1 /* $NetBSD: linux_exec_machdep.c,v 1.25 2024/10/01 16:35:42 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2005 Emmanuel Dreyfus, all rights reserved 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by Emmanuel Dreyfus 17 * 4. The name of the author may not be used to endorse or promote 18 * products derived from this software without specific prior written 19 * permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE THE AUTHOR AND CONTRIBUTORS ``AS IS'' 22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 23 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS 25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 * POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: linux_exec_machdep.c,v 1.25 2024/10/01 16:35:42 riastradh Exp $"); 36 37 #define ELFSIZE 64 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/kernel.h> 42 #include <sys/resource.h> 43 #include <sys/proc.h> 44 #include <sys/conf.h> 45 #include <sys/kmem.h> 46 #include <sys/exec_elf.h> 47 #include <sys/vnode.h> 48 #include <sys/lwp.h> 49 #include <sys/exec.h> 50 #include <sys/stat.h> 51 #include <sys/kauth.h> 52 #include <sys/cprng.h> 53 54 #include <sys/cpu.h> 55 #include <machine/vmparam.h> 56 #include <sys/syscallargs.h> 57 58 #include <compat/linux/common/linux_types.h> 59 #include <compat/linux/common/linux_signal.h> 60 #include <compat/linux/common/linux_machdep.h> 61 #include <compat/linux/common/linux_util.h> 62 #include <compat/linux/common/linux_ioctl.h> 63 #include <compat/linux/common/linux_hdio.h> 64 #include <compat/linux/common/linux_exec.h> 65 #include <compat/linux/common/linux_errno.h> 66 #include <compat/linux/common/linux_prctl.h> 67 #include <compat/linux/common/linux_ipc.h> 68 #include <compat/linux/common/linux_sem.h> 69 #include <compat/linux/linux_syscallargs.h> 70 71 int 72 linux_exec_setup_stack(struct lwp *l, struct exec_package *epp) 73 { 74 u_long max_stack_size; 75 u_long access_linear_min, access_size; 76 u_long noaccess_linear_min, noaccess_size; 77 78 #ifndef USRSTACK32 79 #define USRSTACK32 (0x00000000ffffffffL & ~PGOFSET) 80 #endif 81 82 if (epp->ep_flags & EXEC_32) { 83 epp->ep_minsaddr = USRSTACK32; 84 max_stack_size = MAXSSIZ; 85 if (epp->ep_minsaddr > LINUX_USRSTACK32) 86 epp->ep_minsaddr = LINUX_USRSTACK32; 87 } else { 88 epp->ep_minsaddr = USRSTACK; 89 max_stack_size = MAXSSIZ; 90 if (epp->ep_minsaddr > LINUX_USRSTACK) 91 epp->ep_minsaddr = LINUX_USRSTACK; 92 93 } 94 95 epp->ep_maxsaddr = (u_long)STACK_GROW(epp->ep_minsaddr, 96 max_stack_size); 97 epp->ep_ssize = l->l_proc->p_rlimit[RLIMIT_STACK].rlim_cur; 98 99 /* 100 * set up commands for stack. note that this takes *two*, one to 101 * map the part of the stack which we can access, and one to map 102 * the part which we can't. 103 * 104 * arguably, it could be made into one, but that would require the 105 * addition of another mapping proc, which is unnecessary 106 */ 107 access_size = epp->ep_ssize; 108 access_linear_min = (u_long)STACK_ALLOC(epp->ep_minsaddr, access_size); 109 noaccess_size = max_stack_size - access_size; 110 noaccess_linear_min = (u_long)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr, 111 access_size), noaccess_size); 112 if (noaccess_size > 0) { 113 NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, noaccess_size, 114 noaccess_linear_min, NULLVP, 0, VM_PROT_NONE, VMCMD_STACK); 115 } 116 KASSERT(access_size > 0); 117 NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, access_size, 118 access_linear_min, NULLVP, 0, VM_PROT_READ | VM_PROT_WRITE, 119 VMCMD_STACK); 120 121 return 