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Commit ceb689ec authored by David Mosberger's avatar David Mosberger
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ia64: Rewrite the relocator in the kernel module loader. Fix some bugs and simplify 

	the handling of loader-created sections.
parent 1bdbba7a
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Showing with 460 additions and 202 deletions
arch/ia64/kernel/module.c
View file @ ceb689ec
...@@ -7,6 +7,23 @@ ...@@ -7,6 +7,23 @@
* Loosely based on patch by Rusty Russell. * Loosely based on patch by Rusty Russell.
*/ */
/* relocs tested so far:
DIR64LSB
FPTR64LSB
GPREL22
LDXMOV
LDXMOV
LTOFF22
LTOFF22X
LTOFF22X
LTOFF_FPTR22
PCREL21B
PCREL64LSB
SECREL32LSB
SEGREL64LSB
*/
#include <linux/config.h> #include <linux/config.h>
#include <linux/kernel.h> #include <linux/kernel.h>
...@@ -16,20 +33,107 @@ ...@@ -16,20 +33,107 @@
#include <linux/string.h> #include <linux/string.h>
#include <linux/vmalloc.h> #include <linux/vmalloc.h>
#ifdef CONFIG_ITANIUM #include <asm/unaligned.h>
# define USE_BRL 0
#else
# define USE_BRL 1
#endif
#define ARCH_MODULE_DEBUG 0 #define ARCH_MODULE_DEBUG 0
#if ARCH_MODULE_DEBUG #if ARCH_MODULE_DEBUG
# define DEBUGP printk # define DEBUGP printk
# define inline
#else #else
# define DEBUGP(fmt , a...) # define DEBUGP(fmt , a...)
#endif #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
struct got_entry { struct got_entry {
uint64_t val; uint64_t val;
}; };
...@@ -42,10 +146,10 @@ struct fdesc { ...@@ -42,10 +146,10 @@ struct fdesc {
/* Opaque struct for insns, to protect against derefs. */ /* Opaque struct for insns, to protect against derefs. */
struct insn; struct insn;
static inline void * static inline uint64_t
bundle (const struct insn *insn) bundle (const struct insn *insn)
{ {
return (void *) ((uint64_t) insn & ~0xfUL); return (uint64_t) insn & ~0xfUL;
} }
static inline int static inline int
...@@ -58,7 +162,7 @@ slot (const struct insn *insn) ...@@ -58,7 +162,7 @@ slot (const struct insn *insn)
static void static void
apply (struct insn *insn, uint64_t mask, uint64_t val) apply (struct insn *insn, uint64_t mask, uint64_t val)
{ {
uint64_t m0, m1, v0, v1, b0, b1, *b = bundle(insn); uint64_t m0, m1, v0, v1, b0, b1, *b = (uint64_t *) bundle(insn);
# define insn_mask ((1UL << 41) - 1) # define insn_mask ((1UL << 41) - 1)
unsigned long shift; unsigned long shift;
...@@ -76,9 +180,13 @@ apply (struct insn *insn, uint64_t mask, uint64_t val) ...@@ -76,9 +180,13 @@ apply (struct insn *insn, uint64_t mask, uint64_t val)
} }
static int static int
apply_imm64 (struct insn *insn, uint64_t val) apply_imm64 (struct module *mod, struct insn *insn, uint64_t val)
{ {
BUG_ON(slot(insn) != 2); if (slot(insn) != 2) {
printk(KERN_ERR "%s: illegal slot number %d for IMM64\n",
mod->name, slot(insn));
return 0;
}
apply(insn, 0x01fffefe000, ( ((val & 0x8000000000000000) >> 27) /* bit 63 -> 36 */ apply(insn, 0x01fffefe000, ( ((val & 0x8000000000000000) >> 27) /* bit 63 -> 36 */
