INTERNAL_SYSCALL_SVC0(name, err,nr, args))
#undef INTERNAL_SYSCALL_ERROR_P
#define INTERNAL_SYSCALL_ERROR_P(val, err) \
((unsigned int) (val) >= 0xfffff001u)
#undef INTERNAL_SYSCALL_ERRNO
#define INTERNAL_SYSCALL_ERRNO(val, err) (-(val))
#define DECLARGS_0()
#define DECLARGS_1(arg1) \
register unsigned long gpr2 __asm__ ("2") = (unsigned long)(arg1);
#define DECLARGS_2(arg1, arg2) \
DECLARGS_1(arg1) \
register unsigned long gpr3 __asm__ ("3") = (unsigned long)(arg2);
#define DECLARGS_3(arg1, arg2, arg3) \
DECLARGS_2(arg1, arg2) \
register unsigned long gpr4 __asm__ ("4") = (unsigned long)(arg3);
#define DECLARGS_4(arg1, arg2, arg3, arg4) \
DECLARGS_3(arg1, arg2, arg3) \
register unsigned long gpr5 __asm__ ("5") = (unsigned long)(arg4);
#define DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
DECLARGS_4(arg1, arg2, arg3, arg4) \
register unsigned long gpr6 __asm__ ("6") = (unsigned long)(arg5);
#define DECLARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
register unsigned long gpr7 __asm__ ("7") = (unsigned long)(arg6);
#define ASMFMT_0
#define ASMFMT_1 , "0" (gpr2)
#define ASMFMT_2 , "0" (gpr2), "d" (gpr3)
#define ASMFMT_3 , "0" (gpr2), "d" (gpr3), "d" (gpr4)
#define ASMFMT_4 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5)
#define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
#define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7)
/* Pointer mangling support. */
#if IS_IN (rtld)
/* We cannot use the thread descriptor because in ld.so we use setjmp
earlier than the descriptor is initialized. */
#else
/* For the time being just use stack_guard rather than a separate
pointer_guard. */
# ifdef __ASSEMBLER__
# define PTR_MANGLE(reg, tmpreg) \
ear tmpreg,%a0; \
x reg,STACK_GUARD(tmpreg)
# define PTR_MANGLE2(reg, tmpreg) \
x reg,STACK_GUARD(tmpreg)
# define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
# else
# define PTR_MANGLE(var) \
(var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
# define PTR_DEMANGLE(var) PTR_MANGLE (var)
# endif
#endif
#endif /* _LINUX_S390_SYSDEP_H */
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