Re: [PATCH V12 17/24] LoongArch: Add ELF and module support

From: Jiaxun Yang
Date: Wed Jun 01 2022 - 08:31:34 EST

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在2022年6月1日六月上午10:59，Huacai Chen写道：
> Add ELF-related definition and module relocation code for basic
> LoongArch support.
>
> Cc: Jessica Yu <jeyu@xxxxxxxxxx>
> Reviewed-by: WANG Xuerui <git@xxxxxxxxxx>
> Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>

Reviewed-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>

> ---
> arch/loongarch/include/asm/cpufeature.h | 24 ++
> arch/loongarch/include/asm/elf.h | 301 ++++++++++++++++++
> arch/loongarch/include/asm/exec.h | 10 +
> arch/loongarch/include/asm/module.h | 80 +++++
> arch/loongarch/include/asm/module.lds.h | 7 +
> arch/loongarch/include/asm/vermagic.h | 19 ++
> arch/loongarch/include/uapi/asm/auxvec.h | 17 ++
> arch/loongarch/include/uapi/asm/hwcap.h | 20 ++
> arch/loongarch/kernel/elf.c | 30 ++
> arch/loongarch/kernel/inst.c | 40 +++
> arch/loongarch/kernel/module-sections.c | 121 ++++++++
> arch/loongarch/kernel/module.c | 374 +++++++++++++++++++++++
> 12 files changed, 1043 insertions(+)
> create mode 100644 arch/loongarch/include/asm/cpufeature.h
> create mode 100644 arch/loongarch/include/asm/elf.h
> create mode 100644 arch/loongarch/include/asm/exec.h
> create mode 100644 arch/loongarch/include/asm/module.h
> create mode 100644 arch/loongarch/include/asm/module.lds.h
> create mode 100644 arch/loongarch/include/asm/vermagic.h
> create mode 100644 arch/loongarch/include/uapi/asm/auxvec.h
> create mode 100644 arch/loongarch/include/uapi/asm/hwcap.h
> create mode 100644 arch/loongarch/kernel/elf.c
> create mode 100644 arch/loongarch/kernel/inst.c
> create mode 100644 arch/loongarch/kernel/module-sections.c
> create mode 100644 arch/loongarch/kernel/module.c
>
> diff --git a/arch/loongarch/include/asm/cpufeature.h
> b/arch/loongarch/include/asm/cpufeature.h
> new file mode 100644
> index 000000000000..4da22a8e63de
> --- /dev/null
> +++ b/arch/loongarch/include/asm/cpufeature.h
> @@ -0,0 +1,24 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * CPU feature definitions for module loading, used by
> + * module_cpu_feature_match(), see uapi/asm/hwcap.h for LoongArch CPU
> features.
> + *
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __ASM_CPUFEATURE_H
> +#define __ASM_CPUFEATURE_H
> +
> +#include <uapi/asm/hwcap.h>
> +#include <asm/elf.h>
> +
> +#define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap))
> +
> +#define cpu_feature(x) ilog2(HWCAP_ ## x)
> +
> +static inline bool cpu_have_feature(unsigned int num)
> +{
> + return elf_hwcap & (1UL << num);
> +}
> +
> +#endif /* __ASM_CPUFEATURE_H */
> diff --git a/arch/loongarch/include/asm/elf.h
> b/arch/loongarch/include/asm/elf.h
> new file mode 100644
> index 000000000000..f3960b18a90e
> --- /dev/null
> +++ b/arch/loongarch/include/asm/elf.h
> @@ -0,0 +1,301 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +#ifndef _ASM_ELF_H
> +#define _ASM_ELF_H
> +
> +#include <linux/auxvec.h>
> +#include <linux/fs.h>
> +#include <uapi/linux/elf.h>
> +
> +#include <asm/current.h>
> +#include <asm/vdso.h>
> +
> +/* The ABI of a file. */
> +#define EF_LOONGARCH_ABI_LP64_SOFT_FLOAT 0x1
> +#define EF_LOONGARCH_ABI_LP64_SINGLE_FLOAT 0x2
> +#define EF_LOONGARCH_ABI_LP64_DOUBLE_FLOAT 0x3
> +
> +#define EF_LOONGARCH_ABI_ILP32_SOFT_FLOAT 0x5
> +#define EF_LOONGARCH_ABI_ILP32_SINGLE_FLOAT 0x6
> +#define EF_LOONGARCH_ABI_ILP32_DOUBLE_FLOAT 0x7
> +
> +/* LoongArch relocation types used by the dynamic linker */
> +#define R_LARCH_NONE 0
> +#define R_LARCH_32 1
> +#define R_LARCH_64 2
> +#define R_LARCH_RELATIVE 3
> +#define R_LARCH_COPY 4
> +#define R_LARCH_JUMP_SLOT 5
> +#define R_LARCH_TLS_DTPMOD32 6
> +#define R_LARCH_TLS_DTPMOD64 7
> +#define R_LARCH_TLS_DTPREL32 8