| ((val & 0x0000000000200000) << 0) /* bit 21 -> 21 */ | ((val & 0x0000000000200000) << 0) /* bit 21 -> 21 */
| ((val & 0x00000000001f0000) << 6) /* bit 16 -> 22 */ | ((val & 0x00000000001f0000) << 6) /* bit 16 -> 22 */
...@@ -89,9 +197,17 @@ apply_imm64 (struct insn *insn, uint64_t val) ...@@ -89,9 +197,17 @@ apply_imm64 (struct insn *insn, uint64_t val)
} }
static int static int
apply_imm60 (struct insn *insn, uint64_t val) apply_imm60 (struct module *mod, struct insn *insn, uint64_t val)
{ {
BUG_ON(slot(insn) != 2); if (slot(insn) != 2) {
printk(KERN_ERR "%s: illegal 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, (int64_t) val);
return 0;
}
apply(insn, 0x011ffffe000, ( ((val & 0x1000000000000000) >> 24) /* bit 60 -> 36 */ apply(insn, 0x011ffffe000, ( ((val & 0x1000000000000000) >> 24) /* bit 60 -> 36 */
| ((val & 0x00000000000fffff) << 13) /* bit 0 -> 13 */)); | ((val & 0x00000000000fffff) << 13) /* bit 0 -> 13 */));
apply((void *) insn - 1, 0x1fffffffffc, val >> 18); apply((void *) insn - 1, 0x1fffffffffc, val >> 18);
...@@ -102,7 +218,7 @@ static int ...@@ -102,7 +218,7 @@ static int
apply_imm22 (struct module *mod, struct insn *insn, uint64_t val) apply_imm22 (struct module *mod, struct insn *insn, uint64_t val)
{ {
if (val + (1 << 21) >= (1 << 22)) { if (val + (1 << 21) >= (1 << 22)) {
printk(KERN_ERR "%s: value %li out of range\n", mod->name, (int64_t)val); printk(KERN_ERR "%s: value %li out of IMM22 range\n", mod->name, (int64_t)val);
return 0; return 0;
} }
apply(insn, 0x01fffcfe000, ( ((val & 0x200000) << 15) /* bit 21 -> 36 */ apply(insn, 0x01fffcfe000, ( ((val & 0x200000) << 15) /* bit 21 -> 36 */
...@@ -116,7 +232,7 @@ static int ...@@ -116,7 +232,7 @@ static int
apply_imm21b (struct module *mod, struct insn *insn, uint64_t val) apply_imm21b (struct module *mod, struct insn *insn, uint64_t val)
{ {
if (val + (1 << 20) >= (1 << 21)) { if (val + (1 << 20) >= (1 << 21)) {
printk(KERN_ERR "%s: value %li out of range\n", mod->name, (int64_t)val); printk(KERN_ERR "%s: value %li out of IMM21b range\n", mod->name, (int64_t)val);
return 0; return 0;
} }
apply(insn, 0x11ffffe000, ( ((val & 0x100000) << 16) /* bit 20 -> 36 */ apply(insn, 0x11ffffe000, ( ((val & 0x100000) << 16) /* bit 20 -> 36 */
...@@ -146,12 +262,14 @@ static const struct plt_entry ia64_plt_template = { ...@@ -146,12 +262,14 @@ static const struct plt_entry ia64_plt_template = {
} }
}; };
static void static int
patch_plt (struct plt_entry *plt, long target_ip, unsigned long target_gp) patch_plt (struct module *mod, struct plt_entry *plt, long target_ip, unsigned long target_gp)
{ {
apply_imm64((struct insn *) (plt->bundle[0] + 2), target_gp); if (apply_imm64(mod, (struct insn *) (plt->bundle[0] + 2), target_gp)
apply_imm60((struct insn *) (plt->bundle[1] + 2), && apply_imm60(mod, (struct insn *) (plt->bundle[1] + 2),
(target_ip - (long) plt->bundle[1]) / 16); (target_ip - (int64_t) plt->bundle[1]) / 16))
return 1;
return 0;
} }
unsigned long unsigned long
