linux_exec_machdep.c revision 1.23
1 /* $NetBSD: linux_exec_machdep.c,v 1.23 2020/01/12 18:30:58 ad 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 1.23 2020/01/12 18:30:58 ad 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 <uvm/uvm.h> 59 60 #include <compat/linux/common/linux_types.h> 61 #include <compat/linux/common/linux_signal.h> 62 #include <compat/linux/common/linux_machdep.h> 63 #include <compat/linux/common/linux_util.h> 64 #include <compat/linux/common/linux_ioctl.h> 65 #include <compat/linux/common/linux_hdio.h> 66 #include <compat/linux/common/linux_exec.h> 67 #include <compat/linux/common/linux_errno.h> 68 #include <compat/linux/common/linux_prctl.h> 69 #include <compat/linux/common/linux_ipc.h> 70 #include <compat/linux/common/linux_sem.h> 71 #include <compat/linux/linux_syscallargs.h> 72 73 int 74 linux_exec_setup_stack(struct lwp *l, struct exec_package *epp) 75 { 76 u_long max_stack_size; 77 u_long access_linear_min, access_size; 78 u_long noaccess_linear_min, noaccess_size; 79 80 #ifndef USRSTACK32 81 #define USRSTACK32 (0x00000000ffffffffL & ~PGOFSET) 82 #endif 83 84 if (epp->ep_flags & EXEC_32) { 85 epp->ep_minsaddr = USRSTACK32; 86 max_stack_size = MAXSSIZ; 87 if (epp->ep_minsaddr > LINUX_USRSTACK32) 88 epp->ep_minsaddr = LINUX_USRSTACK32; 89 } else { 90 epp->ep_minsaddr = USRSTACK; 91 max_stack_size = MAXSSIZ; 92 if (epp->ep_minsaddr > LINUX_USRSTACK) 93 epp->ep_minsaddr = LINUX_USRSTACK; 94 95 } 96 97 epp->ep_maxsaddr = (u_long)STACK_GROW(epp->ep_minsaddr, 98 max_stack_size); 99 epp->ep_ssize = l->l_proc->p_rlimit[RLIMIT_STACK].rlim_cur; 100 101 /* 102 * set up commands for stack. note that this takes *two*, one to 103 * map the part of the stack which we can access, and one to map 104 * the part which we can't. 105 * 106 * arguably, it could be made into one, but that would require the 107 * addition of another mapping proc, which is unnecessary 108 */ 109 access_size = epp->ep_ssize; 110 access_linear_min = (u_long)STACK_ALLOC(epp->ep_minsaddr, access_size); 111 noaccess_size = max_stack_size - access_size; 112 noaccess_linear_min = (u_long)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr, 113 access_size), noaccess_size); 114 if (noaccess_size > 0) { 115 NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, noaccess_size, 116 noaccess_linear_min, NULLVP, 0, VM_PROT_NONE, VMCMD_STACK); 117 } 118 KASSERT(access_size > 0); 119 NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, access_size, 120 access_linear_min, NULLVP, 0, VM_PROT_READ | VM_PROT_WRITE, 121 VMCMD_STACK); 122 123 return 0; 124 } 125 126 int 127 ELFNAME2(linux,copyargs)(struct lwp *l, struct exec_package *pack, 128 struct ps_strings *arginfo, char **stackp, void *argp) 129 { 130 struct linux_extra_stack_data64 *esdp, esd; 131 struct elf_args *ap; 132 struct vattr *vap; 133 Elf_Ehdr *eh; 134 Elf_Phdr *ph; 135 u_long phsize; 136 Elf_Addr phdr = 0; 137 int error; 138 int i; 139 140 if ((error = copyargs(l, pack, arginfo, stackp, argp)) != 0) 141 return error; 142 143 /* 144 * Push extra arguments on the