From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754155AbdKHGUo (ORCPT ); Wed, 8 Nov 2017 01:20:44 -0500 Received: from mail-pg0-f65.google.com ([74.125.83.65]:47416 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754094AbdKHGUg (ORCPT ); Wed, 8 Nov 2017 01:20:36 -0500 X-Google-Smtp-Source: ABhQp+TEusNEb9ig/9l8n8YN86Bd3dj4O7TdqNSp+K6FiCmM3I86ZvhrqExeuyih80N34tP4AsD79Q== From: Greentime Hu To: greentime@andestech.com, linux-kernel@vger.kernel.org, arnd@arndb.de, linux-arch@vger.kernel.org, tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com, robh+dt@kernel.org, netdev@vger.kernel.org Cc: green.hu@gmail.com, Vincent Chen Subject: [PATCH 15/31] nds32: System calls handling Date: Wed, 8 Nov 2017 13:55:03 +0800 Message-Id: <61b5cd5e7f2cf2f485a990cdf238788b817a1d53.1510118606.git.green.hu@gmail.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greentime Hu Signed-off-by: Vincent Chen Signed-off-by: Greentime Hu --- arch/nds32/include/asm/syscall.h | 203 ++++++++++++++++++++++++++++++++++ arch/nds32/include/asm/syscalls.h | 27 +++++ arch/nds32/include/asm/unistd.h | 21 ++++ arch/nds32/include/uapi/asm/unistd.h | 36 ++++++ arch/nds32/kernel/ex-scall.S | 146 ++++++++++++++++++++++++ arch/nds32/kernel/sys_nds32.c | 63 +++++++++++ arch/nds32/kernel/syscall_table.c | 28 +++++ 7 files changed, 524 insertions(+) create mode 100644 arch/nds32/include/asm/syscall.h create mode 100644 arch/nds32/include/asm/syscalls.h create mode 100644 arch/nds32/include/asm/unistd.h create mode 100644 arch/nds32/include/uapi/asm/unistd.h create mode 100644 arch/nds32/kernel/ex-scall.S create mode 100644 arch/nds32/kernel/sys_nds32.c create mode 100644 arch/nds32/kernel/syscall_table.c diff --git a/arch/nds32/include/asm/syscall.h b/arch/nds32/include/asm/syscall.h new file mode 100644 index 0000000..3066bae --- /dev/null +++ b/arch/nds32/include/asm/syscall.h @@ -0,0 +1,203 @@ +/* + * Access to user system call parameters and results + * + * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved. + * Copyright (C) 2005-2017 Andes Technology Corporation + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU General Public License v.2. + * + * This file is a stub providing documentation for what functions + * asm-ARCH/syscall.h files need to define. Most arch definitions + * will be simple inlines. + * + * All of these functions expect to be called with no locks, + * and only when the caller is sure that the task of interest + * cannot return to user mode while we are looking at it. + */ + +#ifndef _ASM_NDS32_SYSCALL_H +#define _ASM_NDS32_SYSCALL_H 1 + +#include +struct task_struct; +struct pt_regs; + +/** + * syscall_get_nr - find what system call a task is executing + * @task: task of interest, must be blocked + * @regs: task_pt_regs() of @task + * + * If @task is executing a system call or is at system call + * tracing about to attempt one, returns the system call number. + * If @task is not executing a system call, i.e. it's blocked + * inside the kernel for a fault or signal, returns -1. + * + * Note this returns int even on 64-bit machines. Only 32 bits of + * system call number can be meaningful. If the actual arch value + * is 64 bits, this truncates to 32 bits so 0xffffffff means -1. + * + * It's only valid to call this when @task is known to be blocked. + */ +int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) +{ + return regs->syscallno; +} + +/** + * syscall_rollback - roll back registers after an aborted system call + * @task: task of interest, must be in system call exit tracing + * @regs: task_pt_regs() of @task + * + * It's only valid to call this when @task is stopped for system + * call exit tracing (due to TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT), + * after tracehook_report_syscall_entry() returned nonzero to prevent + * the system call from taking place. + * + * This rolls back the register state in @regs so it's as if the + * system call instruction was a no-op. The registers containing + * the system call number and arguments are as they were before the + * system call instruction. This may not be the same as what the + * register state looked like at system call entry tracing. + */ +void syscall_rollback(struct task_struct *task, struct pt_regs *regs) +{ + regs->uregs[0] = regs->orig_r0; +} + +/** + * syscall_get_error - check result of traced system call + * @task: task of interest, must be blocked + * @regs: task_pt_regs() of @task + * + * Returns 0 if the system call succeeded, or -ERRORCODE if it failed. + * + * It's only valid to call this when @task is stopped for tracing on exit + * from a system call, due to %TIF_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. + */ +long syscall_get_error(struct task_struct *task, struct pt_regs *regs) +{ + unsigned long error = regs->uregs[0]; + return IS_ERR_VALUE(error) ? error : 0; +} + +/** + * syscall_get_return_value - get the return value of a traced system call + * @task: task of interest, must be blocked + * @regs: task_pt_regs() of @task + * + * Returns the return value of the successful system call. + * This value is meaningless if syscall_get_error() returned nonzero. + * + * It's only valid to call this when @task is stopped for tracing on exit + * from a system call, due to %TIF_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. + */ +long syscall_get_return_value(struct task_struct *task, struct pt_regs *regs) +{ + return regs->uregs[0]; +} + +/** + * syscall_set_return_value - change the return value of a traced system call + * @task: task of interest, must be blocked + * @regs: task_pt_regs() of @task + * @error: negative error code, or zero to indicate success + * @val: user return value if @error is zero + * + * This changes the results of the system call that user mode will see. + * If @error is zero, the user sees a successful system call with a + * return value of @val. If @error is nonzero, it's a negated errno + * code; the user sees a failed system call with this errno code. + * + * It's only valid to call this when @task is stopped for tracing on exit + * from a system call, due to %TIF_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. + */ +void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, + int error, long val) +{ + regs->uregs[0] = (long)error ? error : val; +} + +/** + * syscall_get_arguments - extract system call parameter values + * @task: task of interest, must be blocked + * @regs: task_pt_regs() of @task + * @i: argument index [0,5] + * @n: number of arguments; n+i must be [1,6]. + * @args: array filled with argument values + * + * Fetches @n arguments to the system call starting with the @i'th argument + * (from 0 through 5). Argument @i is stored in @args[0], and so on. + * An arch inline version is probably optimal when @i and @n are constants. + * + * It's only valid to call this when @task is stopped for tracing on + * entry to a system call, due to %TIF_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. + * It's invalid to call this with @i + @n > 6; we only support system calls + * taking up to 6 arguments. + */ +#define SYSCALL_MAX_ARGS 6 +void syscall_get_arguments(struct task_struct *task, struct pt_regs *regs, + unsigned int i, unsigned int n, unsigned long *args) +{ + if (n == 0) + return; + if (i + n > SYSCALL_MAX_ARGS) { + unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i; + unsigned int n_bad = n + i - SYSCALL_MAX_ARGS; + pr_warning("%s called with max args %d, handling only %d\n", + __func__, i + n, SYSCALL_MAX_ARGS); + memset(args_bad, 0, n_bad * sizeof(args[0])); + memset(args_bad, 0, n_bad * sizeof(args[0])); + } + + if (i == 0) { + args[0] = regs->orig_r0; + args++; + i++; + n--; + } + + memcpy(args, ®s->uregs[0] + i, n * sizeof(args[0])); +} + +/** + * syscall_set_arguments - change system call parameter value + * @task: task of interest, must be in system call entry tracing + * @regs: task_pt_regs() of @task + * @i: argument index [0,5] + * @n: number of arguments; n+i must be [1,6]. + * @args: array of argument values to store + * + * Changes @n arguments to the system call starting with the @i'th