svn commit: r274407 - head/sys/boot/common

[Peter Grehan]

Author: grehan
Date: Tue Nov 11 22:03:11 2014
New Revision: 274407
URL: https://svnweb.freebsd.org/changeset/base/274407

Log:
  Fix incorrect reading of 32-bit modinfo by 64-bit loaders.
  
  The various structures in the mod_metadata set of a FreeBSD kernel and
  modules contain pointers. The FreeBSD loader correctly deals with a
  mismatch in loader and kernel pointer size (e.g. 32-bit i386/ppc
  loader, loading 64-bit amd64/ppc64 kernels), but wasn't dealing with
  the inverse case where a 64-bit loader was loading a 32-bit kernel.
  
  Reported by:	ktcallbox at gmail.com with a bhyve/i386 and ZFS root install
  Differential Revision:	https://reviews.freebsd.org/D1129
  Reviewed by:	neel, jhb
  MFC after:	1 week

Modified:
  head/sys/boot/common/load_elf.c

Modified: head/sys/boot/common/load_elf.c
==============================================================================
--- head/sys/boot/common/load_elf.c	Tue Nov 11 21:52:10 2014	(r274406)
+++ head/sys/boot/common/load_elf.c	Tue Nov 11 22:03:11 2014	(r274407)
@@ -640,6 +640,14 @@ struct mod_metadata64 {
 	u_int64_t	md_cval;	/* common string label */
 };
 #endif
+#if defined(__amd64__) && __ELF_WORD_SIZE == 32
+struct mod_metadata32 {
+	int		md_version;	/* structure version MDTV_* */  
+	int		md_type;	/* type of entry MDT_* */
+	u_int32_t	md_data;	/* specific data */
+	u_int32_t	md_cval;	/* common string label */
+};
+#endif
 
 int
 __elfN(parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef)
@@ -647,6 +655,8 @@ __elfN(parse_modmetadata)(struct preload
     struct mod_metadata md;
 #if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64
     struct mod_metadata64 md64;
+#elif defined(__amd64__) && __ELF_WORD_SIZE == 32
+    struct mod_metadata32 md32;
 #endif
     struct mod_depend *mdepend;
     struct mod_version mver;
@@ -682,6 +692,18 @@ __elfN(parse_modmetadata)(struct preload
 	md.md_type = md64.md_type;
 	md.md_cval = (const char *)(uintptr_t)md64.md_cval;
 	md.md_data = (void *)(uintptr_t)md64.md_data;
+#elif defined(__amd64__) && __ELF_WORD_SIZE == 32
+	COPYOUT(v, &md32, sizeof(md32));
+	error = __elfN(reloc_ptr)(fp, ef, v, &md32, sizeof(md32));
+	if (error == EOPNOTSUPP) {
+	    md32.md_cval += ef->off;
+	    md32.md_data += ef->off;
+	} else if (error != 0)
+	    return (error);
+	md.md_version = md32.md_version;
+	md.md_type = md32.md_type;
+	md.md_cval = (const char *)(uintptr_t)md32.md_cval;
+	md.md_data = (void *)(uintptr_t)md32.md_data;
 #else
 	COPYOUT(v, &md, sizeof(md));
 	error = __elfN(reloc_ptr)(fp, ef, v, &md, sizeof(md));