from netbsd:

Don't rely on the protection bits of segments anymore to decide whether
it's text or data; use the entry point instead (this solves some trouble
with ELF executables with strange permissions)
Incorporate some fixes from r_friedl@informatik.uni-kl.de sent to
netbsd-bugs a while ago

2 files changed, 43 insertions, 95 deletions

diff --git a/sys/kern/exec_elf.c b/sys/kern/exec_elf.c
index 095f59fc0aa..e065eef5152 100644
--- a/sys/kern/exec_elf.c
+++ b/sys/kern/exec_elf.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: exec_elf.c,v 1.3 1995/09/16 00:28:08 thorpej Exp $	*/
+/*	$NetBSD: exec_elf.c,v 1.4 1996/01/16 23:07:18 fvdl Exp $	*/
 
 /*
  * Copyright (c) 1994 Christos Zoulas
@@ -64,8 +64,6 @@ int (*elf_probe_funcs[])() = {
 #endif
 };
 
-static int elf_set_segment __P((struct exec_package *, u_long, u_long,
-	int));
 static int elf_read_from __P((struct proc *, struct vnode *, u_long,
 	caddr_t, int));
 static void elf_load_psection __P((struct exec_vmcmd_set *,
@@ -84,48 +82,20 @@ elf_copyargs(pack, arginfo, stack, argp)
 	void *stack;
 	void *argp;
 {
-	char **cpp = stack;
-	char *dp, *sp;
 	size_t len;
-	void *nullp = NULL;
-	int argc = arginfo->ps_nargvstr;
-	int envc = arginfo->ps_nenvstr;
-	AuxInfo *a;
+	AuxInfo ai[ELF_AUX_ENTRIES], *a;
 	struct elf_args *ap;
 
-	if (copyout(&argc, cpp++, sizeof(argc)))
-		return NULL;
-
-	dp = (char *) (cpp + argc + envc + 2 + pack->ep_emul->e_arglen);
-	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;
-
-	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)))
+	stack = copyargs(pack, arginfo, stack, argp);
+	if (!stack)
 		return NULL;
 
 	/*
 	 * Push extra arguments on the stack needed by dynamically
 	 * linked binaries
 	 */
-	a = (AuxInfo *) cpp;
 	if ((ap = (struct elf_args *) pack->ep_emul_arg)) {
+		a = ai;
 
 		a->au_id = AUX_phdr;
 		a->au_v = ap->arg_phaddr;
@@ -160,8 +130,12 @@ elf_copyargs(pack, arginfo, stack, argp)
 		a++;
 
 		free((char *) ap, M_TEMP);
+		len = ELF_AUX_ENTRIES * sizeof (AuxInfo);
+		if (copyout(ai, stack, len))
+			return NULL;
+		stack += len;
 	}
-	return a;
+	return stack;
 }
 
 /*
@@ -260,48 +234,6 @@ elf_load_psection(vcset, vp, ph, addr, size, prot)
 }
 
 /*
- * elf_set_segment():
- *
- * Decide if the segment is text or data, depending on the protection
- * and set it appropriately
- */
-static int
-elf_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 or rw-.
-         */
-	switch (prot) {
-	case (VM_PROT_READ | VM_PROT_EXECUTE):
-		if (epp->ep_tsize != ELF32_NO_ADDR)
-			return ENOEXEC;
-		epp->ep_taddr = vaddr;
-		epp->ep_tsize = size;
-		break;
-
-	case (VM_PROT_READ | VM_PROT_WRITE):
-	case (VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE):
-		if (epp->ep_dsize != ELF32_NO_ADDR)
-			return ENOEXEC;
-		epp->ep_daddr = vaddr;
-		epp->ep_dsize = size;
-		break;
-
-	default:
-		return ENOEXEC;
-	}
-	return 0;
-}
-
-/*
  * elf_read_from():
  *
  *	Read from vnode into buffer at offset.
@@ -325,7 +257,7 @@ elf_read_from(p, vp, off, buf, size)
          * See if we got all of it
          */
 	if (resid != 0)
-		return error;
+		return ENOEXEC;
 	return 0;
 }
 