...@@ -194,11 +312,13 @@ static const struct plt_entry ia64_plt_template = { ...@@ -194,11 +312,13 @@ static const struct plt_entry ia64_plt_template = {
} }
}; };
static void static int
patch_plt (struct plt_entry *plt, unsigned long target_ip, unsigned long target_gp) patch_plt (struct plt_entry *plt, unsigned long target_ip, unsigned long target_gp)
{ {
apply_imm64((struct insn *) (plt->bundle[0] + 2), target_ip); if (apply_imm64((struct insn *) (plt->bundle[0] + 2), target_ip)
apply_imm64((struct insn *) (plt->bundle[1] + 2), target_gp); && apply_imm64((struct insn *) (plt->bundle[1] + 2), target_gp))
return 1;
return 0;
} }
unsigned long unsigned long
...@@ -256,6 +376,14 @@ count_gots (const Elf64_Rela *rela, unsigned int num) ...@@ -256,6 +376,14 @@ count_gots (const Elf64_Rela *rela, unsigned int num)
for (i = 0; i < num; i++) { for (i = 0; i < num; i++) {
switch (ELF64_R_TYPE(rela[i].r_info)) { switch (ELF64_R_TYPE(rela[i].r_info)) {
case R_IA64_LTOFF22: 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)) if (!duplicate_reloc(rela, i))
ret++; ret++;
break; break;
...@@ -275,6 +403,12 @@ count_plts (const Elf64_Rela *rela, unsigned int num) ...@@ -275,6 +403,12 @@ count_plts (const Elf64_Rela *rela, unsigned int num)
for (i = 0; i < num; i++) { for (i = 0; i < num; i++) {
switch (ELF64_R_TYPE(rela[i].r_info)) { switch (ELF64_R_TYPE(rela[i].r_info)) {
case R_IA64_PCREL21B: 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)) if (!duplicate_reloc(rela, i))
ret++; ret++;
break; break;
...@@ -293,7 +427,19 @@ count_fdescs (const Elf64_Rela *rela, unsigned int num) ...@@ -293,7 +427,19 @@ count_fdescs (const Elf64_Rela *rela, unsigned int num)
/* Sure, this is order(n^2), but it's usually short, and not time critical. */ /* Sure, this is order(n^2), but it's usually short, and not time critical. */
for (i = 0; i < num; i++) { for (i = 0; i < num; i++) {
switch (ELF64_R_TYPE(rela[i].r_info)) { 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_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 * Jumps to static functions sometimes go straight to their
* offset. Of course, that may not be possible if the jump is * offset. Of course, that may not be possible if the jump is
...@@ -315,18 +461,27 @@ module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings, ...@@ -315,18 +461,27 @@ module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings,
{ {
unsigned long core_plts = 0, init_plts = 0, gots = 0, fdescs = 0; unsigned long core_plts = 0, init_plts = 0, gots = 0, fdescs = 0;
Elf64_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum; Elf64_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum;
Elf64_Shdr *core_text = NULL, *init_text = NULL;
size_t size;
/* /*
* To store the PLTs and function-descriptors, we expand the .text section for * To store the PLTs and function-descriptors, we expand the .text section for
* core module-code and the .init.text section for initialization code. * core module-code and the .init.text section for initialization code.
