mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-06 02:24:14 +08:00
a2d25a5391
Update handling of cacheflush syscall with changes made in arch/arm counterpart: - return error to userspace when flushing syscall fails - split user cache-flushing into interruptible chunks - don't bother rounding to nearest vma Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> [will: changed internal return value from -EINTR to 0 to match arch/arm/] Signed-off-by: Will Deacon <will.deacon@arm.com>
104 lines
2.7 KiB
C
104 lines
2.7 KiB
C
/*
|
|
* 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.
|
|
*
|
|
* 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 <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <linux/compat.h>
|
|
#include <linux/personality.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#include <asm/cacheflush.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;
|
|
|
|
ret = __flush_cache_user_range(start, start + chunk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
cond_resched();
|
|
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(VERIFY_READ, 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)
|
|
{
|
|
unsigned int no = regs->regs[7];
|
|
|
|
switch (no) {
|
|
/*
|
|
* 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.tp_value = regs->regs[0];
|
|
|
|
/*
|
|
* Protect against register corruption from context switch.
|
|
* See comment in tls_thread_flush.
|
|
*/
|
|
barrier();
|
|
asm ("msr tpidrro_el0, %0" : : "r" (regs->regs[0]));
|
|
return 0;
|
|
|
|
default:
|
|
return -ENOSYS;
|
|
}
|
|
}
|