+2015-08-05 Nick Clifton <nickc@redhat.com>
+
+ * elf.c (_bfd_elf_copy_private_bfd_data): Copy the sh_link and
+ sh_info fields of sections whose type has been changed to
+ SHT_NOBITS.
+
2015-08-04 Yuriy M. Kaminskiy" <yumkam@gmail.com>
Tyler Hicks <tyhicks@canonical.com>
/* Copy object attributes. */
_bfd_elf_copy_obj_attributes (ibfd, obfd);
+
+ /* This is an feature for objcopy --only-keep-debug: When a section's type
+ is changed to NOBITS, we preserve the sh_link and sh_info fields so that
+ they can be matched up with the original. */
+ Elf_Internal_Shdr ** iheaders = elf_elfsections (ibfd);
+ Elf_Internal_Shdr ** oheaders = elf_elfsections (obfd);
+
+ if (iheaders != NULL && oheaders != NULL)
+ {
+ unsigned int i;
+
+ for (i = 0; i < elf_numsections (obfd); i++)
+ {
+ unsigned int j;
+ Elf_Internal_Shdr * oheader = oheaders[i];
+
+ if (oheader == NULL
+ || oheader->sh_type != SHT_NOBITS
+ || oheader->sh_size == 0
+ || (oheader->sh_info != 0 && oheader->sh_link != 0))
+ continue;
+
+ /* Scan for the matching section in the input bfd.
+ FIXME: We could use something better than a linear scan here.
+ Unfortunately we cannot compare names as the output string table
+ is empty, so instead we check size, address and type. */
+ for (j = 0; j < elf_numsections (ibfd); j++)
+ {
+ Elf_Internal_Shdr * iheader = iheaders[j];
+
+ if (iheader->sh_type != SHT_NOBITS
+ && iheader->sh_size == oheader->sh_size
+ && iheader->sh_addr == oheader->sh_addr
+ && (iheader->sh_info != oheader->sh_info
+ || iheader->sh_link != oheader->sh_link))
+ {
+ /* Note: Strictly speaking these assignments are wrong.
+ The sh_link and sh_info fields should point to the
+ relevent sections in the output BFD, which may not be in
+ the same location as they were in the input BFD. But the
+ whole point of this action is to preserve the original
+ values of the sh_link and sh_info fields, so that they
+ can be matched up with the section headers in the
+ original file. So strictly speaking we may be creating
+ an invalid ELF file, but it is only for a file that just
+ contains debug info and only for sections without any
+ contents. */
+ if (oheader->sh_link == 0)
+ oheader->sh_link = iheader->sh_link;
+ if (oheader->sh_info == 0)
+ oheader->sh_info = iheader->sh_info;
+ break;
+ }
+ }
+ }
+ }
+
return TRUE;
}
+2015-08-05 Nick Clifton <nickc@redhat.com>
+
+ * doc/binutils.texi: Document that the --only-keep-debug option
+ to strip and objcopy preserves the section headers of stripped
+ sections.
+
2015-08-04 Yuriy M. Kaminskiy" <yumkam@gmail.com>
Tyler Hicks <tyhicks@canonical.com>
stripped by @option{--strip-debug} and leaving the debugging sections
intact. In ELF files, this preserves all note sections in the output.
+Note - the section headers of the stripped sections are preserved,
+including their sizes, but the contents of the section are discarded.
+The section headers are preserved so that other tools can match up the
+debuginfo file with the real executable, even if that executable has
+been relocated to a different address space.
+
The intention is that this option will be used in conjunction with
@option{--add-gnu-debuglink} to create a two part executable. One a
stripped binary which will occupy less space in RAM and in a
which would otherwise get stripped.
@item --only-keep-debug
-Strip a file, removing contents of any sections that would not be
+Strip a file, emptying the contents of any sections that would not be
stripped by @option{--strip-debug} and leaving the debugging sections
-intact. In ELF files, this preserves all note sections in the output.
+intact. In ELF files, this preserves all the note sections in the
+output as well.
+
+Note - the section headers of the stripped sections are preserved,
+including their sizes, but the contents of the section are discarded.
+The section headers are preserved so that other tools can match up the
+debuginfo file with the real executable, even if that executable has
+been relocated to a different address space.
