Combines three duplicate and almost-duplicate implementations in
modinfo.c, modprobe.c and moduleops_core.c
The new version gets endianness swapping from the implementation in
modinfo.c and bounds checking from the implementation in modprobe.
Signed-off-by: Andreas Robinson <andr345@xxxxxxxxx>
---
elf_core.c | 43 ++++++++++++++++++++++++++++++
modinfo.c | 53 +-------------------------------------
modprobe.c | 76 +++---------------------------------------------------
moduleops_core.c | 21 +-------------
util.c | 28 ++++++++++++++++++++
util.h | 6 ++++
6 files changed, 84 insertions(+), 143 deletions(-)
create mode 100644 elf_core.c
diff --git a/elf_core.c b/elf_core.c
new file mode 100644
index 0000000..1525c36
--- /dev/null
+++ b/elf_core.c
@@ -0,0 +1,43 @@
+void *PERBIT(get_section)(void *file,
+ unsigned long fsize,
+ const char *secname,
+ unsigned long *secsize,
+ int conv)
+{
+ ElfPERBIT(Ehdr) *hdr;
+ ElfPERBIT(Shdr) *sechdrs;
+ ElfPERBIT(Off) e_shoff;
+ ElfPERBIT(Half) e_shnum, e_shstrndx;
+
+ const char *secnames;
+ unsigned int i;
+
+ if (fsize > 0 && fsize < sizeof(*hdr))
+ return NULL;
+
+ hdr = file;
+ e_shoff = END(hdr->e_shoff, conv);
+ e_shnum = END(hdr->e_shnum, conv);
+ e_shstrndx = END(hdr->e_shstrndx, conv);
+
+ if (fsize > 0 && fsize < e_shoff + e_shnum * sizeof(sechdrs[0]))
+ return NULL;
+
+ sechdrs = file + e_shoff;
+
+ if (fsize > 0 && fsize < END(sechdrs[e_shstrndx].sh_offset, conv))
+ return NULL;
+
+ /* Find section by name, return pointer and size. */
+
+ secnames = file + END(sechdrs[e_shstrndx].sh_offset, conv);
+ for (i = 1; i < e_shnum; i++) {
+ if (streq(secnames + END(sechdrs[i].sh_name, conv), secname)) {
+ *secsize = END(sechdrs[i].sh_size, conv);
+ return file + END(sechdrs[i].sh_offset, conv);
+ }
+ }
+ *secsize = 0;
+ return NULL;
+}
+
diff --git a/modinfo.c b/modinfo.c
index 81e40f4..07199c2 100644
--- a/modinfo.c
+++ b/modinfo.c
@@ -21,57 +21,6 @@
#define MODULE_DIR "/lib/modules"
#endif
-static int elf_conv;
-
-#define TO_NATIVE(x) END(x, elf_conv)
-
-static void *get_section32(void *file, unsigned long *size, const char *name)
-{
- Elf32_Ehdr *hdr = file;
- Elf32_Shdr *sechdrs = file + TO_NATIVE(hdr->e_shoff);
- const char *secnames;
- unsigned int i;
-
- secnames = file
- + TO_NATIVE(sechdrs[TO_NATIVE(hdr->e_shstrndx)].sh_offset);
- for (i = 1; i < TO_NATIVE(hdr->e_shnum); i++)
- if (streq(secnames + TO_NATIVE(sechdrs[i].sh_name), name)) {
- *size = TO_NATIVE(sechdrs[i].sh_size);
- return file + TO_NATIVE(sechdrs[i].sh_offset);
- }
- return NULL;
-}
-
-static void *get_section64(void *file, unsigned long *size, const char *name)
-{
- Elf64_Ehdr *hdr = file;
- Elf64_Shdr *sechdrs = file + TO_NATIVE(hdr->e_shoff);
- const char *secnames;
- unsigned int i;
-
- secnames = file
- + TO_NATIVE(sechdrs[TO_NATIVE(hdr->e_shstrndx)].sh_offset);
- for (i = 1; i < TO_NATIVE(hdr->e_shnum); i++)
- if (streq(secnames + TO_NATIVE(sechdrs[i].sh_name), name)) {
- *size = TO_NATIVE(sechdrs[i].sh_size);
- return file + TO_NATIVE(sechdrs[i].sh_offset);
- }
