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linux_machdep.c revision 1.42.2.3
      1 /*	$NetBSD: linux_machdep.c,v 1.42.2.3 2010/03/11 15:03:14 yamt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Eric Haszlakiewicz.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  *
     31  * Based on sys/arch/i386/i386/linux_machdep.c:
     32  *	linux_machdep.c,v 1.42 1998/09/11 12:50:06 mycroft Exp
     33  *	written by Frank van der Linden
     34  *
     35  */
     36 
     37 #include <sys/cdefs.h>
     38 __KERNEL_RCSID(0, "$NetBSD: linux_machdep.c,v 1.42.2.3 2010/03/11 15:03:14 yamt Exp $");
     39 
     40 #include <sys/param.h>
     41 #include <sys/systm.h>
     42 #include <sys/signalvar.h>
     43 #include <sys/kernel.h>
     44 #include <sys/proc.h>
     45 #include <sys/buf.h>
     46 #include <sys/reboot.h>
     47 #include <sys/conf.h>
     48 #include <sys/exec.h>
     49 #include <sys/file.h>
     50 #include <sys/callout.h>
     51 #include <sys/malloc.h>
     52 #include <sys/mbuf.h>
     53 #include <sys/msgbuf.h>
     54 #include <sys/mount.h>
     55 #include <sys/vnode.h>
     56 #include <sys/device.h>
     57 #include <sys/syscallargs.h>
     58 #include <sys/filedesc.h>
     59 #include <sys/exec_elf.h>
     60 #include <sys/ioctl.h>
     61 #include <sys/kauth.h>
     62 
     63 #include <uvm/uvm_extern.h>
     64 
     65 #include <compat/linux/common/linux_types.h>
     66 #include <compat/linux/common/linux_signal.h>
     67 #include <compat/linux/common/linux_siginfo.h>
     68 #include <compat/linux/common/linux_util.h>
     69 #include <compat/linux/common/linux_ioctl.h>
     70 #include <compat/linux/common/linux_exec.h>
     71 #include <compat/linux/common/linux_machdep.h>
     72 #include <compat/linux/common/linux_emuldata.h>
     73 
     74 #include <compat/linux/linux_syscallargs.h>
     75 
     76 #include <machine/alpha.h>
     77 #include <machine/reg.h>
     78 
     79 #if defined(_KERNEL_OPT)
     80 #include "wsdisplay.h"
     81 #endif
     82 #if (NWSDISPLAY >0)
     83 #include <dev/wscons/wsdisplay_usl_io.h>
     84 #endif
     85 #ifdef DEBUG
     86 #include <machine/sigdebug.h>
     87 #endif
     88 
     89 /*
     90  * Deal with some alpha-specific things in the Linux emulation code.
     91  */
     92 
     93 void
     94 linux_setregs(struct lwp *l, struct exec_package *epp, u_long stack)
     95 {
     96 #ifdef DEBUG
     97 	struct trapframe *tfp = l->l_md.md_tf;
     98 #endif
     99 
    100 	setregs(l, epp, stack);
    101 #ifdef DEBUG
    102 	/*
    103 	 * Linux has registers set to zero on entry; for DEBUG kernels
    104 	 * the alpha setregs() fills registers with 0xbabefacedeadbeef.
    105 	 */
    106 	memset(tfp->tf_regs, 0, FRAME_SIZE * sizeof tfp->tf_regs[0]);
    107 #endif
    108 }
    109 
    110 void
    111 setup_linux_rt_sigframe(struct trapframe *tf, int sig, const sigset_t *mask)
    112 {
    113 	struct lwp *l = curlwp;
    114 	struct proc *p = l->l_proc;
    115 	struct linux_rt_sigframe *sfp, sigframe;
    116 	int onstack, error;
    117 	int fsize, rndfsize;
    118 	extern char linux_rt_sigcode[], linux_rt_esigcode[];
    119 
    120 	/* Do we need to jump onto the signal stack? */
    121 	onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
    122 		  (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
    123 
    124 	/* Allocate space for the signal handler context.  */
    125 	fsize = sizeof(struct linux_rt_sigframe);
    126 	rndfsize = ((fsize + 15) / 16) * 16;
    127 
    128 	if (onstack)
    129 		sfp = (struct linux_rt_sigframe *)
    130 		    ((char *)l->l_sigstk.ss_sp + l->l_sigstk.ss_size);
    131 	else
    132 		sfp = (struct linux_rt_sigframe *)(alpha_pal_rdusp());
    133 	sfp = (struct linux_rt_sigframe *)((char *)sfp - rndfsize);
    134 
    135 #ifdef DEBUG
    136 	if ((sigdebug & SDB_KSTACK) && (p->p_pid == sigpid))
    137 		printf("linux_sendsig(%d): sig %d ssp %p usp %p\n", p->p_pid,
    138 		    sig, &onstack, sfp);
    139 #endif /* DEBUG */
    140 
    141 	/*
    142 	 * Build the signal context to be used by sigreturn.