> +#define R_LARCH_TLS_DTPREL64 9
> +#define R_LARCH_TLS_TPREL32 10
> +#define R_LARCH_TLS_TPREL64 11
> +#define R_LARCH_IRELATIVE 12
> +#define R_LARCH_MARK_LA 20
> +#define R_LARCH_MARK_PCREL 21
> +#define R_LARCH_SOP_PUSH_PCREL 22
> +#define R_LARCH_SOP_PUSH_ABSOLUTE 23
> +#define R_LARCH_SOP_PUSH_DUP 24
> +#define R_LARCH_SOP_PUSH_GPREL 25
> +#define R_LARCH_SOP_PUSH_TLS_TPREL 26
> +#define R_LARCH_SOP_PUSH_TLS_GOT 27
> +#define R_LARCH_SOP_PUSH_TLS_GD 28
> +#define R_LARCH_SOP_PUSH_PLT_PCREL 29
> +#define R_LARCH_SOP_ASSERT 30
> +#define R_LARCH_SOP_NOT 31
> +#define R_LARCH_SOP_SUB 32
> +#define R_LARCH_SOP_SL 33
> +#define R_LARCH_SOP_SR 34
> +#define R_LARCH_SOP_ADD 35
> +#define R_LARCH_SOP_AND 36
> +#define R_LARCH_SOP_IF_ELSE 37
> +#define R_LARCH_SOP_POP_32_S_10_5 38
> +#define R_LARCH_SOP_POP_32_U_10_12 39
> +#define R_LARCH_SOP_POP_32_S_10_12 40
> +#define R_LARCH_SOP_POP_32_S_10_16 41
> +#define R_LARCH_SOP_POP_32_S_10_16_S2 42
> +#define R_LARCH_SOP_POP_32_S_5_20 43
> +#define R_LARCH_SOP_POP_32_S_0_5_10_16_S2 44
> +#define R_LARCH_SOP_POP_32_S_0_10_10_16_S2 45
> +#define R_LARCH_SOP_POP_32_U 46
> +#define R_LARCH_ADD8 47
> +#define R_LARCH_ADD16 48
> +#define R_LARCH_ADD24 49
> +#define R_LARCH_ADD32 50
> +#define R_LARCH_ADD64 51
> +#define R_LARCH_SUB8 52
> +#define R_LARCH_SUB16 53
> +#define R_LARCH_SUB24 54
> +#define R_LARCH_SUB32 55
> +#define R_LARCH_SUB64 56
> +#define R_LARCH_GNU_VTINHERIT 57
> +#define R_LARCH_GNU_VTENTRY 58
> +
> +#ifndef ELF_ARCH
> +
> +/* ELF register definitions */
> +
> +/*
> + * General purpose have the following registers:
> + * Register Number
> + * GPRs 32
> + * ORIG_A0 1
> + * ERA 1
> + * BADVADDR 1
> + * CRMD 1
> + * PRMD 1
> + * EUEN 1
> + * ECFG 1
> + * ESTAT 1
> + * Reserved 5
> + */
> +#define ELF_NGREG 45
> +
> +/*
> + * Floating point have the following registers:
> + * Register Number
> + * FPR 32
> + * FCC 1
> + * FCSR 1
> + */
> +#define ELF_NFPREG 34
> +
> +typedef unsigned long elf_greg_t;
> +typedef elf_greg_t elf_gregset_t[ELF_NGREG];
> +
> +typedef double elf_fpreg_t;
> +typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
> +
> +void loongarch_dump_regs64(u64 *uregs, const struct pt_regs *regs);
> +
> +#ifdef CONFIG_32BIT
> +/*
> + * This is used to ensure we don't load something for the wrong
> architecture.
> + */
> +#define elf_check_arch elf32_check_arch
> +
> +/*
> + * These are used to set parameters in the core dumps.
> + */
> +#define ELF_CLASS ELFCLASS32
> +
> +#define ELF_CORE_COPY_REGS(dest, regs) \
> + loongarch_dump_regs32((u32 *)&(dest), (regs));
> +
> +#endif /* CONFIG_32BIT */
> +
> +#ifdef CONFIG_64BIT
> +/*
> + * This is used to ensure we don't load something for the wrong
> architecture.
> + */
> +#define elf_check_arch elf64_check_arch
> +
> +/*
> + * These are used to set parameters in the core dumps.
> + */
> +#define ELF_CLASS ELFCLASS64
> +
> +#define ELF_CORE_COPY_REGS(dest, regs) \
> + loongarch_dump_regs64((u64 *)&(dest), (regs));
> +
> +#endif /* CONFIG_64BIT */
> +
> +/*
> + * These are used to set parameters in the core dumps.
> + */
> +#define ELF_DATA ELFDATA2LSB
> +#define ELF_ARCH EM_LOONGARCH
> +
> +#endif /* !defined(ELF_ARCH) */
> +
> +#define loongarch_elf_check_machine(x) ((x)->e_machine == EM_LOONGARCH)
> +
> +#define vmcore_elf32_check_arch loongarch_elf_check_machine
> +#define vmcore_elf64_check_arch loongarch_elf_check_machine
> +
> +/*
> + * Return non-zero if HDR identifies an 32bit ELF binary.
> + */
> +#define elf32_check_arch(hdr) \
> +({ \
> + int __res = 1; \
> + struct elfhdr *__h = (hdr); \
> + \
> + if (!loongarch_elf_check_machine(__h)) \
> + __res = 0; \
> + if (__h->e_ident[EI_CLASS] != ELFCLASS32) \
> + __res = 0; \
> + \
> + __res; \
> +})
> +
> +/*
> + * Return non-zero if HDR identifies an 64bit ELF binary.