- return NULL;
-}
-
-static void *get_section(void *file, unsigned long filesize,
- unsigned long *size, const char *name)
-{
- switch (elf_ident(file, filesize, &elf_conv)) {
- case ELFCLASS32:
- return get_section32(file, size, name);
- case ELFCLASS64:
- return get_section64(file, size, name);
- default:
- return NULL;
- }
-}
-
struct param
{
struct param *next;
@@ -367,7 +316,7 @@ int main(int argc, char *argv[])
continue;
}
- info = get_section(mod, modulesize, &infosize, ".modinfo");
+ info = get_section(mod, modulesize, ".modinfo", &infosize);
if (!info) {
release_file(mod, modulesize);
free(filename);
diff --git a/modprobe.c b/modprobe.c
index 9d7153e..c2d0ef6 100644
--- a/modprobe.c
+++ b/modprobe.c
@@ -303,75 +303,6 @@ static void replace_modname(struct module *module,
warn("Could not find old name in %s to replace!\n", module->filename);
}
-static void *get_section32(void *file,
- unsigned long size,
- const char *name,
- unsigned long *secsize)
-{
- Elf32_Ehdr *hdr = file;
- Elf32_Shdr *sechdrs = file + hdr->e_shoff;
- const char *secnames;
- unsigned int i;
-
- /* Too short? */
- if (size < sizeof(*hdr))
- return NULL;
- if (size < hdr->e_shoff + hdr->e_shnum * sizeof(sechdrs[0]))
- return NULL;
- if (size < sechdrs[hdr->e_shstrndx].sh_offset)
- return NULL;
-
- secnames = file + sechdrs[hdr->e_shstrndx].sh_offset;
- for (i = 1; i < hdr->e_shnum; i++)
- if (streq(secnames + sechdrs[i].sh_name, name)) {
- *secsize = sechdrs[i].sh_size;
- return file + sechdrs[i].sh_offset;
- }
- return NULL;
-}
-
-static void *get_section64(void *file,
- unsigned long size,
- const char *name,
- unsigned long *secsize)
-{
- Elf64_Ehdr *hdr = file;
- Elf64_Shdr *sechdrs = file + hdr->e_shoff;
- const char *secnames;
- unsigned int i;
-
- /* Too short? */
- if (size < sizeof(*hdr))
- return NULL;
- if (size < hdr->e_shoff + hdr->e_shnum * sizeof(sechdrs[0]))
- return NULL;
- if (size < sechdrs[hdr->e_shstrndx].sh_offset)
- return NULL;
-
- secnames = file + sechdrs[hdr->e_shstrndx].sh_offset;
- for (i = 1; i < hdr->e_shnum; i++)
- if (streq(secnames + sechdrs[i].sh_name, name)) {
- *secsize = sechdrs[i].sh_size;
- return file + sechdrs[i].sh_offset;
- }
- return NULL;
-}
-
-static void *get_section(void *file,
- unsigned long size,
- const char *name,
- unsigned long *secsize)
-{
- switch (elf_ident(file, size, NULL)) {
- case ELFCLASS32:
- return get_section32(file, size, name, secsize);
- case ELFCLASS64:
- return get_section64(file, size, name, secsize);
- default:
- return NULL;
- }
-}
-
static void rename_module(struct module *module,
void *mod,
unsigned long len,
@@ -921,14 +852,15 @@ void dump_modversions(const char *filename, errfn_t error)
struct modver32_info *info32;
struct modver64_info *info64;
int n;
+ int conv;
if (!file) {
error("%s: %s\n", filename, strerror(errno));
return;
}
- switch (elf_ident(file, size, NULL)) {
+ switch (elf_ident(file, size, &conv)) {
case ELFCLASS32:
- info32 = get_section32(file, size, "__versions", &secsize);
+ info32 = get_section32(file, size, "__versions", &secsize, conv);
