Retro68/gcc/libgo/go/syscall/clone_linux.c
2017-10-07 02:16:47 +02:00

103 lines
3.0 KiB
C

/* clone_linux.c -- consistent wrapper around Linux clone syscall
Copyright 2016 The Go Authors. All rights reserved.
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file. */
#include <errno.h>
#include <sys/syscall.h>
#include "runtime.h"
long rawClone (unsigned long flags, void *child_stack, void *ptid,
void *ctid, void *regs)
__asm__ (GOSYM_PREFIX "syscall.rawClone")
__attribute__ ((no_split_stack));
long
rawClone (unsigned long flags, void *child_stack, void *ptid, void *ctid, void *regs)
{
#if defined(__arc__) || defined(__aarch64__) || defined(__arm__) || defined(__mips__) || defined(__hppa__) || defined(__powerpc__) || defined(__score__) || defined(__i386__) || defined(__xtensa__)
// CLONE_BACKWARDS
return syscall(__NR_clone, flags, child_stack, ptid, regs, ctid);
#elif defined(__s390__) || defined(__cris__)
// CLONE_BACKWARDS2
return syscall(__NR_clone, child_stack, flags, ptid, ctid, regs);
#elif defined(__microblaze__)
// CLONE_BACKWARDS3
return syscall(__NR_clone, flags, child_stack, 0, ptid, ctid, regs);
#elif defined(__sparc__)
/* SPARC has a unique return value convention:
Parent --> %o0 == child's pid, %o1 == 0
Child --> %o0 == parent's pid, %o1 == 1
Translate this to look like a normal clone. */
# if defined(__arch64__)
# define SYSCALL_STRING \
"ta 0x6d;" \
"bcc,pt %%xcc, 1f;" \
" mov 0, %%g1;" \
"sub %%g0, %%o0, %%o0;" \
"mov 1, %%g1;" \
"1:"
# define SYSCALL_CLOBBERS \
"f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
"f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \
"f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", \
"f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31", \
"f32", "f34", "f36", "f38", "f40", "f42", "f44", "f46", \
"f48", "f50", "f52", "f54", "f56", "f58", "f60", "f62", \
"cc", "memory"
# else /* __arch64__ */
# define SYSCALL_STRING \
"ta 0x10;" \
"bcc 1f;" \
" mov 0, %%g1;" \
"sub %%g0, %%o0, %%o0;" \
"mov 1, %%g1;" \
"1:"
# define SYSCALL_CLOBBERS \
"f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
"f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \
"f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", \
"f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31", \
"cc", "memory"
# endif /* __arch64__ */
register long o0 __asm__ ("o0") = (long)flags;
register long o1 __asm__ ("o1") = (long)child_stack;
register long o2 __asm__ ("o2") = (long)ptid;
register long o3 __asm__ ("o3") = (long)ctid;
register long o4 __asm__ ("o4") = (long)regs;
register long g1 __asm__ ("g1") = __NR_clone;
__asm __volatile (SYSCALL_STRING :
"=r" (g1), "=r" (o0), "=r" (o1) :
"0" (g1), "1" (o0), "2" (o1),
"r" (o2), "r" (o3), "r" (o4) :
SYSCALL_CLOBBERS);
if (__builtin_expect(g1 != 0, 0))
{
errno = -o0;
o0 = -1L;
}
else
o0 &= (o1 - 1);
return o0;
#else
return syscall(__NR_clone, flags, child_stack, ptid, ctid, regs);
#endif
}