microsoft
/
WSL2-Linux-Kernel
зеркало из https://github.com/microsoft/WSL2-Linux-Kernel.git
1
0
Форкнуть 0
Код Задачи Пакеты Проекты Релизы Вики Активность
WSL2-Linux-Kernel/arch/parisc/kernel/module.c

987 строки
27 KiB
C
Исходник Ответственный История

/* Kernel dynamically loadable module help for PARISC.
*
* The best reference for this stuff is probably the Processor-
* Specific ELF Supplement for PA-RISC:
* http://ftp.parisc-linux.org/docs/arch/elf-pa-hp.pdf
*
* Linux/PA-RISC Project (http://www.parisc-linux.org/)
* Copyright (C) 2003 Randolph Chung <tausq at debian . org>
* Copyright (C) 2008 Helge Deller <deller@gmx.de>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*
* Notes:
* - PLT stub handling
* On 32bit (and sometimes 64bit) and with big kernel modules like xfs or
* ipv6 the relocation types R_PARISC_PCREL17F and R_PARISC_PCREL22F may
* fail to reach their PLT stub if we only create one big stub array for
* all sections at the beginning of the core or init section.
* Instead we now insert individual PLT stub entries directly in front of
* of the code sections where the stubs are actually called.
* This reduces the distance between the PCREL location and the stub entry
* so that the relocations can be fulfilled.
* While calculating the final layout of the kernel module in memory, the
* kernel module loader calls arch_mod_section_prepend() to request the
* to be reserved amount of memory in front of each individual section.
*
* - SEGREL32 handling
* We are not doing SEGREL32 handling correctly. According to the ABI, we
* should do a value offset, like this:
* if (in_init(me, (void *)val))
* val -= (uint32_t)me->init_layout.base;
* else
* val -= (uint32_t)me->core_layout.base;
* However, SEGREL32 is used only for PARISC unwind entries, and we want
* those entries to have an absolute address, and not just an offset.
*
* The unwind table mechanism has the ability to specify an offset for
* the unwind table; however, because we split off the init functions into
* a different piece of memory, it is not possible to do this using a
* single offset. Instead, we use the above hack for now.
*/
#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/bug.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <asm/pgtable.h>
#include <asm/unwind.h>
#include <asm/sections.h>
#if 0
#define DEBUGP printk
#else
#define DEBUGP(fmt...)
#endif
#define RELOC_REACHABLE(val, bits) \
(( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 ) || \
( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \
0 : 1)
#define CHECK_RELOC(val, bits) \
if (!RELOC_REACHABLE(val, bits)) { \
printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \
me->name, strtab + sym->st_name, (unsigned long)val, bits); \
return -ENOEXEC; \
}
/* Maximum number of GOT entries. We use a long displacement ldd from
* the bottom of the table, which has a maximum signed displacement of
* 0x3fff; however, since we're only going forward, this becomes
* 0x1fff, and thus, since each GOT entry is 8 bytes long we can have
* at most 1023 entries.
