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linux32_machdep.c revision 1.35
      1 /*	$NetBSD: linux32_machdep.c,v 1.35 2014/02/15 10:11:15 dsl Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2006 Emmanuel Dreyfus, all rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. All advertising materials mentioning features or use of this software
     15  *    must display the following acknowledgement:
     16  *	This product includes software developed by Emmanuel Dreyfus
     17  * 4. The name of the author may not be used to endorse or promote
     18  *    products derived from this software without specific prior written
     19  *    permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE THE AUTHOR AND CONTRIBUTORS ``AS IS''
     22  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
     23  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
     25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     31  * POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 #include <sys/cdefs.h>
     34 __KERNEL_RCSID(0, "$NetBSD: linux32_machdep.c,v 1.35 2014/02/15 10:11:15 dsl Exp $");
     35 
     36 #include <sys/param.h>
     37 #include <sys/proc.h>
     38 #include <sys/exec.h>
     39 
     40 #include <machine/vmparam.h>
     41 #include <machine/cpufunc.h>
     42 #include <machine/netbsd32_machdep.h>
     43 
     44 #include <compat/netbsd32/netbsd32.h>
     45 #include <compat/netbsd32/netbsd32_syscallargs.h>
     46 
     47 #include <compat/linux/common/linux_types.h>
     48 #include <compat/linux/common/linux_emuldata.h>
     49 #include <compat/linux/common/linux_signal.h>
     50 #include <compat/linux/common/linux_errno.h>
     51 #include <compat/linux/common/linux_exec.h>
     52 #include <compat/linux/common/linux_ipc.h>
     53 #include <compat/linux/common/linux_sem.h>
     54 #include <compat/linux/linux_syscallargs.h>
     55 
     56 #include <compat/linux32/common/linux32_types.h>
     57 #include <compat/linux32/common/linux32_errno.h>
     58 #include <compat/linux32/common/linux32_machdep.h>
     59 #include <compat/linux32/common/linux32_signal.h>
     60 #include <compat/linux32/common/linux32_exec.h>
     61 #include <compat/linux32/common/linux32_ipc.h>
     62 #include <compat/linux32/common/linux32_sem.h>
     63 #include <compat/linux32/linux32_syscallargs.h>
     64 
     65 #ifdef DEBUG_LINUX
     66 #define DPRINTF(a) uprintf a
     67 #else
     68 #define DPRINTF(a)
     69 #endif
     70 
     71 extern char linux32_sigcode[];
     72 extern char linux32_rt_sigcode[];
     73 extern char linux32_esigcode[];
     74 
     75 static void linux32_save_ucontext(struct lwp *, struct trapframe *,
     76     const sigset_t *, struct sigaltstack *, struct linux32_ucontext *);
     77 static void linux32_save_sigcontext(struct lwp *, struct trapframe *,
     78     const sigset_t *, struct linux32_sigcontext *);
     79 static void linux32_rt_sendsig(const ksiginfo_t *, const sigset_t *);
     80 static void linux32_old_sendsig(const ksiginfo_t *, const sigset_t *);
