/* $NetBSD: linux_machdep.c,v 1.51 2021/09/07 11:43:04 riastradh Exp $ */ /*- * Copyright (c) 1995, 2000, 2001 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Frank van der Linden and Emmanuel Dreyfus. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``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 FOUNDATION OR CONTRIBUTORS * 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 __KERNEL_RCSID(0, "$NetBSD: linux_machdep.c,v 1.51 2021/09/07 11:43:04 riastradh Exp $"); #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 #include #include #include /* * To see whether wscons is configured (for virtual console ioctl calls). */ #if defined(_KERNEL_OPT) #include "wsdisplay.h" #endif #if (NWSDISPLAY > 0) #include #include #endif /* * Set set up registers on exec. */ void linux_setregs(struct lwp *l, struct exec_package *pack, vaddr_t stack) { setregs(l, pack, stack); } /* * Send an interrupt to process. * * Adapted from arch/powerpc/powerpc/sig_machdep.c:sendsig and * compat/linux/arch/i386/linux_machdep.c:linux_sendsig * * XXX Does not work well yet with RT signals * */ void linux_sendsig(const ksiginfo_t *ksi, const sigset_t *mask) { const int sig = ksi->ksi_signo; struct lwp *l = curlwp; struct proc *p = l->l_proc; struct trapframe *tf; sig_t catcher = SIGACTION(p, sig).sa_handler; struct linux_sigregs frame; struct linux_pt_regs linux_regs; struct linux_sigcontext sc; register_t fp; int onstack, error; int i; tf = trapframe(l); /* * Do we need to jump onto the signal stack? */ onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 && (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0; /* * Signal stack is broken (see at the end of linux_sigreturn), so we do * not use it yet. XXX fix this. */ onstack=0; /* * Allocate space for the signal handler context. */ if (onstack) { fp = (register_t) ((char *)l->l_sigstk.ss_sp + l->l_sigstk.ss_size); } else { fp = tf->tf_fixreg[1]; } #ifdef DEBUG_LINUX printf("fp at start of linux_sendsig = %x\n", fp); #endif fp -= sizeof(struct linux_sigregs); fp &= ~0xf; /* * Prepare a sigcontext for later. */ memset(&sc, 0, sizeof sc); sc.lsignal = (int)native_to_linux_signo[sig]; sc.lhandler = (unsigned long)catcher; native_to_linux_old_extra_sigset(&sc.lmask, &sc._unused[3], mask); sc.lregs = (struct linux_pt_regs*)fp; /* * Setup the signal stack frame as Linux does it in * arch/ppc/kernel/signal.c:setup_frame() * * Save register context. */ memset(&linux_regs, 0, sizeof(linux_regs)); for (i = 0; i < 32; i++) linux_regs.lgpr[i] = tf->tf_fixreg[i]; linux_regs.lnip = tf->tf_srr0; linux_regs.lmsr = tf->tf_srr1 & PSL_USERSRR1; linux_regs.lorig_gpr3 = tf->tf_fixreg[3]; /* XXX Is that right? */ linux_regs.lctr = tf->tf_ctr; linux_regs.llink = tf->tf_lr; linux_regs.lxer = tf->tf_xer; linux_regs.lccr = tf->tf_cr; linux_regs.lmq = 0; /* Unused, 601 only */ linux_regs.ltrap = tf->tf_exc; linux_regs.ldar = tf->tf_dar; linux_regs.ldsisr = tf->tf_dsisr; linux_regs.lresult = 0; memset(&frame, 0, sizeof(frame)); memcpy(&frame.lgp_regs, &linux_regs, sizeof(linux_regs)); #ifdef PPC_HAVE_FPU fpu_save(l); #endif memcpy(&frame.lfp_regs, curpcb->pcb_fpu.fpreg, sizeof(frame.lfp_regs)); /* * Copy Linux's signal trampoline on the user stack It should not * be used, but