* To overcome this 14bit displacement with some kernel modules, we'll
* use instead the unusal 16bit displacement method (see reassemble_16a)
* which gives us a maximum positive displacement of 0x7fff, and as such
* allows us to allocate up to 4095 GOT entries. */
#define MAX_GOTS 4095
/* three functions to determine where in the module core
* or init pieces the location is */
static inline int in_init(struct module *me, void *loc)
{
return (loc >= me->init_layout.base &&
loc <= (me->init_layout.base + me->init_layout.size));
}
static inline int in_core(struct module *me, void *loc)
{
return (loc >= me->core_layout.base &&
loc <= (me->core_layout.base + me->core_layout.size));
}
static inline int in_local(struct module *me, void *loc)
{
return in_init(me, loc) || in_core(me, loc);
}
#ifndef CONFIG_64BIT
struct got_entry {
Elf32_Addr addr;
};
struct stub_entry {
Elf32_Word insns[2]; /* each stub entry has two insns */
};
#else
struct got_entry {
Elf64_Addr addr;
};
struct stub_entry {
Elf64_Word insns[4]; /* each stub entry has four insns */
};
#endif
/* Field selection types defined by hppa */
#define rnd(x) (((x)+0x1000)&~0x1fff)
/* fsel: full 32 bits */
#define fsel(v,a) ((v)+(a))
/* lsel: select left 21 bits */
#define lsel(v,a) (((v)+(a))>>11)
/* rsel: select right 11 bits */
#define rsel(v,a) (((v)+(a))&0x7ff)
/* lrsel with rounding of addend to nearest 8k */
#define lrsel(v,a) (((v)+rnd(a))>>11)
/* rrsel with rounding of addend to nearest 8k */
#define rrsel(v,a) ((((v)+rnd(a))&0x7ff)+((a)-rnd(a)))
#define mask(x,sz) ((x) & ~((1<<(sz))-1))
/* The reassemble_* functions prepare an immediate value for
insertion into an opcode. pa-risc uses all sorts of weird bitfields
in the instruction to hold the value. */
static inline int sign_unext(int x, int len)
{
int len_ones;
len_ones = (1 << len) - 1;
return x & len_ones;
}
static inline int low_sign_unext(int x, int len)
{
int sign, temp;
sign = (x >> (len-1)) & 1;
temp = sign_unext(x, len-1);
return (temp << 1) | sign;
}
static inline int reassemble_14(int as14)
{
return (((as14 & 0x1fff) << 1) |
((as14 & 0x2000) >> 13));
}
static inline int reassemble_16a(int as16)
{
int s, t;
/* Unusual 16-bit encoding, for wide mode only. */
t = (as16 << 1) & 0xffff;
s = (as16 & 0x8000);
return (t ^ s ^ (s >> 1)) | (s >> 15);
}
static inline int reassemble_17(int as17)
{
return (((as17 & 0x10000) >> 16) |
((as17 & 0x0f800) << 5) |
((as17 & 0x00400) >> 8) |
((as17 & 0x003ff) << 3));
}
static inline int reassemble_21(int as21)
{
return (((as21 & 0x100000) >> 20) |
((as21 & 0x0ffe00) >> 8) |
((as21 & 0x000180) << 7) |
((as21 & 0x00007c) << 14) |
((as21 & 0x000003) << 12));
}
static inline int reassemble_22(int as22)
{
return (((as22 & 0x200000) >> 21) |
((as22 & 0x1f0000) << 5) |
((as22 & 0x00f800) << 5) |
((as22 & 0x000400) >> 8) |
((as22 & 0x0003ff) << 3));
}
void *module_alloc(unsigned long size)
{
/* using RWX means less protection for modules, but it's
* easier than trying to map the text, data, init_text and
* init_data correctly */
return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
GFP_KERNEL,
PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
__builtin_return_address(0));
}
#ifndef CONFIG_64BIT
static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
{
return 0;
}
static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
{
return 0;
}
static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
{
unsigned long cnt = 0;