> + */
> +#define elf64_check_arch(hdr) \
> +({ \
> + int __res = 1; \
> + struct elfhdr *__h = (hdr); \
> + \
> + if (!loongarch_elf_check_machine(__h)) \
> + __res = 0; \
> + if (__h->e_ident[EI_CLASS] != ELFCLASS64) \
> + __res = 0; \
> + \
> + __res; \
> +})
> +
> +#ifdef CONFIG_32BIT
> +
> +#define SET_PERSONALITY2(ex, state) \
> +do { \
> + current->thread.vdso = &vdso_info; \
> + \
> + loongarch_set_personality_fcsr(state); \
> + \
> + if (personality(current->personality) != PER_LINUX) \
> + set_personality(PER_LINUX); \
> +} while (0)
> +
> +#endif /* CONFIG_32BIT */
> +
> +#ifdef CONFIG_64BIT
> +
> +#define SET_PERSONALITY2(ex, state) \
> +do { \
> + unsigned int p; \
> + \
> + clear_thread_flag(TIF_32BIT_REGS); \
> + clear_thread_flag(TIF_32BIT_ADDR); \
> + \
> + current->thread.vdso = &vdso_info; \
> + loongarch_set_personality_fcsr(state); \
> + \
> + p = personality(current->personality); \
> + if (p != PER_LINUX32 && p != PER_LINUX) \
> + set_personality(PER_LINUX); \
> +} while (0)
> +
> +#endif /* CONFIG_64BIT */
> +
> +#define CORE_DUMP_USE_REGSET
> +#define ELF_EXEC_PAGESIZE PAGE_SIZE
> +
> +/*
> + * This yields a mask that user programs can use to figure out what
> + * instruction set this cpu supports. This could be done in userspace,
> + * but it's not easy, and we've already done it here.
> + */
> +
> +#define ELF_HWCAP (elf_hwcap)
> +extern unsigned int elf_hwcap;
> +#include <asm/hwcap.h>
> +
> +/*
> + * 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 __elf_platform
> +extern const char *__elf_platform;
> +
> +#define ELF_PLAT_INIT(_r, load_addr) do { \
> + _r->regs[1] = _r->regs[2] = _r->regs[3] = _r->regs[4] = 0; \
> + _r->regs[5] = _r->regs[6] = _r->regs[7] = _r->regs[8] = 0; \
> + _r->regs[9] = _r->regs[10] = _r->regs[11] = _r->regs[12] = 0; \
> + _r->regs[13] = _r->regs[14] = _r->regs[15] = _r->regs[16] = 0; \
> + _r->regs[17] = _r->regs[18] = _r->regs[19] = _r->regs[20] = 0; \
> + _r->regs[21] = _r->regs[22] = _r->regs[23] = _r->regs[24] = 0; \
> + _r->regs[25] = _r->regs[26] = _r->regs[27] = _r->regs[28] = 0; \
> + _r->regs[29] = _r->regs[30] = _r->regs[31] = 0; \
> +} while (0)
> +
> +/*
> + * 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)
> +
> +/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries
> changes */
> +#define ARCH_DLINFO \
> +do { \
> + NEW_AUX_ENT(AT_SYSINFO_EHDR, \
> + (unsigned long)current->mm->context.vdso); \
> +} while (0)
> +
> +#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
> +struct linux_binprm;
> +extern int arch_setup_additional_pages(struct linux_binprm *bprm,
> + int uses_interp);
> +
> +struct arch_elf_state {
> + int fp_abi;
> + int interp_fp_abi;
> +};
> +
> +#define LOONGARCH_ABI_FP_ANY (0)
> +
> +#define INIT_ARCH_ELF_STATE { \
> + .fp_abi = LOONGARCH_ABI_FP_ANY, \
> + .interp_fp_abi = LOONGARCH_ABI_FP_ANY, \
> +}
> +
> +#define elf_read_implies_exec(ex, exec_stk) (exec_stk ==
> EXSTACK_DEFAULT)
> +
> +extern int arch_elf_pt_proc(void *ehdr, void *phdr, struct file *elf,
> + bool is_interp, struct arch_elf_state *state);
> +
> +extern int arch_check_elf(void *ehdr, bool has_interpreter, void
> *interp_ehdr,
> + struct arch_elf_state *state);
> +
> +extern void loongarch_set_personality_fcsr(struct arch_elf_state
> *state);
> +
> +#endif /* _ASM_ELF_H */
> diff --git a/arch/loongarch/include/asm/exec.h
> b/arch/loongarch/include/asm/exec.h
> new file mode 100644
> index 000000000000..ba0220812ebb
> --- /dev/null
> +++ b/arch/loongarch/include/asm/exec.h
> @@ -0,0 +1,10 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +#ifndef _ASM_EXEC_H
> +#define _ASM_EXEC_H
> +
> +extern unsigned long arch_align_stack(unsigned long sp);
> +
> +#endif /* _ASM_EXEC_H */
> diff --git a/arch/loongarch/include/asm/module.h
> b/arch/loongarch/include/asm/module.h
> new file mode 100644
> index 000000000000..9f6718df1854
> --- /dev/null
> +++ b/arch/loongarch/include/asm/module.h
> @@ -0,0 +1,80 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +#ifndef _ASM_MODULE_H
> +#define _ASM_MODULE_H
> +
> +#include <asm/inst.h>
> +#include <asm-generic/module.h>
> +
> +#define RELA_STACK_DEPTH 16
> +
> +struct mod_section {
> + Elf_Shdr *shdr;
> + int num_entries;
> + int max_entries;
> +};
> +
