/* $OpenBSD: linux_exec.c,v 1.18 2001/11/06 19:53:17 miod Exp $ */ /* $NetBSD: linux_exec.c,v 1.13 1996/04/05 00:01:10 christos Exp $ */ /* * Copyright (c) 1995 Frank van der Linden * Copyright (c) 1994 Christos Zoulas * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * based on exec_aout.c, sunos_exec.c and svr4_exec.c */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static void *linux_aout_copyargs __P((struct exec_package *, struct ps_strings *, void *, void *)); #define LINUX_AOUT_AUX_ARGSIZ 2 #define LINUX_ELF_AUX_ARGSIZ (sizeof(AuxInfo) * 8 / sizeof(char *)) const char linux_emul_path[] = "/emul/linux"; extern int linux_error[]; extern char linux_sigcode[], linux_esigcode[]; extern struct sysent linux_sysent[]; #ifdef SYSCALL_DEBUG extern char *linux_syscallnames[]; #endif int exec_linux_aout_prep_zmagic __P((struct proc *, struct exec_package *)); int exec_linux_aout_prep_nmagic __P((struct proc *, struct exec_package *)); int exec_linux_aout_prep_omagic __P((struct proc *, struct exec_package *)); int exec_linux_aout_prep_qmagic __P((struct proc *, struct exec_package *)); struct emul emul_linux_aout = { "linux", linux_error, linux_sendsig, LINUX_SYS_syscall, LINUX_SYS_MAXSYSCALL, linux_sysent, #ifdef SYSCALL_DEBUG linux_syscallnames, #else NULL, #endif LINUX_AOUT_AUX_ARGSIZ, linux_aout_copyargs, setregs, NULL, linux_sigcode, linux_esigcode, }; struct emul emul_linux_elf = { "linux", linux_error, linux_sendsig, LINUX_SYS_syscall, LINUX_SYS_MAXSYSCALL, linux_sysent, #ifdef SYSCALL_DEBUG linux_syscallnames, #else NULL, #endif LINUX_ELF_AUX_ARGSIZ, elf32_copyargs, setregs, exec_elf32_fixup, linux_sigcode, linux_esigcode, }; static void * linux_aout_copyargs(pack, arginfo, stack, argp) struct exec_package *pack; struct ps_strings *arginfo; void *stack; void *argp; { char **cpp = stack; char **stk = stack; char *dp, *sp; size_t len; void *nullp = NULL; int argc = arginfo->ps_nargvstr; int envc = arginfo->ps_nenvstr; if (copyout(&argc, cpp++, sizeof(argc))) return (NULL); /* leave room for envp and argv */ cpp += 2; if (copyout(&cpp, &stk[1], sizeof (cpp))) return (NULL); dp = (char *)(cpp + argc + envc + 2); sp = argp; /* XXX don't copy them out, remap them! */ arginfo->ps_argvstr = cpp; /* remember location of argv for later */ for (; --argc >= 0; sp += len, dp += len) if (copyout(&dp, cpp++, sizeof(dp)) || copyoutstr(sp, dp, ARG_MAX, &len)) return (NULL); if (copyout(&nullp, cpp++, sizeof(nullp))) return (NULL); if (copyout(&cpp, &stk[2], sizeof (cpp))) return (NULL); arginfo->ps_envstr = cpp; /* remember location of envp for later */ for (; --envc >= 0; sp += len, dp += len) if (copyout(&dp, cpp++, sizeof(dp)) || copyoutstr(sp, dp, ARG_MAX, &len)) return (NULL); if (copyout(&nullp, cpp++, sizeof(nullp))) return (NULL); return (cpp); } int exec_linux_aout_makecmds(p, epp) struct proc *p; struct exec_package *epp; { struct exec *linux_ep = epp->ep_hdr; int machtype, magic; int error = ENOEXEC; magic = LINUX_N_MAGIC(linux_ep); machtype = LINUX_N_MACHTYPE(linux_ep); if (machtype != LINUX_MID_MACHINE) return (ENOEXEC); switch (magic) { case QMAGIC: error = exec_linux_aout_prep_qmagic(p, epp); break; case ZMAGIC: error = exec_linux_aout_prep_zmagic(p, epp); break; case NMAGIC: error = exec_linux_aout_prep_nmagic(p, epp); break; case OMAGIC: error = exec_linux_aout_prep_omagic(p, epp); break; } if (error == 0) epp->ep_emul = &emul_linux_aout; return (error); } /* * Since text starts at 0x400 in Linux ZMAGIC executables, and 0x400 * is very likely not page aligned on most architectures, it is treated * as an NMAGIC here. XXX */ int exec_linux_aout_prep_zmagic(p, epp) struct proc *p; struct exec_package *epp; { struct exec *execp = epp->ep_hdr; epp->ep_taddr = LINUX_N_TXTADDR(*execp, ZMAGIC); epp->ep_tsize = execp->a_text; epp->ep_daddr = LINUX_N_DATADDR(*execp, ZMAGIC); epp->ep_dsize = execp->a_data + execp->a_bss; epp->ep_entry = execp->a_entry; /* set up command for text segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, ZMAGIC), VM_PROT_READ|VM_PROT_EXECUTE); /* set up command for data segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, ZMAGIC), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); /* set up command for bss segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, epp->ep_daddr + execp->a_data, NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); return (exec_setup_stack(p, epp)); } /* * exec_aout_prep_nmagic(): Prepare Linux NMAGIC package. * Not different from the normal stuff. */ int exec_linux_aout_prep_nmagic(p, epp) struct proc *p; struct exec_package *epp; { struct exec *execp = epp->ep_hdr; long bsize, baddr; epp->ep_taddr = LINUX_N_TXTADDR(*execp, NMAGIC); epp->ep_tsize = execp->a_text; epp->ep_daddr = LINUX_N_DATADDR(*execp, NMAGIC); epp->ep_dsize = execp->a_data + execp->a_bss; epp->ep_entry = execp->a_entry; /* set up command for text segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, NMAGIC), VM_PROT_READ|VM_PROT_EXECUTE); /* set up command for data segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, NMAGIC), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); /* set up command for bss segment */ baddr = round_page(epp->ep_daddr + execp->a_data); bsize = epp->ep_daddr + epp->ep_dsize - baddr; if (bsize > 0) NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); return (exec_setup_stack(p, epp)); } /* * exec_aout_prep_omagic(): Prepare Linux OMAGIC package. * Business as usual. */ int exec_linux_aout_prep_omagic(p, epp) struct proc *p; struct exec_package *epp; { struct exec *execp = epp->ep_hdr; long dsize, bsize, baddr; epp->ep_taddr = LINUX_N_TXTADDR(*execp, OMAGIC); epp->ep_tsize = execp->a_text; epp->ep_daddr = LINUX_N_DATADDR(*execp, OMAGIC); epp->ep_dsize = execp->a_data + execp->a_bss; epp->ep_entry = execp->a_entry; /* set up command for text and data segments */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, OMAGIC), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); /* set up command for bss segment */ baddr = round_page(epp->ep_daddr + execp->a_data); bsize = epp->ep_daddr + epp->ep_dsize - baddr; if (bsize > 0) NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); /* * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' * respectively to page boundaries. * Compensate `ep_dsize' for the amount of data covered by the last * text page. */ dsize = epp->ep_dsize + execp->a_text - round_page(execp->a_text); epp->ep_dsize = (dsize > 0) ? dsize : 0; return (exec_setup_stack(p, epp)); } int exec_linux_aout_prep_qmagic(p, epp) struct proc *p; struct exec_package *epp; { struct exec *execp = epp->ep_hdr; epp->ep_taddr = LINUX_N_TXTADDR(*execp, QMAGIC); epp->ep_tsize = execp->a_text; epp->ep_daddr = LINUX_N_DATADDR(*execp, QMAGIC); epp->ep_dsize = execp->a_data + execp->a_bss; epp->ep_entry = execp->a_entry; /* * check if vnode is in open for writing, because we want to * demand-page out of it. if it is, don't do it, for various * reasons */ if ((execp->a_text != 0 || execp->a_data != 0) && epp->ep_vp->v_writecount != 0) { #ifdef DIAGNOSTIC if (epp->ep_vp->v_flag & VTEXT) panic("exec: a VTEXT vnode has writecount != 0"); #endif return (ETXTBSY); } epp->ep_vp->v_flag |= VTEXT; /* set up command for text segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text, epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, QMAGIC), VM_PROT_READ|VM_PROT_EXECUTE); /* set up command for data segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data, epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, QMAGIC), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); /* set