The intention is that this option will be used in conjunction with
@option{--add-gnu-debuglink} to create a two part executable. One a
+2015-08-05 Nick Clifton <nickc@redhat.com>
+
+ * binutils-all/objcopy.exp (keep_debug_symbols_and_check_links):
+ New proc. Checks that debug-info-only binaries retain the
+ sh_link field in stripped sections.
+
2015-08-04 Nick Clifton <nickc@redhat.com>
* lib/utils-lib.exp (run_dump_test): Document DUMPPROG, readelf
pass $test2
}
+# Tests that in a debug only copy of a file the sections
+# headers whoes types have been changed to NOBITS still
+# retain their sh_link fields.
+
+proc keep_debug_symbols_and_check_links { prog flags test } {
+ global READELF
+
+ remote_file build delete tmpdir/striprog
+ remote_download build tmpdir/copyprog tmpdir/striprog
+ if [is_remote host] {
+ set copyfile [remote_download host tmpdir/striprog]
+ } else {
+ set copyfile tmpdir/striprog
+ }
+
+ set exec_output [binutils_run $prog "$flags ${copyfile}"]
+ if ![string match "" $exec_output] {
+ fail $test
+ return
+ }
+
+ set got [binutils_run $READELF "-S --wide ${copyfile}"]
+
+ set fails 0
+ # Regexp to match a section with NOBITS type and extract its name and sh_link fields
+ while {[regexp \
+ {[^a-zA-Z]+([a-zA-Z0-9_\.]+)[ ]+NOBITS[ ]+[0-9a-fA-F]+ [0-9a-fA-F]+ [0-9a-fA-F]+ [0-9]+[ A]+([0-9]+)(.*)} \
+ $got all name link rest]} {
+ set sh_link 0x$link
+ if {$sh_link == 0} {
+ # Only some NOBITS sections should have a non-zero sh_link field.
+ # Look for them by name.
+ verbose "NOBITS section .$name has a 0 sh_link field\n"
+ switch $name {
+ "rela.*" { set fails 1 ; send_log "Expected non-zero sh_link for .$name\n" }
+ "rel.*" { set fails 1 ; send_log "Expected non-zero sh_link for .$name\n" }
+ "hash" { set fails 1 ; send_log "Expected non-zero sh_link for .$name\n" }
+ "gnu_version" { set fails 1 ; send_log "Expected non-zero sh_link for .$name\n" }
+ "dynsym" { set fails 1 ; send_log "Expected non-zero sh_link for .$name\n" }
+ "gnu.version_r" { set fails 1 ; send_log "Expected non-zero sh_link for .$name\n" }
+ "dynamic" { set fails 1 ; send_log "Expected non-zero sh_link for .$name\n" }
+ "symtab" { set fails 1 ; send_log "Expected non-zero sh_link for .$name\n" }
+ }
+ }
+ set got $rest
+ }
+
+ if {$fails == 0} {
+ pass $test
+ } else {
+ fail $test
+ }
+}
+
+
set test1 "simple objcopy of executable"
set test2 "run objcopy of executable"
set test3 "run stripped executable"
set test4 "run stripped executable with saving a symbol"
set test5 "keep only debug data"
set test6 "simple objcopy of debug data"
+if [is_elf_format] {
+ set test7 "NOBITS sections retain sh_link field"
+}
switch [copy_setup] {
"1" {
untested $test4
untested $test5
untested $test6
+ if [is_elf_format] {
+ untested $test7
+ }
}
"3" {
copy_executable "$OBJCOPY" "$OBJCOPYFLAGS" "$test1" ""
unsupported $test4
unsupported $test5
unsupported $test6
+ if [is_elf_format] {
+ unsupported $test7
+ }
}
"0" {
copy_executable "$OBJCOPY" "$OBJCOPYFLAGS" "$test1" "$test2"
strip_executable_with_saving_a_symbol "$STRIP" "-K main -K _main $STRIPFLAGS" "$test4"
keep_debug_symbols_and_test_copy "$STRIP" "--only-keep-debug $STRIPFLAGS" "$test5" \
"$OBJCOPY" "$OBJCOPYFLAGS" "$test6"
+ if [is_elf_format] {
+ keep_debug_symbols_and_check_links "$STRIP" "--only-keep-debug $STRIPFLAGS" "$test7"
+ }
}
}
projects / external / binutils.git / commitdiff