From 1932fbe36e02f54223ac4c6779b92269ca8b9b60 Mon Sep 17 00:00:00 2001 From: Greentime Hu Date: Wed, 25 Oct 2017 10:37:49 +0800 Subject: nds32: System calls handling This patch adds support for system calls. Signed-off-by: Vincent Chen Signed-off-by: Greentime Hu Reviewed-by: Arnd Bergmann --- arch/nds32/include/asm/syscall.h | 188 +++++++++++++++++++++++++++++++++++ arch/nds32/include/asm/syscalls.h | 13 +++ arch/nds32/include/asm/unistd.h | 6 ++ arch/nds32/include/uapi/asm/unistd.h | 11 ++ arch/nds32/kernel/ex-scall.S | 98 ++++++++++++++++++ arch/nds32/kernel/sys_nds32.c | 50 ++++++++++ arch/nds32/kernel/syscall_table.c | 17 ++++ 7 files changed, 383 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 (limited to 'arch/nds32') diff --git a/arch/nds32/include/asm/syscall.h b/arch/nds32/include/asm/syscall.h new file mode 100644 index 0000000..f7e5e86 --- /dev/null +++ b/arch/nds32/include/asm/syscall.h @@ -0,0 +1,188 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved. +// Copyright (C) 2005-2017 Andes Technology Corporation + +#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..78778ec --- /dev/null +++ b/arch/nds32/include/asm/syscalls.h @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2005-2017 Andes Technology Corporation + +#ifndef __ASM_NDS32_SYSCALLS_H +#define __ASM_NDS32_SYSCALLS_H + +asmlinkage long sys_cacheflush(unsigned long addr, unsigned long len, unsigned int op); +asmlinkage long sys_fadvise64_64_wrapper(int fd, int advice, loff_t offset, loff_t len); +asmlinkage long 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..b586a28 --- /dev/null +++ b/arch/nds32/include/asm/unistd.h @@ -0,0 +1,6 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2005-2017 Andes Technology Corporation + +#define __ARCH_WANT_SYS_CLONE + +#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..6e95901 --- /dev/null +++ b/arch/nds32/include/uapi/asm/unistd.h @@ -0,0 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2005-2017 Andes Technology Corporation + +#define __ARCH_WANT_SYNC_FILE_RANGE2 + +/* Use the standard ABI for syscalls */ +#include + +/* Additional NDS32 specific syscalls. */ +#define __NR_cacheflush (__NR_arch_specific_syscall) +__SYSCALL(__NR_cacheflush, sys_cacheflush) diff --git a/arch/nds32/kernel/ex-scall.S b/arch/nds32/kernel/ex-scall.S new file mode 100644 index 0000000..36aa87e --- /dev/null +++ b/arch/nds32/kernel/ex-scall.S @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2005-2017 Andes Technology Corporation + +#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 + + +#define tbl $r8 + +/* + * $r7 will be writen as syscall nr + */ + .macro get_scno + lwi $r7, [$sp + R15_OFFSET] + 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 + + 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 $r0, $sp + 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 + +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..9de93ab --- /dev/null +++ b/arch/nds32/kernel/sys_nds32.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2005-2017 Andes Technology Corporation + +#include +#include + +#include +#include + +SYSCALL_DEFINE6(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)); +} + +SYSCALL_DEFINE4(fadvise64_64_wrapper,int, fd, int, advice, loff_t, offset, + loff_t, len) +{ + return sys_fadvise64_64(fd, offset, len, advice); +} + +SYSCALL_DEFINE3(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..7879c06 --- /dev/null +++ b/arch/nds32/kernel/syscall_table.c @@ -0,0 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2005-2017 Andes Technology Corporation + +#include +#include +#include +#include + +#undef __SYSCALL +#define __SYSCALL(nr, call) [nr] = (call), + +#define sys_rt_sigreturn sys_rt_sigreturn_wrapper +#define sys_fadvise64_64 sys_fadvise64_64_wrapper +void *sys_call_table[__NR_syscalls] __aligned(8192) = { + [0 ... __NR_syscalls - 1] = sys_ni_syscall, +#include +}; -- cgit v1.1