Blame view

kernel/linux-rt-4.4.41/arch/sparc/net/bpf_jit_asm.S 4.3 KB
5113f6f70   김현기   kernel add
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
  #include <asm/ptrace.h>
  
  #include "bpf_jit.h"
  
  #ifdef CONFIG_SPARC64
  #define SAVE_SZ		176
  #define SCRATCH_OFF	STACK_BIAS + 128
  #define BE_PTR(label)	be,pn %xcc, label
  #define SIGN_EXTEND(reg)	sra reg, 0, reg
  #else
  #define SAVE_SZ		96
  #define SCRATCH_OFF	72
  #define BE_PTR(label)	be label
  #define SIGN_EXTEND(reg)
  #endif
  
  #define SKF_MAX_NEG_OFF	(-0x200000) /* SKF_LL_OFF from filter.h */
  
  	.text
  	.globl	bpf_jit_load_word
  bpf_jit_load_word:
  	cmp	r_OFF, 0
  	bl	bpf_slow_path_word_neg
  	 nop
  	.globl	bpf_jit_load_word_positive_offset
  bpf_jit_load_word_positive_offset:
  	sub	r_HEADLEN, r_OFF, r_TMP
  	cmp	r_TMP, 3
  	ble	bpf_slow_path_word
  	 add	r_SKB_DATA, r_OFF, r_TMP
  	andcc	r_TMP, 3, %g0
  	bne	load_word_unaligned
  	 nop
  	retl
  	 ld	[r_TMP], r_A
  load_word_unaligned:
  	ldub	[r_TMP + 0x0], r_OFF
  	ldub	[r_TMP + 0x1], r_TMP2
  	sll	r_OFF, 8, r_OFF
  	or	r_OFF, r_TMP2, r_OFF
  	ldub	[r_TMP + 0x2], r_TMP2
  	sll	r_OFF, 8, r_OFF
  	or	r_OFF, r_TMP2, r_OFF
  	ldub	[r_TMP + 0x3], r_TMP2
  	sll	r_OFF, 8, r_OFF
  	retl
  	 or	r_OFF, r_TMP2, r_A
  
  	.globl	bpf_jit_load_half
  bpf_jit_load_half:
  	cmp	r_OFF, 0
  	bl	bpf_slow_path_half_neg
  	 nop
  	.globl	bpf_jit_load_half_positive_offset
  bpf_jit_load_half_positive_offset:
  	sub	r_HEADLEN, r_OFF, r_TMP
  	cmp	r_TMP, 1
  	ble	bpf_slow_path_half
  	 add	r_SKB_DATA, r_OFF, r_TMP
  	andcc	r_TMP, 1, %g0
  	bne	load_half_unaligned
  	 nop
  	retl
  	 lduh	[r_TMP], r_A
  load_half_unaligned:
  	ldub	[r_TMP + 0x0], r_OFF
  	ldub	[r_TMP + 0x1], r_TMP2
  	sll	r_OFF, 8, r_OFF
  	retl
  	 or	r_OFF, r_TMP2, r_A
  
  	.globl	bpf_jit_load_byte
  bpf_jit_load_byte:
  	cmp	r_OFF, 0
  	bl	bpf_slow_path_byte_neg
  	 nop
  	.globl	bpf_jit_load_byte_positive_offset
  bpf_jit_load_byte_positive_offset:
  	cmp	r_OFF, r_HEADLEN
  	bge	bpf_slow_path_byte
  	 nop
  	retl
  	 ldub	[r_SKB_DATA + r_OFF], r_A
  
  	.globl	bpf_jit_load_byte_msh
  bpf_jit_load_byte_msh:
  	cmp	r_OFF, 0
  	bl	bpf_slow_path_byte_msh_neg
  	 nop
  	.globl	bpf_jit_load_byte_msh_positive_offset
  bpf_jit_load_byte_msh_positive_offset:
  	cmp	r_OFF, r_HEADLEN
  	bge	bpf_slow_path_byte_msh
  	 nop
  	ldub	[r_SKB_DATA + r_OFF], r_OFF
  	and	r_OFF, 0xf, r_OFF
  	retl
  	 sll	r_OFF, 2, r_X
  
  #define bpf_slow_path_common(LEN)	\
  	save	%sp, -SAVE_SZ, %sp;	\
  	mov	%i0, %o0;		\
  	mov	r_OFF, %o1;		\
  	add	%fp, SCRATCH_OFF, %o2;	\
  	call	skb_copy_bits;		\
  	 mov	(LEN), %o3;		\
  	cmp	%o0, 0;			\
  	restore;
  
  bpf_slow_path_word:
  	bpf_slow_path_common(4)
  	bl	bpf_error
  	 ld	[%sp + SCRATCH_OFF], r_A
  	retl
  	 nop
  bpf_slow_path_half:
  	bpf_slow_path_common(2)
  	bl	bpf_error
  	 lduh	[%sp + SCRATCH_OFF], r_A
  	retl
  	 nop
  bpf_slow_path_byte:
  	bpf_slow_path_common(1)
  	bl	bpf_error
  	 ldub	[%sp + SCRATCH_OFF], r_A
  	retl
  	 nop
  bpf_slow_path_byte_msh:
  	bpf_slow_path_common(1)
  	bl	bpf_error
  	 ldub	[%sp + SCRATCH_OFF], r_A
  	and	r_OFF, 0xf, r_OFF
  	retl
  	 sll	r_OFF, 2, r_X
  
  #define bpf_negative_common(LEN)			\
  	save	%sp, -SAVE_SZ, %sp;			\
  	mov	%i0, %o0;				\
  	mov	r_OFF, %o1;				\
  	SIGN_EXTEND(%o1);				\
  	call	bpf_internal_load_pointer_neg_helper;	\
  	 mov	(LEN), %o2;				\
  	mov	%o0, r_TMP;				\
  	cmp	%o0, 0;					\
  	BE_PTR(bpf_error);				\
  	 restore;
  
  bpf_slow_path_word_neg:
  	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
  	cmp	r_OFF, r_TMP
  	bl	bpf_error
  	 nop
  	.globl	bpf_jit_load_word_negative_offset
  bpf_jit_load_word_negative_offset:
  	bpf_negative_common(4)
  	andcc	r_TMP, 3, %g0
  	bne	load_word_unaligned
  	 nop
  	retl
  	 ld	[r_TMP], r_A
  
  bpf_slow_path_half_neg:
  	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
  	cmp	r_OFF, r_TMP
  	bl	bpf_error
  	 nop
  	.globl	bpf_jit_load_half_negative_offset
  bpf_jit_load_half_negative_offset:
  	bpf_negative_common(2)
  	andcc	r_TMP, 1, %g0
  	bne	load_half_unaligned
  	 nop
  	retl
  	 lduh	[r_TMP], r_A
  
  bpf_slow_path_byte_neg:
  	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
  	cmp	r_OFF, r_TMP
  	bl	bpf_error
  	 nop
  	.globl	bpf_jit_load_byte_negative_offset
  bpf_jit_load_byte_negative_offset:
  	bpf_negative_common(1)
  	retl
  	 ldub	[r_TMP], r_A
  
  bpf_slow_path_byte_msh_neg:
  	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
  	cmp	r_OFF, r_TMP
  	bl	bpf_error
  	 nop
  	.globl	bpf_jit_load_byte_msh_negative_offset
  bpf_jit_load_byte_msh_negative_offset:
  	bpf_negative_common(1)
  	ldub	[r_TMP], r_OFF
  	and	r_OFF, 0xf, r_OFF
  	retl
  	 sll	r_OFF, 2, r_X
  
  bpf_error:
  	/* Make the JIT program return zero.  The JIT epilogue
  	 * stores away the original %o7 into r_saved_O7.  The
  	 * normal leaf function return is to use "retl" which
  	 * would evalute to "jmpl %o7 + 8, %g0" but we want to
  	 * use the saved value thus the sequence you see here.
  	 */
  	jmpl	r_saved_O7 + 8, %g0
  	 clr	%o0