RISC-V: User-facing API

This patch contains code that is in some way visible to the user:
including via system calls, the VDSO, module loading and signal
handling.  It also contains some generic code that is ABI visible.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
This commit is contained in:
Palmer Dabbelt 2017-07-10 18:07:09 -07:00
parent 07037db5d4
commit e2c0cdfba7
27 changed files with 1687 additions and 0 deletions

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/*
* 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, version 2.
*
* 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.
*/
#ifndef _ASM_RISCV_MMU_H
#define _ASM_RISCV_MMU_H
#ifndef __ASSEMBLY__
typedef struct {
void *vdso;
} mm_context_t;
#endif /* __ASSEMBLY__ */
#endif /* _ASM_RISCV_MMU_H */

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/*
* 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, version 2.
*
* 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.
*/
#ifndef _ASM_RISCV_PTRACE_H
#define _ASM_RISCV_PTRACE_H
#include <uapi/asm/ptrace.h>
#include <asm/csr.h>
#ifndef __ASSEMBLY__
struct pt_regs {
unsigned long sepc;
unsigned long ra;
unsigned long sp;
unsigned long gp;
unsigned long tp;
unsigned long t0;
unsigned long t1;
unsigned long t2;
unsigned long s0;
unsigned long s1;
unsigned long a0;
unsigned long a1;
unsigned long a2;
unsigned long a3;
unsigned long a4;
unsigned long a5;
unsigned long a6;
unsigned long a7;
unsigned long s2;
unsigned long s3;
unsigned long s4;
unsigned long s5;
unsigned long s6;
unsigned long s7;
unsigned long s8;
unsigned long s9;
unsigned long s10;
unsigned long s11;
unsigned long t3;
unsigned long t4;
unsigned long t5;
unsigned long t6;
/* Supervisor CSRs */
unsigned long sstatus;
unsigned long sbadaddr;
unsigned long scause;
/* a0 value before the syscall */
unsigned long orig_a0;
};
#ifdef CONFIG_64BIT
#define REG_FMT "%016lx"
#else
#define REG_FMT "%08lx"
#endif
#define user_mode(regs) (((regs)->sstatus & SR_PS) == 0)
/* Helpers for working with the instruction pointer */
#define GET_IP(regs) ((regs)->sepc)
#define SET_IP(regs, val) (GET_IP(regs) = (val))
static inline unsigned long instruction_pointer(struct pt_regs *regs)
{
return GET_IP(regs);
}
static inline void instruction_pointer_set(struct pt_regs *regs,
unsigned long val)
{
SET_IP(regs, val);
}
#define profile_pc(regs) instruction_pointer(regs)
/* Helpers for working with the user stack pointer */
#define GET_USP(regs) ((regs)->sp)
#define SET_USP(regs, val) (GET_USP(regs) = (val))
static inline unsigned long user_stack_pointer(struct pt_regs *regs)
{
return GET_USP(regs);
}
static inline void user_stack_pointer_set(struct pt_regs *regs,
unsigned long val)
{
SET_USP(regs, val);
}
/* Helpers for working with the frame pointer */
#define GET_FP(regs) ((regs)->s0)
#define SET_FP(regs, val) (GET_FP(regs) = (val))
static inline unsigned long frame_pointer(struct pt_regs *regs)
{
return GET_FP(regs);
}
static inline void frame_pointer_set(struct pt_regs *regs,
unsigned long val)
{
SET_FP(regs, val);
}
#endif /* __ASSEMBLY__ */
#endif /* _ASM_RISCV_PTRACE_H */

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/*
* Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved.
* Copyright 2010 Tilera Corporation. All Rights Reserved.
* Copyright 2015 Regents of the University of California, Berkeley
*
* 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, version 2.
*
* 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.
*
* See asm-generic/syscall.h for descriptions of what we must do here.
*/
#ifndef _ASM_RISCV_SYSCALL_H
#define _ASM_RISCV_SYSCALL_H
#include <linux/sched.h>
#include <linux/err.h>
/* The array of function pointers for syscalls. */
extern void *sys_call_table[];
/*
* Only the low 32 bits of orig_r0 are meaningful, so we return int.
* This importantly ignores the high bits on 64-bit, so comparisons
* sign-extend the low 32 bits.
*/
static inline int syscall_get_nr(struct task_struct *task,
struct pt_regs *regs)
{
return regs->a7;
}
static inline void syscall_set_nr(struct task_struct *task,
struct pt_regs *regs,
int sysno)
{
regs->a7 = sysno;
}
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
regs->a0 = regs->orig_a0;
}
static inline long syscall_get_error(struct task_struct *task,
struct pt_regs *regs)
{
unsigned long error = regs->a0;
return IS_ERR_VALUE(error) ? error : 0;
}
static inline long syscall_get_return_value(struct task_struct *task,
struct pt_regs *regs)
{
return regs->a0;
}
static inline void syscall_set_return_value(struct task_struct *task,
struct pt_regs *regs,
int error, long val)
{
regs->a0 = (long) error ?: val;
}
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
unsigned long *args)
{
BUG_ON(i + n > 6);
if (i == 0) {
args[0] = regs->orig_a0;
args++;
i++;
n--;
}
memcpy(args, &regs->a1 + i * sizeof(regs->a1), n * sizeof(args[0]));
}
static inline void syscall_set_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
const unsigned long *args)
{
BUG_ON(i + n > 6);
if (i == 0) {
regs->orig_a0 = args[0];
args++;
i++;
n--;
}
memcpy(&regs->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0));
}
#endif /* _ASM_RISCV_SYSCALL_H */

