6685125 ld/elfdump do not handle ZERO terminator .eh_frame amd64 unwind entry

4 files changed, 31 insertions, 10 deletions

diff --git a/usr/src/cmd/sgs/elfdump/common/elfdump.c b/usr/src/cmd/sgs/elfdump/common/elfdump.c
index ea76beec4c..c8b00357a2 100644
--- a/usr/src/cmd/sgs/elfdump/common/elfdump.c
+++ b/usr/src/cmd/sgs/elfdump/common/elfdump.c
@@ -536,9 +536,22 @@ unwind(Cache *cache, Word shnum, Word phnum, Ehdr *ehdr, const char *file,
 
 			ndx = 0;
 			/*
-			 * extract length in lsb format
+			 * Extract length in lsb format.  A zero length
+			 * indicates that this CIE is a terminator and that
+			 * processing for this unwind information should end.
+			 * However, skip this entry and keep processing, just
+			 * in case there is any other information remaining in
+			 * this section.  Note, ld(1) will terminate the
+			 * processing of the .eh_frame contents for this file
+			 * after a zero length CIE, thus any information that
+			 * does follow is ignored by ld(1), and is therefore
+			 * questionable.
 			 */
-			length = LSB32EXTRACT(data + off + ndx);
+			if ((length = LSB32EXTRACT(data + off + ndx)) == 0) {
+				dbg_print(0, MSG_ORIG(MSG_UNW_ZEROTERM));
+				off += 4;
+				continue;
+			}
 			ndx += 4;
 
 			/*
diff --git a/usr/src/cmd/sgs/elfdump/common/elfdump.msg b/usr/src/cmd/sgs/elfdump/common/elfdump.msg
index 08bd0f3692..d2575f468b 100644
--- a/usr/src/cmd/sgs/elfdump/common/elfdump.msg
+++ b/usr/src/cmd/sgs/elfdump/common/elfdump.msg
@@ -310,6 +310,7 @@
 @ MSG_UNW_BINSRTAB1	"  Binary Search Table:"
 @ MSG_UNW_BINSRTAB2	"      InitialLoc          FdeLoc"
 @ MSG_UNW_BINSRTABENT	"    0x%016llx  0x%016llx"
+@ MSG_UNW_ZEROTERM	"ZERO terminator: [0x00000000]"
 @ MSG_UNW_CIE		"CIE: [0x%08llx]"
 @ MSG_UNW_CIELNGTH	" length: 0x%02x cieid: %d"
 @ MSG_UNW_CIEVERS	" version: %d  augstring: `%s'"
diff --git a/usr/src/cmd/sgs/libld/common/unwind.amd.c b/usr/src/cmd/sgs/libld/common/unwind.amd.c
index 5ba9c33416..a6b671ba81 100644
--- a/usr/src/cmd/sgs/libld/common/unwind.amd.c
+++ b/usr/src/cmd/sgs/libld/common/unwind.amd.c
@@ -356,23 +356,29 @@ make_amd64_unwindhdr(Ofl_desc *ofl)
 	for (LIST_TRAVERSE(&ofl->ofl_unwind, lnp, osp)) {
 		Is_desc	    *isp;
 		Listnode    *_lnp;
+
 		for (LIST_TRAVERSE(&osp->os_isdescs, _lnp, isp)) {
-			unsigned char	*data;
+			uchar_t		*data;
 			size_t		datasize;
 			uint64_t	off;
 			uint_t		length, id;
 
-			data = (unsigned char *)isp->is_indata->d_buf;
+			data = (uchar_t *)isp->is_indata->d_buf;
 			datasize = isp->is_indata->d_size;
 			off = 0;
 			while (off < datasize) {
-				uint_t	    ndx;
+				uint_t	    ndx = 0;
 
-				ndx = 0;
 				/*
-				 * extract length in lsb format
+				 * Extract length in lsb format.  A zero length
+				 * indicates that this CIE is a terminator and
+				 * that processing for this unwind information
+				 * should end.
 				 */
-				length = LSB32EXTRACT(data + off + ndx);
+				if ((length =
+				    LSB32EXTRACT(data + off + ndx)) == 0)
+					break;
+
 				ndx += 4;
 
 				/*
@@ -467,7 +473,7 @@ bintabcompare(const void *p1, const void *p2)
 uintptr_t
 populate_amd64_unwindhdr(Ofl_desc *ofl)
 {
-	unsigned char	*hdrdata;
+	uchar_t		*hdrdata;
 	uint_t		*binarytable;
 	uint_t		hdroff;
 	Listnode	*lnp;
@@ -520,7 +526,7 @@ populate_amd64_unwindhdr(Ofl_desc *ofl)
 	fde_count = 0;
 
 	for (LIST_TRAVERSE(&ofl->ofl_unwind, lnp, osp)) {
-		unsigned char	*fdata;
+		uchar_t		*fdata;
 		uint64_t	fdatasize;
 		uint_t		foff;
 		uint64_t	fndx;
diff --git a/usr/src/cmd/sgs/packages/common/SUNWonld-README b/usr/src/cmd/sgs/packages/common/SUNWonld-README
index 243c7583dd..24acc63911 100644
--- a/usr/src/cmd/sgs/packages/common/SUNWonld-README
+++ b/usr/src/cmd/sgs/packages/common/SUNWonld-README
@@ -1335,3 +1335,4 @@ Bugid   Risk Synopsis
 6681761 lies, darn lies, and linker README files
 6509323 Need to disable the Multiple Files loading - same name, different
 	directories (or its stat() use)
+6685125 ld/elfdump do not handle ZERO terminator .eh_frame amd64 unwind entry