/* $NetBSD: linux_machdep.c,v 1.9 1995/06/22 21:35:42 fvdl Exp $ */ /* * Copyright (c) 1995 Frank van der Linden * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed for the NetBSD Project * by Frank van der Linden * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Deal with some i386-specific things in the Linux emulation code. * This means just signals for now, will include stuff like * I/O map permissions and V86 mode sometime. */ /* * Send an interrupt to process. * * Stack is set up to allow sigcode stored * in u. to call routine, followed by kcall * to sigreturn routine below. After sigreturn * resets the signal mask, the stack, and the * frame pointer, it returns to the user * specified pc, psl. */ void linux_sendsig(catcher, sig, mask, code) sig_t catcher; int sig, mask; u_long code; { register struct proc *p = curproc; register struct trapframe *tf; struct linux_sigframe *fp, frame; struct sigacts *psp = p->p_sigacts; int oonstack; extern char linux_sigcode[], linux_esigcode[]; tf = p->p_md.md_regs; oonstack = psp->ps_sigstk.ss_flags & SA_ONSTACK; /* * Allocate space for the signal handler context. */ if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack && (psp->ps_sigonstack & sigmask(sig))) { fp = (struct linux_sigframe *)(psp->ps_sigstk.ss_base + psp->ps_sigstk.ss_size - sizeof(struct linux_sigframe)); psp->ps_sigstk.ss_flags |= SA_ONSTACK; } else { fp = (struct linux_sigframe *)tf->tf_esp - 1; } frame.sf_handler = catcher; frame.sf_sig = bsd_to_linux_sig(sig); /* * Build the signal context to be used by sigreturn. */ frame.sf_sc.sc_mask = mask; #ifdef VM86 if (tf->tf_eflags & PSL_VM) { frame.sf_sc.sc_gs = tf->tf_vm86_gs; frame.sf_sc.sc_fs = tf->tf_vm86_fs; frame.sf_sc.sc_es = tf->tf_vm86_es; frame.sf_sc.sc_ds = tf->tf_vm86_ds; } else #else { __asm("movl %%gs,%w0" : "=r" (frame.sf_sc.sc_gs)); __asm("movl %%fs,%w0" : "=r" (frame.sf_sc.sc_fs)); frame.sf_sc.sc_es = tf->tf_es; frame.sf_sc.sc_ds = tf->tf_ds; } #endif frame.sf_sc.sc_edi = tf->tf_edi; frame.sf_sc.sc_esi = tf->tf_esi; frame.sf_sc.sc_ebp = tf->tf_ebp; frame.sf_sc.sc_ebx = tf->tf_ebx; frame.sf_sc.sc_edx = tf->tf_edx; frame.sf_sc.sc_ecx = tf->tf_ecx; frame.sf_sc.sc_eax = tf->tf_eax; frame.sf_sc.sc_eip = tf->tf_eip; frame.sf_sc.sc_cs = tf->tf_cs; frame.sf_sc.sc_eflags = tf->tf_eflags; frame.sf_sc.sc_esp_at_signal = tf->tf_esp; frame.sf_sc.sc_ss = tf->tf_ss; frame.sf_sc.sc_err = tf->tf_err; frame.sf_sc.sc_trapno = tf->tf_trapno; if (copyout(&frame, fp, sizeof(frame)) != 0) { /* * Process has trashed its stack; give it an illegal * instruction to halt it in its tracks. */ sigexit(p, SIGILL); /* NOTREACHED */ } /* * Build context to run handler in. */ tf->tf_esp = (int)fp; tf->tf_eip = (int)(((char *)PS_STRINGS) - (linux_esigcode - linux_sigcode)); #ifdef VM86 tf->tf_eflags &= ~PSL_VM; #endif tf->tf_cs = LSEL(LUCODE_SEL, SEL_UPL); tf->tf_ds = LSEL(LUDATA_SEL, SEL_UPL); tf->tf_es = LSEL(LUDATA_SEL, SEL_UPL); tf->tf_ss = LSEL(LUDATA_SEL, SEL_UPL); } /* * System call to cleanup state after a signal * has been taken. Reset signal mask and * stack state from context left by sendsig (above). * Return to previous pc and psl as specified by * context left by sendsig. Check carefully to * make sure that the user has not modified the * psl to gain improper privileges or to cause * a machine fault. */ int linux_sigreturn(p, uap, retval) struct proc *p; struct linux_sigreturn_args /* { syscallarg(struct linux_sigcontext *) scp; } */ *uap; register_t *retval; { struct linux_sigcontext *scp, context; register struct trapframe *tf; tf = p->p_md.md_regs; /* * The trampoline code hands us the context. * It is unsafe to keep track of it ourselves, in the event that a * program