glibc/sysdeps/unix/sysv/linux/s390/sysdep.h
Stefan Liebler e57d8fc97b S390: Always use svc 0
On s390x syscalls are triggered by svc instruction. One can
pass the syscall number encoded in the instruction "svc 123"
or by storing it in r1:
lghi r1,123
svc 0

If the syscall number is encoded in the instruction, this can
cause broken syscall restarts.  Therefore this patch is now just
passing the syscall number in r1.

See also kernel-commit:
"s390/signal: switch to using vdso for sigreturn and syscall restart"
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/s390/[%e2%80%a6]call.c?h=v6.0-rc1&id=df29a7440c4b5c65765c8f60396b3b13063e24e9

As information, the "svc 0" feature was introduced in kernel 2.5.62:
commit b5aad611393ef2e132e3648fa4c6e56a9cfa8708
2022-08-30 10:54:46 +02:00

83 lines
3.2 KiB
C

/* Syscall definitions, Linux s390 version.
Copyright (C) 2019-2022 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
<http://www.gnu.org/licenses/>. */
#ifndef __ASSEMBLY__
#undef SYS_ify
#define SYS_ify(syscall_name) __NR_##syscall_name
#undef INTERNAL_SYSCALL_NCS
#define INTERNAL_SYSCALL_NCS(no, nr, args...) \
({ \
DECLARGS_##nr(args) \
register unsigned long int _nr __asm__("1") = (unsigned long int)(no); \
register long 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, nr, args...) \
INTERNAL_SYSCALL_NCS(__NR_##name, nr, args)
#define DECLARGS_0()
#define DECLARGS_1(arg1) \
register unsigned long int gpr2 __asm__ ("2") = (unsigned long int)(arg1);
#define DECLARGS_2(arg1, arg2) \
DECLARGS_1(arg1) \
register unsigned long int gpr3 __asm__ ("3") = (unsigned long int)(arg2);
#define DECLARGS_3(arg1, arg2, arg3) \
DECLARGS_2(arg1, arg2) \
register unsigned long int gpr4 __asm__ ("4") = (unsigned long int)(arg3);
#define DECLARGS_4(arg1, arg2, arg3, arg4) \
DECLARGS_3(arg1, arg2, arg3) \
register unsigned long int gpr5 __asm__ ("5") = (unsigned long int)(arg4);
#define DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
DECLARGS_4(arg1, arg2, arg3, arg4) \
register unsigned long int gpr6 __asm__ ("6") = (unsigned long int)(arg5);
#define DECLARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
register unsigned long int gpr7 __asm__ ("7") = (unsigned long int)(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)
#define VDSO_NAME "LINUX_2.6.29"
#define VDSO_HASH 123718585
/* List of system calls which are supported as vsyscalls. */
#ifdef __s390x__
#define HAVE_CLOCK_GETRES64_VSYSCALL "__kernel_clock_getres"
#define HAVE_CLOCK_GETTIME64_VSYSCALL "__kernel_clock_gettime"
#else
#define HAVE_CLOCK_GETRES_VSYSCALL "__kernel_clock_getres"
#define HAVE_CLOCK_GETTIME_VSYSCALL "__kernel_clock_gettime"
#endif
#define HAVE_GETTIMEOFDAY_VSYSCALL "__kernel_gettimeofday"
#define HAVE_GETCPU_VSYSCALL "__kernel_getcpu"
#endif