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authorDenis Vlasenko2009-03-29 16:38:59 +0000
committerDenis Vlasenko2009-03-29 16:38:59 +0000
commite1de3af9892a89156c109befa13403359ee8568f (patch)
treec95c223c13eaa470f6749b064e2c6379c1cae138
parentfd303b11efb2c87ed239b36c432566a36f859c8e (diff)
downloadbusybox-e1de3af9892a89156c109befa13403359ee8568f.zip
busybox-e1de3af9892a89156c109befa13403359ee8568f.tar.gz
module loading for 2.4: use fd-based io instead of FILE based;
use xlseek and xread; simpler check for ELF signature. text data bss dec hex filename 824460 476 7616 832552 cb428 busybox_old 824333 476 7616 832425 cb3a9 busybox_unstripped
-rw-r--r--modutils/modutils-24.c62
1 files changed, 27 insertions, 35 deletions
diff --git a/modutils/modutils-24.c b/modutils/modutils-24.c
index 169fe54..89bc30f 100644
--- a/modutils/modutils-24.c
+++ b/modutils/modutils-24.c
@@ -625,7 +625,7 @@ static unsigned long obj_load_size(struct obj_file *f);
static int obj_relocate(struct obj_file *f, ElfW(Addr) base);
-static struct obj_file *obj_load(FILE *f, int loadprogbits);
+static struct obj_file *obj_load(int fd, int loadprogbits);
static int obj_create_image(struct obj_file *f, char *image);
@@ -3191,8 +3191,13 @@ static int obj_create_image(struct obj_file *f, char *image)
/*======================================================================*/
-static struct obj_file *obj_load(FILE *fp, int loadprogbits UNUSED_PARAM)
+static struct obj_file *obj_load(int fd, int loadprogbits UNUSED_PARAM)
{
+#if BB_LITTLE_ENDIAN
+# define ELFMAG_U32 ((uint32_t)(ELFMAG0 + 0x100 * (ELFMAG1 + (0x100 * (ELFMAG2 + 0x100 * ELFMAG3)))))
+#else
+# define ELFMAG_U32 ((uint32_t)((((ELFMAG0 * 0x100) + ELFMAG1) * 0x100 + ELFMAG2) * 0x100 + ELFMAG3))
+#endif
struct obj_file *f;
ElfW(Shdr) * section_headers;
size_t shnum, i;
@@ -3205,16 +3210,10 @@ static struct obj_file *obj_load(FILE *fp, int loadprogbits UNUSED_PARAM)
f->symbol_hash = obj_elf_hash;
f->load_order_search_start = &f->load_order;
- fseek(fp, 0, SEEK_SET);
- if (fread(&f->header, sizeof(f->header), 1, fp) != 1) {
- bb_perror_msg_and_die("error reading ELF header");
- }
+ xlseek(fd, 0, SEEK_SET);
+ xread(fd, &f->header, sizeof(f->header));
- if (f->header.e_ident[EI_MAG0] != ELFMAG0
- || f->header.e_ident[EI_MAG1] != ELFMAG1
- || f->header.e_ident[EI_MAG2] != ELFMAG2
- || f->header.e_ident[EI_MAG3] != ELFMAG3
- ) {
+ if (*(uint32_t*)(&f->header.e_ident) != ELFMAG_U32) {
bb_error_msg_and_die("not an ELF file");
}
if (f->header.e_ident[EI_CLASS] != ELFCLASSM
@@ -3243,10 +3242,8 @@ static struct obj_file *obj_load(FILE *fp, int loadprogbits UNUSED_PARAM)
f->sections = xzalloc(sizeof(f->sections[0]) * (shnum + 4));
section_headers = alloca(sizeof(ElfW(Shdr)) * shnum);
- fseek(fp, f->header.e_shoff, SEEK_SET);
- if (fread(section_headers, sizeof(ElfW(Shdr)), shnum, fp) != shnum) {
