Moved elf brand identification into a function. Fully identify the

brand early in the process of loading an elf file, so that we can
identify the sysentvec, and so that we do not continue if we do not
have a brand (and thus a sysentvec).  Use the values in the sysentvec
for the page size and vm ranges unconditionally, since they are all
filled in now.

1 files changed, 75 insertions, 105 deletions

diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
index 6c9ee86..8ac19a7 100644
--- a/sys/kern/imgact_elf.c
+++ b/sys/kern/imgact_elf.c
@@ -71,6 +71,8 @@ __ElfType(Brandinfo);
 __ElfType(Auxargs);
 
 static int __elfN(check_header)(const Elf_Ehdr *hdr);
+static Elf_Brandinfo *__elfN(get_brandinfo)(const Elf_Ehdr *hdr,
+    const char *interp);
 static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
     u_long *entry, size_t pagesize);
 static int __elfN(load_section)(struct proc *p,
@@ -87,6 +89,7 @@ SYSCTL_INT(_debug, OID_AUTO, elf64_trace, CTLFLAG_RW, &elf_trace, 0, "");
 #endif
 
 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];
+extern int fallback_elf_brand;
 
 int
 __elfN(insert_brand_entry)(Elf_Brandinfo *entry)
@@ -138,6 +141,50 @@ __elfN(brand_inuse)(Elf_Brandinfo *entry)
 	return (rval);
 }
 
+static Elf_Brandinfo *
+__elfN(get_brandinfo)(const Elf_Ehdr *hdr, const char *interp)
+{
+	Elf_Brandinfo *bi;
+	int i;
+
+	/*
+	 * We support three types of branding -- (1) the ELF EI_OSABI field
+	 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
+	 * branding w/in the ELF header, and (3) path of the `interp_path'
+	 * field.  We should also look for an ".note.ABI-tag" ELF section now
+	 * in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones.
+	 */
+
+	/* If the executable has a brand, search for it in the brand list. */
+	for (i = 0; i < MAX_BRANDS; i++) {
+		bi = elf_brand_list[i];
+		if (bi != NULL && hdr->e_machine == bi->machine &&
+		    (hdr->e_ident[EI_OSABI] == bi->brand ||
+		    strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
+		    bi->compat_3_brand, strlen(bi->compat_3_brand)) == 0))
+			return (bi);
+	}
+
+	/* Lacking a known brand, search for a recognized interpreter. */
+	if (interp != NULL) {
+		for (i = 0; i < MAX_BRANDS; i++) {
+			bi = elf_brand_list[i];
+			if (bi != NULL && hdr->e_machine == bi->machine &&
+			    strcmp(interp, bi->interp_path) == 0)
+				return (bi);
+		}
+	}
+
+	/* Lacking a recognized interpreter, try the default brand */
+	for (i = 0; i < MAX_BRANDS; i++) {
+		bi = elf_brand_list[i];
+		if (bi != NULL && hdr->e_machine == bi->machine &&
+		    fallback_elf_brand == bi->brand)
+			return (bi);
+	}
+	return (NULL);
+}
+
 static int
 __elfN(check_header)(const Elf_Ehdr *hdr)
 {
@@ -578,8 +625,6 @@ fail:
 	return (error);
 }
 
-extern int fallback_elf_brand;
-
 static int
 __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
 {
@@ -592,12 +637,12 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
 	u_long text_addr = 0, data_addr = 0;
 	u_long seg_size, seg_addr;
 	u_long addr, entry = 0, proghdr = 0;
-	vm_offset_t maxuser, usrstack, pagesize;
 	int error, i;
 	const char *interp = NULL;
 	Elf_Brandinfo *brand_info;
 	char *path;
 	struct thread *td = curthread;
+	struct sysentvec *sv;
 
 	GIANT_REQUIRED;
 
@@ -625,41 +670,35 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
 
 	VOP_UNLOCK(imgp->vp, 0, td);
 
-	if ((error = exec_extract_strings(imgp)) != 0)
-		goto fail;
-
-	/*
-	 * Tentatively identify the brand based on the machine so that
-	 * we can figure out VM ranges and page sizes.
-	 */
-	brand_info = NULL;
-	for (i = 0; i < MAX_BRANDS; i++) {
-		Elf_Brandinfo *bi = elf_brand_list[i];
-
-		if (bi != NULL &&
-		    hdr->e_machine == bi->machine &&
-		    (hdr->e_ident[EI_OSABI] == bi->brand
-		     || 0 ==
-		     strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
-		     bi->compat_3_brand, strlen(bi->compat_3_brand)))) {
-			brand_info = bi;
+	for (i = 0; i < hdr->e_phnum; i++) {
+		switch (phdr[i].p_type) {
+	  	case PT_INTERP:	/* Path to interpreter */
+			if (phdr[i].p_filesz > MAXPATHLEN ||
+			    phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) {
+				error = ENOEXEC;
+				goto fail;
+			}
+			interp = imgp->image_header + phdr[i].p_offset;
+			break;
+		default:
 			break;
 		}
 	}
 
