static char *module_get_string(struct module *mod, const size_t name) {
// If strings table is empty we shouldn't ask for symbol's name
TRY_PTR(mod->strings);
TRY_TRUE(name < mod->strings_sz);
return mod->strings + name;
CATCH:
return NULL;
}
static uintptr_t module_get_symbol_addr(struct module *mod,
const symbol_t *symbol, const uint32_t type) {
// We skip symbols from special sections and those of not matching type
if (IS_VALID_SHNDX(symbol->st_shndx)
&& (SYM_ST_INFO(symbol->st_info) & type)) {
struct section *section;
TRY_PTR(section = module_get_section(mod, symbol->st_shndx));
return section->addr + symbol->st_value;
}
CATCH:
return 0;
}
static int do_relocation(struct module *mod, struct section *dest_section,
const Elf32_Rel *relocation, getsym_t getsym_fun, void *getsym_arg ) {
size_t symbol_idx = ELF32_R_SYM(relocation->r_info);
TRY_TRUE(symbol_idx < mod->symbols_sz);
symbol_t *symbol = mod->symbols + symbol_idx;
TRY_TRUE(!IS_RES_SHNDX(symbol->st_shndx));
TRY_TRUE(SYM_ST_INFO(symbol->st_info) & ST_ANY_ALLOWED);
uint32_t symbol_addr = 0;
if (symbol->st_shndx == SHN_UNDEF) {
const char *sym_name;
TRY_PTR(sym_name = module_get_string(mod, symbol->st_name));
symbol_addr = (uint32_t) getsym_fun(getsym_arg, sym_name);
TRY_PTR(symbol_addr);
} else {
struct section *section;
TRY_PTR(section = module_get_section(mod, symbol->st_shndx));
if (!section_is_alloc(section)) {
return 0;
}
symbol_addr = (uint32_t) (section->addr + symbol->st_value);
}
uint32_t *destination = (uint32_t *)
(dest_section->addr + relocation->r_offset);
switch (ELF32_R_TYPE(relocation->r_info)) {
case R_386_32:
*destination = *destination + symbol_addr;
break;
case R_386_PC32:
*destination = *destination + symbol_addr - (uint32_t) destination;
break;
default:
// Unrecognized relocation type encountered
TRY_TRUE(0);
}
return 0;
CATCH:
return -1;
}
static inline __must_check int initFreeMinorNumbersPool(void) {
int i;
LOCK_MINOR_NUMBERS_POOL();
TRY_PTR(OR_GOTO(fail), freeMinorNumbers, kmalloc(XORDEV_MAX_DEVS * sizeof(int), GFP_KERNEL),
"allocate character device minor numbers pool");
for (i = 0; i < XORDEV_MAX_DEVS; ++i) {
freeMinorNumbers[i] = 3 * i;
}
UNLOCK_MINOR_NUMBERS_POOL();
return 0;
fail:
UNLOCK_MINOR_NUMBERS_POOL();
return -ENOMEM;
}
static inline __must_check int setup3DeviceDataStructures(struct xordev *dev,
int minorNumber) {
int i;
struct semaphore *mutex;
TRY_PTR(OR_RETURN(-ENOMEM), mutex, kmalloc(sizeof(struct semaphore), GFP_KERNEL),
"allocate memory for mutex for device with MINOR=%d", minorNumber);
sema_init(mutex, 1);
for (i = 0; i < 3; ++i) {
printk(KERN_INFO "xordev: Setting up char device MAJOR=%d MINOR=%d", xordev_major,
minorNumber + i);
dev[i].number = MKDEV(xordev_major, minorNumber + i);
dev[i].mutex = mutex;
}
return 0;
}
static int module_read_strings(struct module *mod, const Elf32_Shdr *elf_shdr,
FILE* elf_file) {
TRY_TRUE(mod->strings == NULL);
TRY_TRUE(elf_shdr->sh_type == SHT_STRTAB);
// Assuming there is only one symbols table (which implies only one
// associated strings table)
mod->strings_sz = elf_shdr->sh_size;
// An empty string table section is permitted.