@@ -388,8 +320,9 @@ elf_load_file(p, path, vcset, entry, ap, last)
 		case Elf32_pt_load:
 			elf_load_psection(vcset, nd.ni_vp, &ph[i], &addr,
 						&size, &prot);
-			/* Assume that the text segment is r-x only */
-			if ((prot & PROT_WRITE) == 0) {
+			/* If entry is within this section it must be text */
+			if (eh.e_entry >= ph[i].p_vaddr &&
+			    eh.e_entry < (ph[i].p_vaddr + size)) {
 				*entry = addr + eh.e_entry;
 				ap->arg_interp = addr;
 			}
@@ -433,7 +366,8 @@ exec_elf_makecmds(p, epp)
 {
 	Elf32_Ehdr *eh = epp->ep_hdr;
 	Elf32_Phdr *ph, *pp;
-	int error, i, n;
+	Elf32_Addr phdr = 0;
+	int error, i, n, nload;
 	char interp[MAXPATHLEN];
 	u_long pos = 0, phsize;
 
@@ -505,7 +439,7 @@ exec_elf_makecmds(p, epp)
 	/*
          * Load all the necessary sections
          */
-	for (i = 0; i < eh->e_phnum; i++) {
+	for (i = nload = 0; i < eh->e_phnum; i++) {
 		u_long  addr = ELF32_NO_ADDR, size = 0;
 		int prot = 0;
 
@@ -513,11 +447,25 @@ exec_elf_makecmds(p, epp)
 
 		switch (ph[i].p_type) {
 		case Elf32_pt_load:
+			/*
+			 * XXX
+			 * Can handle only 2 sections: text and data
+			 */
+			if (nload++ == 2)
+				goto bad;
 			elf_load_psection(&epp->ep_vmcmds, epp->ep_vp,
 				&ph[i], &addr, &size, &prot);
-			if ((error = elf_set_segment(epp, addr, size,
-						      prot)) != 0)
-				goto bad;
+			/*
+			 * Decide whether it's text or data by looking
+			 * at the entry point.
+			 */
+			if (eh->e_entry >= addr && eh->e_entry < (addr + size)){
+				epp->ep_taddr = addr;
+				epp->ep_tsize = size;
+			} else {
+				epp->ep_daddr = addr;
+				epp->ep_dsize = size;
+			}
 			break;
 
 		case Elf32_pt_shlib:
@@ -527,10 +475,14 @@ exec_elf_makecmds(p, epp)
 		case Elf32_pt_interp:
 			/* Already did this one */
 		case Elf32_pt_dynamic:
-		case Elf32_pt_phdr:
 		case Elf32_pt_note:
 			break;
 
+		case Elf32_pt_phdr:
+			/* Note address of program headers (in text segment) */
+			phdr = pp->p_vaddr;
+		break;
+
 		default:
 			/*
 			 * Not fatal, we don't need to understand everything
@@ -554,13 +506,8 @@ exec_elf_makecmds(p, epp)
 			free((char *) ap, M_TEMP);
 			goto bad;
 		}
-		/* Arrange to load the program headers. */
-		pos = ELF_ALIGN(pos + NBPG, NBPG);
-		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_phaddr = phdr;
 
 		ap->arg_phentsize = eh->e_phentsize;
 		ap->arg_phnum = eh->e_phnum;
diff --git a/sys/sys/exec_elf.h b/sys/sys/exec_elf.h
index 86999d87843..a50dc0e56e4 100644
--- a/sys/sys/exec_elf.h
+++ b/sys/sys/exec_elf.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: exec_elf.h,v 1.1 1995/06/22 21:31:03 fvdl Exp $	*/
+/*	$NetBSD: exec_elf.h,v 1.2 1996/01/16 23:19:43 fvdl Exp $	*/
 
 /*
  * Copyright (c) 1994 Christos Zoulas
@@ -141,7 +141,8 @@ enum AuxID {
 
 #ifdef _KERNEL
 
-#define ELF32_NO_ADDR	((u_long) ~0)
+#define ELF32_NO_ADDR	((u_long) ~0)	/* Indicates addr. not yet filled in */
+#define ELF_AUX_ENTRIES	8		/* Size of aux array passed to loader */
 
 struct elf_args {
         u_long  arg_entry;      /* progran entry point */