Linux binaries might expect it to be there. */ frame.ltramp[0] = 0x38997777; /* li r0, 0x7777 */ frame.ltramp[1] = 0x44000002; /* sc */ /* * Move it to the user stack * There is a little trick here, about the LINUX_ABIGAP: the * linux_sigreg structure has a 56 int gap to support rs6000/xcoff * binaries. But the Linux kernel seems to do without it, and it * just skip it when building the stack frame. Hence the LINUX_ABIGAP. */ sendsig_reset(l, sig); mutex_exit(p->p_lock); error = copyout(&frame, (void *)fp, sizeof (frame) - LINUX_ABIGAP); if (error != 0) { /* * Process has trashed its stack; give it an illegal * instruction to halt it in its tracks. */ mutex_enter(p->p_lock); sigexit(l, SIGILL); /* NOTREACHED */ } /* * Add a sigcontext on the stack */ fp -= sizeof(struct linux_sigcontext); error = copyout(&sc, (void *)fp, sizeof (struct linux_sigcontext)); mutex_enter(p->p_lock); if (error != 0) { /* * Process has trashed its stack; give it an illegal * instruction to halt it in its tracks. */ sigexit(l, SIGILL); /* NOTREACHED */ } /* * Set the registers according to how the Linux process expects them. * "Mind the gap" Linux expects a gap here. */ tf->tf_fixreg[1] = fp - LINUX__SIGNAL_FRAMESIZE; tf->tf_lr = (int)catcher; tf->tf_fixreg[3] = (int)native_to_linux_signo[sig]; tf->tf_fixreg[4] = fp; tf->tf_srr0 = (int)p->p_sigctx.ps_sigcode; #ifdef DEBUG_LINUX printf("fp at end of linux_sendsig = %x\n", fp); #endif /* * Remember that we're now on the signal stack. */ if (onstack) l->l_sigstk.ss_flags |= SS_ONSTACK; #ifdef DEBUG_LINUX printf("linux_sendsig: exiting. fp=0x%lx\n",(long)fp); #endif } /* * 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. * * XXX not tested */ int linux_sys_rt_sigreturn(struct lwp *l, const struct linux_sys_rt_sigreturn_args *uap, register_t *retval) { /* { syscallarg(struct linux_rt_sigframe *) sfp; } */ struct proc *p = l->l_proc; struct linux_rt_sigframe *scp, sigframe; struct linux_sigregs sregs; struct linux_pt_regs *lregs; struct trapframe *tf; sigset_t mask; int i; /* * 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, sfp); /* * Get the context from user stack */ if (copyin((void *)scp, &sigframe, sizeof(*scp))) return (EFAULT); /* * Restore register context. */ if (copyin((void *)sigframe.luc.luc_context.lregs, &sregs, sizeof(sregs))) return (EFAULT); lregs = (struct linux_pt_regs *)&sregs.lgp_regs; tf = trapframe(l); #ifdef DEBUG_LINUX printf("linux_sys_rt_sigreturn: trapframe=0x%lx scp=0x%lx\n", (unsigned long)tf, (unsigned long)scp); #endif if (!PSL_USEROK_P(lregs->lmsr)) return (EINVAL); for (i = 0; i < 32; i++) tf->tf_fixreg[i] = lregs->lgpr[i]; tf->tf_lr = lregs->llink; tf->tf_cr = lregs->lccr; tf->tf_xer = lregs->lxer; tf->tf_ctr = lregs->lctr; tf->tf_srr0 = lregs->lnip; tf->tf_srr1 = lregs->lmsr; /* * Make sure the fpu state is discarded */ #ifdef PPC_HAVE_FPU fpu_discard(l); #endif memcpy(curpcb->pcb_fpu.fpreg, (void *)&sregs.lfp_regs, sizeof(curpcb->pcb_fpu.fpreg)); fpu_mark_used(l); mutex_enter(p->p_lock); /* * Restore signal stack. * * XXX cannot find the onstack information in Linux sig context. * Is signal stack really supported on Linux? * * It seems to be supported in libc6... */ /* if (sc.sc_onstack & SS_ONSTACK) l->l_sigstk.ss_flags |= SS_ONSTACK; else */ l->l_sigstk.ss_flags &= ~SS_ONSTACK; /* * Grab the signal mask */ linux_to_native_sigset(&mask, &sigframe.luc.luc_sigmask); (void) sigprocmask1(l, SIG_SETMASK, &mask, 0); mutex_exit(p->p_lock); return (EJUSTRETURN); } /* * The following needs code review for potential security issues */ int linux_sys_sigreturn(struct lwp *l, const struct linux_sys_sigreturn_args *uap, register_t *retval) { /* { syscallarg(struct linux_sigcontext *) scp; } */ struct proc *p = l->l_proc; struct linux_sigcontext *scp, context; struct linux_sigregs sregs; struct linux_pt_regs *lregs; struct trapframe *tf; sigset_t mask; int i; /* * 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); /* * Get the context from user stack */ if (copyin(scp, &context, sizeof(*scp))) return (EFAULT); /* * Restore register context. */ if (copyin((void *)context.lregs, &sregs, sizeof(sregs))) return (EFAULT); lregs = (struct linux_pt_regs *)&sregs.lgp_regs; tf = trapframe(l); #ifdef DEBUG_LINUX printf("linux_sys_sigreturn: trapframe=0x%lx scp=0x%lx\n", (unsigned long)tf, (unsigned long)scp); #endif if (!PSL_USEROK_P(lregs->lmsr)) return (EINVAL); for (i = 0; i < 32; i++) tf->tf_fixreg[i] = lregs->lgpr[i]; tf->tf_lr = lregs->llink; tf->tf_cr = lregs->lccr; tf->tf_xer = lregs->lxer; tf->tf_ctr = lregs->lctr; tf->tf_srr0 = lregs->lnip; tf->tf_srr1 = lregs->lmsr; /* * Make sure the fpu state is discarded */ #ifdef PPC_HAVE_FPU fpu_discard(l); #endif memcpy(curpcb->pcb_fpu.fpreg, (void *)&sregs.lfp_regs, sizeof(curpcb->pcb_fpu.fpreg)); fpu_mark_used(l); mutex_enter(p->p_lock); /* * Restore signal stack. * * XXX cannot find the onstack information in Linux sig context. * Is signal stack really supported on Linux? */ #if 0 if (sc.sc_onstack & SS_ONSTACK) l->l_sigstk.ss_flags |= SS_ONSTACK; else #endif l->l_sigstk.ss_flags &= ~SS_ONSTACK; /* Restore signal mask. */ linux_old_extra_to_native_sigset(&mask, &context.lmask, &context._unused[3]); (void) sigprocmask1(l, SIG_SETMASK, &mask, 0); mutex_exit(p->p_lock); return (EJUSTRETURN); } /* * major device numbers remapping */ dev_t linux_fakedev(dev_t dev, int raw) { /* XXX write me */ return dev; } /* * We come here in a last attempt to satisfy a Linux ioctl() call */ int linux_machdepioctl(struct lwp *l, const struct linux_sys_ioctl_args *uap, register_t *retval) { /* { syscallarg(int) fd; syscallarg(u_long) com; syscallarg(void *) data; } */ struct sys_ioctl_args bia; u_long com; SCARG(&bia, fd) = SCARG(uap, fd); SCARG(&bia, data) = SCARG(uap, data); com = SCARG(uap, com); switch (com) { default: printf("linux_machdepioctl: invalid ioctl %08lx\n", com); return EINVAL; } SCARG(&bia, com) = com; /* XXX NJWLWP */ return sys_ioctl(curlwp, &bia, retval); } /* * wrapper linux_sys_new_uname() -> linux_sys_uname() */ int linux_sys_new_uname(struct lwp *l, const struct linux_sys_new_uname_args *uap, register_t *retval) { return linux_sys_uname(l, (const void *)uap, retval); } /* * wrapper linux_sys_new_select() -> linux_sys_select() */ int linux_sys_new_select(struct lwp *l, const struct linux_sys_new_select_args *uap, register_t *retval) { return linux_sys_select(l, (const void *)uap, retval); } int linux_usertrap(struct lwp *l, vaddr_t trapaddr, void *arg) { return 0; }