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linux-zen-desktop/arch/ia64/kernel/module.c

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// SPDX-License-Identifier: GPL-2.0
/*
* IA-64-specific support for kernel module loader.
*
* Copyright (C) 2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* Loosely based on patch by Rusty Russell.
*/
/* relocs tested so far:
DIR64LSB
FPTR64LSB
GPREL22
LDXMOV
LDXMOV
LTOFF22
LTOFF22X
LTOFF22X
LTOFF_FPTR22
PCREL21B (for br.call only; br.cond is not supported out of modules!)
PCREL60B (for brl.cond only; brl.call is not supported for modules!)
PCREL64LSB
SECREL32LSB
SEGREL64LSB
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/elf.h>
#include <linux/moduleloader.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
#include <asm/patch.h>
#include <asm/unaligned.h>
#include <asm/sections.h>
#define ARCH_MODULE_DEBUG 0
#if ARCH_MODULE_DEBUG
# define DEBUGP printk
# define inline
#else
# define DEBUGP(fmt , a...)
#endif
#ifdef CONFIG_ITANIUM
# define USE_BRL 0
#else
# define USE_BRL 1
#endif
#define MAX_LTOFF ((uint64_t) (1 << 22)) /* max. allowable linkage-table offset */
/* Define some relocation helper macros/types: */
#define FORMAT_SHIFT 0
#define FORMAT_BITS 3
#define FORMAT_MASK ((1 << FORMAT_BITS) - 1)
#define VALUE_SHIFT 3
#define VALUE_BITS 5
#define VALUE_MASK ((1 << VALUE_BITS) - 1)
enum reloc_target_format {
/* direct encoded formats: */
RF_NONE = 0,
RF_INSN14 = 1,
RF_INSN22 = 2,
RF_INSN64 = 3,
RF_32MSB = 4,
RF_32LSB = 5,
RF_64MSB = 6,
RF_64LSB = 7,
/* formats that cannot be directly decoded: */
RF_INSN60,
RF_INSN21B, /* imm21 form 1 */
RF_INSN21M, /* imm21 form 2 */
RF_INSN21F /* imm21 form 3 */
};
enum reloc_value_formula {
RV_DIRECT = 4, /* S + A */
RV_GPREL = 5, /* @gprel(S + A) */
RV_LTREL = 6, /* @ltoff(S + A) */
RV_PLTREL = 7, /* @pltoff(S + A) */
RV_FPTR = 8, /* @fptr(S + A) */
RV_PCREL = 9, /* S + A - P */
RV_LTREL_FPTR = 10, /* @ltoff(@fptr(S + A)) */
RV_SEGREL = 11, /* @segrel(S + A) */
RV_SECREL = 12, /* @secrel(S + A) */
RV_BDREL = 13, /* BD + A */
RV_LTV = 14, /* S + A (like RV_DIRECT, except frozen at static link-time) */
RV_PCREL2 = 15, /* S + A - P */
RV_SPECIAL = 16, /* various (see below) */
RV_RSVD17 = 17,
RV_TPREL = 18, /* @tprel(S + A) */
RV_LTREL_TPREL = 19, /* @ltoff(@tprel(S + A)) */
RV_DTPMOD = 20, /* @dtpmod(S + A) */
RV_LTREL_DTPMOD = 21, /* @ltoff(@dtpmod(S + A)) */
RV_DTPREL = 22, /* @dtprel(S + A) */
RV_LTREL_DTPREL = 23, /* @ltoff(@dtprel(S + A)) */
RV_RSVD24 = 24,
RV_RSVD25 = 25,
RV_RSVD26 = 26,
RV_RSVD27 = 27
/* 28-31 reserved for implementation-specific purposes. */
};
#define N(reloc) [R_IA64_##reloc] = #reloc
static const char *reloc_name[256] = {
N(NONE), N(IMM14), N(IMM22), N(IMM64),
