0e2a7a9730
Reduced kernel size by 512KB by moving private buffer into cstart() function. Replaced assertions with erroneous return values. Removed assertions relating to isuserp(rp), since all processes should become user processes; system processes are now treated similar to other processes.
192 lines
6.2 KiB
C
192 lines
6.2 KiB
C
/* The system call that is implemented in this file:
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* SYS_SIGCTL # signal handling functionality
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*
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* The parameters and types for this system call are:
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* SIG_REQUEST # request to perform (long)
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* SIG_PROC # process to signal/ pending (int)
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* SIG_CTXT_PTR # pointer to sigcontext structure (pointer)
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* SIG_FLAGS # flags for S_SIGRETURN call (int)
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* SIG_MAP # bit map with pending signals (long)
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* SIG_NUMBER # signal number to send to process (int)
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*
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* Supported request types are in the parameter SIG_REQUEST:
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* S_GETSIG # get a pending kernel signal
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* S_ENDSIG # signal has been processed
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* S_SENDSIG # deliver a POSIX-style signal
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* S_SIGRETURN # return from a POSIX-style signal
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* S_KILL # send a signal to a process
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*/
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#include "../kernel.h"
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#include "../system.h"
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#include <signal.h>
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#include <sys/sigcontext.h>
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/* PM is ready to accept signals and repeatedly does a system call to get
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* one. Find a process with pending signals. If no signals are available,
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* return NONE in the process number field.
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*/
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PUBLIC int do_getsig(m_ptr)
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message *m_ptr; /* pointer to request message */
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{
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register struct proc *rp;
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/* Find the next process with pending signals. */
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for (rp = BEG_USER_ADDR; rp < END_PROC_ADDR; rp++) {
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if (rp->p_flags & PENDING) {
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m_ptr->SIG_PROC = rp->p_nr;
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m_ptr->SIG_MAP = rp->p_pending;
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sigemptyset(&rp->p_pending); /* ball is in PM's court */
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rp->p_flags &= ~PENDING; /* blocked by SIG_PENDING */
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return(OK);
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}
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}
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/* No process with pending signals was found. */
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m_ptr->SIG_PROC = NONE;
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return(OK);
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}
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PUBLIC int do_endsig(m_ptr)
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message *m_ptr; /* pointer to request message */
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{
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/* Finish up after a kernel type signal, caused by a SYS_KILL message or a
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* call to cause_sig by a task. This is called by the PM after processing a
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* signal it got with SYS_GETSIG.
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*/
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register struct proc *rp;
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rp = proc_addr(m_ptr->SIG_PROC);
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if (isemptyp(rp)) return(EINVAL); /* process already dead? */
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/* PM has finished one kernel signal. Perhaps process is ready now? */
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if (rp->p_pendcount != 0 && --rp->p_pendcount == 0
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&& (rp->p_flags &= ~SIG_PENDING) == 0)
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lock_ready(rp);
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return(OK);
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}
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PUBLIC int do_sigsend(m_ptr)
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message *m_ptr; /* pointer to request message */
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{
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/* Handle sys_sigsend, POSIX-style signal handling. */
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struct sigmsg smsg;
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register struct proc *rp;
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phys_bytes src_phys, dst_phys;
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struct sigcontext sc, *scp;
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struct sigframe fr, *frp;
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rp = proc_addr(m_ptr->SIG_PROC);
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/* Get the sigmsg structure into our address space. */
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src_phys = umap_local(proc_addr(PM_PROC_NR), D, (vir_bytes)
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m_ptr->SIG_CTXT_PTR, (vir_bytes) sizeof(struct sigmsg));
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if (src_phys == 0) return(EFAULT);
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phys_copy(src_phys,vir2phys(&smsg),(phys_bytes) sizeof(struct sigmsg));
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/* Compute the user stack pointer where sigcontext will be stored. */
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scp = (struct sigcontext *) smsg.sm_stkptr - 1;
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/* Copy the registers to the sigcontext structure. */
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kmemcpy(&sc.sc_regs, &rp->p_reg, sizeof(struct sigregs));
