From: Mark Wielaard <mark@klomp.org>
Date: Thu, 9 Apr 2026 12:40:44 +0000 (+0200)
Subject: elflint: Recognize debug dwo sections
X-Git-Tag: elfutils-0.195~12
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=11c0b56a36e00bae043c690af758a190c2eb97ba;p=thirdparty%2Felfutils.git

elflint: Recognize debug dwo sections

.debug dwo sections can include the SHF_EXCLUDE flag to indicate that
the linker shouldn't process them. Also a .debug_str.dwo section is
like a normal .debug_str section. There is no .debug_line_str.dwo
section, so that doesn't need special casing.

Add some dwo files to run-elflint-test.sh to make sure debug files
with .dwo sections aren't flagged by eu-elflint with --gnu --debug.

	* src/elflint.c (special_sections): Add .debug_str.dwo.
	(IS_DEBUG_DWO): New macro.
	(check_sections): For IS_DEBUG_DWO files allow SHF_EXCLUDE.
	* tests/run-elflint-test.sh: Add .dwo testfiles.

Signed-off-by: Mark Wielaard <mark@klomp.org>
---

diff --git a/src/elflint.c b/src/elflint.c
index a05f37d1..9e1180af 100644
--- a/src/elflint.c
+++ b/src/elflint.c
@@ -3686,6 +3686,7 @@ static const struct
     { ".data", 6, SHT_PROGBITS, exact, SHF_ALLOC | SHF_WRITE, 0 },
     { ".data1", 7, SHT_PROGBITS, exact, SHF_ALLOC | SHF_WRITE, 0 },
     { ".debug_str", 11, SHT_PROGBITS, exact_or_gnuld, SHF_MERGE | SHF_STRINGS, 0 },
+    { ".debug_str.dwo", 15, SHT_PROGBITS, exact_or_gnuld, SHF_MERGE | SHF_STRINGS, 0 },
     { ".debug_line_str", 16, SHT_PROGBITS, exact_or_gnuld, SHF_MERGE | SHF_STRINGS, 0 },
     { ".debug", 6, SHT_PROGBITS, exact, 0, 0 },
     { ".dynamic", 9, SHT_DYNAMIC, atleast, SHF_ALLOC, SHF_WRITE },
@@ -3734,6 +3735,10 @@ static const struct
    && !memcmp (special_sections[idx].name, string, \
 	       sizeof string - (prefix ? 1 : 0)))
 
+#define IS_DEBUG_DWO(name) \
+  (startswith (name, ".debug_") \
+   && strcmp (name + strlen (name) - 4, ".dwo") == 0)
+
 /* Extra section flags that might or might not be added to the section
    and have to be ignored.  */
 #define EXTRA_SHFLAGS (SHF_LINK_ORDER \
@@ -3856,10 +3861,14 @@ section [%2d] '%s' has wrong type: expected %s, is %s\n"),
 		if (special_sections[s].attrflag == exact
 		    || special_sections[s].attrflag == exact_or_gnuld)
 		  {
-		    /* Except for the link order, retain, group bit and
-		       compression flag all the other bits should
-		       match exactly.  */
-		    if ((shdr->sh_flags & ~EXTRA_SHFLAGS)
+		    /* Except for the link order, retain, group bit
+		       and compression flag all the other bits should
+		       match exactly.  .debug.dwo sections can also be
+		       SHF_EXCLUDE. */
+		    GElf_Word extra_shflags = EXTRA_SHFLAGS;
+		    if (IS_DEBUG_DWO (scnname))
+			extra_shflags |= SHF_EXCLUDE;
+		    if ((shdr->sh_flags & ~extra_shflags)
 			!= special_sections[s].attr
 			&& (special_sections[s].attrflag == exact || !gnuld))
 		      ERROR (_("\
diff --git a/tests/run-elflint-test.sh b/tests/run-elflint-test.sh
index caf172a6..41b531ee 100755
--- a/tests/run-elflint-test.sh
+++ b/tests/run-elflint-test.sh
@@ -57,4 +57,12 @@ tempfiles testfile-s390x-hash-bothz
 testrun ${abs_top_builddir}/src/elfcompress -f -q --name='.s??tab' -o testfile-s390x-hash-bothz testfile-s390x-hash-both
 testrun ${abs_top_builddir}/src/elflint -q --gnu-ld testfile-s390x-hash-bothz
 
+# Recognize debug dwo sections
+testfiles testfile-hello4.dwo testfile-world4.dwo
+testfiles testfile-hello5.dwo testfile-world5.dwo
+testrun ${abs_top_builddir}/src/elflint -q --gnu --debug \
+	testfile-hello4.dwo testfile-world4.dwo
+testrun ${abs_top_builddir}/src/elflint -q --gnu --debug \
+	testfile-hello5.dwo testfile-world5.dwo
+
 exit 0