N(DIR32MSB), N(DIR32LSB), N(DIR64MSB), N(DIR64LSB),
N(GPREL22), N(GPREL64I), N(GPREL32MSB), N(GPREL32LSB),
N(GPREL64MSB), N(GPREL64LSB), N(LTOFF22), N(LTOFF64I),
N(PLTOFF22), N(PLTOFF64I), N(PLTOFF64MSB), N(PLTOFF64LSB),
N(FPTR64I), N(FPTR32MSB), N(FPTR32LSB), N(FPTR64MSB),
N(FPTR64LSB), N(PCREL60B), N(PCREL21B), N(PCREL21M),
N(PCREL21F), N(PCREL32MSB), N(PCREL32LSB), N(PCREL64MSB),
N(PCREL64LSB), N(LTOFF_FPTR22), N(LTOFF_FPTR64I), N(LTOFF_FPTR32MSB),
N(LTOFF_FPTR32LSB), N(LTOFF_FPTR64MSB), N(LTOFF_FPTR64LSB), N(SEGREL32MSB),
N(SEGREL32LSB), N(SEGREL64MSB), N(SEGREL64LSB), N(SECREL32MSB),
N(SECREL32LSB), N(SECREL64MSB), N(SECREL64LSB), N(REL32MSB),
N(REL32LSB), N(REL64MSB), N(REL64LSB), N(LTV32MSB),
N(LTV32LSB), N(LTV64MSB), N(LTV64LSB), N(PCREL21BI),
N(PCREL22), N(PCREL64I), N(IPLTMSB), N(IPLTLSB),
N(COPY), N(LTOFF22X), N(LDXMOV), N(TPREL14),
N(TPREL22), N(TPREL64I), N(TPREL64MSB), N(TPREL64LSB),
N(LTOFF_TPREL22), N(DTPMOD64MSB), N(DTPMOD64LSB), N(LTOFF_DTPMOD22),
N(DTPREL14), N(DTPREL22), N(DTPREL64I), N(DTPREL32MSB),
N(DTPREL32LSB), N(DTPREL64MSB), N(DTPREL64LSB), N(LTOFF_DTPREL22)
};
#undef N
/* Opaque struct for insns, to protect against derefs. */
struct insn;
static inline uint64_t
bundle (const struct insn *insn)
{
return (uint64_t) insn & ~0xfUL;
}
static inline int
slot (const struct insn *insn)
{
return (uint64_t) insn & 0x3;
}
static int
apply_imm64 (struct module *mod, struct insn *insn, uint64_t val)
{
if (slot(insn) != 1 && slot(insn) != 2) {
printk(KERN_ERR "%s: invalid slot number %d for IMM64\n",
mod->name, slot(insn));
return 0;
}
ia64_patch_imm64((u64) insn, val);
return 1;
}
static int
apply_imm60 (struct module *mod, struct insn *insn, uint64_t val)
{
if (slot(insn) != 1 && slot(insn) != 2) {
printk(KERN_ERR "%s: invalid slot number %d for IMM60\n",
mod->name, slot(insn));
return 0;
}
if (val + ((uint64_t) 1 << 59) >= (1UL << 60)) {
printk(KERN_ERR "%s: value %ld out of IMM60 range\n",
mod->name, (long) val);
return 0;
}
ia64_patch_imm60((u64) insn, val);
return 1;
}
static int
apply_imm22 (struct module *mod, struct insn *insn, uint64_t val)
{
if (val + (1 << 21) >= (1 << 22)) {
printk(KERN_ERR "%s: value %li out of IMM22 range\n",
mod->name, (long)val);
return 0;
}
ia64_patch((u64) insn, 0x01fffcfe000UL, ( ((val & 0x200000UL) << 15) /* bit 21 -> 36 */
| ((val & 0x1f0000UL) << 6) /* bit 16 -> 22 */
| ((val & 0x00ff80UL) << 20) /* bit 7 -> 27 */
| ((val & 0x00007fUL) << 13) /* bit 0 -> 13 */));
return 1;
}
static int
apply_imm21b (struct module *mod, struct insn *insn, uint64_t val)
{
if (val + (1 << 20) >= (1 << 21)) {
printk(KERN_ERR "%s: value %li out of IMM21b range\n",
mod->name, (long)val);
return 0;
}
ia64_patch((u64) insn, 0x11ffffe000UL, ( ((val & 0x100000UL) << 16) /* bit 20 -> 36 */
