From 730c84556bc2d2761c1c4ea00903ee4df9c3b091 Mon Sep 17 00:00:00 2001
From: Michael Tremer <michael.tremer@ipfire.org>
Date: Sat, 26 Oct 2024 16:06:46 +0000
Subject: [PATCH] linter: Check if ELF files have a debug link

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---
 Makefile.am                  |  2 ++
 configure.ac                 |  1 +
 src/libpakfire/linter-file.c | 25 +++++++++++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/Makefile.am b/Makefile.am
index 97b6ee1fe..f3dc12dd6 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -299,6 +299,7 @@ libpakfire_la_CFLAGS = \
 	$(BPF_CFLAGS) \
 	$(CAP_CFLAGS) \
 	$(CURL_CFLAGS) \
+	$(DW_CFLAGS) \
 	$(ELF_CFLAGS) \
 	$(JSON_C_CFLAGS) \
 	$(KRB5_CFLAGS) \
@@ -331,6 +332,7 @@ libpakfire_la_LIBADD = \
 	$(BPF_LIBS) \
 	$(CAP_LIBS) \
 	$(CURL_LIBS) \
+	$(DW_LIBS) \
 	$(ELF_LIBS) \
 	$(JSON_C_LIBS) \
 	$(KRB5_LIBS) \
diff --git a/configure.ac b/configure.ac
index 4d19764b7..d172344d0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -268,6 +268,7 @@ PKG_CHECK_MODULES([ARCHIVE], [libarchive >= 3.4.0])
 PKG_CHECK_MODULES([BPF], [libbpf])
 PKG_CHECK_MODULES([CAP], [libcap])
 PKG_CHECK_MODULES([CURL], [libcurl])
+PKG_CHECK_MODULES([DW], [libdw])
 PKG_CHECK_MODULES([ELF], [libelf])
 PKG_CHECK_MODULES([PYTHON_DEVEL], [python-${PYTHON_VERSION}-embed],
 	[], [PKG_CHECK_MODULES([PYTHON_DEVEL], [python-${PYTHON_VERSION}])])
diff --git a/src/libpakfire/linter-file.c b/src/libpakfire/linter-file.c
index b40e8ff6b..d6b862778 100644
--- a/src/libpakfire/linter-file.c
+++ b/src/libpakfire/linter-file.c
@@ -23,6 +23,7 @@
 
 // libelf
 #include <gelf.h>
+#include <elfutils/libdwelf.h>
 
 #include <pakfire/ctx.h>
 #include <pakfire/file.h>
@@ -844,6 +845,25 @@ static int pakfire_linter_file_is_stripped(struct pakfire_linter_file* lfile) {
 	return pakfire_linter_file_elf(lfile, __pakfire_linter_file_is_stripped, NULL);
 }
 
+static int __pakfire_linter_file_has_debuglink(
+		struct pakfire_linter_file* lfile, Elf* elf, void* data) {
+	const char* name = NULL;
+	GElf_Word crc32;
+
+	// Fetch the debug link
+	name = dwelf_elf_gnu_debuglink(elf, &crc32);
+	if (!name)
+		return pakfire_linter_file_error(lfile, "Missing Debug Link");
+
+	DEBUG(lfile->ctx, "%s has debug link pointing at %s\n", lfile->path, name);
+
+	return 0;
+}
+
+static int pakfire_linter_file_has_debuglink(struct pakfire_linter_file* lfile) {
+	return pakfire_linter_file_elf(lfile, __pakfire_linter_file_has_debuglink, NULL);
+}
+
 int pakfire_linter_file_lint(struct pakfire_linter_file* lfile) {
 	int r = 0;
 
@@ -871,6 +891,11 @@ int pakfire_linter_file_lint(struct pakfire_linter_file* lfile) {
 		if (r < 0)
 			return r;
 
+		// Check if we have a debug link
+		r = pakfire_linter_file_has_debuglink(lfile);
+		if (r < 0)
+			return r;
+
 		// Check PIE
 		r = pakfire_linter_file_check_pie(lfile);
 		if (r < 0)
-- 
2.39.5