1 /*-
2 * Copyright (c) 2015 Nuxi, https://nuxi.nl/
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28
29 #include <sys/param.h>
30 #include <sys/imgact.h>
31 #include <sys/kernel.h>
32 #include <sys/module.h>
33 #include <sys/proc.h>
34 #include <sys/smp.h>
35 #include <sys/sysctl.h>
36 #include <sys/sysent.h>
37 #include <sys/systm.h>
38
39 #include <contrib/cloudabi/cloudabi32_types.h>
40
41 #include <compat/cloudabi/cloudabi_util.h>
42
43 #include <compat/cloudabi32/cloudabi32_util.h>
44
45 extern char _binary_cloudabi32_vdso_o_start[];
46 extern char _binary_cloudabi32_vdso_o_end[];
47
48 int
cloudabi32_copyout_strings(struct image_params * imgp,uintptr_t * stack_base)49 cloudabi32_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
50 {
51 struct image_args *args;
52 uintptr_t begin;
53 size_t len;
54
55 /* Copy out program arguments. */
56 args = imgp->args;
57 len = exec_args_get_begin_envv(args) - args->begin_argv;
58 begin = rounddown2(imgp->sysent->sv_usrstack - len, sizeof(register_t));
59 *stack_base = begin;
60 return (copyout(args->begin_argv, (void *)begin, len));
61 }
62
63 int
cloudabi32_fixup(uintptr_t * stack_base,struct image_params * imgp)64 cloudabi32_fixup(uintptr_t *stack_base, struct image_params *imgp)
65 {
66 char canarybuf[64], pidbuf[16];
67 Elf32_Auxargs *args;
68 struct thread *td;
69 void *argdata, *canary, *pid;
70 size_t argdatalen;
71 int error;
72
73 /*
74 * CloudABI executables do not store the FreeBSD OS release
75 * number in their header. Set the OS release number to the
76 * latest version of FreeBSD, so that system calls behave as if
77 * called natively.
78 */
79 td = curthread;
80 td->td_proc->p_osrel = __FreeBSD_version;
81
82 argdata = (void *)*stack_base;
83
84 /* Store canary for stack smashing protection. */
85 arc4rand(canarybuf, sizeof(canarybuf), 0);
86 *stack_base -= roundup(sizeof(canarybuf), sizeof(register_t));
87 canary = (void *)*stack_base;
88 error = copyout(canarybuf, canary, sizeof(canarybuf));
89 if (error != 0)
90 return (error);
91
92 /*
93 * Generate a random UUID that identifies the process. Right now
94 * we don't store this UUID in the kernel. Ideally, it should be
95 * exposed through ps(1).
96 */
97 arc4rand(pidbuf, sizeof(pidbuf), 0);
98 pidbuf[6] = (pidbuf[6] & 0x0f) | 0x40;
99 pidbuf[8] = (pidbuf[8] & 0x3f) | 0x80;
100 *stack_base -= roundup(sizeof(pidbuf), sizeof(register_t));
101 pid = (void *)*stack_base;
102 error = copyout(pidbuf, pid, sizeof(pidbuf));
103 if (error != 0)
104 return (error);
105
106 /*
107 * Compute length of program arguments. As the argument data is
108 * binary safe, we had to add a trailing null byte in
109 * exec_copyin_data_fds(). Undo this by reducing the length.
110 */
111 args = (Elf32_Auxargs *)imgp->auxargs;
112 argdatalen = exec_args_get_begin_envv(imgp->args) -
113 imgp->args->begin_argv;
114 if (argdatalen > 0)
115 --argdatalen;
116
117 /* Write out an auxiliary vector. */
118 cloudabi32_auxv_t auxv[] = {
119 #define VAL(type, val) { .a_type = (type), .a_val = (val) }
120 #define PTR(type, ptr) { .a_type = (type), .a_ptr = (uintptr_t)(ptr) }
121 PTR(CLOUDABI_AT_ARGDATA, argdata),
122 VAL(CLOUDABI_AT_ARGDATALEN, argdatalen),
123 VAL(CLOUDABI_AT_BASE, args->base),
124 PTR(CLOUDABI_AT_CANARY, canary),
125 VAL(CLOUDABI_AT_CANARYLEN, sizeof(canarybuf)),
126 VAL(CLOUDABI_AT_NCPUS, mp_ncpus),
127 VAL(CLOUDABI_AT_PAGESZ, args->pagesz),
128 PTR(CLOUDABI_AT_PHDR, args->phdr),
129 VAL(CLOUDABI_AT_PHNUM, args->phnum),
130 PTR(CLOUDABI_AT_PID, pid),
131 PTR(CLOUDABI_AT_SYSINFO_EHDR,
132 imgp->proc->p_sysent->sv_shared_page_base),
133 VAL(CLOUDABI_AT_TID, td->td_tid),
134 #undef VAL
135 #undef PTR
136 { .a_type = CLOUDABI_AT_NULL },
137 };
138 *stack_base -= roundup(sizeof(auxv), sizeof(register_t));
139 error = copyout(auxv, (void *)*stack_base, sizeof(auxv));
140 if (error != 0)
141 return (error);
142
143 /* Reserve space for storing the TCB. */
144 *stack_base -= roundup(sizeof(cloudabi32_tcb_t), sizeof(register_t));
145 return (0);
146 }
147
148 static int
cloudabi32_modevent(module_t mod,int type,void * data)149 cloudabi32_modevent(module_t mod, int type, void *data)
150 {
151
152 switch (type) {
153 case MOD_LOAD:
154 cloudabi_vdso_init(cloudabi32_brand.sysvec,
155 _binary_cloudabi32_vdso_o_start,
156 _binary_cloudabi32_vdso_o_end);
157 if (elf32_insert_brand_entry(&cloudabi32_brand) < 0) {
158 printf("Failed to add CloudABI ELF brand handler\n");
159 return (EINVAL);
160 }
161 return (0);
162 case MOD_UNLOAD:
163 if (elf32_brand_inuse(&cloudabi32_brand))
164 return (EBUSY);
165 if (elf32_remove_brand_entry(&cloudabi32_brand) < 0) {
166 printf("Failed to remove CloudABI ELF brand handler\n");
167 return (EINVAL);
168 }
169 cloudabi_vdso_destroy(cloudabi32_brand.sysvec);
170 return (0);
171 default:
172 return (EOPNOTSUPP);
173 }
174 }
175
176 static moduledata_t cloudabi32_module = {
177 "cloudabi32",
178 cloudabi32_modevent,
179 NULL
180 };
181
182 DECLARE_MODULE_TIED(cloudabi32, cloudabi32_module, SI_SUB_EXEC, SI_ORDER_ANY);
183 MODULE_DEPEND(cloudabi32, cloudabi, 1, 1, 1);
184 FEATURE(cloudabi32, "CloudABI 32bit support");
185