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  *      m_sigcalls.endpt        # process to call signal handler
   6  *      m_sigcalls.sigctx       # pointer to sigcontext structure
   7  *
   8  */
   9
  10 #include "kernel/system.h"
  11 #include <signal.h>
  12 #include <string.h>
  13
  14 #if USE_SIGSEND
  15
  16 /*===========================================================================*
  17  *                            do_sigsend                                     *
  18  *===========================================================================*/
  19 int do_sigsend(struct proc * caller, message * m_ptr)
  20 {
  21 /* Handle sys_sigsend, POSIX-style signal handling. */
  22
  23   struct sigmsg smsg;
  24   register struct proc *rp;
  25   struct sigframe_sigcontext fr, *frp;
  26   int proc_nr, r;
  27
  28   if (!isokendpt(m_ptr->m_sigcalls.endpt, &proc_nr)) return EINVAL;
  29   if (iskerneln(proc_nr)) return EPERM;
  30   rp = proc_addr(proc_nr);
  31
  32   /* Get the sigmsg structure into our address space.  */
  33   if ((r = data_copy_vmcheck(caller, caller->p_endpoint,
  34                 (vir_bytes)m_ptr->m_sigcalls.sigctx, KERNEL,
  35                 (vir_bytes)&smsg, (phys_bytes) sizeof(struct sigmsg))) != OK)
  36         return r;
  37
  38   /* Compute the user stack pointer where sigframe will start. */
  39   smsg.sm_stkptr = arch_get_sp(rp);
  40   frp = (struct sigframe_sigcontext *) smsg.sm_stkptr - 1;
  41
  42   /* Copy the registers to the sigcontext structure. */
  43   memset(&fr, 0, sizeof(fr));
  44   fr.sf_scp = &frp->sf_sc;
  45
  46 #if defined(__i386__)
  47   fr.sf_sc.sc_gs = rp->p_reg.gs;
  48   fr.sf_sc.sc_fs = rp->p_reg.fs;
  49   fr.sf_sc.sc_es = rp->p_reg.es;
  50   fr.sf_sc.sc_ds = rp->p_reg.ds;
  51   fr.sf_sc.sc_edi = rp->p_reg.di;
  52   fr.sf_sc.sc_esi = rp->p_reg.si;
  53   fr.sf_sc.sc_ebp = rp->p_reg.fp;
  54   fr.sf_sc.sc_ebx = rp->p_reg.bx;
  55   fr.sf_sc.sc_edx = rp->p_reg.dx;
  56   fr.sf_sc.sc_ecx = rp->p_reg.cx;
  57   fr.sf_sc.sc_eax = rp->p_reg.retreg;
  58   fr.sf_sc.sc_eip = rp->p_reg.pc;
  59   fr.sf_sc.sc_cs = rp->p_reg.cs;
  60   fr.sf_sc.sc_eflags = rp->p_reg.psw;
  61   fr.sf_sc.sc_esp = rp->p_reg.sp;
  62   fr.sf_sc.sc_ss = rp->p_reg.ss;
  63   fr.sf_fp = rp->p_reg.fp;
  64   fr.sf_signum = smsg.sm_signo;
  65   rp->p_reg.fp = (reg_t) &frp->sf_fp;
  66   fr.sf_scpcopy = fr.sf_scp;
  67   fr.sf_ra_sigreturn = smsg.sm_sigreturn;
  68   fr.sf_ra= rp->p_reg.pc;
  69
  70   fr.sf_sc.trap_style = rp->p_seg.p_kern_trap_style;
  71
  72   if (fr.sf_sc.trap_style == KTS_NONE) {
  73         printf("do_sigsend: sigsend an unsaved process\n");
  74         return EINVAL;
  75   }
  76
  77     if (proc_used_fpu(rp)) {
  78             /* save the FPU context before saving it to the sig context */
  79             save_fpu(rp);
  80             memcpy(&fr.sf_sc.sc_fpu_state, rp->p_seg.fpu_state, FPU_XFP_SIZE);
  81     }
  82 #endif
  83
  84 #if defined(__arm__)
  85   fr.sf_sc.sc_spsr = rp->p_reg.psr;
  86   fr.sf_sc.sc_r0 = rp->p_reg.retreg;
  87   fr.sf_sc.sc_r1 = rp->p_reg.r1;
  88   fr.sf_sc.sc_r2 = rp->p_reg.r2;
  89   fr.sf_sc.sc_r3 = rp->p_reg.r3;
  90   fr.sf_sc.sc_r4 = rp->p_reg.r4;
  91   fr.sf_sc.sc_r5 = rp->p_reg.r5;
  92   fr.sf_sc.sc_r6 = rp->p_reg.r6;
  93   fr.sf_sc.sc_r7 = rp->p_reg.r7;
  94   fr.sf_sc.sc_r8 = rp->p_reg.r8;
  95   fr.sf_sc.sc_r9 = rp->p_reg.r9;
  96   fr.sf_sc.sc_r10 = rp->p_reg.r10;
  97   fr.sf_sc.sc_r11 = rp->p_reg.fp;
  98   fr.sf_sc.sc_r12 = rp->p_reg.r12;
  99   fr.sf_sc.sc_usr_sp = rp->p_reg.sp;
 100   fr.sf_sc.sc_usr_lr = rp->p_reg.lr;
 101   fr.sf_sc.sc_svc_lr = 0;       /* ? */
 102   fr.sf_sc.sc_pc = rp->p_reg.pc;        /* R15 */
 103 #endif
 104
 105   /* Finish the sigcontext initialization. */
 106   fr.sf_sc.sc_mask = smsg.sm_mask;
 107   fr.sf_sc.sc_flags = rp->p_misc_flags & MF_FPU_INITIALIZED;
 108   fr.sf_sc.sc_magic = SC_MAGIC;
 109
 110   /* Initialize the sigframe structure. */
 111
 112   fpu_sigcontext(rp, &fr, &fr.sf_sc);
 113
 114 #if defined(__arm__)
 115   /* use the ARM link register to set the return address from the signal
 116    * handler
 117    */
 118   rp->p_reg.lr = (reg_t) smsg.sm_sigreturn;
 119   if(rp->p_reg.lr & 1) { printf("sigsend: LSB LR makes no sense.\n"); }
 120
 121   /* pass signal handler parameters in registers */
 122   rp->p_reg.retreg = (reg_t) smsg.sm_signo;
 123   rp->p_reg.r1 = 0;     /* sf_code */
 124   rp->p_reg.r2 = (reg_t) fr.sf_scp;
 125   rp->p_misc_flags |= MF_CONTEXT_SET;
 126 #endif
 127
 128   /* Copy the sigframe structure to the user's stack. */
 129   if ((r = data_copy_vmcheck(caller, KERNEL, (vir_bytes)&fr,
 130                 m_ptr->m_sigcalls.endpt, (vir_bytes)frp,
 131                 (vir_bytes)sizeof(struct sigframe_sigcontext))) != OK)
 132       return r;
 133
 134   /* Reset user registers to execute the signal handler. */
 135   rp->p_reg.sp = (reg_t) frp;
 136   rp->p_reg.pc = (reg_t) smsg.sm_sighandler;
 137
 138   /* Signal handler should get clean FPU. */
 139   rp->p_misc_flags &= ~MF_FPU_INITIALIZED;
 140
 141   if(!RTS_ISSET(rp, RTS_PROC_STOP)) {
 142         printf("system: warning: sigsend a running process\n");
 143         printf("caller stack: ");
 144         proc_stacktrace(caller);
 145   }
 146
 147   return OK;
 148 }
 149
 150 #endif /* USE_SIGSEND */
 151