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linux/arch/ia64/kernel/module.c
Sergey Senozhatsky 8e30788816 ia64: Add .opd based function descriptor dereference 
We are moving towards separate kernel and module function descriptor
dereference callbacks. This patch enables it for IA64.

For pointers that belong to the kernel
-  Added __start_opd and __end_opd pointers, to track the kernel
   .opd section address range;

-  Added dereference_kernel_function_descriptor(). Now we
   will dereference only function pointers that are within
   [__start_opd, __end_opd);

For pointers that belong to a module
-  Added dereference_module_function_descriptor() to handle module
   function descriptor dereference. Now we will dereference only
   pointers that are within [module->opd.start, module->opd.end).

Link: http://lkml.kernel.org/r/20171109234830.5067-3-sergey.senozhatsky@gmail.com
To: Fenghua Yu <fenghua.yu@intel.com>
To: Helge Deller <deller@gmx.de>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Paul Mackerras <paulus@samba.org>
To: Michael Ellerman <mpe@ellerman.id.au>
To: James Bottomley <jejb@parisc-linux.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Tony Luck <tony.luck@intel.com> #ia64
Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-01-09 10:45:37 +01:00

933 lines
26 KiB
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->ip) {
if (fdesc->ip == value)
return (uint64_t)fdesc;
if ((uint64_t) ++fdesc >= mod->arch.opd->sh_addr + mod->arch.opd->sh_size)
BUG();
}
/* Create new one */
fdesc->ip = 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);
/* FALL THROUGH */
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 tmp, *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) {
tmp = *e1;
*e1 = *e2;
*e2 = tmp;
}
}
}
/*
* 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)
{
DEBUGP("%s: init: entry=%p\n", __func__, mod->init);
if (mod->arch.unwind)
register_unwind_table(mod);
return 0;
}
void
module_arch_cleanup (struct module *mod)
{
if (mod->arch.init_unw_table)
unw_remove_unwind_table(mod->arch.init_unw_table);
if (mod->arch.core_unw_table)
unw_remove_unwind_table(mod->arch.core_unw_table);
}
void *dereference_module_function_descriptor(struct module *mod, void *ptr)
{
Elf64_Shdr *opd = mod->arch.opd;
if (ptr < (void *)opd->sh_addr ||
ptr >= (void *)(opd->sh_addr + opd->sh_size))
return ptr;
return dereference_function_descriptor(ptr);
}
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