Combines three slightly different implementations found in
depmod.c, modprobe.c and modinfo.c.
This new version will return error codes and optionally also
return the file endianness.
Signed-off-by: Andreas Robinson <andr345@xxxxxxxxx>
---
depmod.c | 22 ++++++++++------------
modinfo.c | 17 +++--------------
modprobe.c | 16 +++-------------
util.c | 20 ++++++++++++++++++++
util.h | 2 ++
5 files changed, 38 insertions(+), 39 deletions(-)
diff --git a/depmod.c b/depmod.c
index 9b6fda7..3544b89 100644
--- a/depmod.c
+++ b/depmod.c
@@ -283,25 +283,23 @@ static struct module *grab_module(const char *dirname, const char *filename)
goto fail_data;
}
- /* "\177ELF" <byte> where byte = 001 for 32-bit, 002 for 64 */
- if (memcmp(new->data, ELFMAG, SELFMAG) != 0) {
- warn("Module %s is not an elf object\n", new->pathname);
- goto fail;
- }
-
- switch (((char *)new->data)[EI_CLASS]) {
+ switch (elf_ident(new->data, new->len, &new->conv)) {
case ELFCLASS32:
new->ops = &mod_ops32;
break;
case ELFCLASS64:
new->ops = &mod_ops64;
break;
- default:
- warn("Module %s has elf unknown identifier %i\n",
- new->pathname, ((char *)new->data)[EI_CLASS]);
+ case -ENOEXEC:
+ warn("Module %s is not an elf object\n", new->pathname);
goto fail;
- }
- new->conv = ((char *)new->data)[EI_DATA] != native_endianness();
+ case -EINVAL:
+ warn("Module %s has unknown endianness\n", new->pathname);
+ goto fail;
+ default:
+ warn("Module %s has unknown word size\n", new->pathname);
+ goto fail;
+ }
return new;
fail:
diff --git a/modinfo.c b/modinfo.c
index 80e00d4..81e40f4 100644
--- a/modinfo.c
+++ b/modinfo.c
@@ -21,9 +21,9 @@
#define MODULE_DIR "/lib/modules"
#endif
-static int elf_endian;
+static int elf_conv;
-#define TO_NATIVE(x) END(x, elf_endian != native_endianness())
+#define TO_NATIVE(x) END(x, elf_conv)
static void *get_section32(void *file, unsigned long *size, const char *name)
{
@@ -59,21 +59,10 @@ static void *get_section64(void *file, unsigned long *size, const char *name)
return NULL;
}
-static int elf_ident(void *mod, unsigned long size)
-{
- /* "\177ELF" <byte> where byte = 001 for 32-bit, 002 for 64 */
- char *ident = mod;
-
- if (size < EI_CLASS || memcmp(mod, ELFMAG, SELFMAG) != 0)
- return ELFCLASSNONE;
- elf_endian = ident[EI_DATA];
- return ident[EI_CLASS];
-}
-
static void *get_section(void *file, unsigned long filesize,
unsigned long *size, const char *name)
{
- switch (elf_ident(file, filesize)) {
+ switch (elf_ident(file, filesize, &elf_conv)) {
case ELFCLASS32:
return get_section32(file, size, name);
case ELFCLASS64:
diff --git a/modprobe.c b/modprobe.c
index 8660f51..9d7153e 100644
--- a/modprobe.c
+++ b/modprobe.c
@@ -357,22 +357,12 @@ static void *get_section64(void *file,
return NULL;
}
-static int elf_ident(void *mod, unsigned long size)
-{
- /* "\177ELF" <byte> where byte = 001 for 32-bit, 002 for 64 */
- char *ident = mod;
-
- if (size < EI_CLASS || memcmp(mod, ELFMAG, SELFMAG) != 0)
- return ELFCLASSNONE;
- return ident[EI_CLASS];
-}
-
static void *get_section(void *file,
unsigned long size,
const char *name,
unsigned long *secsize)
{
- switch (elf_ident(file, size)) {
+ switch (elf_ident(file, size, NULL)) {
case ELFCLASS32:
return get_section32(file, size, name, secsize);
case ELFCLASS64:
@@ -434,7 +424,7 @@ static void strip_section(struct module *module,
unsigned long len,
const char *secname)
{
- switch (elf_ident(mod, len)) {
+ switch (elf_ident(mod, len, NULL)) {
case ELFCLASS32:
invalidate_section32(mod, secname);
break;
@@ -936,7 +926,7 @@ void dump_modversions(const char *filename, errfn_t error)
error("%s: %s\n", filename, strerror(errno));
return;
}
- switch (elf_ident(file, size)) {
+ switch (elf_ident(file, size, NULL)) {
case ELFCLASS32:
info32 = get_section32(file, size, "__versions", &secsize);
if (!info32)
diff --git a/util.c b/util.c
index 3a390f7..c4515a4 100644
--- a/util.c
+++ b/util.c
@@ -2,6 +2,8 @@
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
+#include <errno.h>
+#include <elf.h>
#include "logging.h"
#include "util.h"
@@ -142,3 +144,21 @@ int __attribute__ ((pure)) native_endianness()
*/
return (char) *((uint32_t*)("\1\0\0\2"));
}
+
+/*
+ * Check ELF file header.
+ */
+int elf_ident(void *file, unsigned long fsize, int *conv)
+{
+ /* "\177ELF" <byte> where byte = 001 for 32-bit, 002 for 64 */
+ unsigned char *ident = file;
+
+ if (fsize < EI_CLASS || memcmp(file, ELFMAG, SELFMAG) != 0)
+ return -ENOEXEC; /* Not an ELF object */
+ if (ident[EI_DATA] == 0 || ident[EI_DATA] > 2)
+ return -EINVAL; /* Unknown endianness */
+
+ if (conv != NULL)
+ *conv = native_endianness() != ident[EI_DATA];
+ return ident[EI_CLASS];
+}
diff --git a/util.h b/util.h
index 60e85e1..b545b3a 100644
--- a/util.h
+++ b/util.h
@@ -30,6 +30,8 @@ static inline void __swap_bytes(const void *src, void *dest, unsigned int size)
int native_endianness(void);
+int elf_ident(void *file, unsigned long fsize, int *conv);
+
#define streq(a,b) (strcmp((a),(b)) == 0)
#define strstarts(a,start) (strncmp((a),(start), strlen(start)) == 0)
#define my_basename(path) ((strrchr((path), '/') ?: (path) - 1) + 1)
--
1.5.6.3
--
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