- bb_perror_msg_and_die("error reading ELF section headers");
- }
+ xlseek(fd, f->header.e_shoff, SEEK_SET);
+ xread(fd, section_headers, sizeof(ElfW(Shdr)) * shnum);
/* Read the section data. */
@@ -3278,10 +3275,8 @@ static struct obj_file *obj_load(FILE *fp, int loadprogbits UNUSED_PARAM)
sec->contents = NULL;
if (sec->header.sh_size > 0) {
sec->contents = xmalloc(sec->header.sh_size);
- fseek(fp, sec->header.sh_offset, SEEK_SET);
- if (fread(sec->contents, sec->header.sh_size, 1, fp) != 1) {
- bb_perror_msg_and_die("error reading ELF section data");
- }
+ xlseek(fd, sec->header.sh_offset, SEEK_SET);
+ xread(fd, sec->contents, sec->header.sh_size);
}
break;
#if SHT_RELM == SHT_REL
@@ -3397,27 +3392,24 @@ static struct obj_file *obj_load(FILE *fp, int loadprogbits UNUSED_PARAM)
* kernel for the module
*/
-static int obj_load_progbits(FILE *fp, struct obj_file *f, char *imagebase)
+static int obj_load_progbits(int fd, struct obj_file *f, char *imagebase)
{
ElfW(Addr) base = f->baseaddr;
struct obj_section* sec;
for (sec = f->load_order; sec; sec = sec->load_next) {
-
/* section already loaded? */
if (sec->contents != NULL)
continue;
-
if (sec->header.sh_size == 0)
continue;
-
sec->contents = imagebase + (sec->header.sh_addr - base);
- fseek(fp, sec->header.sh_offset, SEEK_SET);
- if (fread(sec->contents, sec->header.sh_size, 1, fp) != 1) {
+ xlseek(fd, sec->header.sh_offset, SEEK_SET);
+ errno = 0; /* read may be short without errno being set */
+ if (full_read(fd, sec->contents, sec->header.sh_size) != sec->header.sh_size) {
bb_perror_msg("error reading ELF section data");
return 0;
}
-
}
return 1;
}
@@ -3779,22 +3771,23 @@ int FAST_FUNC bb_init_module_24(const char *m_filename, const char *options)
struct utsname uts;
int exit_status = EXIT_FAILURE;
int m_has_modinfo;
- char *m_name;
+ char *m_name, *p;
#if ENABLE_FEATURE_INSMOD_VERSION_CHECKING
char m_strversion[STRVERSIONLEN];
int m_version, m_crcs;
#endif
- FILE *fp;
+ int fd;
uname(&uts);
- fp = fopen_for_read(m_filename);
- if (fp == NULL)
+ fd = open_or_warn(m_filename, O_RDONLY);
+ if (fd < 0)
return EXIT_FAILURE;
m_name = xstrdup(bb_basename(m_filename));
- *strrchr(m_name, '.') = 0;
+ p = strrchr(m_name, '.');
+ if (p) *p = '\0';
- f = obj_load(fp, LOADBITS);
+ f = obj_load(fd, LOADBITS);
m_has_modinfo = (get_modinfo_value(f, "kernel_version") != NULL);
@@ -3876,7 +3869,7 @@ int FAST_FUNC bb_init_module_24(const char *m_filename, const char *options)
* the PROGBITS section was not loaded by the obj_load
* now we can load them directly into the kernel memory
*/
- if (!obj_load_progbits(fp, f, (char*)m_addr)) {
+ if (!obj_load_progbits(fd, f, (char*)m_addr)) {
delete_module(m_name, 0);
goto out;
}
@@ -3898,8 +3891,7 @@ int FAST_FUNC bb_init_module_24(const char *m_filename, const char *options)
exit_status = EXIT_SUCCESS;
out:
- if (fp)
- fclose(fp);
+ close(fd);
free(m_name);
return exit_status;