| ((val & 0x0fffffUL) << 13) /* bit 0 -> 13 */));
return 1;
}
#if USE_BRL
struct plt_entry {
/* Three instruction bundles in PLT. */
unsigned char bundle[2][16];
};
static const struct plt_entry ia64_plt_template = {
{
{
0x04, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */
0x00, 0x00, 0x00, 0x00, 0x00, 0x20, /* movl gp=TARGET_GP */
0x00, 0x00, 0x00, 0x60
},
{
0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* brl.many gp=TARGET_GP */
0x08, 0x00, 0x00, 0xc0
}
}
};
static int
patch_plt (struct module *mod, struct plt_entry *plt, long target_ip, unsigned long target_gp)
{
if (apply_imm64(mod, (struct insn *) (plt->bundle[0] + 2), target_gp)
&& apply_imm60(mod, (struct insn *) (plt->bundle[1] + 2),
(target_ip - (int64_t) plt->bundle[1]) / 16))
return 1;
return 0;
}
unsigned long
plt_target (struct plt_entry *plt)
{
uint64_t b0, b1, *b = (uint64_t *) plt->bundle[1];
long off;
b0 = b[0]; b1 = b[1];
off = ( ((b1 & 0x00fffff000000000UL) >> 36) /* imm20b -> bit 0 */
| ((b0 >> 48) << 20) | ((b1 & 0x7fffffUL) << 36) /* imm39 -> bit 20 */
| ((b1 & 0x0800000000000000UL) << 0)); /* i -> bit 59 */
return (long) plt->bundle[1] + 16*off;
}
#else /* !USE_BRL */
struct plt_entry {
/* Three instruction bundles in PLT. */
unsigned char bundle[3][16];
};
static const struct plt_entry ia64_plt_template = {
{
{
0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* movl r16=TARGET_IP */
0x02, 0x00, 0x00, 0x60
},
{
0x04, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */
0x00, 0x00, 0x00, 0x00, 0x00, 0x20, /* movl gp=TARGET_GP */
0x00, 0x00, 0x00, 0x60
},
{
0x11, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MIB] nop.m 0 */
0x60, 0x80, 0x04, 0x80, 0x03, 0x00, /* mov b6=r16 */
0x60, 0x00, 0x80, 0x00 /* br.few b6 */
}
}
};
static int
patch_plt (struct module *mod, struct plt_entry *plt, long target_ip, unsigned long target_gp)
{
if (apply_imm64(mod, (struct insn *) (plt->bundle[0] + 2), target_ip)
&& apply_imm64(mod, (struct insn *) (plt->bundle[1] + 2), target_gp))
return 1;
return 0;
}
unsigned long
plt_target (struct plt_entry *plt)
{
uint64_t b0, b1, *b = (uint64_t *) plt->bundle[0];
b0 = b[0]; b1 = b[1];
return ( ((b1 & 0x000007f000000000) >> 36) /* imm7b -> bit 0 */
| ((b1 & 0x07fc000000000000) >> 43) /* imm9d -> bit 7 */
| ((b1 & 0x0003e00000000000) >> 29) /* imm5c -> bit 16 */
| ((b1 & 0x0000100000000000) >> 23) /* ic -> bit 21 */
| ((b0 >> 46) << 22) | ((b1 & 0x7fffff) << 40) /* imm41 -> bit 22 */
| ((b1 & 0x0800000000000000) << 4)); /* i -> bit 63 */
}
#endif /* !USE_BRL */
void
module_arch_freeing_init (struct module *mod)
{
if (mod->arch.init_unw_table) {
unw_remove_unwind_table(mod->arch.init_unw_table);
mod->arch.init_unw_table = NULL;
}
}
/* Have we already seen one of these relocations? */
