arch/um/kernel/skas/syscall.c

   1 /*
   2  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/kernel.h"
   7 #include "linux/ptrace.h"
   8 #include "kern_util.h"
   9 #include "sysdep/ptrace.h"
  10 #include "sysdep/syscalls.h"
  11
  12 extern int syscall_table_size;
  13 #define NR_SYSCALLS (syscall_table_size / sizeof(void *))
  14
  15 void handle_syscall(struct uml_pt_regs *r)
  16 {
  17         struct pt_regs *regs = container_of(r, struct pt_regs, regs);
  18         long result;
  19         int syscall;
  20
  21         syscall_trace(r, 0);
  22
  23         /*
  24          * This should go in the declaration of syscall, but when I do that,
  25          * strace -f -c bash -c 'ls ; ls' breaks, sometimes not tracing
  26          * children at all, sometimes hanging when bash doesn't see the first
  27          * ls exit.
  28          * The assembly looks functionally the same to me.  This is
  29          *     gcc version 4.0.1 20050727 (Red Hat 4.0.1-5)
  30          * in case it's a compiler bug.
  31          */
  32         syscall = UPT_SYSCALL_NR(r);
  33         if ((syscall >= NR_SYSCALLS) || (syscall < 0))
  34                 result = -ENOSYS;
  35         else result = EXECUTE_SYSCALL(syscall, regs);
  36
  37         REGS_SET_SYSCALL_RETURN(r->gp, result);
  38
  39         syscall_trace(r, 1);
  40 }