> +struct mod_arch_specific {
> + struct mod_section plt;
> + struct mod_section plt_idx;
> +};
> +
> +struct plt_entry {
> + u32 inst_lu12iw;
> + u32 inst_lu32id;
> + u32 inst_lu52id;
> + u32 inst_jirl;
> +};
> +
> +struct plt_idx_entry {
> + unsigned long symbol_addr;
> +};
> +
> +Elf_Addr module_emit_plt_entry(struct module *mod, unsigned long val);
> +
> +static inline struct plt_entry emit_plt_entry(unsigned long val)
> +{
> + u32 lu12iw, lu32id, lu52id, jirl;
> +
> + lu12iw = (lu12iw_op << 25 | (((val >> 12) & 0xfffff) << 5) |
> LOONGARCH_GPR_T1);
> + lu32id = larch_insn_gen_lu32id(LOONGARCH_GPR_T1, ADDR_IMM(val,
> LU32ID));
> + lu52id = larch_insn_gen_lu52id(LOONGARCH_GPR_T1, LOONGARCH_GPR_T1,
> ADDR_IMM(val, LU52ID));
> + jirl = larch_insn_gen_jirl(0, LOONGARCH_GPR_T1, 0, (val & 0xfff));
> +
> + return (struct plt_entry) { lu12iw, lu32id, lu52id, jirl };
> +}
> +
> +static inline struct plt_idx_entry emit_plt_idx_entry(unsigned long
> val)
> +{
> + return (struct plt_idx_entry) { val };
> +}
> +
> +static inline int get_plt_idx(unsigned long val, const struct
> mod_section *sec)
> +{
> + int i;
> + struct plt_idx_entry *plt_idx = (struct plt_idx_entry
> *)sec->shdr->sh_addr;
> +
> + for (i = 0; i < sec->num_entries; i++) {
> + if (plt_idx[i].symbol_addr == val)
> + return i;
> + }
> +
> + return -1;
> +}
> +
> +static inline struct plt_entry *get_plt_entry(unsigned long val,
> + const struct mod_section *sec_plt,
> + const struct mod_section *sec_plt_idx)
> +{
> + int plt_idx = get_plt_idx(val, sec_plt_idx);
> + struct plt_entry *plt = (struct plt_entry *)sec_plt->shdr->sh_addr;
> +
> + if (plt_idx < 0)
> + return NULL;
> +
> + return plt + plt_idx;
> +}
> +
> +#endif /* _ASM_MODULE_H */
> diff --git a/arch/loongarch/include/asm/module.lds.h
> b/arch/loongarch/include/asm/module.lds.h
> new file mode 100644
> index 000000000000..31c1c0db11a3
> --- /dev/null
> +++ b/arch/loongarch/include/asm/module.lds.h
> @@ -0,0 +1,7 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* Copyright (C) 2020-2022 Loongson Technology Corporation Limited */
> +SECTIONS {
> + . = ALIGN(4);
> + .plt : { BYTE(0) }
> + .plt.idx : { BYTE(0) }
> +}
> diff --git a/arch/loongarch/include/asm/vermagic.h
> b/arch/loongarch/include/asm/vermagic.h
> new file mode 100644
> index 000000000000..8b47ccfe3aad
> --- /dev/null
> +++ b/arch/loongarch/include/asm/vermagic.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +#ifndef _ASM_VERMAGIC_H
> +#define _ASM_VERMAGIC_H
> +
> +#define MODULE_PROC_FAMILY "LOONGARCH "
> +
> +#ifdef CONFIG_32BIT
> +#define MODULE_KERNEL_TYPE "32BIT "
> +#elif defined CONFIG_64BIT
> +#define MODULE_KERNEL_TYPE "64BIT "
> +#endif
> +
> +#define MODULE_ARCH_VERMAGIC \
> + MODULE_PROC_FAMILY MODULE_KERNEL_TYPE
> +
> +#endif /* _ASM_VERMAGIC_H */
> diff --git a/arch/loongarch/include/uapi/asm/auxvec.h
> b/arch/loongarch/include/uapi/asm/auxvec.h
> new file mode 100644
> index 000000000000..922d9e6b5058
> --- /dev/null
> +++ b/arch/loongarch/include/uapi/asm/auxvec.h
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
> +/*
> + * Author: Hanlu Li <lihanlu@xxxxxxxxxxx>
> + * Huacai Chen <chenhuacai@xxxxxxxxxxx>
> + *
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __ASM_AUXVEC_H
> +#define __ASM_AUXVEC_H
> +
> +/* Location of VDSO image. */
> +#define AT_SYSINFO_EHDR 33
> +
> +#define AT_VECTOR_SIZE_ARCH 1 /* entries in ARCH_DLINFO */
> +
> +#endif /* __ASM_AUXVEC_H */
> diff --git a/arch/loongarch/include/uapi/asm/hwcap.h
> b/arch/loongarch/include/uapi/asm/hwcap.h
> new file mode 100644
> index 000000000000..8840b72fa8e8
> --- /dev/null
> +++ b/arch/loongarch/include/uapi/asm/hwcap.h
> @@ -0,0 +1,20 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +#ifndef _UAPI_ASM_HWCAP_H
> +#define _UAPI_ASM_HWCAP_H
> +
> +/* HWCAP flags */
> +#define HWCAP_LOONGARCH_CPUCFG (1 << 0)
> +#define HWCAP_LOONGARCH_LAM (1 << 1)
> +#define HWCAP_LOONGARCH_UAL (1 << 2)
> +#define HWCAP_LOONGARCH_FPU (1 << 3)
> +#define HWCAP_LOONGARCH_LSX (1 << 4)
> +#define HWCAP_LOONGARCH_LASX (1 << 5)
> +#define HWCAP_LOONGARCH_CRC32 (1 << 6)
> +#define HWCAP_LOONGARCH_COMPLEX (1 << 7)
> +#define HWCAP_LOONGARCH_CRYPTO (1 << 8)
> +#define HWCAP_LOONGARCH_LVZ (1 << 9)
> +#define HWCAP_LOONGARCH_LBT_X86 (1 << 10)