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/*
* 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, version 2.
*
* 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.
*/
#define __ARCH_HAVE_MMU
#define __ARCH_WANT_SYS_CLONE
#include <uapi/asm/unistd.h>

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/*
* Copyright (C) 2012 ARM Limited
* Copyright (C) 2014 Regents of the University of California
* 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_RISCV_VDSO_H
#define _ASM_RISCV_VDSO_H
#include <linux/types.h>
struct vdso_data {
};
/*
* The VDSO symbols are mapped into Linux so we can just use regular symbol
* addressing to get their offsets in userspace. The symbols are mapped at an
* offset of 0, but since the linker must support setting weak undefined
* symbols to the absolute address 0 it also happens to support other low
* addresses even when the code model suggests those low addresses would not
* otherwise be availiable.
*/
#define VDSO_SYMBOL(base, name) \
({ \
extern const char __vdso_##name[]; \
(void __user *)((unsigned long)(base) + __vdso_##name); \
})
#endif /* _ASM_RISCV_VDSO_H */

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# UAPI Header export list
include include/uapi/asm-generic/Kbuild.asm
generic-y += setup.h
generic-y += unistd.h
generic-y += errno.h
generic-y += fcntl.h
generic-y += ioctl.h
generic-y += ioctls.h
generic-y += ipcbuf.h
generic-y += mman.h
generic-y += msgbuf.h
generic-y += param.h
generic-y += poll.h
generic-y += posix_types.h
generic-y += resource.h
generic-y += sembuf.h
generic-y += shmbuf.h
generic-y += signal.h
generic-y += socket.h
generic-y += sockios.h
generic-y += stat.h
generic-y += statfs.h
generic-y += swab.h
generic-y += termbits.h
generic-y += termios.h
generic-y += types.h

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/*
* Copyright (C) 2012 ARM Ltd.
* Copyright (C) 2015 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 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 _UAPI_ASM_RISCV_AUXVEC_H
#define _UAPI_ASM_RISCV_AUXVEC_H
/* vDSO location */
#define AT_SYSINFO_EHDR 33
#endif /* _UAPI_ASM_RISCV_AUXVEC_H */

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/*
* Copyright (C) 2012 ARM Ltd.
* Copyright (C) 2015 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 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 _UAPI_ASM_RISCV_BITSPERLONG_H
#define _UAPI_ASM_RISCV_BITSPERLONG_H
#define __BITS_PER_LONG (__SIZEOF_POINTER__ * 8)
#include <asm-generic/bitsperlong.h>
#endif /* _UAPI_ASM_RISCV_BITSPERLONG_H */

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/*
* Copyright (C) 2012 ARM Ltd.
* Copyright (C) 2015 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 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 _UAPI_ASM_RISCV_BYTEORDER_H
#define _UAPI_ASM_RISCV_BYTEORDER_H
#include <linux/byteorder/little_endian.h>
#endif /* _UAPI_ASM_RISCV_BYTEORDER_H */