     81 static int linux32_restore_sigcontext(struct lwp *,
     82     struct linux32_sigcontext *, register_t *);
     83 
     84 void
     85 linux32_sendsig(const ksiginfo_t *ksi, const sigset_t *mask)
     86 {
     87 	if (SIGACTION(curproc, ksi->ksi_signo).sa_flags & SA_SIGINFO)
     88 		linux32_rt_sendsig(ksi, mask);
     89 	else
     90 		linux32_old_sendsig(ksi, mask);
     91 	return;
     92 }
     93 
     94 void
     95 linux32_old_sendsig(const ksiginfo_t *ksi, const sigset_t *mask)
     96 {
     97 	struct lwp *l = curlwp;
     98 	struct proc *p = l->l_proc;
     99 	struct trapframe *tf;
    100 	struct linux32_sigframe *fp, frame;
    101 	int onstack, error;
    102 	int sig = ksi->ksi_signo;
    103 	sig_t catcher = SIGACTION(p, sig).sa_handler;
    104 	struct sigaltstack *sas = &l->l_sigstk;
    105 
    106 	tf = l->l_md.md_regs;
    107 	/* Do we need to jump onto the signal stack? */
    108 	onstack = (sas->ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
    109 	    (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
    110 
    111 
    112 	/* Allocate space for the signal handler context. */
    113 	if (onstack)
    114 		fp = (struct linux32_sigframe *)((char *)sas->ss_sp +
    115 		    sas->ss_size);
    116 	else
    117 		fp = (struct linux32_sigframe *)tf->tf_rsp;
    118 	fp--;
    119 
    120 	DPRINTF(("old: onstack = %d, fp = %p sig = %d rip = 0x%lx\n",
    121 	    onstack, fp, sig, tf->tf_rip));
    122 
    123 	/* Build stack frame for signal trampoline. */
    124 	NETBSD32PTR32(frame.sf_handler, catcher);
    125 	frame.sf_sig = native_to_linux32_signo[sig];
    126 
    127 	linux32_save_sigcontext(l, tf, mask, &frame.sf_sc);
    128 
    129 	sendsig_reset(l, sig);
    130 	mutex_exit(p->p_lock);
    131 	error = copyout(&frame, fp, sizeof(frame));
    132 	mutex_enter(p->p_lock);
    133 
    134 	if (error != 0) {
    135 		/*
    136 		 * Process has trashed its stack; give it an illegal
    137 		 * instruction to halt it in its tracks.
    138 		 */
    139 		sigexit(l, SIGILL);
    140 		/* NOTREACHED */
    141 	}
    142 
    143 	/*
    144 	 * Build context to run handler in.
    145 	 */
    146 	tf->tf_fs = GSEL(GUDATA32_SEL, SEL_UPL) & 0xffffffff;
    147 	tf->tf_es = GSEL(GUDATA32_SEL, SEL_UPL) & 0xffffffff;
    148 	tf->tf_ds = GSEL(GUDATA32_SEL, SEL_UPL) & 0xffffffff;
    149 	tf->tf_rip = ((long)p->p_sigctx.ps_sigcode) & 0xffffffff;
    150 	tf->tf_cs = GSEL(GUCODE32_SEL, SEL_UPL) & 0xffffffff;
    151 	tf->tf_rflags &= ~PSL_CLEARSIG & 0xffffffff;
    152 	tf->tf_rsp = (long)fp & 0xffffffff;
    153 	tf->tf_ss = GSEL(GUDATA32_SEL, SEL_UPL) & 0xffffffff;
    154 
    155 	/* Remember that we're now on the signal stack. */
    156 	if (onstack)
    157 		sas->ss_flags |= SS_ONSTACK;
    158 
    159 	return;
    160 }
    161 
    162 void
    163 linux32_rt_sendsig(const ksiginfo_t *ksi, const sigset_t *mask)
    164 {
    165 	struct lwp *l = curlwp;
    166 	struct proc *p = l->l_proc;
    167 	struct trapframe *tf;
    168 	struct linux32_rt_sigframe *fp, frame;
