diff options
Diffstat (limited to 'usr/klibc/arch/i386/vfork.S')
| -rw-r--r-- | usr/klibc/arch/i386/vfork.S | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/usr/klibc/arch/i386/vfork.S b/usr/klibc/arch/i386/vfork.S new file mode 100644 index 0000000..d32b9b9 --- /dev/null +++ b/usr/klibc/arch/i386/vfork.S @@ -0,0 +1,29 @@ +# +# usr/klibc/arch/i386/vfork.S +# +# vfork is nasty - there must be nothing at all on the stack above +# the stack frame of the enclosing function. +# +# We *MUST* use int $0x80, because calling the vdso would screw up +# our stack handling. +# + +#include <asm/unistd.h> + + .text + .align 4 + .globl vfork + .type vfork, @function +vfork: + popl %edx /* Return address */ + movl $__NR_vfork, %eax + int $0x80 /* DO NOT call the vdso here! */ + pushl %edx + cmpl $-4095, %eax + jae 1f + ret +1: + negl %eax + movl %eax, errno + orl $-1, %eax + ret |