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/*
* 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 _UAPI_ASM_ELF_H
#define _UAPI_ASM_ELF_H
#include <asm/ptrace.h>
/* ELF register definitions */
typedef unsigned long elf_greg_t;
typedef struct user_regs_struct elf_gregset_t;
#define ELF_NGREG (sizeof(elf_gregset_t) / sizeof(elf_greg_t))
typedef union __riscv_fp_state elf_fpregset_t;
#define ELF_RISCV_R_SYM(r_info) ((r_info) >> 32)
#define ELF_RISCV_R_TYPE(r_info) ((r_info) & 0xffffffff)
/*
* RISC-V relocation types
*/
/* Relocation types used by the dynamic linker */
#define R_RISCV_NONE 0
#define R_RISCV_32 1
#define R_RISCV_64 2
#define R_RISCV_RELATIVE 3
#define R_RISCV_COPY 4
#define R_RISCV_JUMP_SLOT 5
#define R_RISCV_TLS_DTPMOD32 6
#define R_RISCV_TLS_DTPMOD64 7
#define R_RISCV_TLS_DTPREL32 8
#define R_RISCV_TLS_DTPREL64 9
#define R_RISCV_TLS_TPREL32 10
#define R_RISCV_TLS_TPREL64 11
/* Relocation types not used by the dynamic linker */
#define R_RISCV_BRANCH 16
#define R_RISCV_JAL 17
#define R_RISCV_CALL 18
#define R_RISCV_CALL_PLT 19
#define R_RISCV_GOT_HI20 20
#define R_RISCV_TLS_GOT_HI20 21
#define R_RISCV_TLS_GD_HI20 22
#define R_RISCV_PCREL_HI20 23
#define R_RISCV_PCREL_LO12_I 24
#define R_RISCV_PCREL_LO12_S 25
#define R_RISCV_HI20 26
#define R_RISCV_LO12_I 27
#define R_RISCV_LO12_S 28
#define R_RISCV_TPREL_HI20 29
#define R_RISCV_TPREL_LO12_I 30
#define R_RISCV_TPREL_LO12_S 31
#define R_RISCV_TPREL_ADD 32
#define R_RISCV_ADD8 33
#define R_RISCV_ADD16 34
#define R_RISCV_ADD32 35
#define R_RISCV_ADD64 36
#define R_RISCV_SUB8 37
#define R_RISCV_SUB16 38
#define R_RISCV_SUB32 39
#define R_RISCV_SUB64 40
#define R_RISCV_GNU_VTINHERIT 41
#define R_RISCV_GNU_VTENTRY 42
#define R_RISCV_ALIGN 43
#define R_RISCV_RVC_BRANCH 44
#define R_RISCV_RVC_JUMP 45
#define R_RISCV_LUI 46
#define R_RISCV_GPREL_I 47
#define R_RISCV_GPREL_S 48
#define R_RISCV_TPREL_I 49
#define R_RISCV_TPREL_S 50
#define R_RISCV_RELAX 51
#endif /* _UAPI_ASM_ELF_H */

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/*
* 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 __UAPI_ASM_HWCAP_H
#define __UAPI_ASM_HWCAP_H
/*
* Linux saves the floating-point registers according to the ISA Linux is
* executing on, as opposed to the ISA the user program is compiled for. This
* is necessary for a handful of esoteric use cases: for example, userpsace
* threading libraries must be able to examine the actual machine state in
* order to fully reconstruct the state of a thread.
*/
#define COMPAT_HWCAP_ISA_I (1 << ('I' - 'A'))
#define COMPAT_HWCAP_ISA_M (1 << ('M' - 'A'))
#define COMPAT_HWCAP_ISA_A (1 << ('A' - 'A'))
#define COMPAT_HWCAP_ISA_F (1 << ('F' - 'A'))
#define COMPAT_HWCAP_ISA_D (1 << ('D' - 'A'))
#define COMPAT_HWCAP_ISA_C (1 << ('C' - 'A'))
#endif

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/*
* 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, version 2.
*
* 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.
*/
#ifndef _UAPI_ASM_RISCV_PTRACE_H
#define _UAPI_ASM_RISCV_PTRACE_H
#ifndef __ASSEMBLY__
#include <linux/types.h>
/*
* User-mode register state for core dumps, ptrace, sigcontext
*
* This decouples struct pt_regs from the userspace ABI.
* struct user_regs_struct must form a prefix of struct pt_regs.
*/
struct user_regs_struct {
unsigned long pc;
unsigned long ra;
unsigned long sp;
unsigned long gp;
unsigned long tp;
unsigned long t0;
unsigned long t1;
unsigned long t2;
unsigned long s0;
unsigned long s1;
unsigned long a0;
unsigned long a1;
unsigned long a2;
unsigned long a3;
unsigned long a4;
unsigned long a5;
unsigned long a6;
unsigned long a7;
unsigned long s2;
unsigned long s3;
unsigned long s4;
unsigned long s5;
unsigned long s6;
unsigned long s7;
unsigned long s8;
unsigned long s9;
unsigned long s10;
unsigned long s11;
unsigned long t3;
unsigned long t4;
unsigned long t5;
unsigned long t6;
};
struct __riscv_f_ext_state {
__u32 f[32];
__u32 fcsr;
};
struct __riscv_d_ext_state {
__u64 f[32];
__u32 fcsr;
};
struct __riscv_q_ext_state {
__u64 f[64] __attribute__((aligned(16)));
__u32 fcsr;
/*
* Reserved for expansion of sigcontext structure. Currently zeroed
* upon signal, and must be zero upon sigreturn.
*/
__u32 reserved[3];
};
union __riscv_fp_state {
struct __riscv_f_ext_state f;
struct __riscv_d_ext_state d;
struct __riscv_q_ext_state q;
};
#endif /* __ASSEMBLY__ */
#endif /* _UAPI_ASM_RISCV_PTRACE_H */

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/*
* 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, version 2.
*
* 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.
*/
#ifndef _UAPI_ASM_RISCV_SIGCONTEXT_H
#define _UAPI_ASM_RISCV_SIGCONTEXT_H
#include <asm/ptrace.h>
/*
* Signal context structure
*
* This contains the context saved before a signal handler is invoked;
* it is restored by sys_sigreturn / sys_rt_sigreturn.
*/
struct sigcontext {
struct user_regs_struct sc_regs;
union __riscv_fp_state sc_fpregs;
};
#endif /* _UAPI_ASM_RISCV_SIGCONTEXT_H */