-	pagesize = PAGE_SIZE;
-	maxuser = VM_MAXUSER_ADDRESS;
-	usrstack = USRSTACK;
-	if (brand_info) {
-		if (brand_info->sysvec->sv_pagesize)
-			pagesize = brand_info->sysvec->sv_pagesize;
-		if (brand_info->sysvec->sv_maxuser)
-			maxuser = brand_info->sysvec->sv_maxuser;
-		if (brand_info->sysvec->sv_usrstack)
-			usrstack = brand_info->sysvec->sv_usrstack;
+	brand_info = __elfN(get_brandinfo)(hdr, interp);
+	if (brand_info == NULL) {
+		uprintf("ELF binary type \"%u\" not known.\n",
+		    hdr->e_ident[EI_OSABI]);
+		error = ENOEXEC;
+		goto fail;
 	}
+	sv = brand_info->sysvec;
 
-	exec_new_vmspace(imgp, VM_MIN_ADDRESS, maxuser, usrstack);
+	if ((error = exec_extract_strings(imgp)) != 0)
+		goto fail;
+
+	exec_new_vmspace(imgp, sv->sv_minuser, sv->sv_maxuser,
+	    sv->sv_usrstack);
 
 	vmspace = imgp->proc->p_vmspace;
 
@@ -687,7 +726,7 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
 			    imgp->vp, imgp->object, phdr[i].p_offset,
 			    (caddr_t)(uintptr_t)phdr[i].p_vaddr,
 			    phdr[i].p_memsz, phdr[i].p_filesz, prot,
-			    pagesize)) != 0)
+			    sv->sv_pagesize)) != 0)
   				goto fail;
 
 			seg_addr = trunc_page(phdr[i].p_vaddr);
@@ -730,14 +769,6 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
 				entry = (u_long)hdr->e_entry;
 			}
 			break;
-	  	case PT_INTERP:	/* Path to interpreter */
-			if (phdr[i].p_filesz > MAXPATHLEN ||
-			    phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) {
-				error = ENOEXEC;
-				goto fail;
-			}
-			interp = imgp->image_header + phdr[i].p_offset;
-			break;
 		case PT_PHDR: 	/* Program header table info */
 			proghdr = phdr[i].p_vaddr;
 			break;
@@ -755,76 +786,15 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
 
 	imgp->entry_addr = entry;
 
-	brand_info = NULL;
-
-	/* We support three types of branding -- (1) the ELF EI_OSABI field
-	 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
-	 * branding w/in the ELF header, and (3) path of the `interp_path'
-	 * field.  We should also look for an ".note.ABI-tag" ELF section now
-	 * in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones.
-	 */
-
-	/* If the executable has a brand, search for it in the brand list. */
-	if (brand_info == NULL) {
-		for (i = 0; i < MAX_BRANDS; i++) {
-			Elf_Brandinfo *bi = elf_brand_list[i];
-
-			if (bi != NULL &&
-			    hdr->e_machine == bi->machine &&
-			    (hdr->e_ident[EI_OSABI] == bi->brand
-			    || 0 ==
-			    strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
-			    bi->compat_3_brand, strlen(bi->compat_3_brand)))) {
-				brand_info = bi;
-				break;
-			}
-		}
-	}
-
-	/* Lacking a known brand, search for a recognized interpreter. */
-	if (brand_info == NULL && interp != NULL) {
-		for (i = 0; i < MAX_BRANDS; i++) {
-			Elf_Brandinfo *bi = elf_brand_list[i];
-
-			if (bi != NULL &&
-			    hdr->e_machine == bi->machine &&
-			    strcmp(interp, bi->interp_path) == 0) {
-				brand_info = bi;
-				break;
-			}
-		}
-	}
-
-	/* Lacking a recognized interpreter, try the default brand */
-	if (brand_info == NULL) {
-		for (i = 0; i < MAX_BRANDS; i++) {
-			Elf_Brandinfo *bi = elf_brand_list[i];
-
-			if (bi != NULL &&
-			    hdr->e_machine == bi->machine &&
-			    fallback_elf_brand == bi->brand) {
-				brand_info = bi;
-				break;
-			}
-		}
-	}
-
-	if (brand_info == NULL) {
-		uprintf("ELF binary type \"%u\" not known.\n",
-		    hdr->e_ident[EI_OSABI]);
-		error = ENOEXEC;
-		goto fail;
-	}
-
-	imgp->proc->p_sysent = brand_info->sysvec;
+	imgp->proc->p_sysent = sv;
 	if (interp != NULL) {
 		path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 		snprintf(path, MAXPATHLEN, "%s%s", brand_info->emul_path,
 		    interp);
 		if ((error = __elfN(load_file)(imgp->proc, path, &addr,
-		    &imgp->entry_addr, pagesize)) != 0) {
+		    &imgp->entry_addr, sv->sv_pagesize)) != 0) {
 			if ((error = __elfN(load_file)(imgp->proc, interp,
-			    &addr, &imgp->entry_addr, pagesize)) != 0) {
+			    &addr, &imgp->entry_addr, sv->sv_pagesize)) != 0) {
 				uprintf("ELF interpreter %s not found\n",
 				    path);
 				free(path, M_TEMP);