RISC-V: ELF and module implementation

/*

 * 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_COMPAT_H

#define __ASM_COMPAT_H

#ifdef CONFIG_COMPAT

#if defined(CONFIG_64BIT)

#define COMPAT_UTS_MACHINE "riscv64\0\0"

#elif defined(CONFIG_32BIT)

#define COMPAT_UTS_MACHINE "riscv32\0\0"

#else

#error "Unknown RISC-V base ISA"

#endif

#endif /*CONFIG_COMPAT*/

#endif /*__ASM_COMPAT_H*/

/*

 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>

 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>

 * Copyright (C) 2012 Regents of the University of California

 *

 * 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.

 */

#ifndef _ASM_RISCV_ELF_H

#define _ASM_RISCV_ELF_H

#include <uapi/asm/elf.h>

#include <asm/auxvec.h>

#include <asm/byteorder.h>

/* TODO: Move definition into include/uapi/linux/elf-em.h */

#define EM_RISCV	0xF3

/*

 * These are used to set parameters in the core dumps.

 */

#define ELF_ARCH	EM_RISCV

#ifdef CONFIG_64BIT

#define ELF_CLASS	ELFCLASS64

#else

#define ELF_CLASS	ELFCLASS32

#endif

#if defined(__LITTLE_ENDIAN)

#define ELF_DATA	ELFDATA2LSB

#elif defined(__BIG_ENDIAN)

#define ELF_DATA	ELFDATA2MSB

#else

#error "Unknown endianness"

#endif

/*

 * This is used to ensure we don't load something for the wrong architecture.

 */

#define elf_check_arch(x) ((x)->e_machine == EM_RISCV)

#define CORE_DUMP_USE_REGSET

#define ELF_EXEC_PAGESIZE	(PAGE_SIZE)

/*

 * This is the location that an ET_DYN program is loaded if exec'ed.  Typical

 * use of this is to invoke "./ld.so someprog" to test out a new version of

 * the loader.  We need to make sure that it is out of the way of the program

 * that it will "exec", and that there is sufficient room for the brk.

 */

#define ELF_ET_DYN_BASE		((TASK_SIZE / 3) * 2)

/*

 * This yields a mask that user programs can use to figure out what

 * instruction set this CPU supports.  This could be done in user space,

 * but it's not easy, and we've already done it here.

 */

#define ELF_HWCAP	(elf_hwcap)

extern unsigned long elf_hwcap;

/*

 * This yields a string that ld.so will use to load implementation

 * specific libraries for optimization.  This is more specific in

 * intent than poking at uname or /proc/cpuinfo.

 */

#define ELF_PLATFORM	(NULL)

#define ARCH_DLINFO						\

do {								\

	NEW_AUX_ENT(AT_SYSINFO_EHDR,				\

		(elf_addr_t)current->mm->context.vdso);		\

} while (0)

#define ARCH_HAS_SETUP_ADDITIONAL_PAGES

struct linux_binprm;

extern int arch_setup_additional_pages(struct linux_binprm *bprm,

	int uses_interp);

#endif /* _ASM_RISCV_ELF_H */

/*

 * Copied from arch/arm64/include/asm/hwcap.h

 *

 * Copyright (C) 2012 ARM Ltd.

 * Copyright (C) 2017 SiFive

 *

 * 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_HWCAP_H

#define __ASM_HWCAP_H

#include <uapi/asm/hwcap.h>

#ifndef __ASSEMBLY__

/*

 * This yields a mask that user programs can use to figure out what

 * instruction set this cpu supports.

 */

#define ELF_HWCAP		(elf_hwcap)

enum {

	CAP_HWCAP = 1,

};

extern unsigned long elf_hwcap;

#endif

#endif

/*

 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.

 *  Lennox Wu <lennox.wu@sunplusct.com>

 *  Chen Liqin <liqin.chen@sunplusct.com>

 * Copyright (C) 2013 Regents of the University of California

 *

 * 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, see the file COPYING, or write

 * to the Free Software Foundation, Inc.,

 */

#include <linux/extable.h>

#include <linux/module.h>

#include <linux/uaccess.h>

int fixup_exception(struct pt_regs *regs)

{

	const struct exception_table_entry *fixup;

	fixup = search_exception_tables(regs->sepc);

	if (fixup) {

		regs->sepc = fixup->fixup;

		return 1;

	}

	return 0;

}