arch/um/kernel/tt/trap_user.c

   1 /*
   2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stdlib.h>
   7 #include <errno.h>
   8 #include <signal.h>
   9 #include "sysdep/ptrace.h"
  10 #include "sysdep/sigcontext.h"
  11 #include "user_util.h"
  12 #include "kern_util.h"
  13 #include "task.h"
  14 #include "tt.h"
  15 #include "os.h"
  16
  17 void sig_handler_common_tt(int sig, void *sc_ptr)
  18 {
  19         struct sigcontext *sc = sc_ptr;
  20         struct tt_regs save_regs, *r;
  21         int save_errno = errno, is_user = 0;
  22         void (*handler)(int, union uml_pt_regs *);
  23
  24         /* This is done because to allow SIGSEGV to be delivered inside a SEGV
  25          * handler.  This can happen in copy_user, and if SEGV is disabled,
  26          * the process will die.
  27          */
  28         if(sig == SIGSEGV)
  29                 change_sig(SIGSEGV, 1);
  30
  31         r = &TASK_REGS(get_current())->tt;
  32         if ( sig == SIGFPE || sig == SIGSEGV ||
  33              sig == SIGBUS || sig == SIGILL ||
  34              sig == SIGTRAP ) {
  35                 GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
  36         }
  37         save_regs = *r;
  38         if (sc)
  39                 is_user = user_context(SC_SP(sc));
  40         r->sc = sc;
  41         if(sig != SIGUSR2)
  42                 r->syscall = -1;
  43
  44         handler = sig_info[sig];
  45
  46         /* unblock SIGALRM, SIGVTALRM, SIGIO if sig isn't IRQ signal */
  47         if (sig != SIGIO && sig != SIGWINCH &&
  48             sig != SIGVTALRM && sig != SIGALRM)
  49                 unblock_signals();
  50
  51         handler(sig, (union uml_pt_regs *) r);
  52
  53         if(is_user){
  54                 interrupt_end();
  55                 block_signals();
  56                 set_user_mode(NULL);
  57         }
  58         *r = save_regs;
  59         errno = save_errno;
  60 }
  61
  62 /*
  63  * Overrides for Emacs so that we follow Linus's tabbing style.
  64  * Emacs will notice this stuff at the end of the file and automatically
  65  * adjust the settings for this buffer only.  This must remain at the end
  66  * of the file.
  67  * ---------------------------------------------------------------------------
  68  * Local variables:
  69  * c-file-style: "linux"
  70  * End:
  71  */