*/ */
for (s = sechdrs; s < sechdrs_end; ++s) for (s = sechdrs; s < sechdrs_end; ++s)
if (strcmp(".text", secstrings + s->sh_name) == 0) if (strcmp(".core.plt", secstrings + s->sh_name) == 0)
core_text = mod->arch.core_text_sec = s; mod->arch.core_plt = s;
else if (strcmp(".init.text", secstrings + s->sh_name) == 0) else if (strcmp(".init.plt", secstrings + s->sh_name) == 0)
init_text = mod->arch.init_text_sec = s; 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... */ /* GOT and PLTs can occur in any relocated section... */
for (s = sechdrs + 1; s < sechdrs_end; ++s) { for (s = sechdrs + 1; s < sechdrs_end; ++s) {
...@@ -344,90 +499,90 @@ module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings, ...@@ -344,90 +499,90 @@ module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings,
core_plts += count_plts(rels, numrels); core_plts += count_plts(rels, numrels);
} }
if ((core_plts | fdescs | gots) > 0 && !core_text) { mod->arch.core_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
printk(KERN_ERR "module %s: no .text section\n", mod->name); mod->arch.core_plt->sh_addralign = 16;
return -ENOEXEC; mod->arch.core_plt->sh_size = core_plts * sizeof(struct plt_entry);
} mod->arch.init_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
if (init_plts > 0 && !init_text) { mod->arch.init_plt->sh_addralign = 16;
printk(KERN_ERR "module %s: no .init.text section\n", mod->name); mod->arch.init_plt->sh_size = init_plts * sizeof(struct plt_entry);
return -ENOEXEC; 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_flags = SHF_ALLOC;
* Note: text sections must be at leasts 16-byte aligned, so we should be fine mod->arch.opd->sh_addralign = 8;
* here without any extra work. mod->arch.opd->sh_size = fdescs * sizeof(struct fdesc);
*/ DEBUGP("%s: core.plt=%lx, init.plt=%lx, got=%lx, fdesc=%lx\n",
size = core_text->sh_size; __FUNCTION__, mod->arch.core_plt->sh_size, mod->arch.init_plt->sh_size,
mod->arch.core_plt_offset = size; size += core_plts * sizeof(struct plt_entry); mod->arch.got->sh_size, mod->arch.opd->sh_size);
mod->arch.fdesc_offset = size; size += fdescs * sizeof(struct fdesc);
mod->arch.got_offset = size; size += gots * sizeof(struct got_entry);
core_text->sh_size = size;
DEBUGP("%s: core: sz=%lu, plt=+%lx, fdesc=+%lx, got=+%lx\n",
__FUNCTION__, size, mod->arch.core_plt_offset, mod->arch.fdesc_offset,
mod->arch.got_offset);
size = init_text->sh_size;
mod->arch.init_plt_offset = size; size += init_plts * sizeof(struct plt_entry);
init_text->sh_size = size;
DEBUGP("%s: init: sz=%lu, plt=+%lx\n", __FUNCTION__, size, mod->arch.init_plt_offset);
return 0; return 0;
} }
static inline int static inline int
in_init (const struct module *mod, void *addr) in_init (const struct module *mod, uint64_t addr)
{ {
return (uint64_t) (addr - mod->module_init) < mod->init_size; return addr - (uint64_t) mod->module_init < mod->init_size;
} }
static inline int static inline int
in_core (const struct module *mod, void *addr) in_core (const struct module *mod, uint64_t addr)
{ {
return (uint64_t) (addr - mod->module_core) < mod->core_size; return addr - (uint64_t) mod->module_core < mod->core_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 GOT entry for this value (gp points to start of GOT). Returns -1 on * Get gp-relative offset for the linkage-table entry of VALUE.
* failure.
*/ */
static uint64_t static uint64_t
get_got (struct module *mod, uint64_t value) get_ltoff (struct module *mod, uint64_t value, int *okp)
{ {
struct got_entry *got; struct got_entry *got, *e;
unsigned int i;
if (value == 0) { if (!*okp)
printk(KERN_ERR "%s: zero value in GOT\n", mod->name); return 0;
return (uint64_t) -1;
}
