arch/um/sys-x86_64/syscall_table.c

   1 /*
   2  * System call table for UML/x86-64, copied from arch/x86_64/kernel/syscall.c
   3  * with some changes for UML.
   4  */
   5
   6 #include <linux/linkage.h>
   7 #include <linux/sys.h>
   8 #include <linux/cache.h>
   9 #include <kern_constants.h>
  10
  11 #define __NO_STUBS
  12
  13 /*
  14  * Below you can see, in terms of #define's, the differences between the x86-64
  15  * and the UML syscall table.
  16  */
  17
  18 /* Not going to be implemented by UML, since we have no hardware. */
  19 #define stub_iopl sys_ni_syscall
  20 #define sys_ioperm sys_ni_syscall
  21
  22 /*
  23  * The UML TLS problem. Note that x86_64 does not implement this, so the below
  24  * is needed only for the ia32 compatibility.
  25  */
  26
  27 /* On UML we call it this way ("old" means it's not mmap2) */
  28 #define sys_mmap old_mmap
  29
  30 #define stub_clone sys_clone
  31 #define stub_fork sys_fork
  32 #define stub_vfork sys_vfork
  33 #define stub_execve sys_execve
  34 #define stub_rt_sigsuspend sys_rt_sigsuspend
  35 #define stub_sigaltstack sys_sigaltstack
  36 #define stub_rt_sigreturn sys_rt_sigreturn
  37
  38 #define __SYSCALL(nr, sym) extern asmlinkage void sym(void) ;
  39 #undef _ASM_X86_UNISTD_64_H
  40 #include "../../x86/include/asm/unistd_64.h"
  41
  42 #undef __SYSCALL
  43 #define __SYSCALL(nr, sym) [ nr ] = sym,
  44 #undef _ASM_X86_UNISTD_64_H
  45
  46 typedef void (*sys_call_ptr_t)(void);
  47
  48 extern void sys_ni_syscall(void);
  49
  50 /*
  51  * We used to have a trick here which made sure that holes in the
  52  * x86_64 table were filled in with sys_ni_syscall, but a comment in
  53  * unistd_64.h says that holes aren't allowed, so the trick was
  54  * removed.
  55  * The trick looked like this
  56  *      [0 ... UM_NR_syscall_max] = &sys_ni_syscall
  57  * before including unistd_64.h - the later initializations overwrote
  58  * the sys_ni_syscall filler.
  59  */
  60
  61 sys_call_ptr_t sys_call_table[] __cacheline_aligned = {
  62 #include "../../x86/include/asm/unistd_64.h"
  63 };
  64
  65 int syscall_table_size = sizeof(sys_call_table);