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 <compat/cloudabi64/cloudabi64_syscalldefs.h>
40 #include <compat/cloudabi64/cloudabi64_util.h>
41
42 register_t *
cloudabi64_copyout_strings(struct image_params * imgp)43 cloudabi64_copyout_strings(struct image_params *imgp)
44 {
45 struct image_args *args;
46 uintptr_t begin;
47 size_t len;
48
49 /* Copy out program arguments. */
50 args = imgp->args;
51 len = args->begin_envv - args->begin_argv;
52 begin = rounddown2(imgp->sysent->sv_usrstack - len, sizeof(register_t));
53 copyout(args->begin_argv, (void *)begin, len);
54 return ((register_t *)begin);
55 }
56
57 int
cloudabi64_fixup(register_t ** stack_base,struct image_params * imgp)58 cloudabi64_fixup(register_t **stack_base, struct image_params *imgp)
59 {
60 char canarybuf[64];
61 Elf64_Auxargs *args;
62 struct thread *td;
63 void *argdata, *canary;
64 size_t argdatalen;
65 int error;
66
67 /*
68 * CloudABI executables do not store the FreeBSD OS release
69 * number in their header. Set the OS release number to the
70 * latest version of FreeBSD, so that system calls behave as if
71 * called natively.
72 */
73 td = curthread;
74 td->td_proc->p_osrel = __FreeBSD_version;
75
76 /* Store canary for stack smashing protection. */
77 argdata = *stack_base;
78 arc4rand(canarybuf, sizeof(canarybuf), 0);
79 *stack_base -= howmany(sizeof(canarybuf), sizeof(register_t));
80 canary = *stack_base;
81 error = copyout(canarybuf, canary, sizeof(canarybuf));
82 if (error != 0)
83 return (error);
84
85 /*
86 * Compute length of program arguments. As the argument data is
87 * binary safe, we had to add a trailing null byte in
88 * exec_copyin_data_fds(). Undo this by reducing the length.
89 */
90 args = (Elf64_Auxargs *)imgp->auxargs;
91 argdatalen = imgp->args->begin_envv - imgp->args->begin_argv;
92 if (argdatalen > 0)
93 --argdatalen;
94
95 /* Write out an auxiliary vector. */
96 cloudabi64_auxv_t auxv[] = {
97 #define VAL(type, val) { .a_type = (type), .a_val = (val) }
98 #define PTR(type, ptr) { .a_type = (type), .a_ptr = (uintptr_t)(ptr) }
99 PTR(CLOUDABI_AT_ARGDATA, argdata),
100 VAL(CLOUDABI_AT_ARGDATALEN, argdatalen),
101 PTR(CLOUDABI_AT_CANARY, canary),
102 VAL(CLOUDABI_AT_CANARYLEN, sizeof(canarybuf)),
103 VAL(CLOUDABI_AT_NCPUS, mp_ncpus),
104 VAL(CLOUDABI_AT_PAGESZ, args->pagesz),
105 PTR(CLOUDABI_AT_PHDR, args->phdr),
106 VAL(CLOUDABI_AT_PHNUM, args->phnum),
107 VAL(CLOUDABI_AT_TID, td->td_tid),
108 #undef VAL
109 #undef PTR
110 { .a_type = CLOUDABI_AT_NULL },
111 };
112 *stack_base -= howmany(sizeof(auxv), sizeof(register_t));
113 return (copyout(auxv, *stack_base, sizeof(auxv)));
114 }
115
116 static int
cloudabi64_modevent(module_t mod,int type,void * data)117 cloudabi64_modevent(module_t mod, int type, void *data)
118 {
119
120 switch (type) {
121 case MOD_LOAD:
122 if (elf64_insert_brand_entry(&cloudabi64_brand) < 0) {
123 printf("Failed to add CloudABI ELF brand handler\n");
124 return (EINVAL);
125 }
126 return (0);
127 case MOD_UNLOAD:
128 if (elf64_brand_inuse(&cloudabi64_brand))
129 return (EBUSY);
130 if (elf64_remove_brand_entry(&cloudabi64_brand) < 0) {
131 printf("Failed to remove CloudABI ELF brand handler\n");
132 return (EINVAL);
133 }
134 return (0);
135 default:
136 return (EOPNOTSUPP);
137 }
138 }
139
140 static moduledata_t cloudabi64_module = {
141 "cloudabi64",
142 cloudabi64_modevent,
143 NULL
144 };
145
146 DECLARE_MODULE_TIED(cloudabi64, cloudabi64_module, SI_SUB_EXEC, SI_ORDER_ANY);
147 MODULE_DEPEND(cloudabi64, cloudabi, 1, 1, 1);
148 FEATURE(cloudabi64, "CloudABI 64bit support");
149