Created sysctl kern.fallback_elf_brand. Defaults to "none", which will

give the same behaviour produced before today.  If sysadmin sets it
to a valid ELF brand, ELF image activator will attempt to run unbranded
ELF exectutables as if they were branded with that value.

Suggested by: Dima Ruban <dima@best.net>

1 files changed, 25 insertions, 1 deletions

diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
index 4bc0fac..1cecde6 100644
--- a/sys/kern/imgact_elf.c
+++ b/sys/kern/imgact_elf.c
@@ -26,7 +26,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *	$Id: imgact_elf.c,v 1.47 1999/01/29 22:59:43 dillon Exp $
+ *	$Id: imgact_elf.c,v 1.48 1999/02/04 12:42:31 newton Exp $
  */
 
 #include "opt_rlimit.h"
@@ -83,6 +83,12 @@ static int exec_elf_imgact __P((struct image_params *imgp));
 static int elf_trace = 0;
 SYSCTL_INT(_debug, OID_AUTO, elf_trace, CTLFLAG_RW, &elf_trace, 0, "");
 
+/*
+ * XXX Maximum length of an ELF brand (sysctl wants a statically-allocated
+ * buffer).
+ */
+#define	MAXBRANDLEN	16
+
 static struct sysentvec elf_freebsd_sysvec = {
         SYS_MAXSYSCALL,
         sysent,
@@ -406,6 +412,11 @@ fail:
 	return error;
 }
 
+static char fallback_elf_brand[MAXBRANDLEN+1] = { "none" };
+SYSCTL_STRING(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW,
+		fallback_elf_brand, sizeof(fallback_elf_brand),
+		"ELF brand of last resort");
+
 static int
 exec_elf_imgact(struct image_params *imgp)
 {
@@ -542,6 +553,19 @@ exec_elf_imgact(struct image_params *imgp)
 		}
 	}
 
+	/* Lacking a recognized interpreter, try the default brand */
+	if (brand_info == NULL & fallback_elf_brand[0] != '\0') {
+		for (i = 0; i < MAX_BRANDS; i++) {
+			Elf_Brandinfo *bi = elf_brand_list[i];
+
+			if (bi != NULL
+			    && strcmp(fallback_elf_brand, bi->brand) == 0) {
+				brand_info = bi;
+				break;
+			}
+		}
+	}
+
 #ifdef __alpha__
 	/* XXX - Assume FreeBSD on the alpha. */
 	if (brand_info == NULL)