got = (void *) (mod->arch.core_text_sec->sh_addr + mod->arch.got_offset); got = (void *) mod->arch.got->sh_addr;
for (i = 0; got[i].val; i++) for (e = got; e < got + mod->arch.next_got_entry; ++e)
if (got[i].val == value) if (e->val == value)
return i * sizeof(struct got_entry); goto found;
/* Not enough GOT entries? */ /* Not enough GOT entries? */
if (got + i >= (struct got_entry *) (mod->arch.core_text_sec->sh_addr if (e >= (struct got_entry *) (mod->arch.got->sh_addr + mod->arch.got->sh_size))
+ mod->arch.core_text_sec->sh_size))
BUG(); BUG();
got[i].val = value; e->val = value;
return i * sizeof(struct got_entry); ++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. */ /* Get PC-relative PLT entry for this value. Returns 0 on failure. */
static uint64_t static uint64_t
get_plt (struct module *mod, const struct insn *insn, uint64_t value) get_plt (struct module *mod, const struct insn *insn, uint64_t value, int *okp)
{ {
struct plt_entry *plt, *plt_end; struct plt_entry *plt, *plt_end;
uint64_t target_ip, target_gp; uint64_t target_ip, target_gp;
if (in_init(mod, (void *) insn)) { if (!*okp)
plt = (void *) (mod->arch.init_text_sec->sh_addr + mod->arch.init_plt_offset); return 0;
plt_end = (void *) plt + mod->arch.init_text_sec->sh_size;
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 { } else {
plt = (void *) (mod->arch.core_text_sec->sh_addr + mod->arch.core_plt_offset); plt = (void *) mod->arch.core_plt->sh_addr;
plt_end = (void *) (mod->arch.core_text_sec->sh_addr + mod->arch.fdesc_offset); 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: */ /* "value" is a pointer to a function-descriptor; fetch the target ip/gp from it: */
...@@ -442,46 +597,214 @@ get_plt (struct module *mod, const struct insn *insn, uint64_t value) ...@@ -442,46 +597,214 @@ get_plt (struct module *mod, const struct insn *insn, uint64_t value)
BUG(); BUG();
} }
*plt = ia64_plt_template; *plt = ia64_plt_template;
patch_plt(plt, target_ip, target_gp); if (!patch_plt(mod, plt, target_ip, target_gp)) {
*okp = 0;
return 0;
}
#if ARCH_MODULE_DEBUG #if ARCH_MODULE_DEBUG
if (plt_target(plt) != target_ip) if (plt_target(plt) != target_ip) {
printk("%s: mistargeted PLT: wanted %lx, got %lx\n", printk("%s: mistargeted PLT: wanted %lx, got %lx\n",
__FUNCTION__, target_ip, plt_target(plt)); __FUNCTION__, target_ip, plt_target(plt));
*okp = 0;
return 0;
}
#endif #endif
found: found:
return (uint64_t) plt; return (uint64_t) plt;
} }
/* Get function descriptor for this function. Returns 0 on failure. */ /* Get function descriptor for VALUE. */
static uint64_t static uint64_t
get_fdesc (struct module *mod, uint64_t value) get_fdesc (struct module *mod, uint64_t value, int *okp)
{ {
struct fdesc *fdesc = (void *) (mod->arch.core_text_sec->sh_addr + mod->arch.fdesc_offset); struct fdesc *fdesc = (void *) mod->arch.opd->sh_addr;
if (!*okp)
return 0;
if (!value) { if (!value) {
printk(KERN_ERR "%s: fdesc for zero requested!\n", mod->name); printk(KERN_ERR "%s: fdesc for zero requested!\n", mod->name);
return 0; 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. */ /* Look for existing function descriptor. */
while (fdesc->ip) { while (fdesc->ip) {
if (fdesc->ip == value) if (fdesc->ip == value)
return (uint64_t)fdesc; return (uint64_t)fdesc;
if ((uint64_t) ++fdesc >= (mod->arch.core_text_sec->sh_addr if ((uint64_t) ++fdesc >= mod->arch.opd->sh_addr + mod->arch.opd->sh_size)
+ mod->arch.core_text_sec->sh_size))
BUG(); BUG();
} }
/* Create new one */ /* Create new one */
fdesc->ip = value; fdesc->ip = value;
fdesc->gp = mod->arch.core_text_sec->sh_addr + mod->arch.got_offset; fdesc->gp = mod->arch.gp;
return (uint64_t)fdesc; return (uint64_t) fdesc;
} }
static inline int static inline int