    143 	 */
    144 	memset(&sigframe.uc, 0, sizeof(struct linux_ucontext));
    145 	sigframe.uc.uc_mcontext.sc_onstack = onstack;
    146 
    147 	/* Setup potentially partial signal mask in sc_mask. */
    148 	/* But get all of it in uc_sigmask */
    149 	native_to_linux_old_sigset(&sigframe.uc.uc_mcontext.sc_mask, mask);
    150 	native_to_linux_sigset(&sigframe.uc.uc_sigmask, mask);
    151 
    152 	sigframe.uc.uc_mcontext.sc_pc = tf->tf_regs[FRAME_PC];
    153 	sigframe.uc.uc_mcontext.sc_ps = ALPHA_PSL_USERMODE;
    154 	frametoreg(tf, (struct reg *)sigframe.uc.uc_mcontext.sc_regs);
    155 	sigframe.uc.uc_mcontext.sc_regs[R_SP] = alpha_pal_rdusp();
    156 
    157 	alpha_enable_fp(l, 1);
    158 	sigframe.uc.uc_mcontext.sc_fpcr = alpha_read_fpcr();
    159 	sigframe.uc.uc_mcontext.sc_fp_control = alpha_read_fp_c(l);
    160 	alpha_pal_wrfen(0);
    161 
    162 	sigframe.uc.uc_mcontext.sc_traparg_a0 = tf->tf_regs[FRAME_A0];
    163 	sigframe.uc.uc_mcontext.sc_traparg_a1 = tf->tf_regs[FRAME_A1];
    164 	sigframe.uc.uc_mcontext.sc_traparg_a2 = tf->tf_regs[FRAME_A2];
    165 
    166 	/*
    167 	 * XXX XAX Create bogus siginfo data.  This can't really
    168 	 * XXX be fixed until NetBSD has realtime signals.
    169 	 * XXX Or we do the emuldata thing.
    170 	 * XXX -erh
    171 	 */
    172 	memset(&sigframe.info, 0, sizeof(struct linux_siginfo));
    173 	sigframe.info.lsi_signo = sig;
    174 	sigframe.info.lsi_code = LINUX_SI_USER;
    175 	sigframe.info.lsi_pid = p->p_pid;
    176 	sigframe.info.lsi_uid = kauth_cred_geteuid(l->l_cred);	/* Use real uid here? */
    177 
    178 	sendsig_reset(l, sig);
    179 	mutex_exit(p->p_lock);
    180 	error = copyout((void *)&sigframe, (void *)sfp, fsize);
    181 	mutex_enter(p->p_lock);
    182 
    183 	if (error != 0) {
    184 #ifdef DEBUG
    185 		if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
    186 			printf("sendsig(%d): copyout failed on sig %d\n",
    187 			    p->p_pid, sig);
    188 #endif
    189 		/*
    190 		 * Process has trashed its stack; give it an illegal
    191 		 * instruction to halt it in its tracks.
