linux/arch/um/sys-x86_64/stub.S
Jeff Dike 4bdf8bc4a1 uml: borrow const.h techniques
Suggested by Geert Uytterhoeven - use const.h to get constants that are usable
in both C and assembly.  I can't include it directly since this code can't
include kernel headers.  const.h is also for numeric constants that can be
typed by tacking a "UL" or similar on the end.  The constants here have to be
typed by casting them.

So, the relevant parts of const.h are copied here and modified in order to
allow the constants to be uncasted in assembly and casted in C.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:26 -08:00

67 lines
1.1 KiB
ArmAsm

#include "uml-config.h"
#include "as-layout.h"
.globl syscall_stub
.section .__syscall_stub, "x"
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