dt_module_update(dtrace_hdl_t *dtp, struct kld_file_stat *k_stat)
#endif
{
char fname[MAXPATHLEN];
struct stat64 st;
int fd, err, bits;
dt_module_t *dmp;
const char *s;
size_t shstrs;
GElf_Shdr sh;
Elf_Data *dp;
Elf_Scn *sp;
#if defined(sun)
(void) snprintf(fname, sizeof (fname),
"%s/%s/object", OBJFS_ROOT, name);
#else
GElf_Ehdr ehdr;
GElf_Phdr ph;
char name[MAXPATHLEN];
uintptr_t mapbase, alignmask;
int i = 0;
int is_elf_obj;
(void) strlcpy(name, k_stat->name, sizeof(name));
(void) strlcpy(fname, k_stat->pathname, sizeof(fname));
#endif
if ((fd = open(fname, O_RDONLY)) == -1 || fstat64(fd, &st) == -1 ||
(dmp = dt_module_create(dtp, name)) == NULL) {
dt_dprintf("failed to open %s: %s\n", fname, strerror(errno));
(void) close(fd);
return;
}
/*
* Since the module can unload out from under us (and /system/object
* will return ENOENT), tell libelf to cook the entire file now and
* then close the underlying file descriptor immediately. If this
* succeeds, we know that we can continue safely using dmp->dm_elf.
*/
dmp->dm_elf = elf_begin(fd, ELF_C_READ, NULL);
err = elf_cntl(dmp->dm_elf, ELF_C_FDREAD);
(void) close(fd);
if (dmp->dm_elf == NULL || err == -1 ||
elf_getshdrstrndx(dmp->dm_elf, &shstrs) == -1) {
dt_dprintf("failed to load %s: %s\n",
fname, elf_errmsg(elf_errno()));
dt_module_destroy(dtp, dmp);
return;
}
switch (gelf_getclass(dmp->dm_elf)) {
case ELFCLASS32:
dmp->dm_ops = &dt_modops_32;
bits = 32;
break;
case ELFCLASS64:
dmp->dm_ops = &dt_modops_64;
bits = 64;
break;
default:
dt_dprintf("failed to load %s: unknown ELF class\n", fname);
dt_module_destroy(dtp, dmp);
return;
}
#if defined(__FreeBSD__)
mapbase = (uintptr_t)k_stat->address;
gelf_getehdr(dmp->dm_elf, &ehdr);
is_elf_obj = (ehdr.e_type == ET_REL);
if (is_elf_obj) {
dmp->dm_sec_offsets =
malloc(ehdr.e_shnum * sizeof(*dmp->dm_sec_offsets));
if (dmp->dm_sec_offsets == NULL) {
dt_dprintf("failed to allocate memory\n");
dt_module_destroy(dtp, dmp);
return;
}
}
#endif
/*
* Iterate over the section headers locating various sections of
* interest and use their attributes to flesh out the dt_module_t.
*/
for (sp = NULL; (sp = elf_nextscn(dmp->dm_elf, sp)) != NULL; ) {
if (gelf_getshdr(sp, &sh) == NULL || sh.sh_type == SHT_NULL ||
(s = elf_strptr(dmp->dm_elf, shstrs, sh.sh_name)) == NULL)
continue; /* skip any malformed sections */
#if defined(__FreeBSD__)
if (sh.sh_size == 0)
continue;
if (sh.sh_type == SHT_PROGBITS || sh.sh_type == SHT_NOBITS) {
alignmask = sh.sh_addralign - 1;
mapbase += alignmask;
mapbase &= ~alignmask;
sh.sh_addr = mapbase;
if (is_elf_obj)
dmp->dm_sec_offsets[elf_ndxscn(sp)] = sh.sh_addr;
mapbase += sh.sh_size;
}
#endif
if (strcmp(s, ".text") == 0) {
dmp->dm_text_size = sh.sh_size;
dmp->dm_text_va = sh.sh_addr;
} else if (strcmp(s, ".data") == 0) {
dmp->dm_data_size = sh.sh_size;
dmp->dm_data_va = sh.sh_addr;
} else if (strcmp(s, ".bss") == 0) {
dmp->dm_bss_size = sh.sh_size;
dmp->dm_bss_va = sh.sh_addr;
} else if (strcmp(s, ".info") == 0 &&
(dp = elf_getdata(sp, NULL)) != NULL) {
bcopy(dp->d_buf, &dmp->dm_info,
MIN(sh.sh_size, sizeof (dmp->dm_info)));
} else if (strcmp(s, ".filename") == 0 &&
(dp = elf_getdata(sp, NULL)) != NULL) {
(void) strlcpy(dmp->dm_file,
dp->d_buf, sizeof (dmp->dm_file));
}
}
dmp->dm_flags |= DT_DM_KERNEL;
#if defined(sun)
dmp->dm_modid = (int)OBJFS_MODID(st.st_ino);
#else
/*
* Include .rodata and special sections into .text.
