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 register_t * 49 cloudabi32_copyout_strings(struct image_params *imgp) 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 = args->begin_envv - args->begin_argv; 58 begin = rounddown2(imgp->sysent->sv_usrstack - len, sizeof(register_t)); 59 copyout(args->begin_argv, (void *)begin, len); 60 return ((register_t *)begin); 61 } 62 63 int 64 cloudabi32_fixup(register_t **stack_base, struct image_params *imgp) 65 { 66 char canarybuf[64]; 67 Elf32_Auxargs *args; 68 struct thread *td; 69 void *argdata, *canary; 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 /* Store canary for stack smashing protection. */ 83 argdata = *stack_base; 84 arc4rand(canarybuf, sizeof(canarybuf), 0); 85 *stack_base -= howmany(sizeof(canarybuf), sizeof(register_t)); 86 canary = *stack_base; 87 error = copyout(canarybuf, canary, sizeof(canarybuf)); 88 if (error != 0) 89 return (error); 90 91 /* 92 * Compute length of program arguments. As the argument data is 93 * binary safe, we had to add a trailing null byte in 94 * exec_copyin_data_fds(). Undo this by reducing the length. 95 */ 96 args = (Elf32_Auxargs *)imgp->auxargs; 97 argdatalen = imgp->args->begin_envv - imgp->args->begin_argv; 98 if (argdatalen > 0) 99 --argdatalen; 100 101 /* Write out an auxiliary vector. */ 102 cloudabi32_auxv_t auxv[] = { 103 #define VAL(type, val) { .a_type = (type), .a_val = (val) } 104 #define PTR(type, ptr) { .a_type = (type), .a_ptr = (uintptr_t)(ptr) } 105 PTR(CLOUDABI_AT_ARGDATA, argdata), 106 VAL(CLOUDABI_AT_ARGDATALEN, argdatalen), 107 VAL(CLOUDABI_AT_BASE, args->base), 108 PTR(CLOUDABI_AT_CANARY, canary), 109 VAL(CLOUDABI_AT_CANARYLEN, sizeof(canarybuf)), 110 VAL(CLOUDABI_AT_NCPUS, mp_ncpus), 111 VAL(CLOUDABI_AT_PAGESZ, args->pagesz), 112 PTR(CLOUDABI_AT_PHDR, args->phdr), 113 VAL(CLOUDABI_AT_PHNUM, args->phnum), 114 VAL(CLOUDABI_AT_TID, td->td_tid), 115 PTR(CLOUDABI_AT_SYSINFO_EHDR, 116 imgp->proc->p_sysent->sv_shared_page_base), 117 #undef VAL 118 #undef PTR 119 { .a_type = CLOUDABI_AT_NULL }, 120 }; 121 *stack_base -= howmany(sizeof(auxv), sizeof(register_t)); 122 error = copyout(auxv, *stack_base, sizeof(auxv)); 123 if (error != 0) 124 return (error); 125 126 /* Reserve space for storing the TCB. */ 127 *stack_base -= howmany(sizeof(cloudabi32_tcb_t), sizeof(register_t)); 128 return (0); 129 } 130 131 static int 132 cloudabi32_modevent(module_t mod, int type, void *data) 133 { 134 135 switch (type) { 136 case MOD_LOAD: 137 cloudabi_vdso_init(cloudabi32_brand.sysvec, 138 _binary_cloudabi32_vdso_o_start, 139 _binary_cloudabi32_vdso_o_end); 140 if (elf32_insert_brand_entry(&cloudabi32_brand) < 0) { 141 printf("Failed to add CloudABI ELF brand handler\n"); 142 return (EINVAL); 143 } 144 return (0); 145 case MOD_UNLOAD: 146 if (elf32_brand_inuse(&cloudabi32_brand)) 147 return (EBUSY); 148 if (elf32_remove_brand_entry(&cloudabi32_brand) < 0) { 149 printf("Failed to remove CloudABI ELF brand handler\n"); 150 return (EINVAL); 151 } 152 cloudabi_vdso_destroy(cloudabi32_brand.sysvec); 153 return (0); 154 default: 155 return (EOPNOTSUPP); 156 } 157 } 158 159 static moduledata_t cloudabi32_module = { 160 "cloudabi32", 161 cloudabi32_modevent, 162 NULL 163 }; 164 165 DECLARE_MODULE_TIED(cloudabi32, cloudabi32_module, SI_SUB_EXEC, SI_ORDER_ANY); 166 MODULE_DEPEND(cloudabi32, cloudabi, 1, 1, 1); 167 FEATURE(cloudabi32, "CloudABI 32bit support"); 168