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