/* FIXME: we could look in other sections, too --RR */
static int
duplicate_reloc (const Elf64_Rela *rela, unsigned int num)
{
unsigned int i;
for (i = 0; i < num; i++) {
if (rela[i].r_info == rela[num].r_info && rela[i].r_addend == rela[num].r_addend)
return 1;
}
return 0;
}
/* Count how many GOT entries we may need */
static unsigned int
count_gots (const Elf64_Rela *rela, unsigned int num)
{
unsigned int i, ret = 0;
/* Sure, this is order(n^2), but it's usually short, and not
time critical */
for (i = 0; i < num; i++) {
switch (ELF64_R_TYPE(rela[i].r_info)) {
case R_IA64_LTOFF22:
case R_IA64_LTOFF22X:
case R_IA64_LTOFF64I:
case R_IA64_LTOFF_FPTR22:
case R_IA64_LTOFF_FPTR64I:
case R_IA64_LTOFF_FPTR32MSB:
case R_IA64_LTOFF_FPTR32LSB:
case R_IA64_LTOFF_FPTR64MSB:
case R_IA64_LTOFF_FPTR64LSB:
if (!duplicate_reloc(rela, i))
ret++;
break;
}
}
return ret;
}
/* Count how many PLT entries we may need */
static unsigned int
count_plts (const Elf64_Rela *rela, unsigned int num)
{
unsigned int i, ret = 0;
/* Sure, this is order(n^2), but it's usually short, and not
time critical */
for (i = 0; i < num; i++) {
switch (ELF64_R_TYPE(rela[i].r_info)) {
case R_IA64_PCREL21B:
case R_IA64_PLTOFF22:
case R_IA64_PLTOFF64I:
case R_IA64_PLTOFF64MSB:
case R_IA64_PLTOFF64LSB:
case R_IA64_IPLTMSB:
case R_IA64_IPLTLSB:
if (!duplicate_reloc(rela, i))
ret++;
break;
}
}
return ret;
}
/* We need to create an function-descriptors for any internal function
which is referenced. */
static unsigned int
count_fdescs (const Elf64_Rela *rela, unsigned int num)
{
unsigned int i, ret = 0;
/* Sure, this is order(n^2), but it's usually short, and not time critical. */
for (i = 0; i < num; i++) {
switch (ELF64_R_TYPE(rela[i].r_info)) {
case R_IA64_FPTR64I:
case R_IA64_FPTR32LSB:
case R_IA64_FPTR32MSB:
case R_IA64_FPTR64LSB:
case R_IA64_FPTR64MSB:
case R_IA64_LTOFF_FPTR22:
case R_IA64_LTOFF_FPTR32LSB:
case R_IA64_LTOFF_FPTR32MSB:
case R_IA64_LTOFF_FPTR64I:
case R_IA64_LTOFF_FPTR64LSB:
case R_IA64_LTOFF_FPTR64MSB:
case R_IA64_IPLTMSB:
case R_IA64_IPLTLSB:
/*
* Jumps to static functions sometimes go straight to their
* offset. Of course, that may not be possible if the jump is
* from init -> core or vice. versa, so we need to generate an
* FDESC (and PLT etc) for that.
*/
case R_IA64_PCREL21B:
if (!duplicate_reloc(rela, i))
ret++;
break;
}
}
return ret;
}
int
module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings,
struct module *mod)
{
unsigned long core_plts = 0, init_plts = 0, gots = 0, fdescs = 0;
Elf64_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum;
/*
* To store the PLTs and function-descriptors, we expand the .text section for
* core module-code and the .init.text section for initialization code.