is_internal (const struct module *mod, uint64_t value) do_reloc (struct module *mod, uint8_t r_type, Elf64_Sym *sym, uint64_t addend,
Elf64_Shdr *sec, void *location)
{ {
return in_init(mod, (void *)value) || in_core(mod, (void *)value); 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:
/* special because it can cross into other module/kernel-core. */
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->module_init : mod->module_core);
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",
__FUNCTION__, reloc_name[r_type], 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", __FUNCTION__, location);
apply(location, 0x1fff80fe000, 0x10000000000);
}
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", __FUNCTION__, 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 int
...@@ -490,12 +813,10 @@ apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symind ...@@ -490,12 +813,10 @@ apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symind
{ {
unsigned int i, n = sechdrs[relsec].sh_size / sizeof(Elf64_Rela); unsigned int i, n = sechdrs[relsec].sh_size / sizeof(Elf64_Rela);
Elf64_Rela *rela = (void *) sechdrs[relsec].sh_addr; Elf64_Rela *rela = (void *) sechdrs[relsec].sh_addr;
Elf64_Sym *symtab, *sym;
Elf64_Shdr *target_sec; Elf64_Shdr *target_sec;
void *base, *location; int ret;
uint64_t value;
DEBUGP("apply_relocate_add: applying section %u (%u relocs) to %u\n", DEBUGP("%s: applying section %u (%u relocs) to %u\n", __FUNCTION__,
relsec, n, sechdrs[relsec].sh_info); relsec, n, sechdrs[relsec].sh_info);
target_sec = sechdrs + sechdrs[relsec].sh_info; target_sec = sechdrs + sechdrs[relsec].sh_info;
...@@ -507,99 +828,26 @@ apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symind ...@@ -507,99 +828,26 @@ apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symind
*/ */
return 0; return 0;
base = (void *) target_sec->sh_addr; if (!mod->arch.gp) {
symtab = (Elf64_Sym *) sechdrs[symindex].sh_addr; /*
DEBUGP("base=%p, symtab=%p\n", base, symtab); * XXX Should have an arch-hook for running this after final section
* addresses have been selected...
*/
uint64_t gp = (uint64_t) mod->module_core + MAX_LTOFF / 2;
if ((mod->arch.got->sh_addr + mod->arch.got->sh_size) - gp >= MAX_LTOFF)
gp = mod->arch.got->sh_addr + mod->arch.got->sh_size - MAX_LTOFF / 2;
mod->arch.gp = gp;
DEBUGP("%s: placing gp at 0x%lx\n", __FUNCTION__, gp);
}
for (i = 0; i < n; i++) { for (i = 0; i < n; i++) {
/* This is where to make the change */ ret = do_reloc(mod, ELF64_R_TYPE(rela[i].r_info),
location = base + rela[i].r_offset; ((Elf64_Sym *) sechdrs[symindex].sh_addr
+ ELF64_R_SYM(rela[i].r_info)),
/* This is the symbol it is referring to */ rela[i].r_addend, target_sec,
sym = symtab + ELF64_R_SYM(rela[i].r_info); (void *) target_sec->sh_addr + rela[i].r_offset);
if (!sym->st_value) if (ret < 0)
return -ENOENT; return ret;
/* `Everything is relative'. */
value = sym->st_value + rela[i].r_addend;
DEBUGP("loc=%p, val=0x%lx, sym=%p: ", location, value, sym);
switch (ELF64_R_TYPE(rela[i].r_info)) {
case R_IA64_LTOFF22:
value = get_got(mod, value);
DEBUGP("LTOFF22 0x%lx\n", value);
if (value == (uint64_t)-1 || !apply_imm22(mod, location, value))
return -ENOEXEC;
break;
case R_IA64_PCREL21B:
if (!is_internal(mod, value))
value = get_plt(mod, location, value);
DEBUGP("PCREL21B 0x%lx\n", value);
value -= (uint64_t) bundle(location);
if (!apply_imm21b(mod, location, (long) value / 16))
return -ENOEXEC;
break;
case R_IA64_DIR32LSB:
DEBUGP("DIR32LSB 0x%lx\n", value);
*((uint32_t *)location) = value;
break;
case R_IA64_SEGREL64LSB:
/* My definition of "segment" is a little fuzzy here, but quoth
David Mosberger-Tang:
As long as it's used consistently, it doesn't matter much. All