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/*
* Copyright (C) 2012 ARM Ltd.
* Copyright (C) 2016 SiFive, Inc.
*
* 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_SIGINFO_H
#define __ASM_SIGINFO_H
#define __ARCH_SI_PREAMBLE_SIZE (__SIZEOF_POINTER__ == 4 ? 12 : 16)
#include <asm-generic/siginfo.h>
#endif

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/*
* Copyright (C) 2012 ARM Ltd.
* Copyright (C) 2017 SiFive, Inc.
*
* 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/>.
*
* This file was copied from arch/arm64/include/uapi/asm/ucontext.h
*/
#ifndef _UAPI__ASM_UCONTEXT_H
#define _UAPI__ASM_UCONTEXT_H
#include <linux/types.h>
struct ucontext {
unsigned long uc_flags;
struct ucontext *uc_link;
stack_t uc_stack;
sigset_t uc_sigmask;
/* There's some padding here to allow sigset_t to be expanded in the
* future. Though this is unlikely, other architectures put uc_sigmask
* at the end of this structure and explicitly state it can be
* expanded, so we didn't want to box ourselves in here. */
__u8 __unused[1024 / 8 - sizeof(sigset_t)];
/* We can't put uc_sigmask at the end of this structure because we need
* to be able to expand sigcontext in the future. For example, the
* vector ISA extension will almost certainly add ISA state. We want
* to ensure all user-visible ISA state can be saved and restored via a
* ucontext, so we're putting this at the end in order to allow for
* infinite extensibility. Since we know this will be extended and we
* assume sigset_t won't be extended an extreme amount, we're
* prioritizing this. */
struct sigcontext uc_mcontext;
};
#endif /* _UAPI__ASM_UCONTEXT_H */

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/*
* Copied from arch/arm64/kernel/cpufeature.c
*
* Copyright (C) 2015 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/>.
*/
#include <linux/of.h>
#include <asm/processor.h>
#include <asm/hwcap.h>
unsigned long elf_hwcap __read_mostly;
void riscv_fill_hwcap(void)
{
struct device_node *node;
const char *isa;
size_t i;
static unsigned long isa2hwcap[256] = {0};
isa2hwcap['i'] = isa2hwcap['I'] = COMPAT_HWCAP_ISA_I;
isa2hwcap['m'] = isa2hwcap['M'] = COMPAT_HWCAP_ISA_M;
isa2hwcap['a'] = isa2hwcap['A'] = COMPAT_HWCAP_ISA_A;
isa2hwcap['f'] = isa2hwcap['F'] = COMPAT_HWCAP_ISA_F;
isa2hwcap['d'] = isa2hwcap['D'] = COMPAT_HWCAP_ISA_D;
isa2hwcap['c'] = isa2hwcap['C'] = COMPAT_HWCAP_ISA_C;
elf_hwcap = 0;
/*
* We don't support running Linux on hertergenous ISA systems. For
* now, we just check the ISA of the first processor.
*/
node = of_find_node_by_type(NULL, "cpu");
if (!node) {
pr_warning("Unable to find \"cpu\" devicetree entry");
return;
}
if (of_property_read_string(node, "riscv,isa", &isa)) {
pr_warning("Unable to find \"riscv,isa\" devicetree entry");
return;
}
for (i = 0; i < strlen(isa); ++i)
elf_hwcap |= isa2hwcap[(unsigned char)(isa[i])];
pr_info("elf_hwcap is 0x%lx", elf_hwcap);
}

