diff options
Diffstat (limited to 'arch/um/sys-x86_64/stub.S')
| -rw-r--r-- | arch/um/sys-x86_64/stub.S | 50 |
1 files changed, 40 insertions, 10 deletions
diff --git a/arch/um/sys-x86_64/stub.S b/arch/um/sys-x86_64/stub.S index 957f2ef..03c2797 100644 --- a/arch/um/sys-x86_64/stub.S +++ b/arch/um/sys-x86_64/stub.S @@ -16,21 +16,51 @@ syscall_stub: .globl batch_syscall_stub batch_syscall_stub: - movq $(UML_CONFIG_STUB_DATA >> 32), %rbx - salq $32, %rbx - movq $(UML_CONFIG_STUB_DATA & 0xffffffff), %rcx - or %rcx, %rbx - movq %rbx, %rsp -again: pop %rax - cmpq $0, %rax -jz done + mov $(UML_CONFIG_STUB_DATA >> 32), %rbx + sal $32, %rbx + mov $(UML_CONFIG_STUB_DATA & 0xffffffff), %rax + or %rax, %rbx + /* load pointer to first operation */ + mov %rbx, %rsp + add $0x10, %rsp +again: + /* load length of additional data */ + mov 0x0(%rsp), %rax + + /* if(length == 0) : end of list */ + /* write possible 0 to header */ + mov %rax, 8(%rbx) + cmp $0, %rax + jz done + + /* save current pointer */ + mov %rsp, 8(%rbx) + + /* skip additional data */ + add %rax, %rsp + + /* load syscall-# */ + pop %rax + + /* load syscall params */ pop %rdi pop %rsi pop %rdx pop %r10 pop %r8 pop %r9 + + /* execute syscall */ syscall + + /* check return value */ + pop %rcx + cmp %rcx, %rax + je again + +done: + /* save return value */ mov %rax, (%rbx) - jmp again -done: int3 + + /* stop */ + int3 |