    192 		 */
    193 		sigexit(l, SIGILL);
    194 		/* NOTREACHED */
    195 	}
    196 
    197 	/* Pass pointers to siginfo and ucontext in the regs */
    198 	tf->tf_regs[FRAME_A1] = (unsigned long)&sfp->info;
    199 	tf->tf_regs[FRAME_A2] = (unsigned long)&sfp->uc;
    200 
    201 	/* Address of trampoline code.  End up at this PC after mi_switch */
    202 	tf->tf_regs[FRAME_PC] =
    203 	    (u_int64_t)(p->p_psstr - (linux_rt_esigcode - linux_rt_sigcode));
    204 
    205 	/* Adjust the stack */
    206 	alpha_pal_wrusp((unsigned long)sfp);
    207 
    208 	/* Remember that we're now on the signal stack. */
    209 	if (onstack)
    210 		l->l_sigstk.ss_flags |= SS_ONSTACK;
    211 }
    212 
    213 void setup_linux_sigframe(tf, sig, mask)
    214 	struct trapframe *tf;
    215 	int sig;
    216 	const sigset_t *mask;
    217 {
    218 	struct lwp *l = curlwp;
    219 	struct proc *p = l->l_proc;
    220 	struct linux_sigframe *sfp, sigframe;
    221 	int onstack, error;
    222 	int fsize, rndfsize;
    223 	extern char linux_sigcode[], linux_esigcode[];
    224 
    225 	/* Do we need to jump onto the signal stack? */
    226 	onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
    227 		  (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
    228 
    229 	/* Allocate space for the signal handler context.  */
    230 	fsize = sizeof(struct linux_sigframe);
    231 	rndfsize = ((fsize + 15) / 16) * 16;
    232 
    233 	if (onstack)
    234 		sfp = (struct linux_sigframe *)
    235 		    ((char *)l->l_sigstk.ss_sp + l->l_sigstk.ss_size);
    236 	else
    237 		sfp = (struct linux_sigframe *)(alpha_pal_rdusp());
    238 	sfp = (struct linux_sigframe *)((char *)sfp - rndfsize);
    239 
    240 #ifdef DEBUG
    241 	if ((sigdebug & SDB_KSTACK) && (p->p_pid == sigpid))
    242 		printf("linux_sendsig(%d): sig %d ssp %p usp %p\n", p->p_pid,
    243 		    sig, &onstack, sfp);
    244 #endif /* DEBUG */
    245 
    246 	/*
    247 	 * Build the signal context to be used by sigreturn.
    248 	 */
    249 	memset(&sigframe.sf_sc, 0, sizeof(struct linux_sigcontext));
    250 	sigframe.sf_sc.sc_onstack = onstack;
    251 	native_to_linux_old_sigset(&sigframe.sf_sc.sc_mask, mask);
    252 	sigframe.sf_sc.sc_pc = tf->tf_regs[FRAME_PC];
    253 	sigframe.sf_sc.sc_ps = ALPHA_PSL_USERMODE;
    254 	frametoreg(tf, (struct reg *)sigframe.sf_sc.sc_regs);
    255 	sigframe.sf_sc.sc_regs[R_SP] = alpha_pal_rdusp();
    256 
    257 	if (l == fpcurlwp) {
    258 		struct pcb *pcb = lwp_getpcb(l);
    259 
    260 		alpha_pal_wrfen(1);
    261 		savefpstate(&pcb->pcb_fp);
    262 		alpha_pal_wrfen(0);
    263 		sigframe.sf_sc.sc_fpcr = pcb->pcb_fp.fpr_cr;
    264 		fpcurlwp = NULL;
    265 	}
    266 	/* XXX ownedfp ? etc...? */
    267 
    268 	sigframe.sf_sc.sc_traparg_a0 = tf->tf_regs[FRAME_A0];
    269 	sigframe.sf_sc.sc_traparg_a1 = tf->tf_regs[FRAME_A1];
    270 	sigframe.sf_sc.sc_traparg_a2 = tf->tf_regs[FRAME_A2];
    271 
    272 	sendsig_reset(l, sig);
    273 	mutex_exit(p->p_lock);
    274 	error = copyout((void *)&sigframe, (void *)sfp, fsize);
    275 	mutex_enter(p->p_lock);
    276 
    277 	if (error != 0) {
    278 #ifdef DEBUG
    279 		if ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)
    280 			printf("sendsig(%d): copyout failed on sig %d\n",
    281 			    p->p_pid, sig);
    282 #endif
    283 		/*
    284 		 * Process has trashed its stack; give it an illegal
    285 		 * instruction to halt it in its tracks.
    286 		 */
    287 		sigexit(l, SIGILL);
    288 		/* NOTREACHED */
    289 	}
    290 
    291 	/* Pass pointers to sigcontext in the regs */
    292 	tf->tf_regs[FRAME_A1] = 0;
    293 	tf->tf_regs[FRAME_A2] = (unsigned long)&sfp->sf_sc;
    294 
    295 	/* Address of trampoline code.  End up at this PC after mi_switch */
    296 	tf->tf_regs[FRAME_PC] =
    297 	    (u_int64_t)(p->p_psstr - (linux_esigcode - linux_sigcode));
    298 
    299 	/* Adjust the stack */
    300 	alpha_pal_wrusp((unsigned long)sfp);
    301 
    302 	/* Remember that we're now on the signal stack. */
    303 	if (onstack)
    304 		l->l_sigstk.ss_flags |= SS_ONSTACK;
    305 }
    306 
    307 /*
    308  * Send an interrupt to process.