> +#define HWCAP_LOONGARCH_LBT_ARM (1 << 11)
> +#define HWCAP_LOONGARCH_LBT_MIPS (1 << 12)
> +
> +#endif /* _UAPI_ASM_HWCAP_H */
> diff --git a/arch/loongarch/kernel/elf.c b/arch/loongarch/kernel/elf.c
> new file mode 100644
> index 000000000000..183e94fc9c69
> --- /dev/null
> +++ b/arch/loongarch/kernel/elf.c
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Author: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/binfmts.h>
> +#include <linux/elf.h>
> +#include <linux/export.h>
> +#include <linux/sched.h>
> +
> +#include <asm/cpu-features.h>
> +#include <asm/cpu-info.h>
> +
> +int arch_elf_pt_proc(void *_ehdr, void *_phdr, struct file *elf,
> + bool is_interp, struct arch_elf_state *state)
> +{
> + return 0;
> +}
> +
> +int arch_check_elf(void *_ehdr, bool has_interpreter, void
> *_interp_ehdr,
> + struct arch_elf_state *state)
> +{
> + return 0;
> +}
> +
> +void loongarch_set_personality_fcsr(struct arch_elf_state *state)
> +{
> + current->thread.fpu.fcsr = boot_cpu_data.fpu_csr0;
> +}
> diff --git a/arch/loongarch/kernel/inst.c b/arch/loongarch/kernel/inst.c
> new file mode 100644
> index 000000000000..b1df0ec34bd1
> --- /dev/null
> +++ b/arch/loongarch/kernel/inst.c
> @@ -0,0 +1,40 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +#include <asm/inst.h>
> +
> +u32 larch_insn_gen_lu32id(enum loongarch_gpr rd, int imm)
> +{
> + union loongarch_instruction insn;
> +
> + insn.reg1i20_format.opcode = lu32id_op;
> + insn.reg1i20_format.rd = rd;
> + insn.reg1i20_format.immediate = imm;
> +
> + return insn.word;
> +}
> +
> +u32 larch_insn_gen_lu52id(enum loongarch_gpr rd, enum loongarch_gpr
> rj, int imm)
> +{
> + union loongarch_instruction insn;
> +
> + insn.reg2i12_format.opcode = lu52id_op;
> + insn.reg2i12_format.rd = rd;
> + insn.reg2i12_format.rj = rj;
> + insn.reg2i12_format.immediate = imm;
> +
> + return insn.word;
> +}
> +
> +u32 larch_insn_gen_jirl(enum loongarch_gpr rd, enum loongarch_gpr rj,
> unsigned long pc, unsigned long dest)
> +{
> + union loongarch_instruction insn;
> +
> + insn.reg2i16_format.opcode = jirl_op;
> + insn.reg2i16_format.rd = rd;
> + insn.reg2i16_format.rj = rj;
> + insn.reg2i16_format.immediate = (dest - pc) >> 2;
> +
> + return insn.word;
> +}
> diff --git a/arch/loongarch/kernel/module-sections.c
> b/arch/loongarch/kernel/module-sections.c
> new file mode 100644
> index 000000000000..6d498288977d
> --- /dev/null
> +++ b/arch/loongarch/kernel/module-sections.c
> @@ -0,0 +1,121 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/elf.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +
> +Elf_Addr module_emit_plt_entry(struct module *mod, unsigned long val)
> +{
> + int nr;
> + struct mod_section *plt_sec = &mod->arch.plt;
> + struct mod_section *plt_idx_sec = &mod->arch.plt_idx;
> + struct plt_entry *plt = get_plt_entry(val, plt_sec, plt_idx_sec);
> + struct plt_idx_entry *plt_idx;
> +
> + if (plt)
> + return (Elf_Addr)plt;
> +
> + nr = plt_sec->num_entries;
> +
> + /* There is no duplicate entry, create a new one */
> + plt = (struct plt_entry *)plt_sec->shdr->sh_addr;
> + plt[nr] = emit_plt_entry(val);
> + plt_idx = (struct plt_idx_entry *)plt_idx_sec->shdr->sh_addr;
> + plt_idx[nr] = emit_plt_idx_entry(val);
> +
> + plt_sec->num_entries++;
> + plt_idx_sec->num_entries++;
> + BUG_ON(plt_sec->num_entries > plt_sec->max_entries);
> +
> + return (Elf_Addr)&plt[nr];
> +}
> +
> +static int is_rela_equal(const Elf_Rela *x, const Elf_Rela *y)
> +{
> + return x->r_info == y->r_info && x->r_addend == y->r_addend;
> +}
> +
> +static bool duplicate_rela(const Elf_Rela *rela, int idx)
> +{
> + int i;
> +
> + for (i = 0; i < idx; i++) {
> + if (is_rela_equal(&rela[i], &rela[idx]))
> + return true;
> + }
> +
> + return false;
> +}
> +
> +static void count_max_entries(Elf_Rela *relas, int num, unsigned int
> *plts)
> +{
> + unsigned int i, type;
> +
> + for (i = 0; i < num; i++) {
> + type = ELF_R_TYPE(relas[i].r_info);
> + if (type == R_LARCH_SOP_PUSH_PLT_PCREL) {
> + if (!duplicate_rela(relas, i))
> + (*plts)++;
> + }
> + }
> +}
> +
> +int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
> + char *secstrings, struct module *mod)
> +{
> + unsigned int i, num_plts = 0;
> +
> + /*
> + * Find the empty .plt sections.
