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[PATCH 2/9] add qemu-modinfo utility
From: |
Gerd Hoffmann |
Subject: |
[PATCH 2/9] add qemu-modinfo utility |
Date: |
Wed, 2 Jun 2021 11:17:20 +0200 |
For now only dump metadata.
TODO:
* store in some file format (json?).
* make qemu parse it, replace hard-coded lists in util/module.c
* fix windows (seems to not have glob).
* do we need non-elf support?
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
qemu-modinfo.c | 182 +++++++++++++++++++++++++++++++++++++++++++++++++
meson.build | 3 +
2 files changed, 185 insertions(+)
create mode 100644 qemu-modinfo.c
diff --git a/qemu-modinfo.c b/qemu-modinfo.c
new file mode 100644
index 000000000000..ecd5f6c3adf2
--- /dev/null
+++ b/qemu-modinfo.c
@@ -0,0 +1,182 @@
+/*
+ * QEMU module parser
+ *
+ * read modules, find modinfo section, parse & store metadata.
+ *
+ * Copyright Red Hat, Inc. 2021
+ *
+ * Authors:
+ * Gerd Hoffmann <kraxel@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+#include "elf.h"
+#include <glob.h>
+
+#define Elf_Ehdr Elf64_Ehdr
+#define Elf_Shdr Elf64_Shdr
+#define ELFCLASS ELFCLASS64
+
+static const char *moddir = CONFIG_QEMU_MODDIR;
+static const char *dsosuf = CONFIG_HOST_DSOSUF;
+
+static void modinfo(const char *module, char *info, size_t size)
+{
+ size_t pos = 0, len;
+
+ fprintf(stderr, "%s\n", module);
+ do {
+ fprintf(stderr, " -> %s\n", info + pos);
+ len = strlen(info + pos) + 1;
+ pos += len;
+ } while (pos < size);
+}
+
+static void elf_read_section_hdr(FILE *fp, Elf_Ehdr *ehdr,
+ int section, Elf_Shdr *shdr)
+{
+ size_t pos, len;
+ int ret;
+
+ pos = ehdr->e_shoff + section * ehdr->e_shentsize;
+ len = MIN(ehdr->e_shentsize, sizeof(*shdr));
+
+ ret = fseek(fp, pos, SEEK_SET);
+ if (ret != 0) {
+ fprintf(stderr, "seek error\n");
+ exit(1);
+ }
+
+ memset(shdr, 0, sizeof(*shdr));
+ ret = fread(shdr, len, 1, fp);
+ if (ret != 1) {
+ fprintf(stderr, "read error\n");
+ exit(1);
+ }
+}
+
+static void *elf_read_section(FILE *fp, Elf_Ehdr *ehdr,
+ int section, size_t *size)
+{
+ Elf_Shdr shdr;
+ void *data;
+ int ret;
+
+ elf_read_section_hdr(fp, ehdr, section, &shdr);
+ if (shdr.sh_offset && shdr.sh_size) {
+ ret = fseek(fp, shdr.sh_offset, SEEK_SET);
+ if (ret != 0) {
+ fprintf(stderr, "seek error\n");
+ exit(1);
+ }
+
+ data = g_malloc(shdr.sh_size);
+ ret = fread(data, shdr.sh_size, 1, fp);
+ if (ret != 1) {
+ fprintf(stderr, "read error\n");
+ exit(1);
+ }
+ *size = shdr.sh_size;
+ } else {
+ data = NULL;
+ *size = 0;
+ }
+ return data;
+}
+
+static void elf_parse_module(const char *module)
+{
+ Elf_Ehdr ehdr;
+ Elf_Shdr shdr;
+ FILE *fp;
+ int ret, i;
+ char *str;
+ size_t str_size;
+ char *info;
+ size_t info_size;
+
+ fp = fopen(module, "r");
+ if (NULL == fp) {
+ fprintf(stderr, "open %s: %s\n", module, strerror(errno));
+ exit(1);
+ }
+
+ ret = fread(&ehdr, sizeof(ehdr), 1, fp);
+ if (ret != 1) {