argument. + * Argument @i gets value @args[0], and so on. + * An arch inline version is probably optimal when @i and @n are constants. + * + * It's only valid to call this when @task is stopped for tracing on + * entry to a system call, due to %TIF_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. + * It's invalid to call this with @i + @n > 6; we only support system calls + * taking up to 6 arguments. + */ +void syscall_set_arguments(struct task_struct *task, struct pt_regs *regs, + unsigned int i, unsigned int n, + const unsigned long *args) +{ + if (n == 0) + return; + + if (i + n > SYSCALL_MAX_ARGS) { + pr_warn("%s called with max args %d, handling only %d\n", + __func__, i + n, SYSCALL_MAX_ARGS); + n = SYSCALL_MAX_ARGS - i; + } + + if (i == 0) { + regs->orig_r0 = args[0]; + args++; + i++; + n--; + } + + memcpy(®s->uregs[0] + i, args, n * sizeof(args[0])); +} +#endif /* _ASM_NDS32_SYSCALL_H */ diff --git a/arch/nds32/include/asm/syscalls.h b/arch/nds32/include/asm/syscalls.h new file mode 100644 index 0000000..741ccdc --- /dev/null +++ b/arch/nds32/include/asm/syscalls.h @@ -0,0 +1,27 @@ +/* + * Copyright (C) 2005-2017 Andes Technology Corporation + * + * 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_NDS32_SYSCALLS_H +#define __ASM_NDS32_SYSCALLS_H + +int sys_cacheflush(unsigned long addr, unsigned long len, unsigned int op); +long sys_fadvise64_64_wrapper(int fd, int advice, loff_t offset, loff_t len); +asmlinkage int sys_syscall(void); +asmlinkage int sys_rt_sigreturn_wrapper(void); + +#include + +#endif /* __ASM_NDS32_SYSCALLS_H */ diff --git a/arch/nds32/include/asm/unistd.h b/arch/nds32/include/asm/unistd.h new file mode 100644 index 0000000..b30adca --- /dev/null +++ b/arch/nds32/include/asm/unistd.h @@ -0,0 +1,21 @@ +/* + * Copyright (C) 2005-2017 Andes Technology Corporation + * + * 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 . + */ + +#define __ARCH_WANT_SYS_LLSEEK +#define __ARCH_WANT_SYS_CLONE +#define __ARCH_WANT_SYS_OLD_MMAP + +#include diff --git a/arch/nds32/include/uapi/asm/unistd.h b/arch/nds32/include/uapi/asm/unistd.h new file mode 100644 index 0000000..01b466d --- /dev/null +++ b/arch/nds32/include/uapi/asm/unistd.h @@ -0,0 +1,36 @@ +/* + * Copyright (C) 2005-2017 Andes Technology Corporation + * + * 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 . + */ + +#define __ARCH_WANT_RENAMEAT +#define __ARCH_WANT_SYSCALL_OFF_T + +/* Use the standard ABI for syscalls */ +#include + +/* Additional NDS32 specific syscalls. */ +#define __NR_cacheflush (__NR_arch_specific_syscall) +#define __NR_syscall (__NR_arch_specific_syscall + 1) +#define __NR_ipc (__NR_arch_specific_syscall + 2) +#define __NR_sysfs (__NR_arch_specific_syscall + 3) +#define __NR__llseek __NR_llseek +__SYSCALL(__NR_cacheflush, sys_cacheflush) +__SYSCALL(__NR_syscall, sys_syscall) +__SYSCALL(__NR_ipc, sys_ipc) +__SYSCALL(__NR_sysfs, sys_sysfs) + +__SYSCALL(__NR_fadvise64_64, sys_fadvise64_64_wrapper) +__SYSCALL(__NR_rt_sigreturn, sys_rt_sigreturn_wrapper) +__SYSCALL(__NR_mmap, sys_old_mmap) diff --git a/arch/nds32/kernel/ex-scall.S b/arch/nds32/kernel/ex-scall.S new file mode 100644 index 0000000..52691ce --- /dev/null +++ b/arch/nds32/kernel/ex-scall.S @@ -0,0 +1,146 @@ +/* + * Copyright (C) 2005-2017 Andes Technology Corporation + * + * 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 . + */ + +#include +#include +#include +#include +#include +#include +#include + +/* + * $r0 = previous task_struct, + * $r1 = next task_struct, + * previous and next are guaranteed not to be the same. + */ + +ENTRY(__switch_to) + + la $p0, __entry_task + sw $r1, [$p0] + move $p1, $r0 + addi $p1, $p1, #THREAD_CPU_CONTEXT + smw.bi $r6, [$p1], $r14, #0xb ! push r6~r14, fp, lp, sp + move $r25, $r1 + addi $r1, $r1, #THREAD_CPU_CONTEXT + lmw.bi $r6, [$r1], $r14, #0xb ! pop r6~r14, fp, lp, sp + ret + +/* + * These are the registers used in the syscall handler, and allow us + * to have in theory up to 6 arguments to a function - $r0 to $r5. + * + * We must set at least "tsk" and "tbl" when calling