if (mod->strings_sz > 0) {
TRY_PTR(mod->strings = malloc(mod->strings_sz));
TRY_TRUE(fseek(elf_file, elf_shdr->sh_offset, SEEK_SET) == 0);
TRY_TRUE(fread(mod->strings, mod->strings_sz, 1, elf_file) == 1);
TRY_TRUE(mod->strings[0] == '\0');
TRY_TRUE(mod->strings[mod->strings_sz - 1] == '\0');
}
return 0;
CATCH:
free(mod->strings);
mod->strings = NULL;
return -1;
}
static int module_read_symbols(struct module *mod, const Elf32_Shdr *elf_shdr,
FILE* elf_file) {
TRY_TRUE(mod->symbols == NULL);
TRY_TRUE(elf_shdr->sh_type == SHT_SYMTAB);
TRY_TRUE(sizeof(Elf32_Sym) == elf_shdr->sh_entsize);
size_t rem = elf_shdr->sh_size % elf_shdr->sh_entsize;
TRY_TRUE(rem == 0);
// Assuming there is only one symbols table
TRY_TRUE(fseek(elf_file, elf_shdr->sh_offset, SEEK_SET) == 0);
mod->symbols_sz = elf_shdr->sh_size / elf_shdr->sh_entsize;
// We read symbols as Elf32_Sym but we store them internally as symbol_t
// Elf32_Sym is known only to loading code
TRY_TRUE(sizeof(Elf32_Sym) == sizeof(symbol_t));
TRY_PTR(mod->symbols = malloc(mod->symbols_sz * sizeof(symbol_t)));
TRY_TRUE(fread(mod->symbols, sizeof(symbol_t), mod->symbols_sz,
elf_file) == mod->symbols_sz);
return 0;
CATCH:
free(mod->symbols);
mod->symbols = NULL;
return -1;
}
static inline __must_check int allocQueues(struct xordev *dev) {
dev->dmaSource1 = NULL;
dev->dmaSource2 = NULL;
dev->dmaDestination = NULL;
dev->source1 = NULL;
dev->source2 = NULL;
dev->destination = NULL;
dev->dmaSize = NULL;
dev->deviceState = NULL;
dev->deviceStateSpinlock = NULL;
dev->waitSource1 = NULL;
dev->waitSource2 = NULL;
dev->waitDestination = NULL;
pci_set_master(dev->pciDev);
TRY_NORES(OR_GOTO(fail), pci_set_dma_mask(dev->pciDev, DMA_BIT_MASK(32)), "set dma mast");
TRY_PTR(OR_GOTO(fail), dev->dmaSource1PciAddr, kmalloc(sizeof(dma_addr_t), GFP_KERNEL));
TRY_PTR(OR_GOTO(fail), dev->dmaSource2PciAddr, kmalloc(sizeof(dma_addr_t), GFP_KERNEL));
TRY_PTR(OR_GOTO(fail), dev->dmaDestinationPciAddr, kmalloc(sizeof(dma_addr_t), GFP_KERNEL));
TRY_PTR(OR_GOTO(fail), dev->dmaSource1, dma_alloc_coherent(&dev->pciDev->dev, DMA_BUFFER_BYTES,
dev->dmaSource1PciAddr, GFP_KERNEL));
TRY_PTR(OR_GOTO(fail), dev->dmaSource2, dma_alloc_coherent(&dev->pciDev->dev, DMA_BUFFER_BYTES,
dev->dmaSource2PciAddr, GFP_KERNEL));
TRY_PTR(OR_GOTO(fail), dev->dmaDestination, dma_alloc_coherent(&dev->pciDev->dev, DMA_BUFFER_BYTES,
dev->dmaDestinationPciAddr, GFP_KERNEL));
TRY_PTR(OR_GOTO(fail), dev->dmaSize, kmalloc(sizeof(size_t), GFP_KERNEL));
TRY_PTR(OR_GOTO(fail), dev->deviceState, kmalloc(sizeof(int), GFP_KERNEL));
*dev->deviceState = DEVICE_UNOCCUPIED;
TRY_PTR(OR_GOTO(fail), dev->deviceStateSpinlock, kmalloc(sizeof(spinlock_t), GFP_KERNEL));
spin_lock_init(dev->deviceStateSpinlock);
TRY_PTR(OR_GOTO(fail), dev->waitSource1, kmalloc(sizeof(wait_queue_t), GFP_KERNEL));
