Blob Blame History Raw
commit 6f5934c1afa8f34bfb8f86b191ded9af854e757f
Author: Jan Kratochvil <jan.kratochvil@redhat.com>
Date:   Sat Feb 7 15:08:20 2015 +0100

    libelf: Consider sh_addralign 0 as 1
    
    Currently the Koji build for arm32 fails with:
    	extracting debug info from /builddir/build/BUILDROOT/etcd-2.0.0-0.3.rc1.fc22.arm/usr/bin/etcd
    	Failed to write file: invalid section alignment
    
    This is because the binary etcd
    	http://people.redhat.com/jkratoch/etcdctl.xz
    contains:
    	Section Headers:
    	  [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
    	  [11] .rel.plt          REL             00459ee0 449ee0 000088 08   A 13   0  0
    	                                                                               ^
    which corresponds to golang's code:
    	go/src/cmd/ld/elf.c
    		case EM_X86_64:
    			sh = elfshname(".rela.plt");
    			sh->addralign = RegSize;
    		default:
    			sh = elfshname(".rel.plt");
    			<nothing>
    
    ELF spec says:
    	Values 0 and 1 mean the section has no alignment constraints.
    and libelf/elf32_updatenull.c really parses it that way at line 204
    	ElfW2(LIBELFBITS,Word) sh_align = shdr->sh_addralign ?: 1;
    but unfortunately the later line being patched no longer does.
    
    libelf/
    2015-02-07  Jan Kratochvil  <jan.kratochvil@redhat.com>
    
    	* elf32_updatenull.c (__elfw2(LIBELFBITS,updatenull_wrlock)): Consider
    	sh_addralign 0 as 1.
    
    Signed-off-by: Jan Kratochvil <jan.kratochvil@redhat.com>

diff --git a/libelf/elf32_updatenull.c b/libelf/elf32_updatenull.c
index be4cea0..5e809b7 100644
--- a/libelf/elf32_updatenull.c
+++ b/libelf/elf32_updatenull.c
@@ -328,7 +328,7 @@ __elfw2(LIBELFBITS,updatenull_wrlock) (Elf *elf, int *change_bop, size_t shnum)
 		     enough for the largest alignment required by a data
 		     block.  */
 		  if (unlikely (! powerof2 (shdr->sh_addralign))
-		      || unlikely (shdr->sh_addralign < sh_align))
+		      || unlikely ((shdr->sh_addralign ?: 1) < sh_align))
 		    {
 		      __libelf_seterrno (ELF_E_INVALID_ALIGN);
 		      return -1;