*/
for (s = sechdrs; s < sechdrs_end; ++s)
if (strcmp(".core.plt", secstrings + s->sh_name) == 0)
mod->arch.core_plt = s;
else if (strcmp(".init.plt", secstrings + s->sh_name) == 0)
mod->arch.init_plt = s;
else if (strcmp(".got", secstrings + s->sh_name) == 0)
mod->arch.got = s;
else if (strcmp(".opd", secstrings + s->sh_name) == 0)
mod->arch.opd = s;
else if (strcmp(".IA_64.unwind", secstrings + s->sh_name) == 0)
mod->arch.unwind = s;
if (!mod->arch.core_plt || !mod->arch.init_plt || !mod->arch.got || !mod->arch.opd) {
printk(KERN_ERR "%s: sections missing\n", mod->name);
return -ENOEXEC;
}
/* GOT and PLTs can occur in any relocated section... */
for (s = sechdrs + 1; s < sechdrs_end; ++s) {
const Elf64_Rela *rels = (void *)ehdr + s->sh_offset;
unsigned long numrels = s->sh_size/sizeof(Elf64_Rela);
if (s->sh_type != SHT_RELA)
continue;
gots += count_gots(rels, numrels);
fdescs += count_fdescs(rels, numrels);
if (strstr(secstrings + s->sh_name, ".init"))
init_plts += count_plts(rels, numrels);
else
core_plts += count_plts(rels, numrels);
}
mod->arch.core_plt->sh_type = SHT_NOBITS;
mod->arch.core_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
mod->arch.core_plt->sh_addralign = 16;
mod->arch.core_plt->sh_size = core_plts * sizeof(struct plt_entry);
mod->arch.init_plt->sh_type = SHT_NOBITS;
mod->arch.init_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
mod->arch.init_plt->sh_addralign = 16;
mod->arch.init_plt->sh_size = init_plts * sizeof(struct plt_entry);
mod->arch.got->sh_type = SHT_NOBITS;
mod->arch.got->sh_flags = ARCH_SHF_SMALL | SHF_ALLOC;
mod->arch.got->sh_addralign = 8;
mod->arch.got->sh_size = gots * sizeof(struct got_entry);
mod->arch.opd->sh_type = SHT_NOBITS;
mod->arch.opd->sh_flags = SHF_ALLOC;
mod->arch.opd->sh_addralign = 8;
mod->arch.opd->sh_size = fdescs * sizeof(struct fdesc);
DEBUGP("%s: core.plt=%lx, init.plt=%lx, got=%lx, fdesc=%lx\n",
__func__, mod->arch.core_plt->sh_size, mod->arch.init_plt->sh_size,
mod->arch.got->sh_size, mod->arch.opd->sh_size);
return 0;
}
static inline int
in_init (const struct module *mod, uint64_t addr)
{
return addr - (uint64_t) mod->init_layout.base < mod->init_layout.size;
}
static inline int
in_core (const struct module *mod, uint64_t addr)
{
return addr - (uint64_t) mod->core_layout.base < mod->core_layout.size;
}
static inline int
is_internal (const struct module *mod, uint64_t value)
{
return in_init(mod, value) || in_core(mod, value);
}
/*
* Get gp-relative offset for the linkage-table entry of VALUE.
*/
static uint64_t
get_ltoff (struct module *mod, uint64_t value, int *okp)
{
struct got_entry *got, *e;
if (!*okp)
return 0;
got = (void *) mod->arch.got->sh_addr;
for (e = got; e < got + mod->arch.next_got_entry; ++e)
if (e->val == value)
goto found;
/* Not enough GOT entries? */
BUG_ON(e >= (struct got_entry *) (mod->arch.got->sh_addr + mod->arch.got->sh_size));
e->val = value;
++mod->arch.next_got_entry;
found:
return (uint64_t) e - mod->arch.gp;
}
static inline int
gp_addressable (struct module *mod, uint64_t value)
{
return value - mod->arch.gp + MAX_LTOFF/2 < MAX_LTOFF;
}
/* Get PC-relative PLT entry for this value. Returns 0 on failure. */
static uint64_t
get_plt (struct module *mod, const struct insn *insn, uint64_t value, int *okp)
{
struct plt_entry *plt, *plt_end;
uint64_t target_ip, target_gp;
if (!*okp)
return 0;
if (in_init(mod, (uint64_t) insn)) {
plt = (void *) mod->arch.init_plt->sh_addr;
plt_end = (void *) plt + mod->arch.init_plt->sh_size;
} else {
plt = (void *) mod->arch.core_plt->sh_addr;
plt_end = (void *) plt + mod->arch.core_plt->sh_size;
}
/* "value" is a pointer to a function-descriptor; fetch the target ip/gp from it: */
target_ip = ((uint64_t *) value)[0];
target_gp = ((uint64_t *) value)[1];
/* Look for existing PLT entry. */
while (plt->bundle[0][0]) {
if (plt_target(plt) == target_ip)
goto found;
if (++plt >= plt_end)
BUG();
}
*plt = ia64_plt_template;
if (!patch_plt(mod, plt, target_ip, target_gp)) {
*okp = 0;
return 0;
}
#if ARCH_MODULE_DEBUG
if (plt_target(plt) != target_ip) {
printk("%s: mistargeted PLT: wanted %lx, got %lx\n",
__func__, target_ip, plt_target(plt));
*okp = 0;
return 0;
}
#endif
found:
return (uint64_t) plt;
}
/* Get function descriptor for VALUE. */
static uint64_t
get_fdesc (struct module *mod, uint64_t value, int *okp)
{
struct fdesc *fdesc = (void *) mod->arch.opd->sh_addr;
if (!*okp)
return 0;
if (!value) {
printk(KERN_ERR "%s: fdesc for zero requested!\n", mod->name);
return 0;
}
if (!is_internal(mod, value))
/*
* If it's not a module-local entry-point, "value" already points to a
* function-descriptor.
