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

   1 /*
   2  * Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <signal.h>
   7 #include <errno.h>
   8 #include "kern_util.h"
   9 #include "as-layout.h"
  10 #include "task.h"
  11 #include "sigcontext.h"
  12 #include "skas.h"
  13 #include "ptrace_user.h"
  14 #include "sysdep/ptrace.h"
  15 #include "sysdep/ptrace_user.h"
  16 #include "os.h"
  17
  18 static union uml_pt_regs ksig_regs[UM_NR_CPUS];
  19
  20 void sig_handler_common_skas(int sig, void *sc_ptr)
  21 {
  22         struct sigcontext *sc = sc_ptr;
  23         union uml_pt_regs *r;
  24         void (*handler)(int, union uml_pt_regs *);
  25         int save_user, save_errno = errno;
  26
  27         /* This is done because to allow SIGSEGV to be delivered inside a SEGV
  28          * handler.  This can happen in copy_user, and if SEGV is disabled,
  29          * the process will die.
  30          * XXX Figure out why this is better than SA_NODEFER
  31          */
  32         if(sig == SIGSEGV) {
  33                 change_sig(SIGSEGV, 1);
  34                 /* For segfaults, we want the data from the
  35                  * sigcontext.  In this case, we don't want to mangle
  36                  * the process registers, so use a static set of
  37                  * registers.  For other signals, the process
  38                  * registers are OK.
  39                  */
  40                 r = &ksig_regs[cpu()];
  41                 copy_sc(r, sc_ptr);
  42         }
  43         else r = TASK_REGS(get_current());
  44
  45         save_user = r->skas.is_user;
  46         r->skas.is_user = 0;
  47         if ( sig == SIGFPE || sig == SIGSEGV ||
  48              sig == SIGBUS || sig == SIGILL ||
  49              sig == SIGTRAP ) {
  50                 GET_FAULTINFO_FROM_SC(r->skas.faultinfo, sc);
  51         }
  52
  53         change_sig(SIGUSR1, 1);
  54
  55         handler = sig_info[sig];
  56
  57         /* unblock SIGALRM, SIGVTALRM, SIGIO if sig isn't IRQ signal */
  58         if (sig != SIGIO && sig != SIGWINCH &&
  59             sig != SIGVTALRM && sig != SIGALRM)
  60                 unblock_signals();
  61
  62         handler(sig, r);
  63
  64         errno = save_errno;
  65         r->skas.is_user = save_user;
  66 }