unwind offsets are 64-bit offsets anyhow, so you could just use
a segment base of zero (the reason SEGREL relocs are used is to
make it possible to have the unwind tables be read-only in
shared libraries, but since you need to do relocation anyhow,
that's a moot issue). */
/* Fall thru */
case R_IA64_DIR64LSB:
DEBUGP("DIR64LSB 0x%lx\n", value);
*((uint64_t *)location) = value;
break;
case R_IA64_FPTR64LSB:
/* Create a function descriptor for internal functions only. */
if (is_internal(mod, value))
value = get_fdesc(mod, value);
DEBUGP("FPTR64LSB 0x%lx\n", value);
*((uint64_t *)location) = value;
break;
case R_IA64_GPREL22:
value -= mod->arch.core_text_sec->sh_addr + mod->arch.got_offset;
DEBUGP("GPREL22 0x%lx\n", value);
if (!apply_imm22(mod, location, value))
return -ENOEXEC;
break;
case R_IA64_LTOFF_FPTR22:
DEBUGP("LTOFF_FPTR22: orig=%lx, ", value);
if (is_internal(mod, value))
value = get_fdesc(mod, value);
DEBUGP("fdesc=%lx, ", value);
value = get_got(mod, value);
DEBUGP("got=%lx\n", value);
if (value == (uint64_t) -1 || !apply_imm22(mod, location, value))
return -ENOEXEC;
break;
case R_IA64_SECREL32LSB:
DEBUGP("SECREL32LSB: orig=0x%lx, val=0x%lx\n",
value, value - (uint64_t) base);
*(uint32_t *) location = value - (uint64_t) base;
break;
default:
printk(KERN_ERR "%s: Unknown RELA relocation: %lu\n",
mod->name, ELF64_R_TYPE(rela[i].r_info));
return -ENOEXEC;
}
} }
return 0; return 0;
} }
...@@ -616,5 +864,17 @@ int ...@@ -616,5 +864,17 @@ int
module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod) module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod)
{ {
DEBUGP("%s: init: entry=%p\n", __FUNCTION__, mod->init); DEBUGP("%s: init: entry=%p\n", __FUNCTION__, mod->init);
if (mod->arch.unwind)
mod->arch.unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp,
(void *) mod->arch.unwind->sh_addr,
((void *) mod->arch.unwind->sh_addr
+ mod->arch.unwind->sh_size));
return 0; return 0;
} }
void
module_arch_cleanup (struct module *mod)
{
if (mod->arch.unwind)
unw_remove_unwind_table(mod->arch.unw_table);
}
include/asm-ia64/module.h
View file @ ceb689ec
...@@ -11,19 +11,15 @@ ...@@ -11,19 +11,15 @@
struct elf64_shdr; /* forward declration */ struct elf64_shdr; /* forward declration */
struct mod_arch_specific { struct mod_arch_specific {
/* struct elf64_shdr *core_plt; /* core PLT section */
* PLTs need to be within 16MB of the call-site. Since the core and the init struct elf64_shdr *init_plt; /* init PLT section */
* sections are allocated separately, we need to maintain separate PLT areas struct elf64_shdr *got; /* global offset table */
* for them. Function descriptors and global-offset-table entries are, in struct elf64_shdr *opd; /* official procedure descriptors */
* contrast, always allocated in the core. struct elf64_shdr *unwind; /* unwind-table section */
*/ unsigned long gp; /* global-pointer for module */
struct elf64_shdr *init_text_sec; /* .init.text section (or NULL) */
unsigned long init_plt_offset; void *unw_table; /* unwind-table cookie returned by unwinder */
unsigned int next_got_entry; /* index of next available got entry */
struct elf64_shdr *core_text_sec; /* .text section (or NULL) */
unsigned long core_plt_offset;
unsigned long fdesc_offset;
unsigned long got_offset;
}; };
#define Elf_Shdr Elf64_Shdr #define Elf_Shdr Elf64_Shdr
...@@ -33,4 +29,6 @@ struct mod_arch_specific { ...@@ -33,4 +29,6 @@ struct mod_arch_specific {
#define MODULE_PROC_FAMILY "ia64" #define MODULE_PROC_FAMILY "ia64"
#define MODULE_ARCH_VERMAGIC MODULE_PROC_FAMILY #define MODULE_ARCH_VERMAGIC MODULE_PROC_FAMILY
#define ARCH_SHF_SMALL SHF_IA_64_SHORT
#endif /* _ASM_IA64_MODULE_H */ #endif /* _ASM_IA64_MODULE_H */
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