217
arch/riscv/kernel/module.c Normal file
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/*
* 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.
*
* Copyright (C) 2017 Zihao Yu
*/
#include <linux/elf.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/moduleloader.h>
static int apply_r_riscv_64_rela(struct module *me, u32 *location, Elf_Addr v)
{
*(u64 *)location = v;
return 0;
}
static int apply_r_riscv_branch_rela(struct module *me, u32 *location,
Elf_Addr v)
{
s64 offset = (void *)v - (void *)location;
u32 imm12 = (offset & 0x1000) << (31 - 12);
u32 imm11 = (offset & 0x800) >> (11 - 7);
u32 imm10_5 = (offset & 0x7e0) << (30 - 10);
u32 imm4_1 = (offset & 0x1e) << (11 - 4);
*location = (*location & 0x1fff07f) | imm12 | imm11 | imm10_5 | imm4_1;
return 0;
}
static int apply_r_riscv_jal_rela(struct module *me, u32 *location,
Elf_Addr v)
{
s64 offset = (void *)v - (void *)location;
u32 imm20 = (offset & 0x100000) << (31 - 20);
u32 imm19_12 = (offset & 0xff000);
u32 imm11 = (offset & 0x800) << (20 - 11);
u32 imm10_1 = (offset & 0x7fe) << (30 - 10);
*location = (*location & 0xfff) | imm20 | imm19_12 | imm11 | imm10_1;
return 0;
}
static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location,
Elf_Addr v)
{
s64 offset = (void *)v - (void *)location;
s32 hi20;
if (offset != (s32)offset) {
pr_err(
"%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
me->name, v, location);
return -EINVAL;
}
hi20 = (offset + 0x800) & 0xfffff000;
*location = (*location & 0xfff) | hi20;
return 0;
}
static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, u32 *location,
Elf_Addr v)
{
/*
* v is the lo12 value to fill. It is calculated before calling this
* handler.
*/
*location = (*location & 0xfffff) | ((v & 0xfff) << 20);
return 0;
}
static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location,
Elf_Addr v)
{
/*
* v is the lo12 value to fill. It is calculated before calling this
* handler.
*/
u32 imm11_5 = (v & 0xfe0) << (31 - 11);
u32 imm4_0 = (v & 0x1f) << (11 - 4);
*location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
return 0;
}
static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location,
Elf_Addr v)
{
s64 offset = (void *)v - (void *)location;
s32 fill_v = offset;
u32 hi20, lo12;
if (offset != fill_v) {
pr_err(
"%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
me->name, v, location);
return -EINVAL;
}
hi20 = (offset + 0x800) & 0xfffff000;
lo12 = (offset - hi20) & 0xfff;
*location = (*location & 0xfff) | hi20;
*(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
return 0;
}
static int apply_r_riscv_relax_rela(struct module *me, u32 *location,
Elf_Addr v)
{
return 0;
}
static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
Elf_Addr v) = {
[R_RISCV_64] = apply_r_riscv_64_rela,
[R_RISCV_BRANCH] = apply_r_riscv_branch_rela,
[R_RISCV_JAL] = apply_r_riscv_jal_rela,
[R_RISCV_PCREL_HI20] = apply_r_riscv_pcrel_hi20_rela,
[R_RISCV_PCREL_LO12_I] = apply_r_riscv_pcrel_lo12_i_rela,
[R_RISCV_PCREL_LO12_S] = apply_r_riscv_pcrel_lo12_s_rela,
[R_RISCV_CALL_PLT] = apply_r_riscv_call_plt_rela,
[R_RISCV_RELAX] = apply_r_riscv_relax_rela,
};
int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
unsigned int symindex, unsigned int relsec,
struct module *me)
{
Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr;
int (*handler)(struct module *me, u32 *location, Elf_Addr v);
Elf_Sym *sym;
u32 *location;
unsigned int i, type;
Elf_Addr v;
int res;
pr_debug("Applying relocate section %u to %u\n", relsec,
sechdrs[relsec].sh_info);
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_RISCV_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_warning("%s: Unknown symbol %s\n",
me->name, strtab + sym->st_name);
return -ENOENT;
}
type = ELF_RISCV_R_TYPE(rel[i].r_info);
if (type < ARRAY_SIZE(reloc_handlers_rela))
handler = reloc_handlers_rela[type];
else
handler = NULL;
if (!handler) {
pr_err("%s: Unknown relocation type %u\n",
me->name, type);
return -EINVAL;
}
v = sym->st_value + rel[i].r_addend;
if (type == R_RISCV_PCREL_LO12_I || type == R_RISCV_PCREL_LO12_S) {
unsigned int j;
for (j = 0; j < sechdrs[relsec].sh_size / sizeof(*rel); j++) {
u64 hi20_loc =
sechdrs[sechdrs[relsec].sh_info].sh_addr
+ rel[j].r_offset;
/* Find the corresponding HI20 PC-relative relocation entry */
if (hi20_loc == sym->st_value) {
Elf_Sym *hi20_sym =
(Elf_Sym *)sechdrs[symindex].sh_addr
+ ELF_RISCV_R_SYM(rel[j].r_info);
u64 hi20_sym_val =
hi20_sym->st_value
+ rel[j].r_addend;
/* Calculate lo12 */
s64 offset = hi20_sym_val - hi20_loc;
s32 hi20 = (offset + 0x800) & 0xfffff000;
s32 lo12 = offset - hi20;
v = lo12;
break;
}
}
if (j == sechdrs[relsec].sh_size / sizeof(*rel)) {
pr_err(
"%s: Can not find HI20 PC-relative relocation information\n",
me->name);
return -EINVAL;
}
}
res = handler(me, location, v);
if (res)
return res;
}
return 0;
}

