From 2129a235c098960c57d4b6ef23be842a98d97ac9 Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Mon, 10 Jul 2017 18:03:49 -0700 Subject: [PATCH] RISC-V: ELF and module implementation This patch contains the code that interfaces with ELF objects on RISC-V systems, the vast majority of which is present to load kernel modules. Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/compat.h | 29 ++++++++++++ arch/riscv/include/asm/elf.h | 84 +++++++++++++++++++++++++++++++++ arch/riscv/include/asm/hwcap.h | 37 +++++++++++++++ arch/riscv/mm/extable.c | 37 +++++++++++++++ 4 files changed, 187 insertions(+) create mode 100644 arch/riscv/include/asm/compat.h create mode 100644 arch/riscv/include/asm/elf.h create mode 100644 arch/riscv/include/asm/hwcap.h create mode 100644 arch/riscv/mm/extable.c diff --git a/arch/riscv/include/asm/compat.h b/arch/riscv/include/asm/compat.h new file mode 100644 index 000000000000..044aecff8854 --- /dev/null +++ b/arch/riscv/include/asm/compat.h @@ -0,0 +1,29 @@ +/* + * 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 . + */ +#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*/ diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h new file mode 100644 index 000000000000..a1ef503d616e --- /dev/null +++ b/arch/riscv/include/asm/elf.h @@ -0,0 +1,84 @@ +/* + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * 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 +#include +#include + +/* 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 */ diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h new file mode 100644 index 000000000000..8a4ed7bbcbea --- /dev/null +++ b/arch/riscv/include/asm/hwcap.h @@ -0,0 +1,37 @@ +/* + * 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 . + */ +#ifndef __ASM_HWCAP_H +#define __ASM_HWCAP_H + +#include + +#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 diff --git a/arch/riscv/mm/extable.c b/arch/riscv/mm/extable.c new file mode 100644 index 000000000000..11bb9417123b --- /dev/null +++ b/arch/riscv/mm/extable.c @@ -0,0 +1,37 @@ +/* + * Copyright (C) 2009 Sunplus Core Technology Co., Ltd. + * Lennox Wu + * Chen Liqin + * 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 +#include +#include + +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; +}