> + */
> + for (i = 0; i < ehdr->e_shnum; i++) {
> + if (!strcmp(secstrings + sechdrs[i].sh_name, ".plt"))
> + mod->arch.plt.shdr = sechdrs + i;
> + else if (!strcmp(secstrings + sechdrs[i].sh_name, ".plt.idx"))
> + mod->arch.plt_idx.shdr = sechdrs + i;
> + }
> +
> + if (!mod->arch.plt.shdr) {
> + pr_err("%s: module PLT section(s) missing\n", mod->name);
> + return -ENOEXEC;
> + }
> + if (!mod->arch.plt_idx.shdr) {
> + pr_err("%s: module PLT.IDX section(s) missing\n", mod->name);
> + return -ENOEXEC;
> + }
> +
> + /* Calculate the maxinum number of entries */
> + for (i = 0; i < ehdr->e_shnum; i++) {
> + int num_rela = sechdrs[i].sh_size / sizeof(Elf_Rela);
> + Elf_Rela *relas = (void *)ehdr + sechdrs[i].sh_offset;
> + Elf_Shdr *dst_sec = sechdrs + sechdrs[i].sh_info;
> +
> + if (sechdrs[i].sh_type != SHT_RELA)
> + continue;
> +
> + /* ignore relocations that operate on non-exec sections */
> + if (!(dst_sec->sh_flags & SHF_EXECINSTR))
> + continue;
> +
> + count_max_entries(relas, num_rela, &num_plts);
> + }
> +
> + mod->arch.plt.shdr->sh_type = SHT_NOBITS;
> + mod->arch.plt.shdr->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
> + mod->arch.plt.shdr->sh_addralign = L1_CACHE_BYTES;
> + mod->arch.plt.shdr->sh_size = (num_plts + 1) * sizeof(struct
> plt_entry);
> + mod->arch.plt.num_entries = 0;
> + mod->arch.plt.max_entries = num_plts;
> +
> + mod->arch.plt_idx.shdr->sh_type = SHT_NOBITS;
> + mod->arch.plt_idx.shdr->sh_flags = SHF_ALLOC;
> + mod->arch.plt_idx.shdr->sh_addralign = L1_CACHE_BYTES;
> + mod->arch.plt_idx.shdr->sh_size = (num_plts + 1) * sizeof(struct
> plt_idx_entry);
> + mod->arch.plt_idx.num_entries = 0;
> + mod->arch.plt_idx.max_entries = num_plts;
> +
> + return 0;
> +}
> diff --git a/arch/loongarch/kernel/module.c
> b/arch/loongarch/kernel/module.c
> new file mode 100644
> index 000000000000..87b3768f1eef
> --- /dev/null
> +++ b/arch/loongarch/kernel/module.c
> @@ -0,0 +1,374 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Author: Hanlu Li <lihanlu@xxxxxxxxxxx>
> + * Huacai Chen <chenhuacai@xxxxxxxxxxx>
> + *
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +
> +#define pr_fmt(fmt) "kmod: " fmt
> +
> +#include <linux/moduleloader.h>
> +#include <linux/elf.h>
> +#include <linux/mm.h>
> +#include <linux/vmalloc.h>
> +#include <linux/slab.h>
> +#include <linux/fs.h>
> +#include <linux/string.h>
> +#include <linux/kernel.h>
> +
> +static inline bool signed_imm_check(long val, unsigned int bit)
> +{
> + return -(1L << (bit - 1)) <= val && val < (1L << (bit - 1));
> +}
> +
> +static inline bool unsigned_imm_check(unsigned long val, unsigned int
> bit)
> +{
> + return val < (1UL << bit);
> +}
> +
> +static int rela_stack_push(s64 stack_value, s64 *rela_stack, size_t
> *rela_stack_top)
> +{
> + if (*rela_stack_top >= RELA_STACK_DEPTH)
> + return -ENOEXEC;
> +
> + rela_stack[(*rela_stack_top)++] = stack_value;
> + pr_debug("%s stack_value = 0x%llx\n", __func__, stack_value);
> +
> + return 0;
> +}
> +
> +static int rela_stack_pop(s64 *stack_value, s64 *rela_stack, size_t
> *rela_stack_top)
> +{
> + if (*rela_stack_top == 0)
> + return -ENOEXEC;
> +
> + *stack_value = rela_stack[--(*rela_stack_top)];
> + pr_debug("%s stack_value = 0x%llx\n", __func__, *stack_value);
> +
> + return 0;
> +}
> +
> +static int apply_r_larch_none(struct module *mod, u32 *location,
> Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
> +{
> + return 0;
> +}
> +
> +static int apply_r_larch_error(struct module *me, u32 *location,
> Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
> +{
> + pr_err("%s: Unsupport relocation type %u, please add its support.\n",
> me->name, type);
> + return -EINVAL;
> +}
> +
> +static int apply_r_larch_32(struct module *mod, u32 *location,
> Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
> +{
> + *location = v;
> + return 0;
> +}
> +
> +static int apply_r_larch_64(struct module *mod, u32 *location,
> Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
> +{
> + *(Elf_Addr *)location = v;
> + return 0;
> +}
> +
> +static int apply_r_larch_sop_push_pcrel(struct module *mod, u32
> *location, Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
> +{
> + return rela_stack_push(v - (u64)location, rela_stack, rela_stack_top);
> +}
> +
> +static int apply_r_larch_sop_push_absolute(struct module *mod, u32
> *location, Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
