cca24d06d8
kernel (sys task). The main reason is that these would have to become cpu local variables on SMP. Once the system task is not a task but a genuine part of the kernel there is even less reason to have these extra variables as proc_ptr will already contain all neccessary information. In addition converting who_e to the process pointer and back again all the time will be avoided. Although proc_ptr will contain all important information, accessing it as a cpu local variable will be fairly expensive, hence the value would be assigned to some on stack local variable. Therefore it is better to add the 'caller' argument to the syscall handlers to pass the value on stack anyway. It also clearly denotes on who's behalf is the syscall being executed. This patch also ANSIfies the syscall function headers. Last but not least, it also fixes a potential bug in virtual_copy_f() in case the check is disabled. So far the function in case of a failure could possible reuse an old who_p in case this function had not been called from the system task. virtual_copy_f() takes the caller as a parameter too. In case the checking is disabled, the caller must be NULL and non NULL if it is enabled as we must be able to suspend the caller.
131 lines
3.9 KiB
C
131 lines
3.9 KiB
C
/* The kernel call that is implemented in this file:
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* m_type: SYS_SIGSEND
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*
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* The parameters for this kernel call are:
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* m2_i1: SIG_ENDPT # process to call signal handler
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* m2_p1: SIG_CTXT_PTR # pointer to sigcontext structure
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* m2_i3: SIG_FLAGS # flags for S_SIGRETURN call
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*
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*/
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#include "../system.h"
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#include <signal.h>
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#include <string.h>
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#include <sys/sigcontext.h>
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#if USE_SIGSEND
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/*===========================================================================*
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* do_sigsend *
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*===========================================================================*/
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PUBLIC int do_sigsend(struct proc * caller, message * m_ptr)
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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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struct sigcontext sc, *scp;
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struct sigframe fr, *frp;
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int proc_nr, r;
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#if (_MINIX_CHIP == _CHIP_INTEL)
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unsigned short int fp_error;
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#endif
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if (!isokendpt(m_ptr->SIG_ENDPT, &proc_nr)) return(EINVAL);
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if (iskerneln(proc_nr)) return(EPERM);
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rp = proc_addr(proc_nr);
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/* Get the sigmsg structure into our address space. */
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if((r=data_copy_vmcheck(caller, caller->p_endpoint,
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(vir_bytes) m_ptr->SIG_CTXT_PTR, SYSTEM, (vir_bytes) &smsg,
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(phys_bytes) sizeof(struct sigmsg))) != OK)
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return r;
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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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memcpy(&sc.sc_regs, (char *) &rp->p_reg, sizeof(sigregs));
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#if (_MINIX_CHIP == _CHIP_INTEL)
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if(rp->p_misc_flags & MF_FPU_INITIALIZED)
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memcpy(&sc.sc_fpu_state, rp->p_fpu_state.fpu_save_area_p,
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FPU_XFP_SIZE);
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#endif
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/* Finish the sigcontext initialization. */
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sc.sc_mask = smsg.sm_mask;
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sc.sc_flags = 0 | rp->p_misc_flags & MF_FPU_INITIALIZED;
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/* Copy the sigcontext structure to the user's stack. */
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if((r=data_copy_vmcheck(caller, SYSTEM, (vir_bytes) &sc, m_ptr->SIG_ENDPT,
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(vir_bytes) scp, (vir_bytes) sizeof(struct sigcontext))) != OK)
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return r;
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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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#if (_MINIX_CHIP == _CHIP_INTEL)
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if (osfxsr_feature == 1) {
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fp_error = sc.sc_fpu_state.xfp_regs.fp_status &
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~sc.sc_fpu_state.xfp_regs.fp_control;
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} else {
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fp_error = sc.sc_fpu_state.fpu_regs.fp_status &
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~sc.sc_fpu_state.fpu_regs.fp_control;
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}
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if (fp_error & 0x001) { /* Invalid op */
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/*
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* swd & 0x240 == 0x040: Stack Underflow
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* swd & 0x240 == 0x240: Stack Overflow
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* User must clear the SF bit (0x40) if set
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*/
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fr.sf_code = FPE_FLTINV;
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} else if (fp_error & 0x004) {
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fr.sf_code = FPE_FLTDIV; /* Divide by Zero */
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} else if (fp_error & 0x008) {
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fr.sf_code = FPE_FLTOVF; /* Overflow */
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} else if (fp_error & 0x012) {
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fr.sf_code = FPE_FLTUND; /* Denormal, Underflow */
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} else if (fp_error & 0x020) {
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fr.sf_code = FPE_FLTRES; /* Precision */
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} else {
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fr.sf_code = 0; /* XXX - probably should be used for FPE_INTOVF or
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* FPE_INTDIV */
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}
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#else
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fr.sf_code = 0;
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#endif
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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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if((r=data_copy_vmcheck(caller, SYSTEM, (vir_bytes) &fr,
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m_ptr->SIG_ENDPT, (vir_bytes) frp,
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(vir_bytes) sizeof(struct sigframe))) != OK)
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return r;
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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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/* Signal handler should get clean FPU. */
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rp->p_misc_flags &= ~MF_FPU_INITIALIZED;
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if(!RTS_ISSET(rp, RTS_PROC_STOP)) {
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kprintf("system: warning: sigsend a running process\n");
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kprintf("caller stack: ");
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proc_stacktrace(caller);
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}
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return(OK);
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}
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#endif /* USE_SIGSEND */
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