1 /* $NetBSD: linux32_exec_machdep.c,v 1.2 2023/04/09 12:29:26 riastradh Exp $ */
2
3 /*
4 * Copyright (c) 1993, 1994, 1996 Christopher G. Demetriou
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Christopher G. Demetriou.
18 * 4. The name of the author may not be used to endorse or promote products
19 * derived from this software without specific prior written permission
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: linux32_exec_machdep.c,v 1.2 2023/04/09 12:29:26 riastradh Exp $");
35
36 #include <sys/param.h>
37 #include <sys/types.h>
38 #include <sys/exec.h>
39 #include <sys/lwp.h>
40 #include <sys/syscallargs.h>
41 #include <sys/vnode.h>
42
43 #include <machine/vmparam.h>
44
45 #include <compat/linux/common/linux_types.h>
46 #include <compat/linux/common/linux_exec.h>
47 #include <compat/linux32/common/linux32_exec.h>
48
49 #ifdef LINUX32_ARM_KUSER_HELPER_ADDR
50 static int
vmcmd_linux32_kuser_helper_map(struct lwp * l,struct exec_vmcmd * cmd)51 vmcmd_linux32_kuser_helper_map(struct lwp *l, struct exec_vmcmd *cmd)
52 {
53 const struct proc *p = l->l_proc;
54 /* l->l_proc->p_emul still points to emul_netbsd at this point */
55 const struct emul *e = &emul_linux32;
56 struct uvm_object *uobj;
57 vsize_t sz;
58 vaddr_t va;
59 int error;
60
61 /*
62 * kuser_helper code share the page prepared for sigcode.
63 * See also sys/compat/linux32/arch/aarch64/linux32_sigcode.S
64 */
65 if (e->e_sigobject == NULL)
66 return 0;
67 uobj = *e->e_sigobject;
68 if (uobj == NULL)
69 return 0;
70
71 va = LINUX32_ARM_KUSER_HELPER_ADDR;
72 sz = LINUX32_ARM_KUSER_HELPER_SIZE;
73
74 (*uobj->pgops->pgo_reference)(uobj);
75 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), uobj, 0, 0,
76 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX,
77 UVM_INH_SHARE, UVM_ADV_RANDOM, 0));
78 if (error) {
79 (*uobj->pgops->pgo_detach)(uobj);
80 return error;
81 }
82
83 return 0;
84 }
85 #endif
86
87 int
linux32_exec_setup_stack(struct lwp * l,struct exec_package * epp)88 linux32_exec_setup_stack(struct lwp *l, struct exec_package *epp)
89 {
90 vaddr_t access_linear_min, noaccess_linear_min;
91 vsize_t access_size, noaccess_size;
92 vsize_t max_stack_size;
93
94 #ifndef LINUX32_USRSTACK
95 #define LINUX32_USRSTACK USRSTACK32
96 #endif
97 #ifndef LINUX32_MAXSSIZ
98 #define LINUX32_MAXSSIZ MAXSSIZ32
99 #endif
100
101 KASSERT((epp->ep_flags & EXEC_32) != 0);
102 epp->ep_minsaddr = LINUX32_USRSTACK;
103 max_stack_size = LINUX32_MAXSSIZ;
104
105 epp->ep_ssize =
106 MIN(l->l_proc->p_rlimit[RLIMIT_STACK].rlim_cur, max_stack_size);
107 epp->ep_maxsaddr =
108 (vaddr_t)STACK_GROW(epp->ep_minsaddr, max_stack_size);
109
110 l->l_proc->p_stackbase = epp->ep_minsaddr;
111
112 /*
113 * set up commands for stack. note that this takes *two*, one to
114 * map the part of the stack which we can access, and one to map
115 * the part which we can't.
116 *
117 * arguably, it could be made into one, but that would require the
118 * addition of another mapping proc, which is unnecessary
119 */
120 access_size = epp->ep_ssize;
121 access_linear_min = (vaddr_t)STACK_ALLOC(epp->ep_minsaddr, access_size);
122 noaccess_size = max_stack_size - access_size;
123 noaccess_linear_min = (vaddr_t)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr,
124 access_size), noaccess_size);
125
126 if (noaccess_size > 0 && noaccess_size <= max_stack_size) {
127 NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, noaccess_size,
128 noaccess_linear_min, NULLVP, 0, VM_PROT_NONE, VMCMD_STACK);
129 }
130 KASSERT(access_size > 0);
131 KASSERT(access_size <= max_stack_size);
132 NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, access_size,
133 access_linear_min, NULLVP, 0, VM_PROT_READ | VM_PROT_WRITE,
134 VMCMD_STACK);
135
136 #ifdef LINUX32_ARM_KUSER_HELPER_ADDR
137 NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_linux32_kuser_helper_map,
138 LINUX32_ARM_KUSER_HELPER_SIZE, LINUX32_ARM_KUSER_HELPER_ADDR,
139 NULLVP, 0, VM_PROT_READ | VM_PROT_EXECUTE, 0);
140 #endif /* LINUX32_ARM_KUSER_HELPER_ADDR */
141
142 return 0;
143 }
144