init_waitqueue_head(dev->waitSource1);
TRY_PTR(OR_GOTO(fail), dev->waitSource2, kmalloc(sizeof(wait_queue_t), GFP_KERNEL));
init_waitqueue_head(dev->waitSource2);
TRY_PTR(OR_GOTO(fail), dev->waitDestination, kmalloc(sizeof(wait_queue_t), GFP_KERNEL));
init_waitqueue_head(dev->waitDestination);
TRY_NORES(OR_GOTO(fail), memfifoNew(&dev->source1), "create source1 memory queue");
TRY_NORES(OR_GOTO(fail), memfifoNew(&dev->source2), "create source2 memory queue");
TRY_NORES(OR_GOTO(fail), memfifoNew(&dev->destination), "create destination memory queue");
TRY_NORES(OR_GOTO(fail), pci_request_region(dev->pciDev, 0, "xordev"), "request BAR0");
TRY_PTR(OR_GOTO(fail), dev->bar0, pci_iomap(dev->pciDev, 0, BAR0_SIZE), "map pci iomem");
return 0;
fail:
memfifoDelete(&dev->destination);
memfifoDelete(&dev->source2);
memfifoDelete(&dev->source1);
return -ENOMEM;
}
/* export { */
struct module *module_load(const char *filename, getsym_t getsym_fun,
void *getsym_arg) {
FILE* elf_file = NULL;
Elf32_Shdr *section_headers = NULL;
struct module *mod = NULL;
TRY_PTR(mod = malloc(sizeof(struct module)));
module_init(mod);
TRY_PTR(elf_file = fopen(filename, "rb"));
Elf32_Ehdr elf_header;
TRY_TRUE(fread(&elf_header, sizeof(Elf32_Ehdr), 1, elf_file) == 1);
TRY_TRUE(elf_header.e_ident[EI_MAG0] == ELFMAG0
&& elf_header.e_ident[EI_MAG1] == ELFMAG1
&& elf_header.e_ident[EI_MAG2] == ELFMAG2
&& elf_header.e_ident[EI_MAG3] == ELFMAG3);
TRY_TRUE(elf_header.e_ident[EI_CLASS] == ELFCLASS32);
TRY_TRUE(elf_header.e_ident[EI_DATA] == ELFDATA2LSB);
TRY_TRUE(elf_header.e_type == ET_REL);
TRY_TRUE(elf_header.e_machine == EM_386);
TRY_PTR(elf_header.e_shoff);
TRY_TRUE(fseek(elf_file, elf_header.e_shoff, SEEK_SET) == 0);
TRY_TRUE(elf_header.e_shentsize == sizeof(Elf32_Shdr));
// If the number of sections is greater than or equal to SHN_LORESERVE
// (0xff00), e_shnum has the value SHN_UNDEF (0) and the actual number of
// section header table entries is contained in the sh_size field of the
// section header at index 0
// We do not handle this extension
TRY_TRUE(elf_header.e_shnum != SHN_UNDEF);
TRY_TRUE(elf_header.e_shnum < SHN_LORESERVE);
TRY_PTR(section_headers = malloc(sizeof(Elf32_Shdr) * elf_header.e_shnum));
TRY_TRUE(fread(section_headers, elf_header.e_shentsize, elf_header.e_shnum,
elf_file) == elf_header.e_shnum);
// Count and create sections
mod->sections_sz = elf_header.e_shnum;
TRY_PTR(mod->sections = malloc(sizeof(struct section) * mod->sections_sz));
memset(mod->sections, 0, sizeof(struct section) * mod->sections_sz);
// Not actually first global but we will treat all of them as global
size_t global_sym_idx = 0;
size_t symtab_idx = 0;
// Load sections
for (size_t idx = 0; idx < elf_header.e_shnum; idx++) {
