From: Mark Wielaard <mjw@redhat.com>
Date: Sat, 6 Aug 2016 13:13:19 +0000 (+0200)
Subject: strip: Handle compressed relocation target sections.
X-Git-Tag: elfutils-0.167~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6ff6c215bfa4153874751cdc0bae26acfbba4a81;p=thirdparty%2Felfutils.git

strip: Handle compressed relocation target sections.

binutils 2.27 assembler will create compressed sections for x86 ELF
targets. The linker will decompress them again and it doesn't do this
for any other target. This broke one of the run-strip-reloc.sh self tests.

Fix by checking if the target of a relocation section is compressed and
first decompressing it before applying relocations and then compressing
again if necessary.

Add explicit testcases for compressed and uncompressed ET_REL files
to run-strip-reloc.sh.

Signed-off-by: Mark Wielaard <mjw@redhat.com>
---

diff --git a/src/ChangeLog b/src/ChangeLog
index e5a3fce38..835888da1 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2016-08-06  Mark Wielaard  <mjw@redhat.com>
+
+	* strip.c (handle_elf): Uncompress and recompress relocation target
+	section if necessary.
+
 2016-07-08  Mark Wielaard  <mjw@redhat.com>
 
 	* Makefile.am (strip_LDADD): Add libdw.
diff --git a/src/strip.c b/src/strip.c
index 23d3d51bc..f56554f7d 100644
--- a/src/strip.c
+++ b/src/strip.c
@@ -1,5 +1,5 @@
 /* Discard section not used at runtime from object files.
-   Copyright (C) 2000-2012, 2014, 2015 Red Hat, Inc.
+   Copyright (C) 2000-2012, 2014, 2015, 2016 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -1791,10 +1791,18 @@ handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
 	      Elf_Data *reldata = elf_getdata (scn, NULL);
 	      if (reldata == NULL || reldata->d_buf == NULL)
 		INTERNAL_ERROR (fname);
-	      /* We actually wanted the rawdata, but since we already
-		 accessed it earlier as elf_getdata () that won't
-		 work. But debug sections are all ELF_T_BYTE, so it
-		 doesn't really matter.  */
+
+	      /* Make sure we adjust the uncompressed debug data
+		 (and recompress if necessary at the end).  */
+	      GElf_Chdr tchdr;
+	      int tcompress_type = 0;
+	      if (gelf_getchdr (tscn, &tchdr) != NULL)
+		{
+		  tcompress_type = tchdr.ch_type;
+		  if (elf_compress (tscn, 0, 0) != 1)
+		    INTERNAL_ERROR (fname);
+		}
+
 	      Elf_Data *tdata = elf_getdata (tscn, NULL);
 	      if (tdata == NULL || tdata->d_buf == NULL
 		  || tdata->d_type != ELF_T_BYTE)
@@ -1976,6 +1984,10 @@ handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
 	      nrels = next;
 	      shdr->sh_size = reldata->d_size = nrels * shdr->sh_entsize;
 	      gelf_update_shdr (scn, shdr);
+
+	      if (tcompress_type != 0)
+		if (elf_compress (tscn, tcompress_type, 0) != 1)
+		  INTERNAL_ERROR (fname);
 	    }
 	}
     }
diff --git a/tests/ChangeLog b/tests/ChangeLog
index d782ec300..f21a0b794 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,8 @@
+2016-08-06  Mark Wielaard  <mjw@redhat.com>
+
+	* run-strip-reloc.sh: Add explicit compressed and uncompressed
+	test cases.
+
 2016-08-10  Richard Henderson  <rth@redhat.com>
 
 	* file-bpf-dis1.expect.bz2: Fix expected mod and endian operations
diff --git a/tests/run-strip-reloc.sh b/tests/run-strip-reloc.sh
index 9fbba29b8..e587eab3f 100755
--- a/tests/run-strip-reloc.sh
+++ b/tests/run-strip-reloc.sh
@@ -108,4 +108,15 @@ runtest hello_m68k.ko 1
 runtest ${abs_top_builddir}/src/strip 0
 runtest ${abs_top_builddir}/src/strip.o 1
 
+# Copy ET_REL file for self-test and make sure to run with/without
+# elf section compression.
+tempfiles strip-uncompressed.o strip-compressed.o
+testrun ${abs_top_builddir}/src/elfcompress -o strip-uncompressed.o -t none \
+  ${abs_top_builddir}/src/strip.o
+testrun ${abs_top_builddir}/src/elfcompress -o strip-compressed.o -t zlib \
+  --force ${abs_top_builddir}/src/strip.o
+
+runtest strip-uncompressed.o 1
+runtest strip-compressed.o 1
+
 exit $status