125
arch/riscv/kernel/ptrace.c Normal file
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/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
* Copyright 2015 Regents of the University of California
* Copyright 2017 SiFive
*
* 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, version 2.
*
* 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.
*
* Copied from arch/tile/kernel/ptrace.c
*/
#include <asm/ptrace.h>
#include <asm/syscall.h>
#include <asm/thread_info.h>
#include <linux/ptrace.h>
#include <linux/elf.h>
#include <linux/regset.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/tracehook.h>
#include <trace/events/syscalls.h>
enum riscv_regset {
REGSET_X,
};
static int riscv_gpr_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
struct pt_regs *regs;
regs = task_pt_regs(target);
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
}
static int riscv_gpr_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int ret;
struct pt_regs *regs;
regs = task_pt_regs(target);
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
return ret;
}
static const struct user_regset riscv_user_regset[] = {
[REGSET_X] = {
.core_note_type = NT_PRSTATUS,
.n = ELF_NGREG,
.size = sizeof(elf_greg_t),
.align = sizeof(elf_greg_t),
.get = &riscv_gpr_get,
.set = &riscv_gpr_set,
},
};
static const struct user_regset_view riscv_user_native_view = {
.name = "riscv",
.e_machine = EM_RISCV,
.regsets = riscv_user_regset,
.n = ARRAY_SIZE(riscv_user_regset),
};
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
return &riscv_user_native_view;
}
void ptrace_disable(struct task_struct *child)
{
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
}
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
long ret = -EIO;
switch (request) {
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
/*
* Allows PTRACE_SYSCALL to work. These are called from entry.S in
* {handle,ret_from}_syscall.
*/
void do_syscall_trace_enter(struct pt_regs *regs)
{
if (test_thread_flag(TIF_SYSCALL_TRACE))
if (tracehook_report_syscall_entry(regs))
syscall_set_nr(current, regs, -1);
#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_enter(regs, syscall_get_nr(current, regs));
#endif
}
void do_syscall_trace_exit(struct pt_regs *regs)
{
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, 0);
#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_exit(regs, regs->regs[0]);
#endif
}

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@ -0,0 +1,15 @@
/*
* Copyright (C) 2017 Zihao Yu
*
* 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.
*/
#include <linux/export.h>
#include <linux/uaccess.h>
/*
* Assembly functions that may be used (directly or indirectly) by modules
*/
EXPORT_SYMBOL(__copy_user);

