tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright(c) 2016-20 Intel Corporation.
4 */
5
6 .macro ENCLU
7 .byte 0x0f, 0x01, 0xd7
8 .endm
9
10 .section ".tcs", "aw"
11 .balign 4096
12
13 .fill 1, 8, 0 # STATE (set by CPU)
14 .fill 1, 8, 0 # FLAGS
15 .quad encl_ssa # OSSA
16 .fill 1, 4, 0 # CSSA (set by CPU)
17 .fill 1, 4, 1 # NSSA
18 .quad encl_entry # OENTRY
19 .fill 1, 8, 0 # AEP (set by EENTER and ERESUME)
20 .fill 1, 8, 0 # OFSBASE
21 .fill 1, 8, 0 # OGSBASE
22 .fill 1, 4, 0xFFFFFFFF # FSLIMIT
23 .fill 1, 4, 0xFFFFFFFF # GSLIMIT
24 .fill 4024, 1, 0 # Reserved
25
26 # Identical to the previous TCS.
27 .fill 1, 8, 0 # STATE (set by CPU)
28 .fill 1, 8, 0 # FLAGS
29 .quad encl_ssa # OSSA
30 .fill 1, 4, 0 # CSSA (set by CPU)
31 .fill 1, 4, 1 # NSSA
32 .quad encl_entry # OENTRY
33 .fill 1, 8, 0 # AEP (set by EENTER and ERESUME)
34 .fill 1, 8, 0 # OFSBASE
35 .fill 1, 8, 0 # OGSBASE
36 .fill 1, 4, 0xFFFFFFFF # FSLIMIT
37 .fill 1, 4, 0xFFFFFFFF # GSLIMIT
38 .fill 4024, 1, 0 # Reserved
39
40 .text
41
42encl_entry:
43 # RBX contains the base address for TCS, which is also the first address
44 # inside the enclave. By adding the value of le_stack_end to it, we get
45 # the absolute address for the stack.
46 lea (encl_stack)(%rbx), %rax
47 xchg %rsp, %rax
48 push %rax
49
50 push %rcx # push the address after EENTER
51 push %rbx # push the enclave base address
52
53 call encl_body
54
55 pop %rbx # pop the enclave base address
56
57 /* Clear volatile GPRs, except RAX (EEXIT function). */
58 xor %rcx, %rcx
59 xor %rdx, %rdx
60 xor %rdi, %rdi
61 xor %rsi, %rsi
62 xor %r8, %r8
63 xor %r9, %r9
64 xor %r10, %r10
65 xor %r11, %r11
66
67 # Reset status flags.
68 add %rdx, %rdx # OF = SF = AF = CF = 0; ZF = PF = 1
69
70 # Prepare EEXIT target by popping the address of the instruction after
71 # EENTER to RBX.
72 pop %rbx
73
74 # Restore the caller stack.
75 pop %rax
76 mov %rax, %rsp
77
78 # EEXIT
79 mov $4, %rax
80 enclu
81
82 .section ".data", "aw"
83
84encl_ssa:
85 .space 4096
86
87 .balign 4096
88 .space 8192
89encl_stack: