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      1 /*	$NetBSD: linux_exec_machdep.c,v 1.20 2020/09/05 16:30:10 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2004 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Christos Zoulas.
      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 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: linux_exec_machdep.c,v 1.20 2020/09/05 16:30:10 riastradh Exp $");
     34 
     35 #include <sys/param.h>
     36 #include <sys/systm.h>
     37 #include <sys/resource.h>
     38 #include <sys/proc.h>
     39 #include <sys/conf.h>
     40 #include <sys/exec.h>
     41 #include <sys/exec_elf.h>
     42 #include <sys/vnode.h>
     43 #include <sys/lwp.h>
     44 
     45 #include <sys/cpu.h>
     46 #include <machine/vmparam.h>
     47 
     48 #include <sys/syscallargs.h>
     49 
     50 #ifndef DEBUG_LINUX
     51 #define DPRINTF(a)
     52 #else
     53 #define DPRINTF(a)	uprintf a
     54 #endif
     55 
     56 #include <compat/linux/common/linux_types.h>
     57 #include <compat/linux/common/linux_signal.h>
     58 #include <compat/linux/common/linux_machdep.h>
     59 #include <compat/linux/common/linux_util.h>
     60 #include <compat/linux/common/linux_ioctl.h>
     61 #include <compat/linux/common/linux_hdio.h>
     62 #include <compat/linux/common/linux_exec.h>
     63 #include <compat/linux/common/linux_errno.h>
     64 #include <compat/linux/linux_syscallargs.h>
     65 
     66 int
     67 linux_exec_setup_stack(struct lwp *l, struct exec_package *epp)
     68 {
     69 	u_long max_stack_size;
     70 	u_long access_linear_min, access_size;
     71 	u_long noaccess_linear_min, noaccess_size;
     72 
     73 #ifndef	USRSTACK32
     74 #define USRSTACK32	(0x00000000ffffffffL&~PGOFSET)
     75 #endif
     76 
     77 	if (epp->ep_flags & EXEC_32) {
     78 		epp->ep_minsaddr = USRSTACK32;
     79 		max_stack_size = MAXSSIZ;
     80 	} else {
     81 		epp->ep_minsaddr = USRSTACK;
     82 		max_stack_size = MAXSSIZ;
     83 	}
     84 
     85 	if (epp->ep_minsaddr > LINUX_USRSTACK)
     86 		epp->ep_minsaddr = LINUX_USRSTACK;
     87 #ifdef DEBUG_LINUX
     88 	else {
     89 		/*
     90 		 * Someone needs to make KERNBASE and TEXTADDR
     91 		 * java versions < 1.4.2 need the stack to be
     92 		 * at 0xC0000000
     93 		 */
     94 		uprintf("Cannot setup stack to 0xC0000000, "
     95 		    "java will not work properly\n");
     96 	}
     97 #endif
     98 	epp->ep_maxsaddr = (u_long)STACK_GROW(epp->ep_minsaddr,
     99 		max_stack_size);
    100 	epp->ep_ssize = l->l_proc->p_rlimit[RLIMIT_STACK].rlim_cur;
    101 
    102 	/*
    103 	 * set up commands for stack.  note that this takes *two*, one to
    104 	 * map the part of the stack which we can access, and one to map
    105 	 * the part which we can't.
    106 	 *
    107 	 * arguably, it could be made into one, but that would require the
    108 	 * addition of another mapping proc, which is unnecessary
    109 	 */
    110 	access_size = epp->ep_ssize;
    111 	access_linear_min = (u_long)STACK_ALLOC(epp->ep_minsaddr, access_size);
    112 	noaccess_size = max_stack_size - access_size;
    113 	noaccess_linear_min = (u_long)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr,
    114 	    access_size), noaccess_size);
    115 	if (noaccess_size > 0) {
    116 		NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, noaccess_size,
    117 		    noaccess_linear_min, NULLVP, 0, VM_PROT_NONE, VMCMD_STACK);
    118 	}
    119 	KASSERT(access_size > 0);
    120 	NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, access_size,
    121 	    access_linear_min, NULLVP, 0, VM_PROT_READ | VM_PROT_WRITE,
    122 	    VMCMD_STACK);
    123 
    124 	return 0;
    125 }
    126 
    127 int
    128 linux_sys_set_thread_area(struct lwp *l,
    129     const struct linux_sys_set_thread_area_args *uap, register_t *retval)
    130 {
    131 	/* {
    132 		syscallarg(struct linux_user_desc *) desc;
    133 	} */
    134 
    135 	return linux_lwp_setprivate(l, SCARG(uap, desc));
    136 }
    137 
    138 int
    139 linux_sys_get_thread_area(struct lwp *l,
    140     const struct linux_sys_get_thread_area_args *uap, register_t *retval)
    141 {
    142 	/* {
    143 		syscallarg(struct linux_user_desc *) desc;
    144 	} */
    145 
    146 	/* glibc doesn't actually call this. */
    147 	return ENOSYS;
    148 }
    149