4c8cd0c50d
So the SYSENTER instruction is pretty quirky and it has different behavior depending on bitness and CPU maker. Yet we create a false sense of coherency by naming it 'ia32_sysenter_target' in both of the cases. Split the name into its two uses: ia32_sysenter_target (32) -> entry_SYSENTER_32 ia32_sysenter_target (64) -> entry_SYSENTER_compat As per the generic naming scheme for x86 system call entry points: entry_MNEMONIC_qualifier where 'qualifier' is one of _32, _64 or _compat. Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
146 lines
3.1 KiB
ArmAsm
146 lines
3.1 KiB
ArmAsm
/*
|
|
* Asm versions of Xen pv-ops, suitable for either direct use or
|
|
* inlining. The inline versions are the same as the direct-use
|
|
* versions, with the pre- and post-amble chopped off.
|
|
*
|
|
* This code is encoded for size rather than absolute efficiency, with
|
|
* a view to being able to inline as much as possible.
|
|
*
|
|
* We only bother with direct forms (ie, vcpu in pda) of the
|
|
* operations here; the indirect forms are better handled in C, since
|
|
* they're generally too large to inline anyway.
|
|
*/
|
|
|
|
#include <asm/errno.h>
|
|
#include <asm/percpu.h>
|
|
#include <asm/processor-flags.h>
|
|
#include <asm/segment.h>
|
|
#include <asm/asm-offsets.h>
|
|
#include <asm/thread_info.h>
|
|
|
|
#include <xen/interface/xen.h>
|
|
|
|
#include "xen-asm.h"
|
|
|
|
ENTRY(xen_adjust_exception_frame)
|
|
mov 8+0(%rsp), %rcx
|
|
mov 8+8(%rsp), %r11
|
|
ret $16
|
|
|
|
hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32
|
|
/*
|
|
* Xen64 iret frame:
|
|
*
|
|
* ss
|
|
* rsp
|
|
* rflags
|
|
* cs
|
|
* rip <-- standard iret frame
|
|
*
|
|
* flags
|
|
*
|
|
* rcx }
|
|
* r11 }<-- pushed by hypercall page
|
|
* rsp->rax }
|
|
*/
|
|
ENTRY(xen_iret)
|
|
pushq $0
|
|
1: jmp hypercall_iret
|
|
ENDPATCH(xen_iret)
|
|
RELOC(xen_iret, 1b+1)
|
|
|
|
ENTRY(xen_sysret64)
|
|
/*
|
|
* We're already on the usermode stack at this point, but
|
|
* still with the kernel gs, so we can easily switch back
|
|
*/
|
|
movq %rsp, PER_CPU_VAR(rsp_scratch)
|
|
movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
|
|
|
|
pushq $__USER_DS
|
|
pushq PER_CPU_VAR(rsp_scratch)
|
|
pushq %r11
|
|
pushq $__USER_CS
|
|
pushq %rcx
|
|
|
|
pushq $VGCF_in_syscall
|
|
1: jmp hypercall_iret
|
|
ENDPATCH(xen_sysret64)
|
|
RELOC(xen_sysret64, 1b+1)
|
|
|
|
ENTRY(xen_sysret32)
|
|
/*
|
|
* We're already on the usermode stack at this point, but
|
|
* still with the kernel gs, so we can easily switch back
|
|
*/
|
|
movq %rsp, PER_CPU_VAR(rsp_scratch)
|
|
movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
|
|
|
|
pushq $__USER32_DS
|
|
pushq PER_CPU_VAR(rsp_scratch)
|
|
pushq %r11
|
|
pushq $__USER32_CS
|
|
pushq %rcx
|
|
|
|
pushq $0
|
|
1: jmp hypercall_iret
|
|
ENDPATCH(xen_sysret32)
|
|
RELOC(xen_sysret32, 1b+1)
|
|
|
|
/*
|
|
* Xen handles syscall callbacks much like ordinary exceptions, which
|
|
* means we have:
|
|
* - kernel gs
|
|
* - kernel rsp
|
|
* - an iret-like stack frame on the stack (including rcx and r11):
|
|
* ss
|
|
* rsp
|
|
* rflags
|
|
* cs
|
|
* rip
|
|
* r11
|
|
* rsp->rcx
|
|
*
|
|
* In all the entrypoints, we undo all that to make it look like a
|
|
* CPU-generated syscall/sysenter and jump to the normal entrypoint.
|
|
*/
|
|
|
|
.macro undo_xen_syscall
|
|
mov 0*8(%rsp), %rcx
|
|
mov 1*8(%rsp), %r11
|
|
mov 5*8(%rsp), %rsp
|
|
.endm
|
|
|
|
/* Normal 64-bit system call target */
|
|
ENTRY(xen_syscall_target)
|
|
undo_xen_syscall
|
|
jmp system_call_after_swapgs
|
|
ENDPROC(xen_syscall_target)
|
|
|
|
#ifdef CONFIG_IA32_EMULATION
|
|
|
|
/* 32-bit compat syscall target */
|
|
ENTRY(xen_syscall32_target)
|
|
undo_xen_syscall
|
|
jmp entry_SYSCALL_compat
|
|
ENDPROC(xen_syscall32_target)
|
|
|
|
/* 32-bit compat sysenter target */
|
|
ENTRY(xen_sysenter_target)
|
|
undo_xen_syscall
|
|
jmp entry_SYSENTER_compat
|
|
ENDPROC(xen_sysenter_target)
|
|
|
|
#else /* !CONFIG_IA32_EMULATION */
|
|
|
|
ENTRY(xen_syscall32_target)
|
|
ENTRY(xen_sysenter_target)
|
|
lea 16(%rsp), %rsp /* strip %rcx, %r11 */
|
|
mov $-ENOSYS, %rax
|
|
pushq $0
|
|
jmp hypercall_iret
|
|
ENDPROC(xen_syscall32_target)
|
|
ENDPROC(xen_sysenter_target)
|
|
|
|
#endif /* CONFIG_IA32_EMULATION */
|