package: Fix handling of minidebuginfo with newer binutils

Newer versions of binutils (2.38+) have changed how the
"--only-keep-debug" of objcopy behaves when stripping non-debug sections
from an ELF.

  https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=68f543154e92ab0f5d6c569e0fa143f5e8bd2d80

This change causes associated sections to be correctly marked as NOBITS
with the section contents removed from the output. The side effect is
that this causes issues with objcopy's ability to perform symbol and
relocation stripping (-S/--strip-all) on the debug split ELF, such that
with some object files (e.g. kernel modules) objcopy fails to strip
symbols/relocations with an error like the following:

  .../.debug/nls_cp950.ko[.rodata]: file truncated

Because of this it is now problematic to generate minidebuginfo for
these types of ELF objects. However it is not typically useful to inject
minidebuginfo into these types of ELFs, and other distributions (e.g.
Fedora, referring to find-debuginfo.sh of debugedit) only insert
minidebuginfo into executables and shared libraries.

This change causes the minidebuginfo injection to only apply to EXEC/DYN
type ELFs, which limits the injection to executables and shared
libraires.

Additionally this change fixes the parsing of the sections from the
"readelf -W -S" output which was not accounting for the section index
column having leading spaces for single digit index values e.g. "[ 1]".

(From OE-Core rev: 2084cfcb3d15db3e02637f1cd63ab9c997f38a65)

Signed-off-by: Nathan Rossi <nathan.rossi@digi.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 18 insertions, 3 deletions

diff --git a/meta/classes-global/package.bbclass b/meta/classes-global/package.bbclass
index 2d985d8aff..7a0a428b30 100644
--- a/meta/classes-global/package.bbclass
+++ b/meta/classes-global/package.bbclass
@@ -490,16 +490,31 @@ def inject_minidebuginfo(file, dvar, dv, d):
         bb.debug(1, 'ELF file {} has no debuginfo, skipping minidebuginfo injection'.format(file))
         return
 
+    # minidebuginfo does not make sense to apply to ELF objects other than
+    # executables and shared libraries, skip applying the minidebuginfo
+    # generation for objects like kernel modules.
+    for line in subprocess.check_output([readelf, '-h', debugfile], universal_newlines=True).splitlines():
+        if not line.strip().startswith("Type:"):
+            continue
+        elftype = line.split(":")[1].strip()
+        if not any(elftype.startswith(i) for i in ["EXEC", "DYN"]):
+            bb.debug(1, 'ELF file {} is not executable/shared, skipping minidebuginfo injection'.format(file))
+            return
+        break
+
     # Find non-allocated PROGBITS, NOTE, and NOBITS sections in the debuginfo.
     # We will exclude all of these from minidebuginfo to save space.
     remove_section_names = []
     for line in subprocess.check_output([readelf, '-W', '-S', debugfile], universal_newlines=True).splitlines():
-        fields = line.split()
-        if len(fields) < 8:
+        # strip the leading "  [ 1]" section index to allow splitting on space
+        if ']' not in line:
+            continue
+        fields = line[line.index(']') + 1:].split()
+        if len(fields) < 7:
             continue
         name = fields[0]
         type = fields[1]
-        flags = fields[7]
+        flags = fields[6]
         # .debug_ sections will be removed by objcopy -S so no need to explicitly remove them
         if name.startswith('.debug_'):
             continue