backout OS-4141: needs more work

backout OS-4128: needs more work

usr/src/uts/common/exec/elf/elf.c

@@ -216,8 +216,6 @@ mapexec_brand(vnode_t *vp, uarg_t *args, Ehdr *ehdr, Addr *uphdr_vaddr,
 	    &junk, &dtrphdr, NULL, bssbase, brkbase, voffset, &minaddr,
 	    len, &execsz, brksize)) {
 		uprintf("%s: Cannot map %s\n", exec_file, args->pathname);
-		if (uphdr != NULL && uphdr->p_flags == 0)
-			kmem_free(uphdr, sizeof (Phdr));
 		kmem_free(phdrbase, phdrsize);
 		return (error);
 	}
@@ -272,9 +270,6 @@ mapexec_brand(vnode_t *vp, uarg_t *args, Ehdr *ehdr, Addr *uphdr_vaddr,
 
 	if (uphdr != NULL) {
 		*uphdr_vaddr = uphdr->p_vaddr;
-
-		if (uphdr->p_flags == 0)
-			kmem_free(uphdr, sizeof (Phdr));
 	} else {
 		*uphdr_vaddr = (Addr)-1;
 	}
@@ -746,13 +741,8 @@ elfexec(vnode_t *vp, execa_t *uap, uarg_t *args, intpdata_t *idatap,
 
 		/*
 		 * Now obtain the ELF header along with the entire program
-		 * header contained in "nvp".  Before we free our program
-		 * headers, we need to be sure to let go of the uphdr if it
-		 * wasn't dynamically allocated.
+		 * header contained in "nvp".
 		 */
-		if (uphdr != NULL && uphdr->p_flags != 0)
-			uphdr = NULL;
-
 		kmem_free(phdrbase, phdrsize);
 		phdrbase = NULL;
 		if ((error = getelfhead(nvp, CRED(), ehdrp, &nshdrs,
@@ -778,10 +768,9 @@ elfexec(vnode_t *vp, execa_t *uap, uarg_t *args, intpdata_t *idatap,
 
 		dtrphdr = NULL;
 
-		error = mapelfexec(nvp, ehdrp, nphdrs, phdrbase, NULL, &junk,
+		error = mapelfexec(nvp, ehdrp, nphdrs, phdrbase, &junk, &junk,
 		    &junk, &dtrphdr, NULL, NULL, NULL, &voffset, NULL, len,
 		    execsz, NULL);
-
 		if (error || junk != NULL) {
 			VN_RELE(nvp);
 			uprintf("%s: Cannot map %s\n", exec_file, dlnp);
@@ -988,8 +977,6 @@ elfexec(vnode_t *vp, execa_t *uap, uarg_t *args, intpdata_t *idatap,
 	if (error == 0)
 		error = ENOEXEC;
 out:
-	if (uphdr != NULL && uphdr->p_flags == 0)
-		kmem_free(uphdr, sizeof (Phdr));
 	if (phdrbase != NULL)
 		kmem_free(phdrbase, phdrsize);
 	if (cap != NULL)
@@ -1320,6 +1307,9 @@ mapelfexec(
 	for (i = nphdrs; i > 0; i--) {
 		switch (phdr->p_type) {
 		case PT_LOAD:
+			if ((*dyphdr != NULL) && (*uphdr == NULL))
+				return (0);
+
 			ptload = 1;
 			prot = PROT_USER;
 			if (phdr->p_flags & PF_R)
@@ -1331,34 +1321,6 @@ mapelfexec(
 
 			addr = (caddr_t)((uintptr_t)phdr->p_vaddr + *voffset);
 
-			if ((*dyphdr != NULL) && uphdr != NULL &&
-			    (*uphdr == NULL)) {
-				/*
-				 * The PT_PHDR program header is, strictly
-				 * speaking, optional.  If we find that this
-				 * is missing, we will determine the location
-				 * of the program headers based on the address
-				 * of the lowest PT_LOAD segment (namely, this
-				 * one):  we subtract the p_offset to get to
-				 * the ELF header and then add back the program
-				 * header offset to get to the program headers.
-				 * We then cons up a Phdr that corresponds to
-				 * the (missing) PT_PHDR, setting the flags
-				 * to 0 to denote that this is artificial and
-				 * should (must) be freed by the caller.
-				 */
-				Phdr *cons;
-
-				cons = kmem_zalloc(sizeof (Phdr), KM_SLEEP);
-
-				cons->p_flags = 0;
-				cons->p_type = PT_PHDR;
-				cons->p_vaddr = ((uintptr_t)addr -
-				    phdr->p_offset) + ehdr->e_phoff;
-
-				*uphdr = cons;
-			}
-
 			/*
 			 * Keep track of the segment with the lowest starting
 			 * address.
@@ -1475,12 +1437,9 @@ mapelfexec(
 			break;
 
 		case PT_PHDR:
-			if (ptload || phdr->p_flags == 0)
+			if (ptload)
 				goto bad;
-
-			if (uphdr != NULL)
-				*uphdr = phdr;
-
+			*uphdr = phdr;
 			break;
 
 		case PT_NULL: