path: root/arch/ia64/kernel/module.c

/*
 * 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/config.h>

#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>

#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

struct got_entry {
	uint64_t val;
};

struct fdesc {
	uint64_t ip;
	uint64_t gp;
};

/* 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 &</