    169 	int onstack, error;
    170 	linux32_siginfo_t *lsi;
    171 	int sig = ksi->ksi_signo;
    172 	sig_t catcher = SIGACTION(p, sig).sa_handler;
    173 	struct sigaltstack *sas = &l->l_sigstk;
    174 
    175 	tf = l->l_md.md_regs;
    176 	/* Do we need to jump onto the signal stack? */
    177 	onstack = (sas->ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
    178 	    (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
    179 
    180 
    181 	/* Allocate space for the signal handler context. */
    182 	if (onstack)
    183 		fp = (struct linux32_rt_sigframe *)((char *)sas->ss_sp +
    184 		    sas->ss_size);
    185 	else
    186 		fp = (struct linux32_rt_sigframe *)tf->tf_rsp;
    187 	fp--;
    188 
    189 	/* Build stack frame for signal trampoline. */
    190 	NETBSD32PTR32(frame.sf_handler, catcher);
    191 	frame.sf_sig = native_to_linux32_signo[sig];
    192 	NETBSD32PTR32(frame.sf_sip, &fp->sf_si);
    193 	NETBSD32PTR32(frame.sf_ucp, &fp->sf_uc);
    194 
    195 	DPRINTF(("rt: onstack = %d, fp = %p sig = %d rip = 0x%lx\n",
    196 	    onstack, fp, sig, tf->tf_rip));
    197 
    198 	lsi = &frame.sf_si;
    199 	(void)memset(lsi, 0, sizeof(frame.sf_si));
    200 	lsi->lsi_errno = native_to_linux32_errno[ksi->ksi_errno];
    201 	lsi->lsi_code = native_to_linux_si_code(ksi->ksi_code);
    202 	lsi->lsi_signo = frame.sf_sig;
    203 	switch (lsi->lsi_signo) {
    204 	case LINUX32_SIGILL:
    205 	case LINUX32_SIGFPE:
    206 	case LINUX32_SIGSEGV:
    207 	case LINUX32_SIGBUS:
    208 	case LINUX32_SIGTRAP:
    209 		NETBSD32PTR32(lsi->lsi_addr, ksi->ksi_addr);
    210 		break;
    211 	case LINUX32_SIGCHLD:
    212 		lsi->lsi_uid = ksi->ksi_uid;
    213 		lsi->lsi_pid = ksi->ksi_pid;
    214 		lsi->lsi_utime = ksi->ksi_utime;
    215 		lsi->lsi_stime = ksi->ksi_stime;
    216 		lsi->lsi_status = native_to_linux_si_status(ksi->ksi_code,
    217 		    ksi->ksi_status);
    218 		break;
    219 	case LINUX32_SIGIO:
    220 		lsi->lsi_band = ksi->ksi_band;
    221 		lsi->lsi_fd = ksi->ksi_fd;
    222 		break;
    223 	default:
    224 		lsi->lsi_uid = ksi->ksi_uid;
    225 		lsi->lsi_pid = ksi->ksi_pid;
    226 		if (lsi->lsi_signo == LINUX32_SIGALRM ||
    227 		    lsi->lsi_signo >= LINUX32_SIGRTMIN)
    228 			NETBSD32PTR32(lsi->lsi_value.sival_ptr,
    229 			     ksi->ksi_value.sival_ptr);
    230 		break;
    231 	}
    232 
    233 	/* Save register context. */
    234 	linux32_save_ucontext(l, tf, mask, sas, &frame.sf_uc);
    235 	sendsig_reset(l, sig);
    236 	mutex_exit(p->p_lock);
    237 	error = copyout(&frame, fp, sizeof(frame));
    238 	mutex_enter(p->p_lock);
    239 
    240 	if (error != 0) {
    241 		/*
    242 		 * Process has trashed its stack; give it an illegal
    243 		 * instruction to halt it in its tracks.
    244 		 */
    245 		sigexit(l, SIGILL);
    246 		/* NOTREACHED */
    247 	}
    248 
    249 	/*
    250 	 * Build context to run handler in.
    251 	 */
    252 	tf->tf_fs = GSEL(GUDATA32_SEL, SEL_UPL) & 0xffffffff;