0; 122 } 123 124 int 125 ELFNAME2(linux,copyargs)(struct lwp *l, struct exec_package *pack, 126 struct ps_strings *arginfo, char **stackp, void *argp) 127 { 128 struct linux_extra_stack_data64 *esdp, esd; 129 struct elf_args *ap; 130 struct vattr *vap; 131 Elf_Ehdr *eh; 132 Elf_Phdr *ph; 133 u_long phsize; 134 Elf_Addr phdr = 0; 135 int error; 136 int i; 137 138 if ((error = copyargs(l, pack, arginfo, stackp, argp)) != 0) 139 return error; 140 141 /* 142 * Push extra arguments on the stack needed by dynamically 143 * linked binaries and static binaries as well. 144 */ 145 memset(&esd, 0, sizeof(esd)); 146 esdp = (struct linux_extra_stack_data64 *)(*stackp); 147 ap = (struct elf_args *)pack->ep_emul_arg; 148 vap = pack->ep_vap; 149 eh = (Elf_Ehdr *)pack->ep_hdr; 150 151 /* 152 * We forgot this, so we need to reload it now. XXX keep track of it? 153 */ 154 if (ap == NULL) { 155 phsize = eh->e_phnum * sizeof(Elf_Phdr); 156 ph = (Elf_Phdr *)kmem_alloc(phsize, KM_SLEEP); 157 error = exec_read(l, pack->ep_vp, eh->e_phoff, ph, phsize, 0); 158 if (error != 0) { 159 for (i = 0; i < eh->e_phnum; i++) { 160 if (ph[i].p_type == PT_PHDR) { 161 phdr = ph[i].p_vaddr; 162 break; 163 } 164 } 165 } 166 kmem_free(ph, phsize); 167 } 168 169 170 /* 171 * The exec_package doesn't have a proc pointer and it's not 172 * exactly trivial to add one since the credentials are 173 * changing. XXX Linux uses curlwp's credentials. 174 * Why can't we use them too? 175 */ 176 177 i = 0; 178 esd.ai[i].a_type = LINUX_AT_HWCAP; 179 esd.ai[i++].a_v = rcr4(); 180 181 esd.ai[i].a_type = AT_PAGESZ; 182 esd.ai[i++].a_v = PAGE_SIZE; 183 184 esd.ai[i].a_type = LINUX_AT_CLKTCK; 185 esd.ai[i++].a_v = hz; 186 187 esd.ai[i].a_type = AT_PHDR; 188 esd.ai[i++].a_v = (ap ? ap->arg_phaddr: phdr); 189 190 esd.ai[i].a_type = AT_PHENT; 191 esd.ai[i++].a_v = (ap ? ap->arg_phentsize : eh->e_phentsize); 192 193 esd.ai[i].a_type = AT_PHNUM; 194 esd.ai[i++].a_v = (ap ? ap->arg_phnum : eh->e_phnum); 195 196 esd.ai[i].a_type = AT_BASE; 197 esd.ai[i++].a_v = (ap ? ap->arg_interp : 0); 198 199 esd.ai[i].a_type = AT_FLAGS; 200 esd.ai[i++].a_v = 0; 201 202 esd.ai[i].a_type = AT_ENTRY; 203 esd.ai[i++].a_v = (ap ? ap->arg_entry : eh->e_entry); 204 205 esd.ai[i].a_type = LINUX_AT_EGID; 206 esd.ai[i++].a_v = ((vap->va_mode & S_ISGID) ? 207 vap->va_gid : kauth_cred_getegid(l->l_cred)); 208 209 esd.ai[i].a_type = LINUX_AT_GID; 210 esd.ai[i++].a_v = kauth_cred_getgid(l->l_cred); 211 212 esd.ai[i].a_type = LINUX_AT_EUID; 213 esd.ai[i++].a_v = ((vap->va_mode & S_ISUID) ? 214 vap->va_uid : kauth_cred_geteuid(l->l_cred)); 215 216 esd.ai[i].a_type = LINUX_AT_UID; 217 esd.ai[i++].a_v = kauth_cred_getuid(l->l_cred); 218 219 esd.ai[i].a_type = LINUX_AT_SECURE; 220 esd.ai[i++].a_v = 0; 221 222 esd.ai[i].a_type = LINUX_AT_PLATFORM; 223 esd.ai[i++].a_v = (Elf_Addr)&esdp->hw_platform[0]; 224 225 esd.ai[i].a_type = LINUX_AT_RANDOM; 226 esd.ai[i++].a_v = (Elf_Addr)&esdp->randbytes[0]; 227 esd.randbytes[0] = cprng_strong32(); 228 esd.randbytes[1] = cprng_strong32(); 229 esd.randbytes[2] = cprng_strong32(); 230 esd.randbytes[3] = cprng_strong32(); 231 232 esd.ai[i].a_type = AT_NULL; 233 esd.ai[i++].a_v = 0; 234 235 KASSERT(i == LINUX_ELF_AUX_ENTRIES); 236 237 strcpy(esd.hw_platform, LINUX_PLATFORM); 238 239 exec_free_emul_arg(pack); 240 241 /* 242 * Copy out the ELF auxiliary table and hw platform name 243 */ 244 if ((error = copyout(&esd, esdp, sizeof(esd))) != 0) 245 return error; 246 *stackp += sizeof(esd); 247 248 return 0; 249 } 250
Indexes created Sat Sep 20 22:09:52 GMT 2025