for (; n > 0; n--, rela++)
{
switch (ELF32_R_TYPE(rela->r_info)) {
case R_PARISC_PCREL17F:
case R_PARISC_PCREL22F:
cnt++;
}
}
return cnt;
}
#else
static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
{
unsigned long cnt = 0;
for (; n > 0; n--, rela++)
{
switch (ELF64_R_TYPE(rela->r_info)) {
case R_PARISC_LTOFF21L:
case R_PARISC_LTOFF14R:
case R_PARISC_PCREL22F:
cnt++;
}
}
return cnt;
}
static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
{
unsigned long cnt = 0;
for (; n > 0; n--, rela++)
{
switch (ELF64_R_TYPE(rela->r_info)) {
case R_PARISC_FPTR64:
cnt++;
}
}
return cnt;
}
static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
{
unsigned long cnt = 0;
for (; n > 0; n--, rela++)
{
switch (ELF64_R_TYPE(rela->r_info)) {
case R_PARISC_PCREL22F:
cnt++;
}
}
return cnt;
}
#endif
void module_arch_freeing_init(struct module *mod)
{
kfree(mod->arch.section);
mod->arch.section = NULL;
}
/* Additional bytes needed in front of individual sections */
unsigned int arch_mod_section_prepend(struct module *mod,
unsigned int section)
{
/* size needed for all stubs of this section (including
* one additional for correct alignment of the stubs) */
return (mod->arch.section[section].stub_entries + 1)
* sizeof(struct stub_entry);
}
#define CONST
int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
CONST Elf_Shdr *sechdrs,
CONST char *secstrings,
struct module *me)
{
unsigned long gots = 0, fdescs = 0, len;
unsigned int i;
len = hdr->e_shnum * sizeof(me->arch.section[0]);
me->arch.section = kzalloc(len, GFP_KERNEL);
if (!me->arch.section)
return -ENOMEM;
for (i = 1; i < hdr->e_shnum; i++) {
const Elf_Rela *rels = (void *)sechdrs[i].sh_addr;
unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels);
unsigned int count, s;
if (strncmp(secstrings + sechdrs[i].sh_name,
".PARISC.unwind", 14) == 0)
me->arch.unwind_section = i;
if (sechdrs[i].sh_type != SHT_RELA)
continue;
/* some of these are not relevant for 32-bit/64-bit
* we leave them here to make the code common. the
* compiler will do its thing and optimize out the
* stuff we don't need
*/
gots += count_gots(rels, nrels);
fdescs += count_fdescs(rels, nrels);
/* XXX: By sorting the relocs and finding duplicate entries
* we could reduce the number of necessary stubs and save
* some memory. */
count = count_stubs(rels, nrels);
if (!count)
continue;
/* so we need relocation stubs. reserve necessary memory. */
/* sh_info gives the section for which we need to add stubs. */
s = sechdrs[i].sh_info;
/* each code section should only have one relocation section */
WARN_ON(me->arch.section[s].stub_entries);
/* store number of stubs we need for this section */
me->arch.section[s].stub_entries += count;
}
/* align things a bit */
me->core_layout.size = ALIGN(me->core_layout.size, 16);
me->arch.got_offset = me->core_layout.size;
me->core_layout.size += gots * sizeof(struct got_entry);
me->core_layout.size = ALIGN(me->core_layout.size, 16);
me->arch.fdesc_offset = me->core_layout.size;
me->core_layout.size += fdescs * sizeof(Elf_Fdesc);
me->arch.got_max = gots;
me->arch.fdesc_max = fdescs;
return 0;
}
#ifdef CONFIG_64BIT
static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
{
unsigned int i;
struct got_entry *got;
value += addend;
BUG_ON(value == 0);
got = me->core_layout.base + me->arch.got_offset;
for (i = 0; got[i].addr; i++)
if (got[i].addr == value)
goto out;
BUG_ON(++me->arch.got_count > me->arch.got_max);
got[i].addr = value;
