Add a hook to enable load-time inspection of program headers

This hook can be used to perform additional compatibility checks
between shared libraries by inspecting custom program header
information.

	* elf/dl-machine-reject-phdr.h: New file.
	* elf/dl-load.c: #include that.
	(open_verify): Call elf_machine_reject_phdr_p and ignore the file
	if that returned true.

1 files changed, 6 insertions, 0 deletions

diff --git a/elf/dl-load.c b/elf/dl-load.c
index ce5b626b26..7a03ccfd2a 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -41,6 +41,7 @@
 #include <dl-load.h>
 #include <dl-map-segments.h>
 #include <dl-unmap-segments.h>
+#include <dl-machine-reject-phdr.h>
 
 
 #include <endian.h>
@@ -1683,6 +1684,11 @@ open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
 	    }
 	}
 
+      if (__glibc_unlikely (elf_machine_reject_phdr_p
+			    (phdr, ehdr->e_phnum, fbp->buf, fbp->len,
+			     loader, fd)))
+	goto close_and_out;
+
       /* Check .note.ABI-tag if present.  */
       for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
 	if (ph->p_type == PT_NOTE && ph->p_filesz >= 32 && ph->p_align >= 4)