bpf_jit_asm_64.S
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/* SPDX-License-Identifier: GPL-2.0 */
#include <asm/ptrace.h>
#include "bpf_jit_64.h"
#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
#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_RESULT
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_RESULT
.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_RESULT
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_RESULT
.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_RESULT
#define bpf_slow_path_common(LEN) \
save %sp, -SAVE_SZ, %sp; \
mov %i0, %o0; \
mov %i1, %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_RESULT
retl
nop
bpf_slow_path_half:
bpf_slow_path_common(2)
bl bpf_error
lduh [%sp + SCRATCH_OFF], r_RESULT
retl
nop
bpf_slow_path_byte:
bpf_slow_path_common(1)
bl bpf_error
ldub [%sp + SCRATCH_OFF], r_RESULT
retl
nop
#define bpf_negative_common(LEN) \
save %sp, -SAVE_SZ, %sp; \
mov %i0, %o0; \
mov %i1, %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_RESULT
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_RESULT
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_RESULT
bpf_error:
/* Make the JIT program itself return zero. */
ret
restore %g0, %g0, %o0