ret_with_reschedule. + */ +#define tbl $r8 // syscall table pointer + +/* + * $r7 will be writen as syscall nr + * by retrieving from $ITYPE 'SWID' bitfiled + */ + .macro get_scno + mfsr $r7, $ITYPE + srli $r7, $r7, #ITYPE_offSWID + swi $r7, [$sp + SYSCALLNO_OFFSET] + .endm + + .macro updateipc + addi $r17, $r13, #4 ! $r13 is $IPC + swi $r17, [$sp + IPC_OFFSET] + .endm + +ENTRY(eh_syscall) + updateipc + + get_scno + gie_enable + +ENTRY(eh_syscall_phase_2) + lwi $p0, [tsk+#TSK_TI_FLAGS] ! check for syscall tracing + + andi $p1, $p0, #_TIF_WORK_SYSCALL_ENTRY ! are we tracing syscalls? + bnez $p1, __sys_trace + + la $lp, ret_fast_syscall ! return address +jmp_systbl: + addi $p1, $r7, #-__NR_syscalls ! syscall number of syscall instruction is guarded by addembler + bgez $p1, _SCNO_EXCEED ! call sys_* routine + la tbl, sys_call_table ! load syscall table pointer + slli $p1, $r7, #2 + add $p1, tbl, $p1 + lwi $p1, [$p1] + jr $p1 ! no return + +_SCNO_EXCEED: + ori $r0, $r7, #0 + ori $r1, $sp, #0 + b bad_syscall + +/* + * This is the really slow path. We're going to be doing + * context switches, and waiting for our parent to respond. + */ +__sys_trace: + move $r1, $sp + move $r0, $r7 ! trace entry [IP = 0] + bal syscall_trace_enter + move $r7, $r0 + la $lp, __sys_trace_return ! return address + + addi $p1, $r7, #1 + beqz $p1, ret_slow_syscall ! fatal signal is pending + + addi $p1, $sp, #R0_OFFSET ! pointer to regs + lmw.bi $r0, [$p1], $r5 ! have to reload $r0 - $r5 + b jmp_systbl + +__sys_trace_return: + swi $r0, [$sp+#R0_OFFSET] ! T: save returned $r0 + move $r0, $sp ! set pt_regs for syscall_trace_leave + bal syscall_trace_leave + b ret_slow_syscall + +/* + * Special system call wrappers + * + * $r0 = syscall number + * $r8 = syscall table + */ + .type sys_syscall, #function +ENTRY(sys_syscall) + addi $p1, $r0, #-__NR_syscalls + bgtz $p1, 3f + move $p1, $r0 + move $r0, $r1 + move $r1, $r2 + move $r2, $r3 + move $r3, $r4 + move $r4, $r5 +! add for syscall 6 args + lwi $r5, [$sp + #SP_OFFSET ] + lwi $r5, [$r5] +! ~add for syscall 6 args + + lw $p1, [tbl+$p1<<2] + jr $p1 +3: b sys_ni_syscall +ENDPROC(sys_syscall) + +ENTRY(sys_rt_sigreturn_wrapper) + addi $r0, $sp, #0 + b sys_rt_sigreturn +ENDPROC(sys_rt_sigreturn_wrapper) diff --git a/arch/nds32/kernel/sys_nds32.c b/arch/nds32/kernel/sys_nds32.c new file mode 100644 index 0000000..39110fe --- /dev/null +++ b/arch/nds32/kernel/sys_nds32.c @@ -0,0 +1,63 @@ +/* + * Copyright (C) 2005-2017 Andes Technology Corporation + * + * 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 . + */ + +#include + +#include +#include +#include + +long sys_mmap2(unsigned long addr, unsigned long len, + unsigned long prot, unsigned long flags, + unsigned long fd, unsigned long pgoff) +{ + if (pgoff & (~PAGE_MASK >> 12)) + return -EINVAL; + + return sys_mmap_pgoff(addr, len, prot, flags, fd, + pgoff >> (PAGE_SHIFT - 12)); +} + +asmlinkage long sys_fadvise64_64_wrapper(int fd, int advice, loff_t offset, + loff_t len) +{ + return sys_fadvise64_64(fd, offset, len, advice); +} + +int sys_cacheflush(unsigned int start, unsigned int end, int cache) +{ + struct vm_area_struct *vma; + bool flushi = true, wbd = true; + + vma = find_vma(current->mm, start); + if (!vma) + return -EFAULT; + switch (cache) { + case ICACHE: + wbd = false; + break; + case DCACHE: + flushi = false; + break; + case BCACHE: + break; + default: + return -EINVAL; + } + cpu_cache_wbinval_range_check(vma, start, end, flushi, wbd); + + return 0; +} diff --git a/arch/nds32/kernel/syscall_table.c b/arch/nds32/kernel/syscall_table.c new file mode 100644 index 0000000..bafd896 --- /dev/null +++ b/arch/nds32/kernel/syscall_table.c @@ -0,0 +1,28 @@ +/* + * Copyright (C) 2005-2017 Andes Technology Corporation + * + * 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 . + */ + +#include +#include +#include +#include + +#undef __SYSCALL +#define __SYSCALL(nr, call) [nr] = (call), + +void *sys_call_table[__NR_syscalls] __aligned(8192) = { + [0 ... __NR_syscalls - 1] = sys_ni_syscall, +#include +}; -- 1.7.9.5