*/
return value;
/* Look for existing function descriptor. */
while (fdesc->addr) {
if (fdesc->addr == value)
return (uint64_t)fdesc;
if ((uint64_t) ++fdesc >= mod->arch.opd->sh_addr + mod->arch.opd->sh_size)
BUG();
}
/* Create new one */
fdesc->addr = value;
fdesc->gp = mod->arch.gp;
return (uint64_t) fdesc;
}
static inline int
do_reloc (struct module *mod, uint8_t r_type, Elf64_Sym *sym, uint64_t addend,
Elf64_Shdr *sec, void *location)
{
enum reloc_target_format format = (r_type >> FORMAT_SHIFT) & FORMAT_MASK;
enum reloc_value_formula formula = (r_type >> VALUE_SHIFT) & VALUE_MASK;
uint64_t val;
int ok = 1;
val = sym->st_value + addend;
switch (formula) {
case RV_SEGREL: /* segment base is arbitrarily chosen to be 0 for kernel modules */
case RV_DIRECT:
break;
case RV_GPREL: val -= mod->arch.gp; break;
case RV_LTREL: val = get_ltoff(mod, val, &ok); break;
case RV_PLTREL: val = get_plt(mod, location, val, &ok); break;
case RV_FPTR: val = get_fdesc(mod, val, &ok); break;
case RV_SECREL: val -= sec->sh_addr; break;
case RV_LTREL_FPTR: val = get_ltoff(mod, get_fdesc(mod, val, &ok), &ok); break;
case RV_PCREL:
switch (r_type) {
case R_IA64_PCREL21B:
if ((in_init(mod, val) && in_core(mod, (uint64_t)location)) ||
(in_core(mod, val) && in_init(mod, (uint64_t)location))) {
/*
* Init section may have been allocated far away from core,
* if the branch won't reach, then allocate a plt for it.
*/
uint64_t delta = ((int64_t)val - (int64_t)location) / 16;
if (delta + (1 << 20) >= (1 << 21)) {
val = get_fdesc(mod, val, &ok);
val = get_plt(mod, location, val, &ok);
}
} else if (!is_internal(mod, val))
val = get_plt(mod, location, val, &ok);
fallthrough;
default:
val -= bundle(location);
break;
case R_IA64_PCREL32MSB:
case R_IA64_PCREL32LSB:
case R_IA64_PCREL64MSB:
case R_IA64_PCREL64LSB:
val -= (uint64_t) location;
break;
}
switch (r_type) {
case R_IA64_PCREL60B: format = RF_INSN60; break;
case R_IA64_PCREL21B: format = RF_INSN21B; break;
case R_IA64_PCREL21M: format = RF_INSN21M; break;
case R_IA64_PCREL21F: format = RF_INSN21F; break;
default: break;
}
break;
case RV_BDREL:
val -= (uint64_t) (in_init(mod, val) ? mod->init_layout.base : mod->core_layout.base);
break;
case RV_LTV:
/* can link-time value relocs happen here? */
BUG();
break;
case RV_PCREL2:
if (r_type == R_IA64_PCREL21BI) {
if (!is_internal(mod, val)) {
printk(KERN_ERR "%s: %s reloc against "
"non-local symbol (%lx)\n", __func__,
reloc_name[r_type], (unsigned long)val);
return -ENOEXEC;
}
format = RF_INSN21B;
}
val -= bundle(location);
break;
case RV_SPECIAL:
switch (r_type) {
case R_IA64_IPLTMSB:
case R_IA64_IPLTLSB:
val = get_fdesc(mod, get_plt(mod, location, val, &ok), &ok);
format = RF_64LSB;
if (r_type == R_IA64_IPLTMSB)
format = RF_64MSB;
break;
case R_IA64_SUB:
val = addend - sym->st_value;
format = RF_INSN64;
break;
case R_IA64_LTOFF22X:
if (gp_addressable(mod, val))
val -= mod->arch.gp;
else