out:
DEBUGP("GOT ENTRY %d[%x] val %lx\n", i, i*sizeof(struct got_entry),
value);
return i * sizeof(struct got_entry);
}
#endif /* CONFIG_64BIT */
#ifdef CONFIG_64BIT
static Elf_Addr get_fdesc(struct module *me, unsigned long value)
{
Elf_Fdesc *fdesc = me->core_layout.base + me->arch.fdesc_offset;
if (!value) {
printk(KERN_ERR "%s: zero OPD requested!\n", me->name);
return 0;
}
/* Look for existing fdesc entry. */
while (fdesc->addr) {
if (fdesc->addr == value)
return (Elf_Addr)fdesc;
fdesc++;
}
BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max);
/* Create new one */
fdesc->addr = value;
fdesc->gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
return (Elf_Addr)fdesc;
}
#endif /* CONFIG_64BIT */
enum elf_stub_type {
ELF_STUB_GOT,
ELF_STUB_MILLI,
ELF_STUB_DIRECT,
};
static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
{
struct stub_entry *stub;
int __maybe_unused d;
/* initialize stub_offset to point in front of the section */
if (!me->arch.section[targetsec].stub_offset) {
loc0 -= (me->arch.section[targetsec].stub_entries + 1) *
sizeof(struct stub_entry);
/* get correct alignment for the stubs */
loc0 = ALIGN(loc0, sizeof(struct stub_entry));
me->arch.section[targetsec].stub_offset = loc0;
}
/* get address of stub entry */
stub = (void *) me->arch.section[targetsec].stub_offset;
me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry);
/* do not write outside available stub area */
BUG_ON(0 == me->arch.section[targetsec].stub_entries--);
#ifndef CONFIG_64BIT
/* for 32-bit the stub looks like this:
* ldil L'XXX,%r1
* be,n R'XXX(%sr4,%r1)
*/
//value = *(unsigned long *)((value + addend) & ~3); /* why? */
stub->insns[0] = 0x20200000; /* ldil L'XXX,%r1 */
stub->insns[1] = 0xe0202002; /* be,n R'XXX(%sr4,%r1) */
stub->insns[0] |= reassemble_21(lrsel(value, addend));
stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4);
#else
/* for 64-bit we have three kinds of stubs:
* for normal function calls:
* ldd 0(%dp),%dp
* ldd 10(%dp), %r1
* bve (%r1)
* ldd 18(%dp), %dp
*
* for millicode:
* ldil 0, %r1
* ldo 0(%r1), %r1
* ldd 10(%r1), %r1
* bve,n (%r1)
*
* for direct branches (jumps between different section of the
* same module):
* ldil 0, %r1
* ldo 0(%r1), %r1
* bve,n (%r1)
*/
switch (stub_type) {
case ELF_STUB_GOT:
d = get_got(me, value, addend);
if (d <= 15) {
/* Format 5 */
stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp */
stub->insns[0] |= low_sign_unext(d, 5) << 16;
} else {
/* Format 3 */
stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp */
stub->insns[0] |= reassemble_16a(d);
}
stub->insns[1] = 0x53610020; /* ldd 10(%dp),%r1 */
stub->insns[2] = 0xe820d000; /* bve (%r1) */
stub->insns[3] = 0x537b0030; /* ldd 18(%dp),%dp */
break;
case ELF_STUB_MILLI:
stub->insns[0] = 0x20200000; /* ldil 0,%r1 */
stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */
stub->insns[2] = 0x50210020; /* ldd 10(%r1),%r1 */
stub->insns[3] = 0xe820d002; /* bve,n (%r1) */
stub->insns[0] |= reassemble_21(lrsel(value, addend));
stub->insns[1] |= reassemble_14(rrsel(value, addend));
break;
case ELF_STUB_DIRECT:
stub->insns[0] = 0x20200000; /* ldil 0,%r1 */
stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */
stub->insns[2] = 0xe820d002; /* bve,n (%r1) */
stub->insns[0] |= reassemble_21(lrsel(value, addend));
stub->insns[1] |= reassemble_14(rrsel(value, addend));
break;
}
#endif
return (Elf_Addr)stub;
}
#ifndef CONFIG_64BIT