Elf32_Shdr *shdr = section_headers + idx;
struct section *section;
TRY_PTR(section = module_get_section(mod, idx));
switch (shdr->sh_type) {
case SHT_NULL:
case SHT_STRTAB:
// We will read appropriate strings table with symbols table
case SHT_REL:
// We will perform relocations later on
break;
case SHT_SYMTAB:
TRY_TRUE(symtab_idx == 0);
symtab_idx = idx;
TRY_SYS(module_read_symbols(mod, shdr, elf_file));
global_sym_idx = shdr->sh_info;
// Field sh_link contains section header index of associated string table
TRY_TRUE(IS_VALID_SHNDX(shdr->sh_link) && shdr->sh_link < elf_header.e_shnum);
TRY_SYS(module_read_strings(mod, section_headers + shdr->sh_link, elf_file));
break;
case SHT_NOBITS:
if ((shdr->sh_flags & SHF_ALLOC) && shdr->sh_size > 0) {
TRY_SYS(section_alloc(section, shdr));
memset((void *) section->addr, 0, shdr->sh_size);
}
break;
case SHT_PROGBITS:
default:
if ((shdr->sh_flags & SHF_ALLOC) && shdr->sh_size > 0) {
TRY_SYS(section_alloc(section, shdr));
TRY_TRUE(fseek(elf_file, shdr->sh_offset, SEEK_SET) == 0);
TRY_TRUE(fread((void *) section->addr, shdr->sh_size, 1, elf_file) == 1);
}
break;
}
}
// An empty string table section is permitted.
// TRY_PTR(mod->strings);
TRY_PTR(mod->symbols);
// Perform relocations
for (size_t idx = 0; idx < elf_header.e_shnum; idx++) {
Elf32_Shdr *shdr = section_headers + idx;
if (shdr->sh_type == SHT_REL && shdr->sh_link == symtab_idx) {
// mising (shdr->sh_flags & SHF_INFO_LINK)
TRY_TRUE(fseek(elf_file, shdr->sh_offset, SEEK_SET) == 0);
TRY_TRUE(sizeof(Elf32_Rel) == shdr->sh_entsize);
size_t rel_num = shdr->sh_size / shdr->sh_entsize;
TRY_TRUE(shdr->sh_size == rel_num * shdr->sh_entsize);
struct section *dest_section;
TRY_PTR(dest_section = module_get_section(mod, shdr->sh_info));
if (section_is_alloc(dest_section)) {
for (size_t idx = 0; idx < rel_num; idx++) {
Elf32_Rel relocation;
TRY_TRUE(fread(&relocation, sizeof(Elf32_Rel), 1, elf_file) == 1);
TRY_SYS(do_relocation(mod, dest_section, &relocation, getsym_fun,
getsym_arg));
}
}
}
}
// Compress symbol table (remove local symbols after relocations)
TRY_TRUE(global_sym_idx < mod->symbols_sz);
mod->symbols_sz -= global_sym_idx;
memmove(mod->symbols, mod->symbols + global_sym_idx,
mod->symbols_sz * sizeof(symbol_t));
TRY_PTR(mod->symbols = realloc(mod->symbols,
mod->symbols_sz * sizeof(symbol_t)));
// Set-up sections protection
for (size_t idx = 0; idx < elf_header.e_shnum; idx++) {
struct section *section;
TRY_PTR(section = module_get_section(mod, idx));
if (section_is_alloc(section)) {
TRY_SYS(mprotect((void *) section->mmap_start, section->mmap_length,
section->mmap_prot));
}
}
free(section_headers);
fclose(elf_file);
return mod;
CATCH:
free(section_headers);
if (elf_file) {
fclose(elf_file);
}
module_unload(mod);
return NULL;
}
