Commit 1932fbe3 authored by Greentime Hu's avatar Greentime Hu

nds32: System calls handling

This patch adds support for system calls.
Signed-off-by: default avatarVincent Chen <vincentc@andestech.com>
Signed-off-by: default avatarGreentime Hu <greentime@andestech.com>
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 3172c605
// 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 <linux/err.h>
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, &regs->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(&regs->uregs[0] + i, args, n * sizeof(args[0]));
}
#endif /* _ASM_NDS32_SYSCALL_H */
// 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 <asm-generic/syscalls.h>
#endif /* __ASM_NDS32_SYSCALLS_H */
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#define __ARCH_WANT_SYS_CLONE
#include <uapi/asm/unistd.h>
// 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 <asm-generic/unistd.h>
/* Additional NDS32 specific syscalls. */
#define __NR_cacheflush (__NR_arch_specific_syscall)
__SYSCALL(__NR_cacheflush, sys_cacheflush)
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/linkage.h>
#include <asm/unistd.h>
#include <asm/assembler.h>
#include <asm/nds32.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/current.h>
/*
* $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)
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <asm/cachectl.h>
#include <asm/proc-fns.h>
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;
}
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/syscalls.h>
#include <linux/signal.h>
#include <linux/unistd.h>
#include <asm/syscalls.h>
#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 <asm/unistd.h>
};
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