> +{
> + return rela_stack_push(v, rela_stack, rela_stack_top);
> +}
> +
> +static int apply_r_larch_sop_push_dup(struct module *mod, u32
> *location, Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
> +{
> + int err = 0;
> + s64 opr1;
> +
> + err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
> + if (err)
> + return err;
> + err = rela_stack_push(opr1, rela_stack, rela_stack_top);
> + if (err)
> + return err;
> + err = rela_stack_push(opr1, rela_stack, rela_stack_top);
> + if (err)
> + return err;
> +
> + return 0;
> +}
> +
> +static int apply_r_larch_sop_push_plt_pcrel(struct module *mod, u32
> *location, Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
> +{
> + ptrdiff_t offset = (void *)v - (void *)location;
> +
> + if (offset >= SZ_128M)
> + v = module_emit_plt_entry(mod, v);
> +
> + if (offset < -SZ_128M)
> + v = module_emit_plt_entry(mod, v);
> +
> + return apply_r_larch_sop_push_pcrel(mod, location, v, rela_stack,
> rela_stack_top, type);
> +}
> +
> +static int apply_r_larch_sop(struct module *mod, u32 *location,
> Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
> +{
> + int err = 0;
> + s64 opr1, opr2, opr3;
> +
> + if (type == R_LARCH_SOP_IF_ELSE) {
> + err = rela_stack_pop(&opr3, rela_stack, rela_stack_top);
> + if (err)
> + return err;
> + }
> +
> + err = rela_stack_pop(&opr2, rela_stack, rela_stack_top);
> + if (err)
> + return err;
> + err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
> + if (err)
> + return err;
> +
> + switch (type) {
> + case R_LARCH_SOP_AND:
> + err = rela_stack_push(opr1 & opr2, rela_stack, rela_stack_top);
> + break;
> + case R_LARCH_SOP_ADD:
> + err = rela_stack_push(opr1 + opr2, rela_stack, rela_stack_top);
> + break;
> + case R_LARCH_SOP_SUB:
> + err = rela_stack_push(opr1 - opr2, rela_stack, rela_stack_top);
> + break;
> + case R_LARCH_SOP_SL:
> + err = rela_stack_push(opr1 << opr2, rela_stack, rela_stack_top);
> + break;
> + case R_LARCH_SOP_SR:
> + err = rela_stack_push(opr1 >> opr2, rela_stack, rela_stack_top);
> + break;
> + case R_LARCH_SOP_IF_ELSE:
> + err = rela_stack_push(opr1 ? opr2 : opr3, rela_stack,
> rela_stack_top);
> + break;
> + default:
> + pr_err("%s: Unsupport relocation type %u\n", mod->name, type);
> + return -EINVAL;
> + }
> +
> + return err;
> +}
> +
> +static int apply_r_larch_sop_imm_field(struct module *mod, u32
> *location, Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
> +{
> + int err = 0;
> + s64 opr1;
> + union loongarch_instruction *insn = (union loongarch_instruction
> *)location;
> +
> + err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
> + if (err)
> + return err;
> +
> + switch (type) {
> + case R_LARCH_SOP_POP_32_U_10_12:
> + if (!unsigned_imm_check(opr1, 12))
> + goto overflow;
> +
> + /* (*(uint32_t *) PC) [21 ... 10] = opr [11 ... 0] */
> + insn->reg2i12_format.immediate = opr1 & 0xfff;
> + return 0;
> + case R_LARCH_SOP_POP_32_S_10_12:
> + if (!signed_imm_check(opr1, 12))
> + goto overflow;
> +
> + insn->reg2i12_format.immediate = opr1 & 0xfff;
> + return 0;
> + case R_LARCH_SOP_POP_32_S_10_16:
> + if (!signed_imm_check(opr1, 16))
> + goto overflow;
> +
> + insn->reg2i16_format.immediate = opr1 & 0xffff;
> + return 0;
> + case R_LARCH_SOP_POP_32_S_10_16_S2:
> + if (opr1 % 4)
> + goto unaligned;
> +
> + if (!signed_imm_check(opr1, 18))
> + goto overflow;
> +
> + insn->reg2i16_format.immediate = (opr1 >> 2) & 0xffff;
> + return 0;
> + case R_LARCH_SOP_POP_32_S_5_20:
> + if (!signed_imm_check(opr1, 20))
> + goto overflow;
> +
> + insn->reg1i20_format.immediate = (opr1) & 0xfffff;
> + return 0;
> + case R_LARCH_SOP_POP_32_S_0_5_10_16_S2:
> + if (opr1 % 4)
> + goto unaligned;
> +
> + if (!signed_imm_check(opr1, 23))
> + goto overflow;
> +
> + opr1 >>= 2;
> + insn->reg1i21_format.immediate_l = opr1 & 0xffff;
> + insn->reg1i21_format.immediate_h = (opr1 >> 16) & 0x1f;
> + return 0;
> + case R_LARCH_SOP_POP_32_S_0_10_10_16_S2:
> + if (opr1 % 4)
> + goto unaligned;
> +
> + if (!signed_imm_check(opr1, 28))
> + goto overflow;
> +
> + opr1 >>= 2;
> + insn->reg0i26_format.immediate_l = opr1 & 0xffff;
> + insn->reg0i26_format.immediate_h = (opr1 >> 16) & 0x3ff;
> + return 0;
> + case R_LARCH_SOP_POP_32_U:
> + if (!unsigned_imm_check(opr1, 32))
> + goto overflow;
> +
> + /* (*(uint32_t *) PC) = opr */
> + *location = (u32)opr1;
> + return 0;
> + default:
> + pr_err("%s: Unsupport relocation type %u\n", mod->name, type);