292
arch/riscv/kernel/signal.c Normal file
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@ -0,0 +1,292 @@
/*
* Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
* Chen Liqin <liqin.chen@sunplusct.com>
* Lennox Wu <lennox.wu@sunplusct.com>
* 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.
*
* 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/signal.h>
#include <linux/uaccess.h>
#include <linux/syscalls.h>
#include <linux/tracehook.h>
#include <linux/linkage.h>
#include <asm/ucontext.h>
#include <asm/vdso.h>
#include <asm/switch_to.h>
#include <asm/csr.h>
#define DEBUG_SIG 0
struct rt_sigframe {
struct siginfo info;
struct ucontext uc;
};
static long restore_d_state(struct pt_regs *regs,
struct __riscv_d_ext_state __user *state)
{
long err;
err = __copy_from_user(&current->thread.fstate, state, sizeof(*state));
if (likely(!err))
fstate_restore(current, regs);
return err;
}
static long save_d_state(struct pt_regs *regs,
struct __riscv_d_ext_state __user *state)
{
fstate_save(current, regs);
return __copy_to_user(state, &current->thread.fstate, sizeof(*state));
}
static long restore_sigcontext(struct pt_regs *regs,
struct sigcontext __user *sc)
{
long err;
size_t i;
/* sc_regs is structured the same as the start of pt_regs */
err = __copy_from_user(regs, &sc->sc_regs, sizeof(sc->sc_regs));
if (unlikely(err))
return err;
/* Restore the floating-point state. */
err = restore_d_state(regs, &sc->sc_fpregs.d);
if (unlikely(err))
return err;
/* We support no other extension state at this time. */
for (i = 0; i < ARRAY_SIZE(sc->sc_fpregs.q.reserved); i++) {
u32 value;
err = __get_user(value, &sc->sc_fpregs.q.reserved[i]);
if (unlikely(err))
break;
if (value != 0)
return -EINVAL;
}
return err;
}
SYSCALL_DEFINE0(rt_sigreturn)
{
struct pt_regs *regs = current_pt_regs();
struct rt_sigframe __user *frame;
struct task_struct *task;
sigset_t set;
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
frame = (struct rt_sigframe __user *)regs->sp;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
goto badframe;
if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
return regs->a0;
badframe:
task = current;
if (show_unhandled_signals) {
pr_info_ratelimited(
"%s[%d]: bad frame in %s: frame=%p pc=%p sp=%p\n",
task->comm, task_pid_nr(task), __func__,
frame, (void *)regs->sepc, (void *)regs->sp);
}
force_sig(SIGSEGV, task);
return 0;
}
static long setup_sigcontext(struct rt_sigframe __user *frame,
struct pt_regs *regs)
{
struct sigcontext __user *sc = &frame->uc.uc_mcontext;
long err;
size_t i;
/* sc_regs is structured the same as the start of pt_regs */
err = __copy_to_user(&sc->sc_regs, regs, sizeof(sc->sc_regs));
/* Save the floating-point state. */
err |= save_d_state(regs, &sc->sc_fpregs.d);
/* We support no other extension state at this time. */
for (i = 0; i < ARRAY_SIZE(sc->sc_fpregs.q.reserved); i++)
err |= __put_user(0, &sc->sc_fpregs.q.reserved[i]);
return err;
}
static inline void __user *get_sigframe(struct ksignal *ksig,
struct pt_regs *regs, size_t framesize)
{
unsigned long sp;
/* Default to using normal stack */
sp = regs->sp;
/*
* If we are on the alternate signal stack and would overflow it, don't.
* Return an always-bogus address instead so we will die with SIGSEGV.
*/
if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
return (void __user __force *)(-1UL);
/* This is the X/Open sanctioned signal stack switching. */
sp = sigsp(sp, ksig) - framesize;
/* Align the stack frame. */
sp &= ~0xfUL;
return (void __user *)sp;
}
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
long err = 0;
frame = get_sigframe(ksig, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
err |= copy_siginfo_to_user(&frame->info, &ksig->info);
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(NULL, &frame->uc.uc_link);
err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
err |= setup_sigcontext(frame, regs);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
return -EFAULT;
/* Set up to return from userspace. */
regs->ra = (unsigned long)VDSO_SYMBOL(
current->mm->context.vdso, rt_sigreturn);
/*
* Set up registers for signal handler.
* Registers that we don't modify keep the value they had from
* user-space at the time we took the signal.
* We always pass siginfo and mcontext, regardless of SA_SIGINFO,
* since some things rely on this (e.g. glibc's debug/segfault.c).
*/
regs->sepc = (unsigned long)ksig->ka.sa.sa_handler;
regs->sp = (unsigned long)frame;
regs->a0 = ksig->sig; /* a0: signal number */
regs->a1 = (unsigned long)(&frame->info); /* a1: siginfo pointer */
regs->a2 = (unsigned long)(&frame->uc); /* a2: ucontext pointer */
#if DEBUG_SIG
pr_info("SIG deliver (%s:%d): sig=%d pc=%p ra=%p sp=%p\n",
current->comm, task_pid_nr(current), ksig->sig,
(void *)regs->sepc, (void *)regs->ra, frame);
#endif
return 0;
}
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
sigset_t *oldset = sigmask_to_save();
int ret;
/* Are we from a system call? */
if (regs->scause == EXC_SYSCALL) {
/* If so, check system call restarting.. */
switch (regs->a0) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
regs->a0 = -EINTR;
break;
case -ERESTARTSYS:
if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
regs->a0 = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->a0 = regs->orig_a0;
regs->sepc -= 0x4;
break;
}
}
/* Set up the stack frame */
ret = setup_rt_frame(ksig, oldset, regs);
signal_setup_done(ret, ksig, 0);
}
static void do_signal(struct pt_regs *regs)
{
struct ksignal ksig;
if (get_signal(&ksig)) {
/* Actually deliver the signal */
handle_signal(&ksig, regs);
return;
}
/* Did we come from a system call? */
if (regs->scause == EXC_SYSCALL) {
/* Restart the system call - no handlers present */
switch (regs->a0) {
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
regs->a0 = regs->orig_a0;
regs->sepc -= 0x4;
break;
case -ERESTART_RESTARTBLOCK:
regs->a0 = regs->orig_a0;
regs->a7 = __NR_restart_syscall;
regs->sepc -= 0x4;
break;
}
}
/*
* If there is no signal to deliver, we just put the saved
* sigmask back.
*/
restore_saved_sigmask();
}
/*
* notification of userspace execution resumption
* - triggered by the _TIF_WORK_MASK flags
*/
asmlinkage void do_notify_resume(struct pt_regs *regs,
unsigned long thread_info_flags)
{
/* Handle pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
}

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@ -0,0 +1,49 @@
/*
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2014 Darius Rad <darius@bluespec.com>
* 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
* as published by the Free Software Foundation, version 2.
*
* 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.
*/
#include <linux/syscalls.h>
#include <asm/cmpxchg.h>
#include <asm/unistd.h>
static long riscv_sys_mmap(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
unsigned long fd, off_t offset,
unsigned long page_shift_offset)
{
if (unlikely(offset & (~PAGE_MASK >> page_shift_offset)))
return -EINVAL;
return sys_mmap_pgoff(addr, len, prot, flags, fd,
offset >> (PAGE_SHIFT - page_shift_offset));
}
#ifdef CONFIG_64BIT
SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags,
unsigned long, fd, off_t, offset)
{
return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 0);
}
#else
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags,
unsigned long, fd, off_t, offset)
{
/*
* Note that the shift for mmap2 is constant (12),
* regardless of PAGE_SIZE
*/
return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 12);
}
#endif /* !CONFIG_64BIT */

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/*
* Copyright (C) 2009 Arnd Bergmann <arnd@arndb.de>
* 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, version 2.
*
* 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.
*/
#include <linux/linkage.h>
#include <linux/syscalls.h>
#include <asm-generic/syscalls.h>
#undef __SYSCALL
#define __SYSCALL(nr, call) [nr] = (call),
void *sys_call_table[__NR_syscalls] = {
[0 ... __NR_syscalls - 1] = sys_ni_syscall,
#include <asm/unistd.h>
};

