arch/um/kernel/tt/syscall_user.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <unistd.h>
   7 #include <signal.h>
   8 #include <errno.h>
   9 #include <asm/unistd.h>
  10 #include "sysdep/ptrace.h"
  11 #include "sigcontext.h"
  12 #include "ptrace_user.h"
  13 #include "task.h"
  14 #include "user_util.h"
  15 #include "kern_util.h"
  16 #include "syscall.h"
  17 #include "tt.h"
  18
  19 void do_sigtrap(void *task)
  20 {
  21         UPT_SYSCALL_NR(TASK_REGS(task)) = -1;
  22 }
  23
  24 void do_syscall(void *task, int pid, int local_using_sysemu)
  25 {
  26         unsigned long proc_regs[FRAME_SIZE];
  27
  28         if(ptrace_getregs(pid, proc_regs) < 0)
  29                 tracer_panic("Couldn't read registers");
  30
  31         UPT_SYSCALL_NR(TASK_REGS(task)) = PT_SYSCALL_NR(proc_regs);
  32
  33 #ifdef UPT_ORIGGPR2
  34         UPT_ORIGGPR2(TASK_REGS(task)) = REGS_ORIGGPR2(proc_regs);
  35 #endif
  36
  37         if(((unsigned long *) PT_IP(proc_regs) >= &_stext) &&
  38            ((unsigned long *) PT_IP(proc_regs) <= &_etext))
  39                 tracer_panic("I'm tracing myself and I can't get out");
  40
  41         /* advanced sysemu mode set syscall number to -1 automatically */
  42         if (local_using_sysemu==2)
  43                 return;
  44
  45         /* syscall number -1 in sysemu skips syscall restarting in host */
  46         if(ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
  47                   local_using_sysemu ? -1 : __NR_getpid) < 0)
  48                 tracer_panic("do_syscall : Nullifying syscall failed, "
  49                              "errno = %d", errno);
  50 }
  51
  52 /*
  53  * Overrides for Emacs so that we follow Linus's tabbing style.
  54  * Emacs will notice this stuff at the end of the file and automatically
  55  * adjust the settings for this buffer only.  This must remain at the end
  56  * of the file.
  57  * ---------------------------------------------------------------------------
  58  * Local variables:
  59  * c-file-style: "linux"
  60  * End:
  61  */