int apply_relocate_add(Elf_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
int i;
Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
Elf32_Sym *sym;
Elf32_Word *loc;
Elf32_Addr val;
Elf32_Sword addend;
Elf32_Addr dot;
Elf_Addr loc0;
unsigned int targetsec = sechdrs[relsec].sh_info;
//unsigned long dp = (unsigned long)$global$;
register unsigned long dp asm ("r27");
DEBUGP("Applying relocate section %u to %u\n", relsec,
targetsec);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
/* This is where to make the change */
loc = (void *)sechdrs[targetsec].sh_addr
+ rel[i].r_offset;
/* This is the start of the target section */
loc0 = sechdrs[targetsec].sh_addr;
/* This is the symbol it is referring to */
sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+ ELF32_R_SYM(rel[i].r_info);
if (!sym->st_value) {
printk(KERN_WARNING "%s: Unknown symbol %s\n",
me->name, strtab + sym->st_name);
return -ENOENT;
}
//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
dot = (Elf32_Addr)loc & ~0x03;
val = sym->st_value;
addend = rel[i].r_addend;
#if 0
#define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t :
DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n",
strtab + sym->st_name,
(uint32_t)loc, val, addend,
r(R_PARISC_PLABEL32)
r(R_PARISC_DIR32)
r(R_PARISC_DIR21L)
r(R_PARISC_DIR14R)
r(R_PARISC_SEGREL32)
r(R_PARISC_DPREL21L)
r(R_PARISC_DPREL14R)
r(R_PARISC_PCREL17F)
r(R_PARISC_PCREL22F)
"UNKNOWN");
#undef r
#endif
switch (ELF32_R_TYPE(rel[i].r_info)) {
case R_PARISC_PLABEL32:
/* 32-bit function address */
/* no function descriptors... */
*loc = fsel(val, addend);
break;
case R_PARISC_DIR32:
/* direct 32-bit ref */
*loc = fsel(val, addend);
break;
case R_PARISC_DIR21L:
/* left 21 bits of effective address */
val = lrsel(val, addend);
*loc = mask(*loc, 21) | reassemble_21(val);
break;
case R_PARISC_DIR14R:
/* right 14 bits of effective address */
val = rrsel(val, addend);
*loc = mask(*loc, 14) | reassemble_14(val);
break;
case R_PARISC_SEGREL32:
/* 32-bit segment relative address */
/* See note about special handling of SEGREL32 at
* the beginning of this file.
*/
*loc = fsel(val, addend);
break;
case R_PARISC_SECREL32:
/* 32-bit section relative address. */
*loc = fsel(val, addend);
break;
case R_PARISC_DPREL21L:
/* left 21 bit of relative address */
val = lrsel(val - dp, addend);
*loc = mask(*loc, 21) | reassemble_21(val);
break;
case R_PARISC_DPREL14R:
/* right 14 bit of relative address */
val = rrsel(val - dp, addend);
*loc = mask(*loc, 14) | reassemble_14(val);
break;
case R_PARISC_PCREL17F:
/* 17-bit PC relative address */
/* calculate direct call offset */
val += addend;
val = (val - dot - 8)/4;
if (!RELOC_REACHABLE(val, 17)) {
/* direct distance too far, create
* stub entry instead */
val = get_stub(me, sym->st_value, addend,
ELF_STUB_DIRECT, loc0, targetsec);
val = (val - dot - 8)/4;
CHECK_RELOC(val, 17);
}
*loc = (*loc & ~0x1f1ffd) | reassemble_17(val);
break;
case R_PARISC_PCREL22F:
/* 22-bit PC relative address; only defined for pa20 */
/* calculate direct call offset */
val += addend;
val = (val - dot - 8)/4;
if (!RELOC_REACHABLE(val, 22)) {
/* direct distance too far, create
* stub entry instead */
val = get_stub(me, sym->st_value, addend,
ELF_STUB_DIRECT, loc0, targetsec);
val = (val - dot - 8)/4;
CHECK_RELOC(val, 22);
}
*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
break;
case R_PARISC_PCREL32:
/* 32-bit PC relative address */
*loc = val - dot - 8 + addend;
break;
