/* $NetBSD: svr4_exec.c,v 1.7 1994/10/29 00:43:16 christos Exp $ */ /* * 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define SVR4_ALIGN(a, b) ((a) & ~((b) - 1)) #define SVR4_PAGESIZE 4096 #define SVR4_AUX_ARGSIZ (sizeof(AuxInfo) * 8) /* * I know this is horrible, but I cannot load the interpreter after * the data segment because brk(2) breaks. I have to load it somewhere * before. Programs start at 0x08000000 so I load the interpreter far * before. */ #define SVR4_INTERP_ADDR 0x01000000 struct svr4_args { u_long arg_entry; /* progran entry point */ u_long arg_interp; /* Interpreter load address */ u_long arg_phaddr; /* program header address */ u_long arg_phentsize; /* Size of program header */ u_long arg_phnum; /* Number of program headers */ }; static void svr4_setup_args __P((int, struct proc *, struct exec_package *, void *)); static int svr4_check_header __P((Elf32_Ehdr *, int)); static void svr4_load_psection __P((struct exec_package *, struct vnode *, Elf32_Phdr *, u_long *, u_long *, int *)); static int svr4_set_segment __P((struct exec_package *, u_long, u_long, int)); static int svr4_read_from __P((struct vnode *, u_long, struct proc *, caddr_t, int)); static int svr4_load_interp __P((struct proc *, char *, struct exec_package *, struct svr4_args *, u_long * last)); #ifdef DEBUG_EXEC_SVR4 static void print_Ehdr(e) Elf32_Ehdr *e; { printf("e_ident %s, ", e->e_ident); printf("e_type %d, ", e->e_type); printf("e_machine %d, ", e->e_machine); printf("e_version %ld, ", e->e_version); printf("e_entry %lx, ", e->e_entry); printf("e_phoff %lx, ", e->e_phoff); printf("e_shoff %lx, ", e->e_shoff); printf("e_flags %lx, ", e->e_flags); printf("e_ehsize %d, ", e->e_ehsize); printf("e_phentsize %d, ", e->e_phentsize); printf("e_phnum %d, ", e->e_phnum); printf("e_shentsize %d, ", e->e_shentsize); printf("e_shnum %d, ", e->e_shnum); printf("e_shstrndx %d\n", e->e_shstrndx); } static void print_Phdr(p) Elf32_Phdr *p; { static char *types[] = { "null", "load", "dynamic", "interp", "note", "shlib", "phdr", "entry7" }; printf("p_type %ld [%s], ", p->p_type, types[p->p_type & 7]); printf("p_offset %lx, ", p->p_offset); printf("p_vaddr %lx, ", p->p_vaddr); printf("p_paddr %lx, ", p->p_paddr); printf("p_filesz %ld, ", p->p_filesz); printf("p_memsz %ld, ", p->p_memsz); printf("p_flags %lx, ", p->p_flags); printf("p_align %ld\n", p->p_align); } #endif /* * svr4_setup_args(): * * Push extra arguments on the stack needed by dynamically linked binaries */ static void svr4_setup_args(cmd, pp, ep, sp) int cmd; struct proc *pp; struct exec_package *ep; void *sp; { AuxInfo *a = sp; struct svr4_args *ap = (struct svr4_args *) ep->ep_setup_arg; if (cmd == EXEC_SETUP_CLEANUP) { if (ap != NULL) free((char *) ap, M_TEMP); return; } if (cmd != EXEC_SETUP_ADDARGS) return; DPRINTF(("phaddr=0x%x, phsize=%d, phnum=%d, interp=0x%x, entry=0x%x\n", ap->arg_phaddr, ap->arg_phentsize, ap->arg_phnum, ap->arg_interp, ap->arg_entry)); a->au_id = AUX_phdr; a->au_v = ap->arg_phaddr; a++; a->au_id = AUX_phent; a->au_v = ap->arg_phentsize; a++; a->au_id = AUX_phnum; a->au_v = ap->arg_phnum; a++; a->au_id = AUX_pagesz; a->au_v = SVR4_PAGESIZE; a++; a->au_id = AUX_base; a->au_v = ap->arg_interp; a++; a->au_id = AUX_flags; a->au_v = 0; a++; a->au_id = AUX_entry; a->au_v = ap->arg_entry; a++; a->au_id = AUX_null; a->au_v = 0; } /* * svr4_check_header(): * * Check header for validity; return 0 of ok ENOEXEC if error */ static int svr4_check_header(eh, type) Elf32_Ehdr *eh; int type; { if (memcmp(eh->e_ident, Elf32_e_ident, Elf32_e_siz) != 0) { DPRINTF(("Not an elf file\n")); return ENOEXEC; } if (eh->e_machine != Elf32_em_386 && eh->e_machine != Elf32_em_486) { DPRINTF(("Not an elf/386 or 486 executable\n")); return ENOEXEC; } if (eh->e_type != type) { DPRINTF(("Not an elf executable\n")); return ENOEXEC; } return 0; } /* * svr4_load_psection(): * * Load a psection at the appropriate address */ static void svr4_load_psection(epp, vp, ph, addr, size, prot) struct exec_package *epp; struct vnode *vp; Elf32_Phdr *ph; u_long *addr; u_long *size; int *prot; { u_long uaddr; long diff; long offset; u_long msize; /* * If the user specified an address, then we load there. */ if (*addr != ~0) { uaddr = *addr + ph->p_align; *addr = SVR4_ALIGN(uaddr, ph->p_align); uaddr = SVR4_ALIGN(ph->p_vaddr, ph->p_align); diff = ph->p_vaddr - uaddr; } else { uaddr = ph->p_vaddr; *addr = SVR4_ALIGN(uaddr, ph->p_align); diff = uaddr - *addr; } *prot |= (ph->p_flags & Elf32_pf_r) ? VM_PROT_READ : 0; *prot |= (ph->p_flags & Elf32_pf_w) ? VM_PROT_WRITE : 0; *prot |= (ph->p_flags & Elf32_pf_x) ? VM_PROT_EXECUTE : 0; offset = ph->p_offset - diff; *size = ph->p_filesz + diff; msize = ph->p_memsz + diff; DPRINTF(("Elf Seg@ 0x%x/0x%x sz %d/%d off 0x%x/0x%x[%d] algn 0x%x\n", ph->p_vaddr, *addr, *size, msize, ph->p_offset, offset, diff, ph->p_align)); NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, *size, *addr, vp, offset, *prot); /* * Check if we need to extend the size of the segment */ { u_long rm = round_page(*addr + msize); u_long rf = round_page(*addr + *size); if (rm != rf) { DPRINTF(("zeropad 0x%x-0x%x\n", rf, rm)); NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, rm - rf, rf, NULLVP, 0, *prot); *size = msize; } } } /* * svr4_set_segment(): * * Decide if the segment is text or data, depending on the protection * and set it appropriately */ static int svr4_set_segment(epp, vaddr, size, prot) struct exec_package *epp; u_long vaddr; u_long size; int prot; { /* * Kludge: Unfortunately the current implementation of * exec package assumes a single text and data segment. * In Elf we can have more, but here we limit ourselves * to two and hope :-( * We also assume that the text is r-x, and data is rwx. */ switch (prot) { case (VM_PROT_READ | VM_PROT_EXECUTE): if (epp->ep_tsize != ~0) { DPRINTF(("More than one text segment\n")); return ENOEXEC; } epp->ep_taddr = vaddr; epp->ep_tsize = size; DPRINTF(("Elf Text@ 0x%x, size %d\n", vaddr, size)); break; case (VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE): if (epp->ep_dsize != ~0) { DPRINTF(("More than one data segment\n")); return ENOEXEC; } epp->ep_daddr = vaddr; epp->ep_dsize = size; DPRINTF(("Elf Data@ 0x%x, size %d\n", vaddr, size)); break; default: DPRINTF(("Bad protection 0%o\n", prot)); return ENOEXEC; } return 0; } /* * svr4_read_from(): * * Read from vnode into buffer at offset. */ static int svr4_read_from(vp, off, p, buf, size) struct vnode *vp; u_long off; struct proc *p; caddr_t buf; int size; { int error; int resid; DPRINTF(("read from 0x%x to 0x%x size %d\n", off, buf, size)); if ((error = vn_rdwr(UIO_READ, vp, buf, size, off, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid, p)) != 0) { DPRINTF(("Bad read error %d\n", error)); return error; } /* * See if we got all of it */ if (resid != 0) { DPRINTF(("Incomplete read for header ask=%d, rem=%d\n", size, resid)); return error; } return 0; } /* * svr4_load_interp(): * * Load an interpreter pointed to by path [stolen from coff_load_shlib()] */ static int svr4_load_interp(p, path, epp, ap, last) struct proc *p; char *path; struct exec_package *epp; struct svr4_args *ap; u_long *last; { int error, i; struct nameidata nd; Elf32_Ehdr eh; Elf32_Phdr *ph = NULL; u_long phsize; char *bp = NULL; u_long addr = *last; DPRINTF(("Loading interpreter %s\n", path)); if ((error = svr4_emul_find(p, NULL, svr4_emul_path, path, &bp)) != 0) bp = NULL; else path = bp; /* * 1. open interp file * 2. read filehdr * 3. map text, data, and bss out of it using VM_* */ NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, path, p); /* first get the vnode */ if ((error = namei(&nd)) != 0) { DPRINTF(("Can't find interpreter %s\n", path)); if (bp != NULL) free((char *) bp, M_TEMP); return error; } if ((error = svr4_read_from(nd.ni_vp, 0, p, (caddr_t) &eh, sizeof(eh))) != 0) goto bad; #ifdef DEBUG_EXEC_SVR4 print_Ehdr(&eh); #endif if ((error = svr4_check_header(&eh, Elf32_et_dyn)) != 0) goto bad; phsize = eh.e_phnum * sizeof(Elf32_Phdr); ph = (Elf32_Phdr *) malloc(phsize, M_TEMP, M_WAITOK); if ((error = svr4_read_from(nd.ni_vp, eh.e_phoff, p, (caddr_t) ph, phsize)) != 0) goto bad; /* * Load all the necessary sections */ for (i = 0; i < eh.e_phnum; i++) { u_long size = 0; int prot = 0; #ifdef DEBUG_EXEC_SVR4 print_Phdr(&ph[i]); #endif switch (ph[i].p_type) { case Elf32_pt_load: svr4_load_psection(epp, nd.ni_vp, &ph[i], &addr, &size, &prot); /* Assume that the text segment is r-x only */ if ((prot & PROT_WRITE) == 0) { epp->ep_entry = addr + eh.e_entry; ap->arg_interp = addr; DPRINTF(("Interpreter@ 0x%x\n", addr)); } addr += size; break; case Elf32_pt_dynamic: case Elf32_pt_phdr: case Elf32_pt_note: break; default: DPRINTF(("interp: Unexpected program header type %d\n", ph[i].p_type)); break; } } bad: if (ph != NULL) free((char *) ph, M_TEMP); if (bp != NULL) free((char *) bp, M_TEMP); *last = addr; vrele(nd.ni_vp); return error; } /* * exec_svr4_elf_makecmds(): Prepare an Elf binary's exec package * * First, set of the various offsets/lengths in the exec package. * * Then, mark the text image busy (so it can be demand paged) or error * out if this is not possible. Finally, set up vmcmds for the * text, data, bss, and stack segments. */ int