* This depends on default section layout produced by GNU ld
* for ELF objects and libraries:
* [Text][R/O data][R/W data][Dynamic][BSS][Non loadable]
*/
dmp->dm_text_size = dmp->dm_data_va - dmp->dm_text_va;
#if defined(__i386__)
/*
* Find the first load section and figure out the relocation
* offset for the symbols. The kernel module will not need
* relocation, but the kernel linker modules will.
*/
for (i = 0; gelf_getphdr(dmp->dm_elf, i, &ph) != NULL; i++) {
if (ph.p_type == PT_LOAD) {
dmp->dm_reloc_offset = k_stat->address - ph.p_vaddr;
break;
}
}
#endif
#endif
if (dmp->dm_info.objfs_info_primary)
dmp->dm_flags |= DT_DM_PRIMARY;
dt_dprintf("opened %d-bit module %s (%s) [%d]\n",
bits, dmp->dm_name, dmp->dm_file, dmp->dm_modid);
}
/*
* Update our module cache by adding an entry for the specified module 'name'.
* We create the dt_module_t and populate it using /system/object/<name>/.
*/
static void
dt_module_update(dtrace_hdl_t *dtp, const char *name)
{
char fname[MAXPATHLEN];
struct stat64 st;
int fd, err, bits;
dt_module_t *dmp;
const char *s;
size_t shstrs;
GElf_Shdr sh;
Elf_Data *dp;
Elf_Scn *sp;
unsigned read_cmd = ELF_C_READ;
if (0 == strcmp("mach_kernel", name)) {
if (dtrace_kernel_path(fname, sizeof(fname)) != 0) {
dt_dprintf("failed to retrieve the kernel binary, the module cache will not be updated\n");
return;
}
read_cmd = ELF_C_RDKERNTYPE;
}
if ((fd = open(fname, O_RDONLY)) == -1 || fstat64(fd, &st) == -1 ||
(dmp = dt_module_create(dtp, name)) == NULL) {
dt_dprintf("failed to open %s: %s\n", fname, strerror(errno));
(void) close(fd);
return;
}
/*
* Since the module can unload out from under us (and /system/object
* will return ENOENT), tell libelf to cook the entire file now and
* then close the underlying file descriptor immediately. If this
* succeeds, we know that we can continue safely using dmp->dm_elf.
*/
dmp->dm_elf = elf_begin(fd, read_cmd, NULL);
err = elf_cntl(dmp->dm_elf, ELF_C_FDREAD);
(void) close(fd);
if (dmp->dm_elf == NULL || err == -1 ||
elf_getshstrndx(dmp->dm_elf, &shstrs) == 0) {
dt_dprintf("failed to load %s: %s\n",
fname, elf_errmsg(elf_errno()));
dt_module_destroy(dtp, dmp);
return;
}
switch (gelf_getclass(dmp->dm_elf)) {
case ELFCLASS32:
dmp->dm_ops = (dmp->dm_elf->ed_kind == ELF_K_MACHO ? &dt_modops_macho_32 : &dt_modops_32);
bits = 32;
break;
case ELFCLASS64:
dmp->dm_ops = (dmp->dm_elf->ed_kind == ELF_K_MACHO ? &dt_modops_macho_64 : &dt_modops_64);
bits = 64;
break;
default:
dt_dprintf("failed to load %s: unknown ELF class\n", fname);
dt_module_destroy(dtp, dmp);
return;
}
/*
* Iterate over the section headers locating various sections of
* interest and use their attributes to flesh out the dt_module_t.
*/
for (sp = NULL; (sp = elf_nextscn(dmp->dm_elf, sp)) != NULL; ) {
if (gelf_getshdr(sp, &sh) == NULL || sh.sh_type == SHT_NULL ||
(s = elf_strptr(dmp->dm_elf, shstrs, sh.sh_name)) == NULL)
continue; /* skip any malformed sections */
if (strcmp(s, ".text") == 0) {
dmp->dm_text_size = sh.sh_size;
dmp->dm_text_va = sh.sh_addr;
} else if (strcmp(s, ".data") == 0) {
dmp->dm_data_size = sh.sh_size;
dmp->dm_data_va = sh.sh_addr;
} else if (strcmp(s, ".bss") == 0) {
dmp->dm_bss_size = sh.sh_size;
dmp->dm_bss_va = sh.sh_addr;
} else if (strcmp(s, ".info") == 0 &&
(dp = elf_getdata(sp, NULL)) != NULL) {
bcopy(dp->d_buf, &dmp->dm_info,
MIN(sh.sh_size, sizeof (dmp->dm_info)));
} else if (strcmp(s, ".filename") == 0 &&
(dp = elf_getdata(sp, NULL)) != NULL) {
(void) strlcpy(dmp->dm_file,
dp->d_buf, sizeof (dmp->dm_file));
}
}
dmp->dm_flags |= DT_DM_KERNEL;
dmp->dm_modid = (int)OBJFS_MODID(st.st_ino);
if (dmp->dm_info.objfs_info_primary)
dmp->dm_flags |= DT_DM_PRIMARY;
dt_dprintf("opened %d-bit module %s (%s) [%d]\n",
bits, dmp->dm_name, dmp->dm_file, dmp->dm_modid);
}