2
arch/riscv/kernel/vdso/.gitignore vendored Normal file
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@ -0,0 +1,2 @@
vdso.lds
*.tmp

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@ -0,0 +1,63 @@
# Copied from arch/tile/kernel/vdso/Makefile
# Symbols present in the vdso
vdso-syms = rt_sigreturn
# Files to link into the vdso
obj-vdso = $(patsubst %, %.o, $(vdso-syms))
# Build rules
targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
obj-y += vdso.o vdso-syms.o
CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
# Disable gcov profiling for VDSO code
GCOV_PROFILE := n
# Force dependency
$(obj)/vdso.o: $(obj)/vdso.so
# link rule for the .so file, .lds has to be first
SYSCFLAGS_vdso.so.dbg = $(c_flags)
$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,vdsold)
# We also create a special relocatable object that should mirror the symbol
# table and layout of the linked DSO. With ld -R we can then refer to
# these symbols in the kernel code rather than hand-coded addresses.
SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
$(call cc-ldoption, -Wl$(comma)--hash-style=both)
$(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
$(call if_changed,vdsold)
LDFLAGS_vdso-syms.o := -r -R
$(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
$(call if_changed,ld)
# strip rule for the .so file
$(obj)/%.so: OBJCOPYFLAGS := -S
$(obj)/%.so: $(obj)/%.so.dbg FORCE
$(call if_changed,objcopy)
# actual build commands
# The DSO images are built using a special linker script
# Add -lgcc so rv32 gets static muldi3 and lshrdi3 definitions.
# Make sure only to export the intended __vdso_xxx symbol offsets.
quiet_cmd_vdsold = VDSOLD $@
cmd_vdsold = $(CC) $(KCFLAGS) -nostdlib $(SYSCFLAGS_$(@F)) \
-Wl,-T,$(filter-out FORCE,$^) -o $@.tmp -lgcc && \
$(CROSS_COMPILE)objcopy \
$(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@
# install commands for the unstripped file
quiet_cmd_vdso_install = INSTALL $@
cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
vdso.so: $(obj)/vdso.so.dbg
@mkdir -p $(MODLIB)/vdso
$(call cmd,vdso_install)
vdso_install: vdso.so

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/*
* Copyright (C) 2014 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, version 2.
*
* 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.
*/
#include <linux/linkage.h>
#include <asm/unistd.h>
.text
ENTRY(__vdso_rt_sigreturn)
.cfi_startproc
.cfi_signal_frame
li a7, __NR_rt_sigreturn
scall
.cfi_endproc
ENDPROC(__vdso_rt_sigreturn)

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/*
* Copyright (C) 2014 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, version 2.
*
* 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.
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/page.h>
__PAGE_ALIGNED_DATA
.globl vdso_start, vdso_end
.balign PAGE_SIZE
vdso_start:
.incbin "arch/riscv/kernel/vdso/vdso.so"
.balign PAGE_SIZE
vdso_end:
.previous

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/*
* 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, version 2.
*
* 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.
*/
OUTPUT_ARCH(riscv)
SECTIONS
{
. = SIZEOF_HEADERS;
.hash : { *(.hash) } :text
.gnu.hash : { *(.gnu.hash) }
.dynsym : { *(.dynsym) }
.dynstr : { *(.dynstr) }
.gnu.version : { *(.gnu.version) }
.gnu.version_d : { *(.gnu.version_d) }
.gnu.version_r : { *(.gnu.version_r) }
.note : { *(.note.*) } :text :note
.dynamic : { *(.dynamic) } :text :dynamic
.eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
.eh_frame : { KEEP (*(.eh_frame)) } :text
.rodata : { *(.rodata .rodata.* .gnu.linkonce.r.*) }
/*
* This linker script is used both with -r and with -shared.
* For the layouts to match, we need to skip more than enough
* space for the dynamic symbol table, etc. If this amount is
* insufficient, ld -shared will error; simply increase it here.
*/
. = 0x800;
.text : { *(.text .text.*) } :text
.data : {
*(.got.plt) *(.got)
*(.data .data.* .gnu.linkonce.d.*)
*(.dynbss)
*(.bss .bss.* .gnu.linkonce.b.*)
}
}
/*
* We must supply the ELF program headers explicitly to get just one
* PT_LOAD segment, and set the flags explicitly to make segments read-only.
*/
PHDRS
{
text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
note PT_NOTE FLAGS(4); /* PF_R */
eh_frame_hdr PT_GNU_EH_FRAME;
}
/*
* This controls what symbols we export from the DSO.
*/
VERSION
{
LINUX_4.15 {
global:
__vdso_rt_sigreturn;
__vdso_cmpxchg32;
__vdso_cmpxchg64;
local: *;
};
}