+ fprintf(stderr, "read error (%s)\n", module);
+ exit(1);
+ }
+
+ if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
+ ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
+ ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
+ ehdr.e_ident[EI_MAG3] != ELFMAG3) {
+ fprintf(stderr, "not an elf file (%s)\n", module);
+ exit(1);
+ }
+ if (ehdr.e_ident[EI_CLASS] != ELFCLASS64) {
+ fprintf(stderr, "elf class mismatch (%s)\n", module);
+ exit(1);
+ }
+ if (ehdr.e_shoff == 0) {
+ fprintf(stderr, "no section header (%s)\n", module);
+ exit(1);
+ }
+
+ /* read string table */
+ if (ehdr.e_shstrndx == 0) {
+ fprintf(stderr, "no section strings (%s)\n", module);
+ exit(1);
+ }
+ str = elf_read_section(fp, &ehdr, ehdr.e_shstrndx, &str_size);
+ if (NULL == str) {
+ fprintf(stderr, "no section strings (%s)\n", module);
+ exit(1);
+ }
+
+ /* find and read modinfo section */
+ info = NULL;
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ elf_read_section_hdr(fp, &ehdr, i, &shdr);
+ if (!shdr.sh_name) {
+ continue;
+ }
+ if (strcmp(str + shdr.sh_name, ".modinfo") == 0) {
+ info = elf_read_section(fp, &ehdr, i, &info_size);
+ }
+ }
+
+ if (info) {
+ modinfo(module, info, info_size);
+ }
+
+ fclose(fp);
+}
+
+int main(int argc, char **argv)
+{
+ char *pattern;
+ glob_t files;
+ int ret, i;
+
+ if (argc > 1) {
+ moddir = argv[1];
+ }
+
+ pattern = g_strdup_printf("%s/*%s", moddir, dsosuf);
+ ret = glob(pattern, 0, NULL, &files);
+ if (ret != 0) {
+ fprintf(stderr, "glob(%s) failed: %d\n", pattern, ret);
+ exit(1);
+ }
+
+ for (i = 0; i < files.gl_pathc; i++) {
+ elf_parse_module(files.gl_pathv[i]);
+ }
+
+ globfree(&files);
+ g_free(pattern);
+ return 0;
+}
diff --git a/meson.build b/meson.build
index a45f1a844f13..179e92aa7ae1 100644
--- a/meson.build
+++ b/meson.build
@@ -2358,6 +2358,9 @@ if xkbcommon.found()
dependencies: [qemuutil, xkbcommon], install:
have_tools)
endif
+qemu_modinfo = executable('qemu-modinfo', files('qemu-modinfo.c') + genh,
+ dependencies: [glib], install: have_tools)
+
if have_tools
qemu_img = executable('qemu-img', [files('qemu-img.c'), hxdep],
dependencies: [authz, block, crypto, io, qom, qemuutil], install:
true)
--
2.31.1
- [PATCH 0/9] [RFC] store module metadata in .modinfo elf section, Gerd Hoffmann, 2021/06/02
- [PATCH 3/9] virtio-gpu module annotations, Gerd Hoffmann, 2021/06/02
- [PATCH 2/9] add qemu-modinfo utility,
Gerd Hoffmann <=
- [PATCH 1/9] Add module metadata macros, add qxl module annotations, Gerd Hoffmann, 2021/06/02
- [PATCH 4/9] chardev module annotations, Gerd Hoffmann, 2021/06/02
- [PATCH 6/9] usb-redir module annotations, Gerd Hoffmann, 2021/06/02
- [PATCH 5/9] audio module annotations, Gerd Hoffmann, 2021/06/02
- [PATCH 8/9] ui module annotations, Gerd Hoffmann, 2021/06/02
- [PATCH 9/9] s390x module annotations, Gerd Hoffmann, 2021/06/02
- [PATCH 7/9] ccid module annotations, Gerd Hoffmann, 2021/06/02