cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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syscall.c (1596B)

      1// SPDX-License-Identifier: GPL-2.0+
      2/*
      3 * Author: Hanlu Li <lihanlu@loongson.cn>
      4 *         Huacai Chen <chenhuacai@loongson.cn>
      5 *
      6 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
      7 */
      8#include <linux/capability.h>
      9#include <linux/entry-common.h>
     10#include <linux/errno.h>
     11#include <linux/linkage.h>
     12#include <linux/syscalls.h>
     13#include <linux/unistd.h>
     14
     15#include <asm/asm.h>
     16#include <asm/signal.h>
     17#include <asm/switch_to.h>
     18#include <asm-generic/syscalls.h>
     19
     20#undef __SYSCALL
     21#define __SYSCALL(nr, call)	[nr] = (call),
     22
     23SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, unsigned long,
     24		prot, unsigned long, flags, unsigned long, fd, off_t, offset)
     25{
     26	if (offset & ~PAGE_MASK)
     27		return -EINVAL;
     28
     29	return ksys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
     30}
     31
     32void *sys_call_table[__NR_syscalls] = {
     33	[0 ... __NR_syscalls - 1] = sys_ni_syscall,
     34#include <asm/unistd.h>
     35};
     36
     37typedef long (*sys_call_fn)(unsigned long, unsigned long,
     38	unsigned long, unsigned long, unsigned long, unsigned long);
     39
     40void noinstr do_syscall(struct pt_regs *regs)
     41{
     42	unsigned long nr;
     43	sys_call_fn syscall_fn;
     44
     45	nr = regs->regs[11];
     46	/* Set for syscall restarting */
     47	if (nr < NR_syscalls)
     48		regs->regs[0] = nr + 1;
     49
     50	regs->csr_era += 4;
     51	regs->orig_a0 = regs->regs[4];
     52	regs->regs[4] = -ENOSYS;
     53
     54	nr = syscall_enter_from_user_mode(regs, nr);
     55
     56	if (nr < NR_syscalls) {
     57		syscall_fn = sys_call_table[nr];
     58		regs->regs[4] = syscall_fn(regs->orig_a0, regs->regs[5], regs->regs[6],
     59					   regs->regs[7], regs->regs[8], regs->regs[9]);
     60	}
     61
     62	syscall_exit_to_user_mode(regs);
     63}