arch/um/os-Linux/skas/trap.c

   1 /*
   2  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #if 0
   7 #include "kern_util.h"
   8 #include "skas.h"
   9 #include "ptrace_user.h"
  10 #include "sysdep/ptrace_user.h"
  11 #endif
  12
  13 #include <errno.h>
  14 #include <signal.h>
  15 #include "sysdep/ptrace.h"
  16 #include "kern_constants.h"
  17 #include "as-layout.h"
  18 #include "os.h"
  19 #include "sigcontext.h"
  20 #include "task.h"
  21
  22 static struct uml_pt_regs ksig_regs[UM_NR_CPUS];
  23
  24 void sig_handler_common_skas(int sig, void *sc_ptr)
  25 {
  26         struct sigcontext *sc = sc_ptr;
  27         struct uml_pt_regs *r;
  28         void (*handler)(int, struct uml_pt_regs *);
  29         int save_user, save_errno = errno;
  30
  31         /*
  32          * This is done because to allow SIGSEGV to be delivered inside a SEGV
  33          * handler.  This can happen in copy_user, and if SEGV is disabled,
  34          * the process will die.
  35          * XXX Figure out why this is better than SA_NODEFER
  36          */
  37         if (sig == SIGSEGV) {
  38                 change_sig(SIGSEGV, 1);
  39                 /*
  40                  * For segfaults, we want the data from the
  41                  * sigcontext.  In this case, we don't want to mangle
  42                  * the process registers, so use a static set of
  43                  * registers.  For other signals, the process
  44                  * registers are OK.
  45                  */
  46                 r = &ksig_regs[cpu()];
  47                 copy_sc(r, sc_ptr);
  48         }
  49         else r = TASK_REGS(get_current());
  50
  51         save_user = r->is_user;
  52         r->is_user = 0;
  53         if ((sig == SIGFPE) || (sig == SIGSEGV) || (sig == SIGBUS) ||
  54             (sig == SIGILL) || (sig == SIGTRAP))
  55                 GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
  56
  57         change_sig(SIGUSR1, 1);
  58
  59         handler = sig_info[sig];
  60
  61         /* unblock SIGVTALRM, SIGIO if sig isn't IRQ signal */
  62         if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGVTALRM))
  63                 unblock_signals();
  64
  65         handler(sig, r);
  66
  67         errno = save_errno;
  68         r->is_user = save_user;
  69 }