blob: 3c18c2454089b477b3cc012585d731d58a883daf [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
* Based on arch/arm/kernel/sys_arm.c
* Copyright (C) People who wrote linux/arch/i386/kernel/sys_i386.c
* Copyright (C) 1995, 1996 Russell King.
* Copyright (C) 2012 ARM Ltd.
#include <linux/compat.h>
#include <linux/cpufeature.h>
#include <linux/personality.h>
#include <linux/sched.h>
#include <linux/sched/signal.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/system_misc.h>
#include <asm/tlbflush.h>
#include <asm/unistd.h>
static long
__do_compat_cache_op(unsigned long start, unsigned long end)
long ret;
do {
unsigned long chunk = min(PAGE_SIZE, end - start);
if (fatal_signal_pending(current))
return 0;
if (cpus_have_const_cap(ARM64_WORKAROUND_1542419)) {
* The workaround requires an inner-shareable tlbi.
* We pick the reserved-ASID to minimise the impact.
__tlbi(aside1is, __TLBI_VADDR(0, 0));
ret = __flush_cache_user_range(start, start + chunk);
if (ret)
return ret;
start += chunk;
} while (start < end);
return 0;
static inline long
do_compat_cache_op(unsigned long start, unsigned long end, int flags)
if (end < start || flags)
return -EINVAL;
if (!access_ok((const void __user *)start, end - start))
return -EFAULT;
return __do_compat_cache_op(start, end);
* Handle all unrecognised system calls.
long compat_arm_syscall(struct pt_regs *regs, int scno)
void __user *addr;
switch (scno) {
* Flush a region from virtual address 'r0' to virtual address 'r1'
* _exclusive_. There is no alignment requirement on either address;
* user space does not need to know the hardware cache layout.
* r2 contains flags. It should ALWAYS be passed as ZERO until it
* is defined to be something else. For now we ignore it, but may
* the fires of hell burn in your belly if you break this rule. ;)
* (at a later date, we may want to allow this call to not flush
* various aspects of the cache. Passing '0' will guarantee that
* everything necessary gets flushed to maintain consistency in
* the specified region).
case __ARM_NR_compat_cacheflush:
return do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]);
case __ARM_NR_compat_set_tls:
current->thread.uw.tp_value = regs->regs[0];
* Protect against register corruption from context switch.
* See comment in tls_thread_flush.
write_sysreg(regs->regs[0], tpidrro_el0);
return 0;
* Calls 0xf0xxx..0xf07ff are defined to return -ENOSYS
* if not implemented, rather than raising SIGILL. This
* way the calling program can gracefully determine whether
* a feature is supported.
if (scno < __ARM_NR_COMPAT_END)
return -ENOSYS;
addr = (void __user *)instruction_pointer(regs) -
(compat_thumb_mode(regs) ? 2 : 4);
arm64_notify_die("Oops - bad compat syscall(2)", regs,
SIGILL, ILL_ILLTRP, addr, scno);
return 0;