default:
printk(KERN_ERR "module %s: Unknown relocation: %u\n",
me->name, ELF32_R_TYPE(rel[i].r_info));
return -ENOEXEC;
}
}
return 0;
}
#else
int apply_relocate_add(Elf_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
int i;
Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
Elf64_Sym *sym;
Elf64_Word *loc;
Elf64_Xword *loc64;
Elf64_Addr val;
Elf64_Sxword addend;
Elf64_Addr dot;
Elf_Addr loc0;
unsigned int targetsec = sechdrs[relsec].sh_info;
DEBUGP("Applying relocate section %u to %u\n", relsec,
targetsec);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
/* This is where to make the change */
loc = (void *)sechdrs[targetsec].sh_addr
+ rel[i].r_offset;
/* This is the start of the target section */
loc0 = sechdrs[targetsec].sh_addr;
/* This is the symbol it is referring to */
sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
+ ELF64_R_SYM(rel[i].r_info);
if (!sym->st_value) {
printk(KERN_WARNING "%s: Unknown symbol %s\n",
me->name, strtab + sym->st_name);
return -ENOENT;
}
//dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
dot = (Elf64_Addr)loc & ~0x03;
loc64 = (Elf64_Xword *)loc;
val = sym->st_value;
addend = rel[i].r_addend;
#if 0
#define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t :
printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n",
strtab + sym->st_name,
loc, val, addend,
r(R_PARISC_LTOFF14R)
r(R_PARISC_LTOFF21L)
r(R_PARISC_PCREL22F)
r(R_PARISC_DIR64)
r(R_PARISC_SEGREL32)
r(R_PARISC_FPTR64)
"UNKNOWN");
#undef r
#endif
switch (ELF64_R_TYPE(rel[i].r_info)) {
case R_PARISC_LTOFF21L:
/* LT-relative; left 21 bits */
val = get_got(me, val, addend);
DEBUGP("LTOFF21L Symbol %s loc %p val %lx\n",
strtab + sym->st_name,
loc, val);
val = lrsel(val, 0);
*loc = mask(*loc, 21) | reassemble_21(val);
break;
case R_PARISC_LTOFF14R:
/* L(ltoff(val+addend)) */
/* LT-relative; right 14 bits */
val = get_got(me, val, addend);
val = rrsel(val, 0);
DEBUGP("LTOFF14R Symbol %s loc %p val %lx\n",
strtab + sym->st_name,
loc, val);
*loc = mask(*loc, 14) | reassemble_14(val);
break;
case R_PARISC_PCREL22F:
/* PC-relative; 22 bits */
DEBUGP("PCREL22F Symbol %s loc %p val %lx\n",
strtab + sym->st_name,
loc, val);
val += addend;
/* can we reach it locally? */
if (in_local(me, (void *)val)) {
/* this is the case where the symbol is local
* to the module, but in a different section,
* so stub the jump in case it's more than 22
* bits away */
val = (val - dot - 8)/4;
if (!RELOC_REACHABLE(val, 22)) {
/* direct distance too far, create
* stub entry instead */
val = get_stub(me, sym->st_value,
addend, ELF_STUB_DIRECT,
loc0, targetsec);
} else {
/* Ok, we can reach it directly. */
val = sym->st_value;
val += addend;
}
} else {
val = sym->st_value;
if (strncmp(strtab + sym->st_name, "$$", 2)
== 0)
val = get_stub(me, val, addend, ELF_STUB_MILLI,
loc0, targetsec);
else
val = get_stub(me, val, addend, ELF_STUB_GOT,
loc0, targetsec);
}
DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n",
strtab + sym->st_name, loc, sym->st_value,
addend, val);
val = (val - dot - 8)/4;
CHECK_RELOC(val, 22);
*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
break;
case R_PARISC_PCREL32:
/* 32-bit PC relative address */
*loc = val - dot - 8 + addend;
break;
case R_PARISC_DIR64:
/* 64-bit effective address */
*loc64 = val + addend;
break;
case R_PARISC_SEGREL32:
/* 32-bit segment relative address */
/* See note about special handling of SEGREL32 at
* the beginning of this file.
