diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/powerpc/clone.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/powerpc/clone.S | 78 |
1 files changed, 41 insertions, 37 deletions
diff --git a/sysdeps/unix/sysv/linux/powerpc/clone.S b/sysdeps/unix/sysv/linux/powerpc/clone.S index 6209922b6b..69d2c5f586 100644 --- a/sysdeps/unix/sysv/linux/powerpc/clone.S +++ b/sysdeps/unix/sysv/linux/powerpc/clone.S @@ -1,5 +1,5 @@ /* Wrapper around clone system call. - Copyright (C) 1997 Free Software Foundation, Inc. + Copyright (C) 1997, 1998 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 @@ -28,56 +28,60 @@ /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */ ENTRY(__clone) - /* Set up stack frame, save registers. */ - stwu %r1,-32(%r1) /* Check for child_stack == NULL || fn == NULL. */ - cmpwi %cr0,%r4,0 - stw %r31,16(%r1) - cmpwi %cr1,%r3,0 - stw %r30,20(%r1) - beq- %cr0,badargs - beq- %cr1,badargs + 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. */ - addi %r4,%r4,-16 - clrrwi %r4,%r4,4 - li %r0,0 - stw %r0,0(%r4) + clrrwi %r4,%r4,4 + li %r0,0 + stwu %r0,-16(%r4) - /* Save fn, args across syscall. */ - mr %r30,%r3 /* Function in r30. */ - mr %r31,%r6 /* Arguments in r31. */ + /* 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 + mr %r3,%r5 /* Do the call. */ DO_CALL(SYS_ify(clone)) - bso- error - beq child - /* Parent. Restore registers & return. */ - lwz %r31,16(%r1) - lwz %r30,20(%r1) - addi %r1,%r1,32 - blr + /* 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. */ -child: + /* 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. */ - mtlr %r30 - mr %r3,%r31 - blrl + mtctr %r29 + mr %r3,%r31 + bctrl /* Call _exit with result from procedure. */ - b JUMPTARGET(_exit) - -badargs: - li %r3,EINVAL -error: - lwz %r31,16(%r1) - lwz %r30,20(%r1) - addi %r1,%r1,32 - b JUMPTARGET(__syscall_error) + b 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 (__clone) weak_alias (__clone, clone) |