From 68d383c39cef8d58b80940b13dd132d3f41a03f0 Mon Sep 17 00:00:00 2001

Message-Id: <68d383c39cef8d58b80940b13dd132d3f41a03f0.1558430547.git.pmatilai@redhat.com>

From: Panu Matilainen <pmatilai@redhat.com>

Date: Tue, 2 Apr 2019 15:22:07 +0300

Subject: [PATCH 1/2] Detect kernel modules by .modinfo section presence for

 build-id generation

File extension based heuristics only work so far at best, and break

completely on compressed files with arbitrary .gz/.xz etc extension.

This isn't supposed to change any behavior as such, only provide more

reliable detection of kernel modules.

---

 build/files.c | 27 ++++++++++++++++++++++++---

 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/build/files.c b/build/files.c

index dbad9a7f3..3822be3d3 100644

--- a/build/files.c

+++ b/build/files.c

@@ -1739,6 +1739,28 @@ static int addNewIDSymlink(ARGV_t *files,

     return rc;

 }

+static int haveModinfo(Elf *elf)

+{

+    Elf_Scn * scn = NULL;

+    size_t shstrndx;

+    int have_modinfo = 0;

+    const char *sname;

+

+    if (elf_getshdrstrndx(elf, &shstrndx) == 0) {

+	while ((scn = elf_nextscn(elf, scn)) != NULL) {

+	    GElf_Shdr shdr_mem, *shdr = gelf_getshdr(scn, &shdr_mem);

+	    if (shdr == NULL)

+		continue;

+	    sname = elf_strptr(elf, shstrndx, shdr->sh_name);

+	    if (sname && rstreq(sname, ".modinfo")) {

+		have_modinfo = 1;

+		break;

+	    }

+	}

+    }

+    return have_modinfo;

+}

+

 static int generateBuildIDs(FileList fl, ARGV_t *files)

 {

     int rc = 0;

@@ -1803,15 +1825,14 @@ static int generateBuildIDs(FileList fl, ARGV_t *files)

 	    int fd = open (flp->diskPath, O_RDONLY);

 	    if (fd >= 0) {

 		/* Only real ELF files, that are ET_EXEC, ET_DYN or

-		   kernel modules (ET_REL files with names ending in .ko)

+		   kernel modules (ET_REL files with .modinfo section)

 		   should have build-ids. */

 		GElf_Ehdr ehdr;

 		Elf *elf = elf_begin (fd, ELF_C_READ, NULL);

 		if (elf != NULL && elf_kind(elf) == ELF_K_ELF

 		    && gelf_getehdr(elf, &ehdr) != NULL

 		    && (ehdr.e_type == ET_EXEC || ehdr.e_type == ET_DYN

-			|| (ehdr.e_type == ET_REL

-			    && rpmFileHasSuffix (flp->diskPath, ".ko")))) {

+			|| (ehdr.e_type == ET_REL && haveModinfo(elf)))) {

 		    const void *build_id;

 		    ssize_t len = dwelf_elf_gnu_build_id (elf, &build_id);

 		    /* len == -1 means error. Zero means no

-- 

2.21.0