*/
*loc = fsel(val, addend);
break;
case R_PARISC_SECREL32:
/* 32-bit section relative address. */
*loc = fsel(val, addend);
break;
case R_PARISC_FPTR64:
/* 64-bit function address */
if(in_local(me, (void *)(val + addend))) {
*loc64 = get_fdesc(me, val+addend);
DEBUGP("FDESC for %s at %p points to %lx\n",
strtab + sym->st_name, *loc64,
((Elf_Fdesc *)*loc64)->addr);
} else {
/* if the symbol is not local to this
* module then val+addend is a pointer
* to the function descriptor */
DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n",
strtab + sym->st_name,
loc, val);
*loc64 = val + addend;
}
break;
default:
printk(KERN_ERR "module %s: Unknown relocation: %Lu\n",
me->name, ELF64_R_TYPE(rel[i].r_info));
return -ENOEXEC;
}
}
return 0;
}
#endif
static void
register_unwind_table(struct module *me,
const Elf_Shdr *sechdrs)
{
unsigned char *table, *end;
unsigned long gp;
if (!me->arch.unwind_section)
return;
table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr;
end = table + sechdrs[me->arch.unwind_section].sh_size;
gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
me->arch.unwind_section, table, end, gp);
me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end);
}
static void
deregister_unwind_table(struct module *me)
{
if (me->arch.unwind)
unwind_table_remove(me->arch.unwind);
}
int module_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
struct module *me)
{
int i;
unsigned long nsyms;
const char *strtab = NULL;
const Elf_Shdr *s;
char *secstrings;
Elf_Sym *newptr, *oldptr;
Elf_Shdr *symhdr = NULL;
#ifdef DEBUG
Elf_Fdesc *entry;
u32 *addr;
entry = (Elf_Fdesc *)me->init;
printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry,
entry->gp, entry->addr);
addr = (u32 *)entry->addr;
printk("INSNS: %x %x %x %x\n",
addr[0], addr[1], addr[2], addr[3]);
printk("got entries used %ld, gots max %ld\n"
"fdescs used %ld, fdescs max %ld\n",
me->arch.got_count, me->arch.got_max,
me->arch.fdesc_count, me->arch.fdesc_max);
#endif
register_unwind_table(me, sechdrs);
/* haven't filled in me->symtab yet, so have to find it
* ourselves */
for (i = 1; i < hdr->e_shnum; i++) {
if(sechdrs[i].sh_type == SHT_SYMTAB
&& (sechdrs[i].sh_flags & SHF_ALLOC)) {
int strindex = sechdrs[i].sh_link;
/* FIXME: AWFUL HACK
* The cast is to drop the const from
* the sechdrs pointer */
symhdr = (Elf_Shdr *)&sechdrs[i];
strtab = (char *)sechdrs[strindex].sh_addr;
break;
}
}
DEBUGP("module %s: strtab %p, symhdr %p\n",
me->name, strtab, symhdr);
if(me->arch.got_count > MAX_GOTS) {
printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n",
me->name, me->arch.got_count, MAX_GOTS);
return -EINVAL;
}
kfree(me->arch.section);
me->arch.section = NULL;
/* no symbol table */
if(symhdr == NULL)
return 0;
oldptr = (void *)symhdr->sh_addr;
newptr = oldptr + 1; /* we start counting at 1 */
nsyms = symhdr->sh_size / sizeof(Elf_Sym);
DEBUGP("OLD num_symtab %lu\n", nsyms);
for (i = 1; i < nsyms; i++) {
oldptr++; /* note, count starts at 1 so preincrement */
if(strncmp(strtab + oldptr->st_name,
".L", 2) == 0)
continue;
if(newptr != oldptr)
*newptr++ = *oldptr;
else
newptr++;
}
nsyms = newptr - (Elf_Sym *)symhdr->sh_addr;
DEBUGP("NEW num_symtab %lu\n", nsyms);
symhdr->sh_size = nsyms * sizeof(Elf_Sym);
/* find .altinstructions section */
secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
void *aseg = (void *) s->sh_addr;
char *secname = secstrings + s->sh_name;
if (!strcmp(".altinstructions", secname))
/* patch .altinstructions */
apply_alternatives(aseg, aseg + s->sh_size, me->name);
}
return 0;
}
void module_arch_cleanup(struct module *mod)
{
deregister_unwind_table(mod);
}
#ifdef CONFIG_64BIT
void *dereference_module_function_descriptor(struct module *mod, void *ptr)
{
unsigned long start_opd = (Elf64_Addr)mod->core_layout.base +
mod->arch.fdesc_offset;
unsigned long end_opd = start_opd +
mod->arch.fdesc_count * sizeof(Elf64_Fdesc);
if (ptr < (void *)start_opd || ptr >= (void *)end_opd)
return ptr;
return dereference_function_descriptor(ptr);
}
#endif
Ссылка в новой задаче Показать git blame Копировать постоянную ссылку