    253 	tf->tf_es = GSEL(GUDATA32_SEL, SEL_UPL) & 0xffffffff;
    254 	tf->tf_ds = GSEL(GUDATA32_SEL, SEL_UPL) & 0xffffffff;
    255 	tf->tf_rip = (((long)p->p_sigctx.ps_sigcode) +
    256 	    (linux32_rt_sigcode - linux32_sigcode)) & 0xffffffff;
    257 	tf->tf_cs = GSEL(GUCODE32_SEL, SEL_UPL) & 0xffffffff;
    258 	tf->tf_rflags &= ~PSL_CLEARSIG & 0xffffffff;
    259 	tf->tf_rsp = (long)fp & 0xffffffff;
    260 	tf->tf_ss = GSEL(GUDATA32_SEL, SEL_UPL) & 0xffffffff;
    261 
    262 	/* Remember that we're now on the signal stack. */
    263 	if (onstack)
    264 		sas->ss_flags |= SS_ONSTACK;
    265 
    266 	return;
    267 }
    268 
    269 void
    270 linux32_setregs(struct lwp *l, struct exec_package *pack, u_long stack)
    271 {
    272 	struct pcb *pcb = lwp_getpcb(l);
    273 	struct trapframe *tf;
    274 	struct proc *p = l->l_proc;
    275 
    276 #if defined(USER_LDT) && 0
    277 	pmap_ldt_cleanup(p);
    278 #endif
    279 
    280 	netbsd32_adjust_limits(p);
    281 
    282 	fpu_save_area_clear(l, __Linux_NPXCW__);
    283 
    284 	l->l_md.md_flags |= MDL_COMPAT32;	/* Forces iret not sysret */
    285 	pcb->pcb_flags = PCB_COMPAT32;
    286 
    287 	p->p_flag |= PK_32;
    288 
    289 	tf = l->l_md.md_regs;
    290 	tf->tf_rax = 0;
    291 	tf->tf_rbx = (u_int32_t)p->p_psstrp;
    292 	tf->tf_rcx = pack->ep_entry & 0xffffffff;
    293 	tf->tf_rdx = 0;
    294 	tf->tf_rsi = 0;
    295 	tf->tf_rdi = 0;
    296 	tf->tf_rbp = 0;
    297 	tf->tf_rsp = stack & 0xffffffff;
    298 	tf->tf_r8 = 0;
    299 	tf->tf_r9 = 0;
    300 	tf->tf_r10 = 0;
    301 	tf->tf_r11 = 0;
    302 	tf->tf_r12 = 0;
    303 	tf->tf_r13 = 0;
    304 	tf->tf_r14 = 0;
    305 	tf->tf_r15 = 0;
    306 	tf->tf_rip = pack->ep_entry & 0xffffffff;
    307 	tf->tf_rflags = PSL_USERSET;
    308 	tf->tf_cs = GSEL(GUCODE32_SEL, SEL_UPL);
    309 	tf->tf_ss = GSEL(GUDATA32_SEL, SEL_UPL);
    310 	tf->tf_ds = GSEL(GUDATA32_SEL, SEL_UPL);
    311 	tf->tf_es = GSEL(GUDATA32_SEL, SEL_UPL);
    312 	cpu_fsgs_zero(l);
    313 	cpu_fsgs_reload(l, GSEL(GUDATA32_SEL, SEL_UPL), GSEL(GUDATA32_SEL, SEL_UPL));
    314 }
    315 
    316 static void
    317 linux32_save_ucontext(struct lwp *l, struct trapframe *tf,
    318     const sigset_t *mask, struct sigaltstack *sas, struct linux32_ucontext *uc)
    319 {
    320 
    321 	uc->uc_flags = 0;
    322 	NETBSD32PTR32(uc->uc_link, NULL);
    323 	native_to_linux32_sigaltstack(&uc->uc_stack, sas);
    324 	linux32_save_sigcontext(l, tf, mask, &uc->uc_mcontext);
    325 	native_to_linux32_sigset(&uc->uc_sigmask, mask);
    326 	(void)memset(&uc->uc_fpregs_mem, 0, sizeof(uc->uc_fpregs_mem));
    327 }
    328 
    329 static void
    330 linux32_save_sigcontext(struct lwp *l, struct trapframe *tf,
    331 			const sigset_t *mask, struct linux32_sigcontext *sc)
    332 {
    333 	struct pcb *pcb = lwp_getpcb(l);
    334 
    335 	/* Save register context. */
    336 	sc->sc_gs = tf->tf_gs;
    337 	sc->sc_fs = tf->tf_fs;
    338 	sc->sc_es = tf->tf_es;
    339 	sc->sc_ds = tf->tf_ds;
    340 	sc->sc_eflags = tf->tf_rflags;
