linux_dsm_epyc7002/arch/x86/um/syscalls_64.c
Kyle Huey 17a6e1b8e8 x86/arch_prctl/64: Rename do_arch_prctl() to do_arch_prctl_64()
In order to introduce new arch_prctls that are not 64 bit only, rename the
existing 64 bit implementation to do_arch_prctl_64(). Also rename the
second argument of that function from 'addr' to 'arg2', because it will no
longer always be an address.

Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Robert O'Callahan <robert@ocallahan.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Len Brown <len.brown@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack <dmatlack@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/r/20170320081628.18952-5-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-03-20 16:10:32 +01:00

90 lines
2.3 KiB
C

/*
* Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Copyright 2003 PathScale, Inc.
*
* Licensed under the GPL
*/
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <asm/prctl.h> /* XXX This should get the constants from libc */
#include <os.h>
long arch_prctl(struct task_struct *task, int option)
unsigned long __user *arg2)
{
unsigned long *ptr = arg2, tmp;
long ret;
int pid = task->mm->context.id.u.pid;
/*
* With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to
* be safe), we need to call arch_prctl on the host because
* setting %fs may result in something else happening (like a
* GDT or thread.fs being set instead). So, we let the host
* fiddle the registers and thread struct and restore the
* registers afterwards.
*
* So, the saved registers are stored to the process (this
* needed because a stub may have been the last thing to run),
* arch_prctl is run on the host, then the registers are read
* back.
*/
switch (option) {
case ARCH_SET_FS:
case ARCH_SET_GS:
ret = restore_registers(pid, &current->thread.regs.regs);
if (ret)
return ret;
break;
case ARCH_GET_FS:
case ARCH_GET_GS:
/*
* With these two, we read to a local pointer and
* put_user it to the userspace pointer that we were
* given. If addr isn't valid (because it hasn't been
* faulted in or is just bogus), we want put_user to
* fault it in (or return -EFAULT) instead of having
* the host return -EFAULT.
*/
ptr = &tmp;
}
ret = os_arch_prctl(pid, option, ptr);
if (ret)
return ret;
switch (option) {
case ARCH_SET_FS:
current->thread.arch.fs = (unsigned long) ptr;
ret = save_registers(pid, &current->thread.regs.regs);
break;
case ARCH_SET_GS:
ret = save_registers(pid, &current->thread.regs.regs);
break;
case ARCH_GET_FS:
ret = put_user(tmp, arg2);
break;
case ARCH_GET_GS:
ret = put_user(tmp, arg2);
break;
}
return ret;
}
SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
{
return arch_prctl(current, option, (unsigned long __user *) arg2);
}
void arch_switch_to(struct task_struct *to)
{
if ((to->thread.arch.fs == 0) || (to->mm == NULL))
return;
arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
}