diff options
Diffstat (limited to 'arch/x86/um/stub_64.S')
| -rw-r--r-- | arch/x86/um/stub_64.S | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/arch/x86/um/stub_64.S b/arch/x86/um/stub_64.S new file mode 100644 index 000000000000..20e4a96a6dcb --- /dev/null +++ b/arch/x86/um/stub_64.S @@ -0,0 +1,66 @@ +#include "as-layout.h" + + .globl syscall_stub +.section .__syscall_stub, "ax" +syscall_stub: + syscall + /* We don't have 64-bit constants, so this constructs the address + * we need. + */ + movq $(STUB_DATA >> 32), %rbx + salq $32, %rbx + movq $(STUB_DATA & 0xffffffff), %rcx + or %rcx, %rbx + movq %rax, (%rbx) + int3 + + .globl batch_syscall_stub +batch_syscall_stub: + mov $(STUB_DATA >> 32), %rbx + sal $32, %rbx + mov $(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) + + /* stop */ + int3 |