    341 	sc->sc_edi = tf->tf_rdi;
    342 	sc->sc_esi = tf->tf_rsi;
    343 	sc->sc_esp = tf->tf_rsp;
    344 	sc->sc_ebp = tf->tf_rbp;
    345 	sc->sc_ebx = tf->tf_rbx;
    346 	sc->sc_edx = tf->tf_rdx;
    347 	sc->sc_ecx = tf->tf_rcx;
    348 	sc->sc_eax = tf->tf_rax;
    349 	sc->sc_eip = tf->tf_rip;
    350 	sc->sc_cs = tf->tf_cs;
    351 	sc->sc_esp_at_signal = tf->tf_rsp;
    352 	sc->sc_ss = tf->tf_ss;
    353 	sc->sc_err = tf->tf_err;
    354 	sc->sc_trapno = tf->tf_trapno;
    355 	sc->sc_cr2 = pcb->pcb_cr2;
    356 	NETBSD32PTR32(sc->sc_387, NULL);
    357 
    358 	/* Save signal stack. */
    359 	/* Linux doesn't save the onstack flag in sigframe */
    360 
    361 	/* Save signal mask. */
    362 	native_to_linux32_old_sigset(&sc->sc_mask, mask);
    363 }
    364 
    365 int
    366 linux32_sys_sigreturn(struct lwp *l,
    367     const struct linux32_sys_sigreturn_args *uap, register_t *retval)
    368 {
    369 	/* {
    370 		syscallarg(linux32_sigcontextp_t) scp;
    371 	} */
    372 	struct linux32_sigcontext ctx;
    373 	int error;
    374 
    375 	if ((error = copyin(SCARG_P32(uap, scp), &ctx, sizeof(ctx))) != 0)
    376 		return error;
    377 
    378 	return linux32_restore_sigcontext(l, &ctx, retval);
    379 }
    380 
    381 int
    382 linux32_sys_rt_sigreturn(struct lwp *l,
    383     const struct linux32_sys_rt_sigreturn_args *uap, register_t *retval)
    384 {
    385 	/* {
    386 		syscallarg(linux32_ucontextp_t) ucp;
    387 	} */
    388 	struct linux32_ucontext ctx;
    389 	int error;
    390 
    391 	if ((error = copyin(SCARG_P32(uap, ucp), &ctx, sizeof(ctx))) != 0)
    392 		return error;
    393 
    394 	return linux32_restore_sigcontext(l, &ctx.uc_mcontext, retval);
    395 }
    396 
    397 static int
    398 linux32_restore_sigcontext(struct lwp *l, struct linux32_sigcontext *scp,
    399 			register_t *retval)
    400 {
    401 	struct trapframe *tf;
    402 	struct proc *p = l->l_proc;
    403 	struct sigaltstack *sas = &l->l_sigstk;
    404 	struct pcb *pcb;
    405 	sigset_t mask;
    406 	ssize_t ss_gap;
    407 	register_t fssel, gssel;
    408 
    409 	/* Restore register context. */
    410 	tf = l->l_md.md_regs;
    411 	pcb = lwp_getpcb(l);
    412 	DPRINTF(("sigreturn enter rsp=0x%lx rip=0x%lx\n", tf->tf_rsp,
    413 		 tf->tf_rip));
    414 
    415 	/*
    416 	 * Check for security violations.
    417 	 */
    418 	if (((scp->sc_eflags ^ tf->tf_rflags) & PSL_USERSTATIC) != 0 ||
    419 	    !USERMODE(scp->sc_cs, scp->sc_eflags))
    420 		return EINVAL;
    421 
    422 	if (scp->sc_fs != 0 && !VALID_USER_DSEL32(scp->sc_fs) &&
    423 	    !(VALID_USER_FSEL32(scp->sc_fs) && pcb->pcb_fs != 0))
    424 		return EINVAL;
    425 
    426 	if (scp->sc_gs != 0 && !VALID_USER_DSEL32(scp->sc_gs) &&
    427 	    !(VALID_USER_GSEL32(scp->sc_gs) && pcb->pcb_gs != 0))
    428 		return EINVAL;
    429 
    430 	if (scp->sc_es != 0 && !VALID_USER_DSEL32(scp->sc_es))
    431 		return EINVAL;
    432 
    433 	if (!VALID_USER_DSEL32(scp->sc_ds) ||
    434 	    !VALID_USER_DSEL32(scp->sc_ss))