jumps out of a signal handler. */ scp = SCARG(uap, scp); if (copyin((caddr_t)scp, &context, sizeof(*scp)) != 0) return (EFAULT); /* * Check for security violations. */ if (((context.sc_eflags ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 || ISPL(context.sc_cs) != SEL_UPL) return (EINVAL); p->p_sigacts->ps_sigstk.ss_flags &= ~SA_ONSTACK; p->p_sigmask = context.sc_mask & ~sigcantmask; /* * Restore signal context. */ #ifdef VM86 if (context.sc_eflags & PSL_VM) { tf->tf_vm86_gs = context.sc_gs; tf->tf_vm86_fs = context.sc_fs; tf->tf_vm86_es = context.sc_es; tf->tf_vm86_ds = context.sc_ds; } else #endif { /* %fs and %gs were restored by the trampoline. */ tf->tf_es = context.sc_es; tf->tf_ds = context.sc_ds; } tf->tf_edi = context.sc_edi; tf->tf_esi = context.sc_esi; tf->tf_ebp = context.sc_ebp; tf->tf_ebx = context.sc_ebx; tf->tf_edx = context.sc_edx; tf->tf_ecx = context.sc_ecx; tf->tf_eax = context.sc_eax; tf->tf_eip = context.sc_eip; tf->tf_cs = context.sc_cs; tf->tf_eflags = context.sc_eflags; tf->tf_esp = context.sc_esp_at_signal; tf->tf_ss = context.sc_ss; return (EJUSTRETURN); } #ifdef USER_LDT int linux_read_ldt(p, uap, retval) struct proc *p; struct linux_modify_ldt_args /* { syscallarg(int) func; syscallarg(void *) ptr; syscallarg(size_t) bytecount; } */ *uap; register_t *retval; { struct i386_get_ldt_args gl; int error; caddr_t sg; char *parms; sg = stackgap_init(); gl.start = 0; gl.desc = SCARG(uap, ptr); gl.num = SCARG(uap, bytecount) / sizeof(union descriptor); parms = stackgap_alloc(&sg, sizeof(gl)); if (error = copyout(&gl, parms, sizeof(gl))) return (error); if (error = i386_get_ldt(p, parms, retval)) return (error); *retval *= sizeof(union descriptor); return (0); } struct linux_ldt_info { u_int entry_number; u_long base_addr; u_int limit; u_int seg_32bit:1; u_int contents:2; u_int read_exec_only:1; u_int limit_in_pages:1; u_int seg_not_present:1; }; int linux_write_ldt(p, uap, retval) struct proc *p; struct linux_modify_ldt_args /* { syscallarg(int) func; syscallarg(void *) ptr; syscallarg(size_t) bytecount; } */ *uap; register_t *retval; { struct linux_ldt_info ldt_info; struct segment_descriptor sd; struct i386_set_ldt_args sl; int error; caddr_t sg; char *parms; if (SCARG(uap, bytecount) != sizeof(ldt_info)) return (EINVAL); if (error = copyin(SCARG(uap, ptr), &ldt_info, sizeof(ldt_info))) return error; if (ldt_info.contents == 3) return (EINVAL); sg = stackgap_init(); sd.sd_lobase = ldt_info.base_addr & 0xffffff; sd.sd_hibase = (ldt_info.base_addr >> 24) & 0xff; sd.sd_lolimit = ldt_info.limit & 0xffff; sd.sd_hilimit = (ldt_info.limit >> 16) & 0xf; sd.sd_type = 16 | (ldt_info.contents << 2) | (!ldt_info.read_exec_only << 1); sd.sd_dpl = SEL_UPL; sd.sd_p = !ldt_info.seg_not_present; sd.sd_def32 = ldt_info.seg_32bit; sd.sd_gran = ldt_info.limit_in_pages; sl.start = ldt_info.entry_number; sl.desc = stackgap_alloc(&sg, sizeof(sd)); sl.num = 1; #if 0 printf("linux_write_ldt: idx=%d, base=%x, limit=%x\n", ldt_info.entry_number, ldt_info.base_addr, ldt_info.limit); #endif parms = stackgap_alloc(&sg, sizeof(sl)); if (error = copyout(&sd, sl.desc, sizeof(sd))) return (error); if (error = copyout(&sl, parms, sizeof(sl))) return (error); if (error = i386_set_ldt(p, parms, retval)) return (error); *retval = 0; return (0); } #endif /* USER_LDT */ int linux_modify_ldt(p, uap, retval) struct proc *p; struct linux_modify_ldt_args /* { syscallarg(int) func; syscallarg(void *) ptr; syscallarg(size_t) bytecount; } */ *uap; register_t *retval; { switch (SCARG(uap, func)) { #ifdef USER_LDT case 0: return (linux_read_ldt(p, uap, retval)); case 1: return (linux_write_ldt(p, uap, retval)); #endif /* USER_LDT */ default: return (ENOSYS); } }