1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2023 SUSE LLC */
3 #include <linux/bpf.h>
4 #include <bpf/bpf_helpers.h>
5 #include "../../../include/linux/filter.h"
6 #include "bpf_misc.h"
7 
8 SEC("?raw_tp")
9 __success __log_level(2)
10 __msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10")
11 __msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0xfffffff8 goto pc+2")
12 __msg("mark_precise: frame0: regs=r2 stack= before 1: (87) r2 = -r2")
13 __msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 8")
bpf_neg(void)14 __naked int bpf_neg(void)
15 {
16 	asm volatile (
17 		"r2 = 8;"
18 		"r2 = -r2;"
19 		"if r2 != -8 goto 1f;"
20 		"r1 = r10;"
21 		"r1 += r2;"
22 	"1:"
23 		"r0 = 0;"
24 		"exit;"
25 		::: __clobber_all);
26 }
27 
28 SEC("?raw_tp")
29 __success __log_level(2)
30 __msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10")
31 __msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0x0 goto pc+2")
32 __msg("mark_precise: frame0: regs=r2 stack= before 1: (d4) r2 = le16 r2")
33 __msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 0")
bpf_end_to_le(void)34 __naked int bpf_end_to_le(void)
35 {
36 	asm volatile (
37 		"r2 = 0;"
38 		"r2 = le16 r2;"
39 		"if r2 != 0 goto 1f;"
40 		"r1 = r10;"
41 		"r1 += r2;"
42 	"1:"
43 		"r0 = 0;"
44 		"exit;"
45 		::: __clobber_all);
46 }
47 
48 
49 SEC("?raw_tp")
50 __success __log_level(2)
51 __msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10")
52 __msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0x0 goto pc+2")
53 __msg("mark_precise: frame0: regs=r2 stack= before 1: (dc) r2 = be16 r2")
54 __msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 0")
bpf_end_to_be(void)55 __naked int bpf_end_to_be(void)
56 {
57 	asm volatile (
58 		"r2 = 0;"
59 		"r2 = be16 r2;"
60 		"if r2 != 0 goto 1f;"
61 		"r1 = r10;"
62 		"r1 += r2;"
63 	"1:"
64 		"r0 = 0;"
65 		"exit;"
66 		::: __clobber_all);
67 }
68 
69 #if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \
70 	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
71 	defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390)) && \
72 	__clang_major__ >= 18
73 
74 SEC("?raw_tp")
75 __success __log_level(2)
76 __msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10")
77 __msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0x0 goto pc+2")
78 __msg("mark_precise: frame0: regs=r2 stack= before 1: (d7) r2 = bswap16 r2")
79 __msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 0")
bpf_end_bswap(void)80 __naked int bpf_end_bswap(void)
81 {
82 	asm volatile (
83 		"r2 = 0;"
84 		"r2 = bswap16 r2;"
85 		"if r2 != 0 goto 1f;"
86 		"r1 = r10;"
87 		"r1 += r2;"
88 	"1:"
89 		"r0 = 0;"
90 		"exit;"
91 		::: __clobber_all);
92 }
93 
94 #if defined(ENABLE_ATOMICS_TESTS) && \
95 	(defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86))
96 
97 SEC("?raw_tp")
98 __success __log_level(2)
99 __msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r3 = r10")
100 __msg("mark_precise: frame0: regs=r2 stack= before 2: (db) r2 = load_acquire((u64 *)(r10 -8))")
101 __msg("mark_precise: frame0: regs= stack=-8 before 1: (7b) *(u64 *)(r10 -8) = r1")
102 __msg("mark_precise: frame0: regs=r1 stack= before 0: (b7) r1 = 8")
bpf_load_acquire(void)103 __naked int bpf_load_acquire(void)
104 {
105 	asm volatile (
106 	"r1 = 8;"
107 	"*(u64 *)(r10 - 8) = r1;"
108 	".8byte %[load_acquire_insn];" /* r2 = load_acquire((u64 *)(r10 - 8)); */
109 	"r3 = r10;"
110 	"r3 += r2;" /* mark_precise */
111 	"r0 = 0;"
112 	"exit;"
113 	:
114 	: __imm_insn(load_acquire_insn,
115 		     BPF_ATOMIC_OP(BPF_DW, BPF_LOAD_ACQ, BPF_REG_2, BPF_REG_10, -8))
116 	: __clobber_all);
117 }
118 
119 SEC("?raw_tp")
120 __success __log_level(2)
121 __msg("mark_precise: frame0: regs=r1 stack= before 3: (bf) r2 = r10")
122 __msg("mark_precise: frame0: regs=r1 stack= before 2: (79) r1 = *(u64 *)(r10 -8)")
123 __msg("mark_precise: frame0: regs= stack=-8 before 1: (db) store_release((u64 *)(r10 -8), r1)")
124 __msg("mark_precise: frame0: regs=r1 stack= before 0: (b7) r1 = 8")
bpf_store_release(void)125 __naked int bpf_store_release(void)
126 {
127 	asm volatile (
128 	"r1 = 8;"
129 	".8byte %[store_release_insn];" /* store_release((u64 *)(r10 - 8), r1); */
130 	"r1 = *(u64 *)(r10 - 8);"
131 	"r2 = r10;"
132 	"r2 += r1;" /* mark_precise */
133 	"r0 = 0;"
134 	"exit;"
135 	:
136 	: __imm_insn(store_release_insn,
137 		     BPF_ATOMIC_OP(BPF_DW, BPF_STORE_REL, BPF_REG_10, BPF_REG_1, -8))
138 	: __clobber_all);
139 }
140 
141 #endif /* load-acquire, store-release */
142 #endif /* v4 instruction */
143 
144 SEC("?raw_tp")
145 __success __log_level(2)
146 /*
147  * Without the bug fix there will be no history between "last_idx 3 first_idx 3"
148  * and "parent state regs=" lines. "R0_w=6" parts are here to help anchor
149  * expected log messages to the one specific mark_chain_precision operation.
150  *
151  * This is quite fragile: if verifier checkpointing heuristic changes, this
152  * might need adjusting.
153  */
154 __msg("2: (07) r0 += 1                       ; R0_w=6")
155 __msg("3: (35) if r0 >= 0xa goto pc+1")
156 __msg("mark_precise: frame0: last_idx 3 first_idx 3 subseq_idx -1")
157 __msg("mark_precise: frame0: regs=r0 stack= before 2: (07) r0 += 1")
158 __msg("mark_precise: frame0: regs=r0 stack= before 1: (07) r0 += 1")
159 __msg("mark_precise: frame0: regs=r0 stack= before 4: (05) goto pc-4")
160 __msg("mark_precise: frame0: regs=r0 stack= before 3: (35) if r0 >= 0xa goto pc+1")
161 __msg("mark_precise: frame0: parent state regs= stack=:  R0_rw=P4")
162 __msg("3: R0_w=6")
state_loop_first_last_equal(void)163 __naked int state_loop_first_last_equal(void)
164 {
165 	asm volatile (
166 		"r0 = 0;"
167 	"l0_%=:"
168 		"r0 += 1;"
169 		"r0 += 1;"
170 		/* every few iterations we'll have a checkpoint here with
171 		 * first_idx == last_idx, potentially confusing precision
172 		 * backtracking logic
173 		 */
174 		"if r0 >= 10 goto l1_%=;"	/* checkpoint + mark_precise */
175 		"goto l0_%=;"
176 	"l1_%=:"
177 		"exit;"
178 		::: __clobber_common
179 	);
180 }
181 
182 char _license[] SEC("license") = "GPL";
183