> + return -EINVAL;
> + }
> +
> +overflow:
> + pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s (%u)
> relocation\n",
> + mod->name, opr1, __func__, type);
> + return -ENOEXEC;
> +
> +unaligned:
> + pr_err("module %s: opr1 = 0x%llx unaligned! dangerous %s (%u)
> relocation\n",
> + mod->name, opr1, __func__, type);
> + return -ENOEXEC;
> +}
> +
> +static int apply_r_larch_add_sub(struct module *mod, u32 *location,
> Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
> +{
> + switch (type) {
> + case R_LARCH_ADD32:
> + *(s32 *)location += v;
> + return 0;
> + case R_LARCH_ADD64:
> + *(s64 *)location += v;
> + return 0;
> + case R_LARCH_SUB32:
> + *(s32 *)location -= v;
> + return 0;
> + case R_LARCH_SUB64:
> + *(s64 *)location -= v;
> + return 0;
> + default:
> + pr_err("%s: Unsupport relocation type %u\n", mod->name, type);
> + return -EINVAL;
> + }
> +}
> +
> +/*
> + * reloc_handlers_rela() - Apply a particular relocation to a module
> + * @mod: the module to apply the reloc to
> + * @location: the address at which the reloc is to be applied
> + * @v: the value of the reloc, with addend for RELA-style
> + * @rela_stack: the stack used for store relocation info, LOCAL to
> THIS module
> + * @rela_stac_top: where the stack operation(pop/push) applies to
> + *
> + * Return: 0 upon success, else -ERRNO
> + */
> +typedef int (*reloc_rela_handler)(struct module *mod, u32 *location,
> Elf_Addr v,
> + s64 *rela_stack, size_t *rela_stack_top, unsigned int type);
> +
> +/* The handlers for known reloc types */
> +static reloc_rela_handler reloc_rela_handlers[] = {
> + [R_LARCH_NONE ... R_LARCH_SUB64] = apply_r_larch_error,
> +
> + [R_LARCH_NONE] = apply_r_larch_none,
> + [R_LARCH_32] = apply_r_larch_32,
> + [R_LARCH_64] = apply_r_larch_64,
> + [R_LARCH_MARK_LA] = apply_r_larch_none,
> + [R_LARCH_MARK_PCREL] = apply_r_larch_none,
> + [R_LARCH_SOP_PUSH_PCREL] = apply_r_larch_sop_push_pcrel,
> + [R_LARCH_SOP_PUSH_ABSOLUTE] = apply_r_larch_sop_push_absolute,
> + [R_LARCH_SOP_PUSH_DUP] = apply_r_larch_sop_push_dup,
> + [R_LARCH_SOP_PUSH_PLT_PCREL] =
> apply_r_larch_sop_push_plt_pcrel,
> + [R_LARCH_SOP_SUB ... R_LARCH_SOP_IF_ELSE] = apply_r_larch_sop,
> + [R_LARCH_SOP_POP_32_S_10_5 ... R_LARCH_SOP_POP_32_U] =
> apply_r_larch_sop_imm_field,
> + [R_LARCH_ADD32 ... R_LARCH_SUB64] = apply_r_larch_add_sub,
> +};
> +
> +int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
> + unsigned int symindex, unsigned int relsec,
> + struct module *mod)
> +{
> + int i, err;
> + unsigned int type;
> + s64 rela_stack[RELA_STACK_DEPTH];
> + size_t rela_stack_top = 0;
> + reloc_rela_handler handler;
> + void *location;
> + Elf_Addr v;
> + Elf_Sym *sym;
> + Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr;
> +
> + pr_debug("%s: Applying relocate section %u to %u\n", __func__, relsec,
> + sechdrs[relsec].sh_info);
> +
> + rela_stack_top = 0;
> + for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
> + /* This is where to make the change */
> + location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr +
> rel[i].r_offset;
> + /* This is the symbol it is referring to */
> + sym = (Elf_Sym *)sechdrs[symindex].sh_addr +
> ELF_R_SYM(rel[i].r_info);
> + if (IS_ERR_VALUE(sym->st_value)) {
> + /* Ignore unresolved weak symbol */
> + if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
> + continue;
> + pr_warn("%s: Unknown symbol %s\n", mod->name, strtab +
> sym->st_name);
> + return -ENOENT;
> + }
> +
> + type = ELF_R_TYPE(rel[i].r_info);
> +
> + if (type < ARRAY_SIZE(reloc_rela_handlers))
> + handler = reloc_rela_handlers[type];
> + else
> + handler = NULL;
> +
> + if (!handler) {
> + pr_err("%s: Unknown relocation type %u\n", mod->name, type);
> + return -EINVAL;
> + }
> +
> + pr_debug("type %d st_value %llx r_addend %llx loc %llx\n",
> + (int)ELF_R_TYPE(rel[i].r_info),
> + sym->st_value, rel[i].r_addend, (u64)location);
> +
> + v = sym->st_value + rel[i].r_addend;
> + err = handler(mod, location, v, rela_stack, &rela_stack_top, type);
> + if (err)
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +void *module_alloc(unsigned long size)
> +{
> + return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
> + GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
> __builtin_return_address(0));
> +}
> --
> 2.27.0

--
- Jiaxun

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