exec_svr4_elf_makecmds(p, epp) struct proc *p; struct exec_package *epp; { Elf32_Ehdr *eh = epp->ep_hdr; Elf32_Phdr *ph; int error; int i; char interp[MAXPATHLEN]; u_long pos = 0; u_long phsize; #ifdef DEBUG_EXEC_SVR4 print_Ehdr(eh); #endif if (epp->ep_hdrvalid < sizeof(Elf32_Ehdr)) return ENOEXEC; if (svr4_check_header(eh, Elf32_et_exec)) return ENOEXEC; /* * 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 (epp->ep_vp->v_writecount != 0) { #ifdef DIAGNOSTIC if (epp->ep_vp->v_flag & VTEXT) panic("exec: a VTEXT vnode has writecount != 0\n"); #endif return ETXTBSY; } /* * Allocate space to hold all the program headers, and read them * from the file */ phsize = eh->e_phnum * sizeof(Elf32_Phdr); ph = (Elf32_Phdr *) malloc(phsize, M_TEMP, M_WAITOK); if ((error = svr4_read_from(epp->ep_vp, eh->e_phoff, p, (caddr_t) ph, phsize)) != 0) goto bad; epp->ep_emul = EMUL_IBCS2_ELF; epp->ep_tsize = ~0; epp->ep_dsize = ~0; interp[0] = '\0'; /* * Load all the necessary sections */ for (i = 0; i < eh->e_phnum; i++) { u_long addr = ~0, size = 0; int prot = 0; Elf32_Phdr *pp = &ph[i]; #ifdef DEBUG_EXEC_SVR4 print_Phdr(pp); #endif switch (ph[i].p_type) { case Elf32_pt_load: svr4_load_psection(epp, epp->ep_vp, &ph[i], &addr, &size, &prot); if ((error = svr4_set_segment(epp, addr, size, prot)) != 0) goto bad; break; case Elf32_pt_shlib: DPRINTF(("No support for COFF libraries (yet)\n")); error = ENOEXEC; goto bad; case Elf32_pt_interp: if (pp->p_filesz >= sizeof(interp)) { DPRINTF(("Interpreter path too long %d\n", pp->p_filesz)); goto bad; } if ((error = svr4_read_from(epp->ep_vp, pp->p_offset, p, (caddr_t) interp, pp->p_filesz)) != 0) goto bad; break; case Elf32_pt_dynamic: case Elf32_pt_phdr: case Elf32_pt_note: break; default: /* * Not fatal, we don't need to understand everything * :-) */ DPRINTF(("Unsupported program header type %d\n", pp->p_type)); break; } } /* * Check if we found a dynamically linked binary and arrange to load * it's interpreter */ if (interp[0]) { struct svr4_args *ap; pos = SVR4_INTERP_ADDR; ap = (struct svr4_args *) malloc(sizeof(struct svr4_args), M_TEMP, M_WAITOK); if ((error = svr4_load_interp(p, interp, epp, ap, &pos)) != 0) { free((char *) ap, M_TEMP); goto bad; } /* Arrange to load the program headers. */ pos = SVR4_ALIGN(pos + SVR4_PAGESIZE, SVR4_PAGESIZE); DPRINTF(("Program header @0x%x\n", pos)); ap->arg_phaddr = pos; NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, phsize, pos, epp->ep_vp, eh->e_phoff, VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE); pos += phsize; ap->arg_phentsize = eh->e_phentsize; ap->arg_phnum = eh->e_phnum; ap->arg_entry = eh->e_entry; epp->ep_setup = svr4_setup_args; epp->ep_setup_arg = ap; epp->ep_setup_arglen = SVR4_AUX_ARGSIZ / sizeof(char *); } else epp->ep_entry = eh->e_entry; DPRINTF(("taddr 0x%x tsize 0x%x daddr 0x%x dsize 0x%x\n", epp->ep_taddr, epp->ep_tsize, epp->ep_daddr, epp->ep_dsize)); free((char *) ph, M_TEMP); DPRINTF(("Elf entry@ 0x%x\n", epp->ep_entry)); epp->ep_vp->v_flag |= VTEXT; return exec_aout_setup_stack(p, epp); bad: free((char *) ph, M_TEMP); return ENOEXEC; }