    309  *
    310  * Stack is set up to allow sigcode stored
    311  * in u. to call routine, followed by kcall
    312  * to sigreturn routine below.  After sigreturn
    313  * resets the signal mask, the stack, and the
    314  * frame pointer, it returns to the user
    315  * specified pc, psl.
    316  */
    317 void
    318 linux_sendsig(const ksiginfo_t *ksi, const sigset_t *mask)
    319 {
    320 	struct lwp *l = curlwp;
    321 	struct proc *p = l->l_proc;
    322 	struct trapframe *tf = l->l_md.md_tf;
    323 	const int sig = ksi->ksi_signo;
    324 	sig_t catcher = SIGACTION(p, sig).sa_handler;
    325 #ifdef notyet
    326 	struct linux_emuldata *edp;
    327 
    328 	/* Setup the signal frame (and part of the trapframe) */
    329 	/*OLD: if (p->p_sigacts->ps_siginfo & sigmask(sig))*/
    330 /*	XXX XAX this is broken now.  need someplace to store what
    331 	XXX XAX kind of signal handler a signal has.*/
    332 #if 0
    333 	edp = (struct linux_emuldata *)p->p_emuldata;
    334 #else
    335 	edp = 0;
    336 #endif
    337 	if (edp && sigismember(&edp->ps_siginfo, sig))
    338 		setup_linux_rt_sigframe(tf, sig, mask);
    339 	else
    340 #endif /* notyet */
    341 		setup_linux_sigframe(tf, sig, mask);
    342 
    343 	/* Signal handler for trampoline code */
    344 	tf->tf_regs[FRAME_T12] = (u_int64_t)catcher;
    345 	tf->tf_regs[FRAME_A0] = native_to_linux_signo[sig];
    346 
    347 	/*
    348 	 * Linux has a custom restorer option.  To support it we would
    349 	 * need to store an array of restorers and a sigcode block
    350 	 * which knew to use it.  Doesn't seem worth the trouble.
    351 	 * -erh
    352 	 */
    353 
    354 #ifdef DEBUG
    355 	if (sigdebug & SDB_FOLLOW)
    356 		printf("sendsig(%d): pc %lx, catcher %lx\n", l->l_proc->p_pid,
    357 		    tf->tf_regs[FRAME_PC], tf->tf_regs[FRAME_A3]);
    358 	if ((sigdebug & SDB_KSTACK) && l->l_proc->p_pid == sigpid)
    359 		printf("sendsig(%d): sig %d returns\n", l->l_proc->p_pid, sig);
    360 #endif
    361 }
    362 
    363 /*
    364  * System call to cleanup state after a signal
    365  * has been taken.  Reset signal mask and
    366  * stack state from context left by sendsig (above).
    367  * Return to previous pc as specified by context
    368  * left by sendsig.
    369  * Linux real-time signals use a different sigframe,
    370  * but the sigcontext is the same.
    371  */
    372 
    373 int
    374 linux_restore_sigcontext(struct lwp *l, struct linux_sigcontext context,
    375 			 sigset_t *mask)
    376 {
    377 	struct proc *p = l->l_proc;
    378 	struct pcb *pcb;
    379 
    380 	/*
    381 	 * Linux doesn't (yet) have alternate signal stacks.
    382 	 * However, the OSF/1 sigcontext which they use has
    383 	 * an onstack member.  This could be needed in the future.
    384 	 */
    385 	mutex_enter(p->p_lock);
    386 	if (context.sc_onstack & LINUX_SA_ONSTACK)
    387 	    l->l_sigstk.ss_flags |= SS_ONSTACK;
    388 	else
    389 	    l->l_sigstk.ss_flags &= ~SS_ONSTACK;
    390 
    391 	/* Reset the signal mask */
    392 	(void) sigprocmask1(l, SIG_SETMASK, mask, 0);
    393 	mutex_exit(p->p_lock);
    394 
    395 	/*
    396 	 * Check for security violations.
    397 	 * Linux doesn't allow any changes to the PSL.