val = get_ltoff(mod, val, &ok);
format = RF_INSN22;
break;
case R_IA64_LDXMOV:
if (gp_addressable(mod, val)) {
/* turn "ld8" into "mov": */
DEBUGP("%s: patching ld8 at %p to mov\n", __func__, location);
ia64_patch((u64) location, 0x1fff80fe000UL, 0x10000000000UL);
}
return 0;
default:
if (reloc_name[r_type])
printk(KERN_ERR "%s: special reloc %s not supported",
mod->name, reloc_name[r_type]);
else
printk(KERN_ERR "%s: unknown special reloc %x\n",
mod->name, r_type);
return -ENOEXEC;
}
break;
case RV_TPREL:
case RV_LTREL_TPREL:
case RV_DTPMOD:
case RV_LTREL_DTPMOD:
case RV_DTPREL:
case RV_LTREL_DTPREL:
printk(KERN_ERR "%s: %s reloc not supported\n",
mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?");
return -ENOEXEC;
default:
printk(KERN_ERR "%s: unknown reloc %x\n", mod->name, r_type);
return -ENOEXEC;
}
if (!ok)
return -ENOEXEC;
DEBUGP("%s: [%p]<-%016lx = %s(%lx)\n", __func__, location, val,
reloc_name[r_type] ? reloc_name[r_type] : "?", sym->st_value + addend);
switch (format) {
case RF_INSN21B: ok = apply_imm21b(mod, location, (int64_t) val / 16); break;
case RF_INSN22: ok = apply_imm22(mod, location, val); break;
case RF_INSN64: ok = apply_imm64(mod, location, val); break;
case RF_INSN60: ok = apply_imm60(mod, location, (int64_t) val / 16); break;
case RF_32LSB: put_unaligned(val, (uint32_t *) location); break;
case RF_64LSB: put_unaligned(val, (uint64_t *) location); break;
case RF_32MSB: /* ia64 Linux is little-endian... */
case RF_64MSB: /* ia64 Linux is little-endian... */
case RF_INSN14: /* must be within-module, i.e., resolved by "ld -r" */
case RF_INSN21M: /* must be within-module, i.e., resolved by "ld -r" */
case RF_INSN21F: /* must be within-module, i.e., resolved by "ld -r" */
printk(KERN_ERR "%s: format %u needed by %s reloc is not supported\n",
mod->name, format, reloc_name[r_type] ? reloc_name[r_type] : "?");
return -ENOEXEC;
default:
printk(KERN_ERR "%s: relocation %s resulted in unknown format %u\n",
mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?", format);
return -ENOEXEC;
}
return ok ? 0 : -ENOEXEC;
}
int
apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex,
unsigned int relsec, struct module *mod)
{
unsigned int i, n = sechdrs[relsec].sh_size / sizeof(Elf64_Rela);
Elf64_Rela *rela = (void *) sechdrs[relsec].sh_addr;
Elf64_Shdr *target_sec;
int ret;
DEBUGP("%s: applying section %u (%u relocs) to %u\n", __func__,
relsec, n, sechdrs[relsec].sh_info);
target_sec = sechdrs + sechdrs[relsec].sh_info;
if (target_sec->sh_entsize == ~0UL)
/*
* If target section wasn't allocated, we don't need to relocate it.
* Happens, e.g., for debug sections.
*/
return 0;
if (!mod->arch.gp) {
/*
* XXX Should have an arch-hook for running this after final section
* addresses have been selected...
*/
uint64_t gp;
if (mod->core_layout.size > MAX_LTOFF)
/*
* This takes advantage of fact that SHF_ARCH_SMALL gets allocated
* at the end of the module.