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/* Finish the sigcontext initialization. */
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sc.sc_flags = SC_SIGCONTEXT;
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sc.sc_mask = smsg.sm_mask;
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/* Copy the sigcontext structure to the user's stack. */
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dst_phys = umap_local(rp, D, (vir_bytes) scp,
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(vir_bytes) sizeof(struct sigcontext));
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if (dst_phys == 0) return(EFAULT);
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phys_copy(vir2phys(&sc), dst_phys, (phys_bytes) sizeof(struct sigcontext));
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/* Initialize the sigframe structure. */
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frp = (struct sigframe *) scp - 1;
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fr.sf_scpcopy = scp;
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fr.sf_retadr2= (void (*)()) rp->p_reg.pc;
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fr.sf_fp = rp->p_reg.fp;
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rp->p_reg.fp = (reg_t) &frp->sf_fp;
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fr.sf_scp = scp;
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fr.sf_code = 0; /* XXX - should be used for type of FP exception */
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fr.sf_signo = smsg.sm_signo;
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fr.sf_retadr = (void (*)()) smsg.sm_sigreturn;
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/* Copy the sigframe structure to the user's stack. */
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dst_phys = umap_local(rp, D, (vir_bytes) frp,
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(vir_bytes) sizeof(struct sigframe));
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if (dst_phys == 0) return(EFAULT);
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phys_copy(vir2phys(&fr), dst_phys, (phys_bytes) sizeof(struct sigframe));
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/* Reset user registers to execute the signal handler. */
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rp->p_reg.sp = (reg_t) frp;
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rp->p_reg.pc = (reg_t) smsg.sm_sighandler;
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return(OK);
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}
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PUBLIC int do_sigreturn(m_ptr)
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message *m_ptr; /* pointer to request message */
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{
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/* POSIX style signals require sys_sigreturn to put things in order before
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* the signalled process can resume execution
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*/
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struct sigcontext sc;
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register struct proc *rp;
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phys_bytes src_phys;
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rp = proc_addr(m_ptr->SIG_PROC);
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/* Copy in the sigcontext structure. */
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src_phys = umap_local(rp, D, (vir_bytes) m_ptr->SIG_CTXT_PTR,
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(vir_bytes) sizeof(struct sigcontext));
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if (src_phys == 0) return(EFAULT);
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phys_copy(src_phys, vir2phys(&sc), (phys_bytes) sizeof(struct sigcontext));
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/* Make sure that this is not just a jmp_buf. */
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if ((sc.sc_flags & SC_SIGCONTEXT) == 0) return(EINVAL);
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/* Fix up only certain key registers if the compiler doesn't use
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* register variables within functions containing setjmp.
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*/
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if (sc.sc_flags & SC_NOREGLOCALS) {
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rp->p_reg.retreg = sc.sc_retreg;
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rp->p_reg.fp = sc.sc_fp;
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rp->p_reg.pc = sc.sc_pc;
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rp->p_reg.sp = sc.sc_sp;
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return(OK);
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}
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sc.sc_psw = rp->p_reg.psw;
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#if (CHIP == INTEL)
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/* Don't panic kernel if user gave bad selectors. */
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sc.sc_cs = rp->p_reg.cs;
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sc.sc_ds = rp->p_reg.ds;
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sc.sc_es = rp->p_reg.es;
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#if _WORD_SIZE == 4
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sc.sc_fs = rp->p_reg.fs;
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sc.sc_gs = rp->p_reg.gs;
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#endif
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#endif
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/* Restore the registers. */
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kmemcpy(&rp->p_reg, (char *)&sc.sc_regs, sizeof(struct sigregs));
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return(OK);
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}
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/*===========================================================================*
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* do_sigctl *
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*===========================================================================*/
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PUBLIC int do_kill(m_ptr)
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message *m_ptr; /* pointer to request message */
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{
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/* Handle sys_kill(). Cause a signal to be sent to a process via PM.
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* Note that this has nothing to do with the kill (2) system call, this
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* is how the FS (and possibly other servers) get access to cause_sig.
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*/
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cause_sig(m_ptr->SIG_PROC, m_ptr->SIG_NUMBER);
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return(OK);
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}
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