    398 	 */
    399 	if (context.sc_ps != ALPHA_PSL_USERMODE)
    400 	    return(EINVAL);
    401 
    402 	l->l_md.md_tf->tf_regs[FRAME_PC] = context.sc_pc;
    403 	l->l_md.md_tf->tf_regs[FRAME_PS] = context.sc_ps;
    404 
    405 	regtoframe((struct reg *)context.sc_regs, l->l_md.md_tf);
    406 	alpha_pal_wrusp(context.sc_regs[R_SP]);
    407 
    408 	if (l == fpcurlwp)
    409 	    fpcurlwp = NULL;
    410 
    411 	/* Restore fp regs and fpr_cr */
    412 	pcb = lwp_getpcb(l);
    413 	memcpy(&pcb->pcb_fp, (struct fpreg *)context.sc_fpregs,
    414 	    sizeof(struct fpreg));
    415 	/* XXX sc_ownedfp ? */
    416 	/* XXX sc_fp_control ? */
    417 
    418 #ifdef DEBUG
    419 	if (sigdebug & SDB_FOLLOW)
    420 		printf("linux_rt_sigreturn(%d): returns\n", p->p_pid);
    421 #endif
    422 	return (EJUSTRETURN);
    423 }
    424 
    425 int
    426 linux_sys_rt_sigreturn(struct lwp *l, const struct linux_sys_rt_sigreturn_args *uap, register_t *retval)
    427 {
    428 	/* {
    429 		syscallarg(struct linux_rt_sigframe *) sfp;
    430 	} */
    431 	struct linux_rt_sigframe *sfp, sigframe;
    432 	sigset_t mask;
    433 
    434 	/*
    435 	 * The trampoline code hands us the context.
    436 	 * It is unsafe to keep track of it ourselves, in the event that a
    437 	 * program jumps out of a signal handler.
    438 	 */
    439 
    440 	sfp = SCARG(uap, sfp);
    441 
    442 	if (ALIGN(sfp) != (u_int64_t)sfp)
    443 		return(EINVAL);
    444 
    445 	/*
    446 	 * Fetch the frame structure.
    447 	 */
    448 	if (copyin((void *)sfp, &sigframe,
    449 			sizeof(struct linux_rt_sigframe)) != 0)
    450 		return (EFAULT);
    451 
    452 	/* Grab the signal mask */
    453 	linux_to_native_sigset(&mask, &sigframe.uc.uc_sigmask);
    454 
    455 	return(linux_restore_sigcontext(l, sigframe.uc.uc_mcontext, &mask));
    456 }
    457 
    458 
    459 int
    460 linux_sys_sigreturn(struct lwp *l, const struct linux_sys_sigreturn_args *uap, register_t *retval)
    461 {
    462 	/* {
    463 		syscallarg(struct linux_sigframe *) sfp;
    464 	} */
    465 	struct linux_sigframe *sfp, frame;
    466 	sigset_t mask;
    467 
    468 	/*
    469 	 * The trampoline code hands us the context.
    470 	 * It is unsafe to keep track of it ourselves, in the event that a
    471 	 * program jumps out of a signal handler.
    472 	 */
    473 
    474 	sfp = SCARG(uap, sfp);
    475 	if (ALIGN(sfp) != (u_int64_t)sfp)
    476 		return(EINVAL);
    477 
    478 	/*
    479 	 * Fetch the frame structure.
    480 	 */
    481 	if (copyin((void *)sfp, &frame, sizeof(struct linux_sigframe)) != 0)
    482 		return(EFAULT);
    483 
    484 	/* Grab the signal mask. */
    485 	/* XXX use frame.extramask */
    486 	linux_old_to_native_sigset(&mask, frame.sf_sc.sc_mask);
    487 
    488 	return(linux_restore_sigcontext(l, frame.sf_sc, &mask));
    489 }
    490 
    491 /*
    492  * We come here in a last attempt to satisfy a Linux ioctl() call
    493  */
    494 /* XXX XAX update this, add maps, etc... */
    495 int
    496 linux_machdepioctl(struct lwp *l, const struct linux_sys_ioctl_args *uap, register_t *retval)
    497 {
    498 	/* {
    499 		syscallarg(int) fd;
    500 		syscallarg(u_long) com;
    501 		syscallarg(void *) data;
    502 	} */
    503 	struct sys_ioctl_args bia;
    504 	u_long com;
    505 
    506 	SCARG(&bia, fd) = SCARG(uap, fd);
    507 	SCARG(&bia, data) = SCARG(uap, data);
    508 	com = SCARG(uap, com);
    509 
    510 	switch (com) {
    511 	default:
    512 		printf("linux_machdepioctl: invalid ioctl %08lx\n", com);
    513 		return EINVAL;
    514 	}
    515 	SCARG(&bia, com) = com;
    516 	return sys_ioctl(l, &bia, retval);
    517 }
    518 
    519 /* XXX XAX fix this */
    520 dev_t
    521 linux_fakedev(dev_t dev, int raw)
    522 {
    523 	return dev;
    524 }
    525 
    526 int
    527 linux_usertrap(struct lwp *l, vaddr_t trapaddr, void *arg)
    528 {
    529 	return 0;
    530 }
    531