if (!info32)
return; /* Does not seem to be a kernel module */
if (secsize % sizeof(struct modver32_info))
@@ -939,7 +871,7 @@ void dump_modversions(const char *filename, errfn_t error)
break;
case ELFCLASS64:
- info64 = get_section64(file, size, "__versions", &secsize);
+ info64 = get_section64(file, size, "__versions", &secsize, conv);
if (!info64)
return; /* Does not seem to be a kernel module */
if (secsize % sizeof(struct modver64_info))
diff --git a/moduleops_core.c b/moduleops_core.c
index d11457e..0313e27 100644
--- a/moduleops_core.c
+++ b/moduleops_core.c
@@ -1,27 +1,10 @@
/* Load the given section: NULL on error. */
static void *PERBIT(load_section)(ElfPERBIT(Ehdr) *hdr,
const char *secname,
- unsigned long *size,
+ unsigned long *secsize,
int conv)
{
- ElfPERBIT(Shdr) *sechdrs;
- unsigned int i;
- char *secnames;
-
- /* Grab section headers and strings so we can tell who is who */
- sechdrs = (void *)hdr + END(hdr->e_shoff, conv);
- secnames = (void *)hdr
- + END(sechdrs[END(hdr->e_shstrndx, conv)].sh_offset, conv);
-
- /* Find the section they want */
- for (i = 1; i < END(hdr->e_shnum, conv); i++) {
- if (streq(secnames+END(sechdrs[i].sh_name, conv), secname)) {
- *size = END(sechdrs[i].sh_size, conv);
- return (void *)hdr + END(sechdrs[i].sh_offset, conv);
- }
- }
- *size = 0;
- return NULL;
+ return PERBIT(get_section)(hdr, 0, secname, secsize, conv);
}
static void PERBIT(load_symbols)(struct module *module)
diff --git a/util.c b/util.c
index c4515a4..0ee6064 100644
--- a/util.c
+++ b/util.c
@@ -162,3 +162,31 @@ int elf_ident(void *file, unsigned long fsize, int *conv)
*conv = native_endianness() != ident[EI_DATA];
return ident[EI_CLASS];
}
+
+#define PERBIT(x) x##32
+#define ElfPERBIT(x) Elf32_##x
+#define ELFPERBIT(x) ELF32_##x
+#include "elf_core.c"
+
+#undef PERBIT
+#undef ElfPERBIT
+#undef ELFPERBIT
+#define PERBIT(x) x##64
+#define ElfPERBIT(x) Elf64_##x
+#define ELFPERBIT(x) ELF64_##x
+#include "elf_core.c"
+
+void *get_section(void *file, unsigned long filesize,
+ const char *secname, unsigned long *secsize)
+{
+ int conv;
+
+ switch (elf_ident(file, filesize, &conv)) {
+ case ELFCLASS32:
+ return get_section32(file, filesize, secname, secsize, conv);
+ case ELFCLASS64:
+ return get_section64(file, filesize, secname, secsize, conv);
+ default:
+ return NULL;
+ }
+}
diff --git a/util.h b/util.h
index b545b3a..c73ad21 100644
--- a/util.h
+++ b/util.h
@@ -31,6 +31,12 @@ 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);
+void *get_section(void *file, unsigned long filesize,
+ const char *secname, unsigned long *secsize);
+void *get_section32(void *file, unsigned long filesize,
+ const char *secname, unsigned long *secsize, int conv);
+void *get_section64(void *file, unsigned long filesize,
+ const char *secname, unsigned long *secsize, int conv);
#define streq(a,b) (strcmp((a),(b)) == 0)
#define strstarts(a,start) (strncmp((a),(start), strlen(start)) == 0)
--
1.5.6.3
--
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