diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S b/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S new file mode 100644 index 0000000000..97849a5b26 --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S @@ -0,0 +1,94 @@ +/* Wrapper around clone system call. + Copyright (C) 1997,98,99,2000,02 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <sysdep.h> +#define _ERRNO_H 1 +#include <bits/errno.h> +#include <bp-sym.h> +#include <bp-asm.h> + +/* This is the only really unusual system call in PPC linux, but not + because of any weirdness in the system call itself; because of + all the freaky stuff we have to do to make the call useful. */ + +/* int [r3] clone(int (*fn)(void *arg) [r3], void *child_stack [r4], + int flags [r5], void *arg [r6]); */ + +ENTRY (BP_SYM (__clone)) + /* GKM FIXME: add bounds checks, where sensible. */ + DISCARD_BOUNDS (r4) + DISCARD_BOUNDS (r6) + + /* Check for child_stack == NULL || fn == NULL. */ + cmpwi cr0,r4,0 + cmpwi cr1,r3,0 + cror cr0*4+eq,cr1*4+eq,cr0*4+eq + beq- cr0,L(badargs) + + /* Set up stack frame for parent. */ + stwu r1,-32(r1) + stmw r29,16(r1) + + /* Set up stack frame for child. */ + clrrwi r4,r4,4 + li r0,0 + stwu r0,-16(r4) + + /* Save fn, args, stack across syscall. */ + mr r29,r3 /* Function in r29. */ + mr r30,r4 /* Stack pointer in r30. */ + mr r31,r6 /* Argument in r31. */ + + /* 'flags' argument is first parameter to clone syscall. (The other + argument is the stack pointer, already in r4.) */ + mr r3,r5 + + /* Do the call. */ + DO_CALL(SYS_ify(clone)) + + /* Check for child process. */ + cmpwi cr1,r3,0 + crandc cr1*4+eq,cr1*4+eq,cr0*4+so + bne- cr1,L(parent) /* The '-' is to minimise the race. */ + + /* On at least mklinux DR3a5, clone() doesn't actually change + the stack pointer. I'm pretty sure this is a bug, because + it adds a race condition if a signal is sent to a thread + just after it is created (in the previous three instructions). */ + mr r1,r30 + /* Call procedure. */ + mtctr r29 + mr r3,r31 + bctrl + /* Call _exit with result from procedure. */ + b HIDDEN_JUMPTARGET(_exit) + +L(parent): + /* Parent. Restore registers & return. */ + lmw r29,16(r1) + addi r1,r1,32 + bnslr+ + b JUMPTARGET(__syscall_error) + +L(badargs): + li r3,EINVAL + b JUMPTARGET(__syscall_error) +END (BP_SYM (__clone)) + +weak_alias (BP_SYM (__clone), BP_SYM (clone)) |