up command for bss segment */ NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, epp->ep_daddr + execp->a_data, NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); return (exec_setup_stack(p, epp)); } int linux_elf_probe(p, epp, itp, pos, os) struct proc *p; struct exec_package *epp; char *itp; u_long *pos; u_int8_t *os; { Elf32_Ehdr *eh = epp->ep_hdr; char *bp, *brand; int error; size_t len; brand = elf32_check_brand(eh); if (brand && strcmp(brand, "Linux")) return (EINVAL); if (itp[0]) { if ((error = emul_find(p, NULL, linux_emul_path, itp, &bp, 0))) return (error); if ((error = copystr(bp, itp, MAXPATHLEN, &len))) return (error); free(bp, M_TEMP); } epp->ep_emul = &emul_linux_elf; *pos = ELF32_NO_ADDR; if (*os == OOS_NULL) *os = OOS_LINUX; return (0); } /* * The Linux system call to load shared libraries, a.out version. The * a.out shared libs are just files that are mapped onto a fixed * address in the process' address space. The address is given in * a_entry. Read in the header, set up some VM commands and run them. * * Yes, both text and data are mapped at once, so we're left with * writeable text for the shared libs. The Linux crt0 seemed to break * sometimes when data was mapped separately. It munmapped a uselib() * of ld.so by hand, which failed with shared text and data for ld.so * Yuck. * * Because of the problem with ZMAGIC executables (text starts * at 0x400 in the file, but needs to be mapped at 0), ZMAGIC * shared libs are not handled very efficiently :-( */ int linux_sys_uselib(p, v, retval) struct proc *p; void *v; register_t *retval; { struct linux_sys_uselib_args /* { syscallarg(char *) path; } */ *uap = v; caddr_t sg; long bsize, dsize, tsize, taddr, baddr, daddr; struct nameidata ni; struct vnode *vp; struct exec hdr; struct exec_vmcmd_set vcset; int i, magic, error; size_t rem; sg = stackgap_init(p->p_emul); LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path)); NDINIT(&ni, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); if ((error = namei(&ni))) return (error); vp = ni.ni_vp; if ((error = vn_rdwr(UIO_READ, vp, (caddr_t) &hdr, LINUX_AOUT_HDR_SIZE, 0, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &rem, p))) { vrele(vp); return (error); } if (rem != 0) { vrele(vp); return (ENOEXEC); } if (LINUX_N_MACHTYPE(&hdr) != LINUX_MID_MACHINE) return (ENOEXEC); magic = LINUX_N_MAGIC(&hdr); taddr = trunc_page(hdr.a_entry); tsize = hdr.a_text; daddr = taddr + tsize; dsize = hdr.a_data + hdr.a_bss; if ((hdr.a_text != 0 || hdr.a_data != 0) && vp->v_writecount != 0) { vrele(vp); return (ETXTBSY); } vp->v_flag |= VTEXT; VMCMDSET_INIT(&vcset); NEW_VMCMD( &vcset, magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn, hdr.a_text + hdr.a_data, taddr, vp, LINUX_N_TXTOFF(hdr, magic), VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE); baddr = round_page(daddr + hdr.a_data); bsize = daddr + dsize - baddr; if (bsize > 0) { NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr, NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); } for (i = 0; i < vcset.evs_used && !error; i++) { struct exec_vmcmd *vcp; vcp = &vcset.evs_cmds[i]; error = (*vcp->ev_proc)(p, vcp); } kill_vmcmds(&vcset); vrele(vp); return (error); } /* * Execve(2). Just check the alternate emulation path, and pass it on * to the regular execve(). */ int linux_sys_execve(p, v, retval) struct proc *p; void *v; register_t *retval; { struct linux_sys_execve_args /* { syscallarg(char *) path; syscallarg(char **) argv; syscallarg(char **) envp; } */ *uap = v; struct sys_execve_args ap; caddr_t sg; sg = stackgap_init(p->p_emul); LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path)); SCARG(&ap, path) = SCARG(uap, path); SCARG(&ap, argp) = SCARG(uap, argp); SCARG(&ap, envp) = SCARG(uap, envp); return (sys_execve(p, &ap, retval)); }