forked from mirrors/linux
736706bee3
Every in-kernel use of this function defined it to KERNEL_DS (either as an actual define, or as an inline function). It's an entirely historical artifact, and long long long ago used to actually read the segment selector valueof '%ds' on x86. Which in the kernel is always KERNEL_DS. Inspired by a patch from Jann Horn that just did this for a very small subset of users (the ones in fs/), along with Al who suggested a script. I then just took it to the logical extreme and removed all the remaining gunk. Roughly scripted with git grep -l '(get_ds())' -- :^tools/ | xargs sed -i 's/(get_ds())/(KERNEL_DS)/' git grep -lw 'get_ds' -- :^tools/ | xargs sed -i '/^#define get_ds()/d' plus manual fixups to remove a few unusual usage patterns, the couple of inline function cases and to fix up a comment that had become stale. The 'get_ds()' function remains in an x86 kvm selftest, since in user space it actually does something relevant. Inspired-by: Jann Horn <jannh@google.com> Inspired-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
122 lines
3.7 KiB
ArmAsm
122 lines
3.7 KiB
ArmAsm
/******************************************************************************
|
|
* hypercall.S
|
|
*
|
|
* Xen hypercall wrappers
|
|
*
|
|
* Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012
|
|
*
|
|
* 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; or, when distributed
|
|
* separately from the Linux kernel or incorporated into other
|
|
* software packages, subject to the following license:
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this source file (the "Software"), to deal in the Software without
|
|
* restriction, including without limitation the rights to use, copy, modify,
|
|
* merge, publish, distribute, sublicense, and/or sell copies of the Software,
|
|
* and to permit persons to whom the Software is furnished to do so, subject to
|
|
* the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
|
|
* IN THE SOFTWARE.
|
|
*/
|
|
|
|
/*
|
|
* The Xen hypercall calling convention is very similar to the ARM
|
|
* procedure calling convention: the first paramter is passed in r0, the
|
|
* second in r1, the third in r2 and the fourth in r3. Considering that
|
|
* Xen hypercalls have 5 arguments at most, the fifth paramter is passed
|
|
* in r4, differently from the procedure calling convention of using the
|
|
* stack for that case.
|
|
*
|
|
* The hypercall number is passed in r12.
|
|
*
|
|
* The return value is in r0.
|
|
*
|
|
* The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
|
|
* hypercall tag.
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/assembler.h>
|
|
#include <asm/opcodes-virt.h>
|
|
#include <xen/interface/xen.h>
|
|
|
|
|
|
#define XEN_IMM 0xEA1
|
|
|
|
#define HYPERCALL_SIMPLE(hypercall) \
|
|
ENTRY(HYPERVISOR_##hypercall) \
|
|
mov r12, #__HYPERVISOR_##hypercall; \
|
|
__HVC(XEN_IMM); \
|
|
ret lr; \
|
|
ENDPROC(HYPERVISOR_##hypercall)
|
|
|
|
#define HYPERCALL0 HYPERCALL_SIMPLE
|
|
#define HYPERCALL1 HYPERCALL_SIMPLE
|
|
#define HYPERCALL2 HYPERCALL_SIMPLE
|
|
#define HYPERCALL3 HYPERCALL_SIMPLE
|
|
#define HYPERCALL4 HYPERCALL_SIMPLE
|
|
|
|
#define HYPERCALL5(hypercall) \
|
|
ENTRY(HYPERVISOR_##hypercall) \
|
|
stmdb sp!, {r4} \
|
|
ldr r4, [sp, #4] \
|
|
mov r12, #__HYPERVISOR_##hypercall; \
|
|
__HVC(XEN_IMM); \
|
|
ldm sp!, {r4} \
|
|
ret lr \
|
|
ENDPROC(HYPERVISOR_##hypercall)
|
|
|
|
.text
|
|
|
|
HYPERCALL2(xen_version);
|
|
HYPERCALL3(console_io);
|
|
HYPERCALL3(grant_table_op);
|
|
HYPERCALL2(sched_op);
|
|
HYPERCALL2(event_channel_op);
|
|
HYPERCALL2(hvm_op);
|
|
HYPERCALL2(memory_op);
|
|
HYPERCALL2(physdev_op);
|
|
HYPERCALL3(vcpu_op);
|
|
HYPERCALL1(tmem_op);
|
|
HYPERCALL1(platform_op_raw);
|
|
HYPERCALL2(multicall);
|
|
HYPERCALL2(vm_assist);
|
|
HYPERCALL3(dm_op);
|
|
|
|
ENTRY(privcmd_call)
|
|
stmdb sp!, {r4}
|
|
mov r12, r0
|
|
mov r0, r1
|
|
mov r1, r2
|
|
mov r2, r3
|
|
ldr r3, [sp, #8]
|
|
/*
|
|
* Privcmd calls are issued by the userspace. We need to allow the
|
|
* kernel to access the userspace memory before issuing the hypercall.
|
|
*/
|
|
uaccess_enable r4
|
|
|
|
/* r4 is loaded now as we use it as scratch register before */
|
|
ldr r4, [sp, #4]
|
|
__HVC(XEN_IMM)
|
|
|
|
/*
|
|
* Disable userspace access from kernel. This is fine to do it
|
|
* unconditionally as no set_fs(KERNEL_DS) is called before.
|
|
*/
|
|
uaccess_disable r4
|
|
|
|
ldm sp!, {r4}
|
|
ret lr
|
|
ENDPROC(privcmd_call);
|