arch/um/kernel/skas/syscall.c

   1 /*
   2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/sys.h"
   7 #include "linux/ptrace.h"
   8 #include "asm/errno.h"
   9 #include "asm/unistd.h"
  10 #include "asm/ptrace.h"
  11 #include "asm/current.h"
  12 #include "sysdep/syscalls.h"
  13 #include "kern_util.h"
  14 #include "syscall.h"
  15
  16 void handle_syscall(union uml_pt_regs *r)
  17 {
  18         struct pt_regs *regs = container_of(r, struct pt_regs, regs);
  19         long result;
  20         int syscall;
  21 #ifdef UML_CONFIG_SYSCALL_DEBUG
  22         int index;
  23
  24         index = record_syscall_start(UPT_SYSCALL_NR(r));
  25 #endif
  26         syscall_trace(r, 0);
  27
  28         current->thread.nsyscalls++;
  29         nsyscalls++;
  30
  31         /* This should go in the declaration of syscall, but when I do that,
  32          * strace -f -c bash -c 'ls ; ls' breaks, sometimes not tracing
  33          * children at all, sometimes hanging when bash doesn't see the first
  34          * ls exit.
  35          * The assembly looks functionally the same to me.  This is
  36          *     gcc version 4.0.1 20050727 (Red Hat 4.0.1-5)
  37          * in case it's a compiler bug.
  38          */
  39         syscall = UPT_SYSCALL_NR(r);
  40         if((syscall >= NR_syscalls) || (syscall < 0))
  41                 result = -ENOSYS;
  42         else result = EXECUTE_SYSCALL(syscall, regs);
  43
  44         REGS_SET_SYSCALL_RETURN(r->skas.regs, result);
  45
  46         syscall_trace(r, 1);
  47 #ifdef UML_CONFIG_SYSCALL_DEBUG
  48         record_syscall_end(index, result);
  49 #endif
  50 }