tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#ifndef __BPF_HELPERS_H
2#define __BPF_HELPERS_H
3
4/* helper macro to place programs, maps, license in
5 * different sections in elf_bpf file. Section names
6 * are interpreted by elf_bpf loader
7 */
8#define SEC(NAME) __attribute__((section(NAME), used))
9
10/* helper functions called from eBPF programs written in C */
11static void *(*bpf_map_lookup_elem)(void *map, void *key) =
12 (void *) BPF_FUNC_map_lookup_elem;
13static int (*bpf_map_update_elem)(void *map, void *key, void *value,
14 unsigned long long flags) =
15 (void *) BPF_FUNC_map_update_elem;
16static int (*bpf_map_delete_elem)(void *map, void *key) =
17 (void *) BPF_FUNC_map_delete_elem;
18static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr) =
19 (void *) BPF_FUNC_probe_read;
20static unsigned long long (*bpf_ktime_get_ns)(void) =
21 (void *) BPF_FUNC_ktime_get_ns;
22static int (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) =
23 (void *) BPF_FUNC_trace_printk;
24static void (*bpf_tail_call)(void *ctx, void *map, int index) =
25 (void *) BPF_FUNC_tail_call;
26static unsigned long long (*bpf_get_smp_processor_id)(void) =
27 (void *) BPF_FUNC_get_smp_processor_id;
28static unsigned long long (*bpf_get_current_pid_tgid)(void) =
29 (void *) BPF_FUNC_get_current_pid_tgid;
30static unsigned long long (*bpf_get_current_uid_gid)(void) =
31 (void *) BPF_FUNC_get_current_uid_gid;
32static int (*bpf_get_current_comm)(void *buf, int buf_size) =
33 (void *) BPF_FUNC_get_current_comm;
34static int (*bpf_perf_event_read)(void *map, int index) =
35 (void *) BPF_FUNC_perf_event_read;
36static int (*bpf_clone_redirect)(void *ctx, int ifindex, int flags) =
37 (void *) BPF_FUNC_clone_redirect;
38static int (*bpf_redirect)(int ifindex, int flags) =
39 (void *) BPF_FUNC_redirect;
40static int (*bpf_perf_event_output)(void *ctx, void *map, int index, void *data, int size) =
41 (void *) BPF_FUNC_perf_event_output;
42static int (*bpf_get_stackid)(void *ctx, void *map, int flags) =
43 (void *) BPF_FUNC_get_stackid;
44
45/* llvm builtin functions that eBPF C program may use to
46 * emit BPF_LD_ABS and BPF_LD_IND instructions
47 */
48struct sk_buff;
49unsigned long long load_byte(void *skb,
50 unsigned long long off) asm("llvm.bpf.load.byte");
51unsigned long long load_half(void *skb,
52 unsigned long long off) asm("llvm.bpf.load.half");
53unsigned long long load_word(void *skb,
54 unsigned long long off) asm("llvm.bpf.load.word");
55
56/* a helper structure used by eBPF C program
57 * to describe map attributes to elf_bpf loader
58 */
59struct bpf_map_def {
60 unsigned int type;
61 unsigned int key_size;
62 unsigned int value_size;
63 unsigned int max_entries;
64 unsigned int map_flags;
65};
66
67static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) =
68 (void *) BPF_FUNC_skb_store_bytes;
69static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flags) =
70 (void *) BPF_FUNC_l3_csum_replace;
71static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flags) =
72 (void *) BPF_FUNC_l4_csum_replace;
73
74#if defined(__x86_64__)
75
76#define PT_REGS_PARM1(x) ((x)->di)
77#define PT_REGS_PARM2(x) ((x)->si)
78#define PT_REGS_PARM3(x) ((x)->dx)
79#define PT_REGS_PARM4(x) ((x)->cx)
80#define PT_REGS_PARM5(x) ((x)->r8)
81#define PT_REGS_RET(x) ((x)->sp)
82#define PT_REGS_FP(x) ((x)->bp)
83#define PT_REGS_RC(x) ((x)->ax)
84#define PT_REGS_SP(x) ((x)->sp)
85#define PT_REGS_IP(x) ((x)->ip)
86
87#elif defined(__s390x__)
88
89#define PT_REGS_PARM1(x) ((x)->gprs[2])
90#define PT_REGS_PARM2(x) ((x)->gprs[3])
91#define PT_REGS_PARM3(x) ((x)->gprs[4])
92#define PT_REGS_PARM4(x) ((x)->gprs[5])
93#define PT_REGS_PARM5(x) ((x)->gprs[6])
94#define PT_REGS_RET(x) ((x)->gprs[14])
95#define PT_REGS_FP(x) ((x)->gprs[11]) /* Works only with CONFIG_FRAME_POINTER */
96#define PT_REGS_RC(x) ((x)->gprs[2])
97#define PT_REGS_SP(x) ((x)->gprs[15])
98#define PT_REGS_IP(x) ((x)->ip)
99
100#elif defined(__aarch64__)
101
102#define PT_REGS_PARM1(x) ((x)->regs[0])
103#define PT_REGS_PARM2(x) ((x)->regs[1])
104#define PT_REGS_PARM3(x) ((x)->regs[2])
105#define PT_REGS_PARM4(x) ((x)->regs[3])
106#define PT_REGS_PARM5(x) ((x)->regs[4])
107#define PT_REGS_RET(x) ((x)->regs[30])
108#define PT_REGS_FP(x) ((x)->regs[29]) /* Works only with CONFIG_FRAME_POINTER */
109#define PT_REGS_RC(x) ((x)->regs[0])
110#define PT_REGS_SP(x) ((x)->sp)
111#define PT_REGS_IP(x) ((x)->pc)
112
113#elif defined(__powerpc__)
114
115#define PT_REGS_PARM1(x) ((x)->gpr[3])
116#define PT_REGS_PARM2(x) ((x)->gpr[4])
117#define PT_REGS_PARM3(x) ((x)->gpr[5])
118#define PT_REGS_PARM4(x) ((x)->gpr[6])
119#define PT_REGS_PARM5(x) ((x)->gpr[7])
120#define PT_REGS_RC(x) ((x)->gpr[3])
121#define PT_REGS_SP(x) ((x)->sp)
122#define PT_REGS_IP(x) ((x)->nip)
123
124#endif
125
126#ifdef __powerpc__
127#define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ (ip) = (ctx)->link; })
128#define BPF_KRETPROBE_READ_RET_IP BPF_KPROBE_READ_RET_IP
129#else
130#define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ \
131 bpf_probe_read(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })
132#define BPF_KRETPROBE_READ_RET_IP(ip, ctx) ({ \
133 bpf_probe_read(&(ip), sizeof(ip), \
134 (void *)(PT_REGS_FP(ctx) + sizeof(ip))); })
135#endif
136
137#endif