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/*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_MODULE_H
#define __ASM_MODULE_H
#include <asm-generic/module.h>
#define MODULE_ARCH_VERMAGIC "aarch64"
#ifdef CONFIG_ARM64_MODULE_PLTS
struct mod_plt_sec {
struct elf64_shdr *plt;
int plt_num_entries;
int plt_max_entries;
};
struct mod_arch_specific {
struct mod_plt_sec core;
struct mod_plt_sec init;
/* for CONFIG_DYNAMIC_FTRACE */
struct plt_entry *ftrace_trampoline;
};
#endif
u64 module_emit_plt_entry(struct module *mod, void *loc, const Elf64_Rela *rela,
Elf64_Sym *sym);
#ifdef CONFIG_RANDOMIZE_BASE
extern u64 module_alloc_base;
#else
#define module_alloc_base ((u64)_etext - MODULES_VSIZE)
#endif
struct plt_entry {
/*
* A program that conforms to the AArch64 Procedure Call Standard
* (AAPCS64) must assume that a veneer that alters IP0 (x16) and/or
* IP1 (x17) may be inserted at any branch instruction that is
* exposed to a relocation that supports long branches. Since that
* is exactly what we are dealing with here, we are free to use x16
* as a scratch register in the PLT veneers.
*/
__le32 mov0; /* movn x16, #0x.... */
__le32 mov1; /* movk x16, #0x...., lsl #16 */
__le32 mov2; /* movk x16, #0x...., lsl #32 */
__le32 br; /* br x16 */
};
static inline struct plt_entry get_plt_entry(u64 val)
{
/*
* MOVK/MOVN/MOVZ opcode:
* +--------+------------+--------+-----------+-------------+---------+
* | sf[31] | opc[30:29] | 100101 | hw[22:21] | imm16[20:5] | Rd[4:0] |
* +--------+------------+--------+-----------+-------------+---------+
*
* Rd := 0x10 (x16)
* hw := 0b00 (no shift), 0b01 (lsl #16), 0b10 (lsl #32)
* opc := 0b11 (MOVK), 0b00 (MOVN), 0b10 (MOVZ)
* sf := 1 (64-bit variant)
*/
return (struct plt_entry){
cpu_to_le32(0x92800010 | (((~val ) & 0xffff)) << 5),
cpu_to_le32(0xf2a00010 | ((( val >> 16) & 0xffff)) << 5),
cpu_to_le32(0xf2c00010 | ((( val >> 32) & 0xffff)) << 5),
cpu_to_le32(0xd61f0200)
};
}
static inline bool plt_entries_equal(const struct plt_entry *a,
const struct plt_entry *b)
{
return a->mov0 == b->mov0 &&
a->mov1 == b->mov1 &&
a->mov2 == b->mov2;
}
#endif /* __ASM_MODULE_H */
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