    435 		return EINVAL;
    436 
    437 	if (scp->sc_eip >= VM_MAXUSER_ADDRESS32)
    438 		return EINVAL;
    439 
    440 	gssel = (register_t)scp->sc_gs & 0xffff;
    441 	fssel = (register_t)scp->sc_fs & 0xffff;
    442 	cpu_fsgs_reload(l, fssel, gssel);
    443 	tf->tf_es = (register_t)scp->sc_es & 0xffff;
    444 	tf->tf_ds = (register_t)scp->sc_ds & 0xffff;
    445 	tf->tf_rflags &= ~PSL_USER;
    446 	tf->tf_rflags |= ((register_t)scp->sc_eflags & PSL_USER);
    447 	tf->tf_rdi = (register_t)scp->sc_edi & 0xffffffff;
    448 	tf->tf_rsi = (register_t)scp->sc_esi & 0xffffffff;
    449 	tf->tf_rbp = (register_t)scp->sc_ebp & 0xffffffff;
    450 	tf->tf_rbx = (register_t)scp->sc_ebx & 0xffffffff;
    451 	tf->tf_rdx = (register_t)scp->sc_edx & 0xffffffff;
    452 	tf->tf_rcx = (register_t)scp->sc_ecx & 0xffffffff;
    453 	tf->tf_rax = (register_t)scp->sc_eax & 0xffffffff;
    454 	tf->tf_rip = (register_t)scp->sc_eip & 0xffffffff;
    455 	tf->tf_cs = (register_t)scp->sc_cs & 0xffff;
    456 	tf->tf_rsp = (register_t)scp->sc_esp_at_signal & 0xffffffff;
    457 	tf->tf_ss = (register_t)scp->sc_ss & 0xffff;
    458 
    459 	mutex_enter(p->p_lock);
    460 
    461 	/* Restore signal stack. */
    462 	ss_gap = (ssize_t)
    463 	    ((char *)NETBSD32IPTR64(scp->sc_esp_at_signal)
    464 	     - (char *)sas->ss_sp);
    465 	if (ss_gap >= 0 && ss_gap < sas->ss_size)
    466 		sas->ss_flags |= SS_ONSTACK;
    467 	else
    468 		sas->ss_flags &= ~SS_ONSTACK;
    469 
    470 	/* Restore signal mask. */
    471 	linux32_old_to_native_sigset(&mask, &scp->sc_mask);
    472 	(void) sigprocmask1(l, SIG_SETMASK, &mask, 0);
    473 
    474 	mutex_exit(p->p_lock);
    475 
    476 	DPRINTF(("linux32_sigreturn: rip = 0x%lx, rsp = 0x%lx, flags = 0x%lx\n",
    477 	    tf->tf_rip, tf->tf_rsp, tf->tf_rflags));
    478 	return EJUSTRETURN;
    479 }
    480 
    481 int
    482 linux32_sys_set_thread_area(struct lwp *l,
    483     const struct linux32_sys_set_thread_area_args *uap, register_t *retval)
    484 {
    485 	/* {
    486 		syscallarg(linux32_user_descp_t) desc;
    487 	} */
    488 
    489 	return linux_lwp_setprivate(l, SCARG_P32(uap, desc));
    490 }
    491 
    492 int
    493 linux32_sys_get_thread_area(struct lwp *l,
    494     const struct linux32_sys_get_thread_area_args *uap, register_t *retval)
    495 {
    496 	/* {
    497 		syscallarg(linux32_user_descp_t) desc;
    498 	} */
    499 
    500 	/* glibc doesn't actually call this. */
    501 	return ENOSYS;
    502 }
    503 
    504 int
    505 linux32_sys_modify_ldt(struct lwp *l, const struct linux32_sys_modify_ldt_args *uap, register_t *retval)
    506 {
    507 	/* {
    508 		syscallarg(int) func;
    509 		syscallarg(netbsd32_charp) ptr;
    510 		syscallarg(netbsd32_size_t) bytecount;
    511 	} */
    512 	struct linux_sys_modify_ldt_args ua;
    513 
    514 	NETBSD32TO64_UAP(func);
    515 	NETBSD32TOP_UAP(ptr, void *);
    516 	NETBSD32TOX_UAP(bytecount, size_t);
    517 	return linux_sys_modify_ldt(l, &ua, retval);
    518 }
    519