stack needed by dynamically 145 * linked binaries and static binaries as well. 146 */ 147 memset(&esd, 0, sizeof(esd)); 148 esdp = (struct linux_extra_stack_data64 *)(*stackp); 149 ap = (struct elf_args *)pack->ep_emul_arg; 150 vap = pack->ep_vap; 151 eh = (Elf_Ehdr *)pack->ep_hdr; 152 153 /* 154 * We forgot this, so we need to reload it now. XXX keep track of it? 155 */ 156 if (ap == NULL) { 157 phsize = eh->e_phnum * sizeof(Elf_Phdr); 158 ph = (Elf_Phdr *)kmem_alloc(phsize, KM_SLEEP); 159 error = exec_read(l, pack->ep_vp, eh->e_phoff, ph, phsize, 0); 160 if (error != 0) { 161 for (i = 0; i < eh->e_phnum; i++) { 162 if (ph[i].p_type == PT_PHDR) { 163 phdr = ph[i].p_vaddr; 164 break; 165 } 166 } 167 } 168 kmem_free(ph, phsize); 169 } 170 171 172 /* 173 * The exec_package doesn't have a proc pointer and it's not 174 * exactly trivial to add one since the credentials are 175 * changing. XXX Linux uses curlwp's credentials. 176 * Why can't we use them too? 177 */ 178 179 i = 0; 180 esd.ai[i].a_type = LINUX_AT_HWCAP; 181 esd.ai[i++].a_v = rcr4(); 182 183 esd.ai[i].a_type = AT_PAGESZ; 184 esd.ai[i++].a_v = PAGE_SIZE; 185 186 esd.ai[i].a_type = LINUX_AT_CLKTCK; 187 esd.ai[i++].a_v = hz; 188 189 esd.ai[i].a_type = AT_PHDR; 190 esd.ai[i++].a_v = (ap ? ap->arg_phaddr: phdr); 191 192 esd.ai[i].a_type = AT_PHENT; 193 esd.ai[i++].a_v = (ap ? ap->arg_phentsize : eh->e_phentsize); 194 195 esd.ai[i].a_type = AT_PHNUM; 196 esd.ai[i++].a_v = (ap ? ap->arg_phnum : eh->e_phnum); 197 198 esd.ai[i].a_type = AT_BASE; 199 esd.ai[i++].a_v = (ap ? ap->arg_interp : 0); 200 201 esd.ai[i].a_type = AT_FLAGS; 202 esd.ai[i++].a_v = 0; 203 204 esd.ai[i].a_type = AT_ENTRY; 205 esd.ai[i++].a_v = (ap ? ap->arg_entry : eh->e_entry); 206 207 esd.ai[i].a_type = LINUX_AT_EGID; 208 esd.ai[i++].a_v = ((vap->va_mode & S_ISGID) ? 209 vap->va_gid : kauth_cred_getegid(l->l_cred)); 210 211 esd.ai[i].a_type = LINUX_AT_GID; 212 esd.ai[i++].a_v = kauth_cred_getgid(l->l_cred); 213 214 esd.ai[i].a_type = LINUX_AT_EUID; 215 esd.ai[i++].a_v = ((vap->va_mode & S_ISUID) ? 216 vap->va_uid : kauth_cred_geteuid(l->l_cred)); 217 218 esd.ai[i].a_type = LINUX_AT_UID; 219 esd.ai[i++].a_v = kauth_cred_getuid(l->l_cred); 220 221 esd.ai[i].a_type = LINUX_AT_SECURE; 222 esd.ai[i++].a_v = 0; 223 224 esd.ai[i].a_type = LINUX_AT_PLATFORM; 225 esd.ai[i++].a_v = (Elf_Addr)&esdp->hw_platform[0]; 226 227 esd.ai[i].a_type = LINUX_AT_RANDOM; 228 esd.ai[i++].a_v = (Elf_Addr)&esdp->randbytes[0]; 229 esd.randbytes[0] = cprng_strong32(); 230 esd.randbytes[1] = cprng_strong32(); 231 esd.randbytes[2] = cprng_strong32(); 232 esd.randbytes[3] = cprng_strong32(); 233 234 esd.ai[i].a_type = AT_NULL; 235 esd.ai[i++].a_v = 0; 236 237 KASSERT(i == LINUX_ELF_AUX_ENTRIES); 238 239 strcpy(esd.hw_platform, LINUX_PLATFORM); 240 241 exec_free_emul_arg(pack); 242 243 /* 244 * Copy out the ELF auxiliary table and hw platform name 245 */ 246 if ((error = copyout(&esd, esdp, sizeof(esd))) != 0) 247 return error; 248 *stackp += sizeof(esd); 249 250 return 0; 251 } 252
Indexes created Mon Sep 22 10:09:38 GMT 2025