*/
gp = mod->core_layout.size - MAX_LTOFF / 2;
else
gp = mod->core_layout.size / 2;
gp = (uint64_t) mod->core_layout.base + ((gp + 7) & -8);
mod->arch.gp = gp;
DEBUGP("%s: placing gp at 0x%lx\n", __func__, gp);
}
for (i = 0; i < n; i++) {
ret = do_reloc(mod, ELF64_R_TYPE(rela[i].r_info),
((Elf64_Sym *) sechdrs[symindex].sh_addr
+ ELF64_R_SYM(rela[i].r_info)),
rela[i].r_addend, target_sec,
(void *) target_sec->sh_addr + rela[i].r_offset);
if (ret < 0)
return ret;
}
return 0;
}
/*
* Modules contain a single unwind table which covers both the core and the init text
* sections but since the two are not contiguous, we need to split this table up such that
* we can register (and unregister) each "segment" separately. Fortunately, this sounds
* more complicated than it really is.
*/
static void
register_unwind_table (struct module *mod)
{
struct unw_table_entry *start = (void *) mod->arch.unwind->sh_addr;
struct unw_table_entry *end = start + mod->arch.unwind->sh_size / sizeof (*start);
struct unw_table_entry *e1, *e2, *core, *init;
unsigned long num_init = 0, num_core = 0;
/* First, count how many init and core unwind-table entries there are. */
for (e1 = start; e1 < end; ++e1)
if (in_init(mod, e1->start_offset))
++num_init;
else
++num_core;
/*
* Second, sort the table such that all unwind-table entries for the init and core
* text sections are nicely separated. We do this with a stupid bubble sort
* (unwind tables don't get ridiculously huge).
*/
for (e1 = start; e1 < end; ++e1) {
for (e2 = e1 + 1; e2 < end; ++e2) {
if (e2->start_offset < e1->start_offset) {
swap(*e1, *e2);
}
}
}
/*
* Third, locate the init and core segments in the unwind table:
*/
if (in_init(mod, start->start_offset)) {
init = start;
core = start + num_init;
} else {
core = start;
init = start + num_core;
}
DEBUGP("%s: name=%s, gp=%lx, num_init=%lu, num_core=%lu\n", __func__,
mod->name, mod->arch.gp, num_init, num_core);
/*
* Fourth, register both tables (if not empty).
*/
if (num_core > 0) {
mod->arch.core_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp,
core, core + num_core);
DEBUGP("%s: core: handle=%p [%p-%p)\n", __func__,
mod->arch.core_unw_table, core, core + num_core);
}
if (num_init > 0) {
mod->arch.init_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp,
init, init + num_init);
DEBUGP("%s: init: handle=%p [%p-%p)\n", __func__,
mod->arch.init_unw_table, init, init + num_init);
}
}
int
module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod)
{
struct mod_arch_specific *mas = &mod->arch;
DEBUGP("%s: init: entry=%p\n", __func__, mod->init);
if (mas->unwind)
register_unwind_table(mod);
/*
* ".opd" was already relocated to the final destination. Store
* it's address for use in symbolizer.
*/
mas->opd_addr = (void *)mas->opd->sh_addr;
mas->opd_size = mas->opd->sh_size;
/*
* Module relocation was already done at this point. Section
* headers are about to be deleted. Wipe out load-time context.
*/
mas->core_plt = NULL;
mas->init_plt = NULL;
mas->got = NULL;
mas->opd = NULL;
mas->unwind = NULL;
mas->gp = 0;
mas->next_got_entry = 0;
return 0;
}
void
module_arch_cleanup (struct module *mod)
{
if (mod->arch.init_unw_table) {
unw_remove_unwind_table(mod->arch.init_unw_table);
mod->arch.init_unw_table = NULL;
}
if (mod->arch.core_unw_table) {
unw_remove_unwind_table(mod->arch.core_unw_table);
mod->arch.core_unw_table = NULL;
}
}
void *dereference_module_function_descriptor(struct module *mod, void *ptr)
{
struct mod_arch_specific *mas = &mod->arch;
if (ptr < mas->opd_addr || ptr >= mas->opd_addr + mas->opd_size)
return ptr;
return dereference_function_descriptor(ptr);
}
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