kernel/system/do_sigsend.c

   1 /* The kernel call that is implemented in this file:
   2  *   m_type:    SYS_SIGSEND
   3  *
   4  * The parameters for this kernel call are:
   5  *     m2_i1:   SIG_ENDPT       # process to call signal handler
   6  *     m2_p1:   SIG_CTXT_PTR    # pointer to sigcontext structure
   7  *     m2_i3:   SIG_FLAGS       # flags for S_SIGRETURN call
   8  *
   9  */
  10
  11 #include "../system.h"
  12 #include <signal.h>
  13 #include <string.h>
  14 #include <sys/sigcontext.h>
  15
  16 #if USE_SIGSEND
  17
  18 /*===========================================================================*
  19  *                            do_sigsend                                     *
  20  *===========================================================================*/
  21 PUBLIC int do_sigsend(m_ptr)
  22 message *m_ptr;                 /* pointer to request message */
  23 {
  24 /* Handle sys_sigsend, POSIX-style signal handling. */
  25
  26   struct sigmsg smsg;
  27   register struct proc *rp;
  28   phys_bytes src_phys, dst_phys;
  29   struct sigcontext sc, *scp;
  30   struct sigframe fr, *frp;
  31   int proc;
  32
  33   if (!isokendpt(m_ptr->SIG_ENDPT, &proc)) return(EINVAL);
  34   if (iskerneln(proc)) return(EPERM);
  35   rp = proc_addr(proc);
  36
  37   /* Get the sigmsg structure into our address space.  */
  38   src_phys = umap_local(proc_addr(PM_PROC_NR), D, (vir_bytes)
  39       m_ptr->SIG_CTXT_PTR, (vir_bytes) sizeof(struct sigmsg));
  40   if (src_phys == 0) return(EFAULT);
  41   phys_copy(src_phys,vir2phys(&smsg),(phys_bytes) sizeof(struct sigmsg));
  42
  43   /* Compute the user stack pointer where sigcontext will be stored. */
  44   scp = (struct sigcontext *) smsg.sm_stkptr - 1;
  45
  46   /* Copy the registers to the sigcontext structure. */
  47   memcpy(&sc.sc_regs, (char *) &rp->p_reg, sizeof(struct sigregs));
  48 #ifdef POWERPC
  49   memcpy(&sc.sc_regs, (char *) &rp->p_reg, struct(stackframe_s));
  50 #else
  51   memcpy(&sc.sc_regs, (char *) &rp->p_reg, sizeof(struct sigregs));
  52 #endif
  53
  54   /* Finish the sigcontext initialization. */
  55   sc.sc_flags = 0;      /* unused at this time */
  56   sc.sc_mask = smsg.sm_mask;
  57
  58   /* Copy the sigcontext structure to the user's stack. */
  59   dst_phys = umap_local(rp, D, (vir_bytes) scp,
  60       (vir_bytes) sizeof(struct sigcontext));
  61   if (dst_phys == 0) return(EFAULT);
  62   phys_copy(vir2phys(&sc), dst_phys, (phys_bytes) sizeof(struct sigcontext));
  63
  64   /* Initialize the sigframe structure. */
  65   frp = (struct sigframe *) scp - 1;
  66   fr.sf_scpcopy = scp;
  67   fr.sf_retadr2= (void (*)()) rp->p_reg.pc;
  68   fr.sf_fp = rp->p_reg.fp;
  69   rp->p_reg.fp = (reg_t) &frp->sf_fp;
  70   fr.sf_scp = scp;
  71   fr.sf_code = 0;       /* XXX - should be used for type of FP exception */
  72   fr.sf_signo = smsg.sm_signo;
  73   fr.sf_retadr = (void (*)()) smsg.sm_sigreturn;
  74
  75   /* Copy the sigframe structure to the user's stack. */
  76   dst_phys = umap_local(rp, D, (vir_bytes) frp,
  77       (vir_bytes) sizeof(struct sigframe));
  78   if (dst_phys == 0) return(EFAULT);
  79   phys_copy(vir2phys(&fr), dst_phys, (phys_bytes) sizeof(struct sigframe));
  80
  81 #if ( _MINIX_CHIP == _CHIP_POWERPC )  /* stuff that can't be done in the assembler code. */
  82   /* When the signal handlers C code is called it will write this value
  83    * into the signal frame (over the sf_retadr value).
  84    */
  85   rp->p_reg.lr = smsg.sm_sigreturn;
  86   /* The first (and only) parameter for the user signal handler function.
  87    */
  88   rp->p_reg.retreg = smsg.sm_signo;  /* note the retreg == first argument */
  89 #endif
  90
  91   /* Reset user registers to execute the signal handler. */
  92   rp->p_reg.sp = (reg_t) frp;
  93   rp->p_reg.pc = (reg_t) smsg.sm_sighandler;
  94
  95   /* Reschedule if necessary. */
  96   if(RTS_ISSET(rp, NO_PRIORITY))
  97         RTS_LOCK_UNSET(rp, NO_PRIORITY);
  98   else
  99         kprintf("system: warning: sigsend a running process\n");
 100
 101   return(OK);
 102 }
 103
 104 #endif /* USE_SIGSEND */
 105