xref: /linux/tools/lib/bpf/bpf_tracing.h (revision 132db93572821ec2fdf81e354cc40f558faf7e4f)
1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2 #ifndef __BPF_TRACING_H__
3 #define __BPF_TRACING_H__
4 
5 /* Scan the ARCH passed in from ARCH env variable (see Makefile) */
6 #if defined(__TARGET_ARCH_x86)
7 	#define bpf_target_x86
8 	#define bpf_target_defined
9 #elif defined(__TARGET_ARCH_s390)
10 	#define bpf_target_s390
11 	#define bpf_target_defined
12 #elif defined(__TARGET_ARCH_arm)
13 	#define bpf_target_arm
14 	#define bpf_target_defined
15 #elif defined(__TARGET_ARCH_arm64)
16 	#define bpf_target_arm64
17 	#define bpf_target_defined
18 #elif defined(__TARGET_ARCH_mips)
19 	#define bpf_target_mips
20 	#define bpf_target_defined
21 #elif defined(__TARGET_ARCH_powerpc)
22 	#define bpf_target_powerpc
23 	#define bpf_target_defined
24 #elif defined(__TARGET_ARCH_sparc)
25 	#define bpf_target_sparc
26 	#define bpf_target_defined
27 #else
28 	#undef bpf_target_defined
29 #endif
30 
31 /* Fall back to what the compiler says */
32 #ifndef bpf_target_defined
33 #if defined(__x86_64__)
34 	#define bpf_target_x86
35 #elif defined(__s390__)
36 	#define bpf_target_s390
37 #elif defined(__arm__)
38 	#define bpf_target_arm
39 #elif defined(__aarch64__)
40 	#define bpf_target_arm64
41 #elif defined(__mips__)
42 	#define bpf_target_mips
43 #elif defined(__powerpc__)
44 	#define bpf_target_powerpc
45 #elif defined(__sparc__)
46 	#define bpf_target_sparc
47 #endif
48 #endif
49 
50 #if defined(bpf_target_x86)
51 
52 #if defined(__KERNEL__) || defined(__VMLINUX_H__)
53 
54 #define PT_REGS_PARM1(x) ((x)->di)
55 #define PT_REGS_PARM2(x) ((x)->si)
56 #define PT_REGS_PARM3(x) ((x)->dx)
57 #define PT_REGS_PARM4(x) ((x)->cx)
58 #define PT_REGS_PARM5(x) ((x)->r8)
59 #define PT_REGS_RET(x) ((x)->sp)
60 #define PT_REGS_FP(x) ((x)->bp)
61 #define PT_REGS_RC(x) ((x)->ax)
62 #define PT_REGS_SP(x) ((x)->sp)
63 #define PT_REGS_IP(x) ((x)->ip)
64 
65 #define PT_REGS_PARM1_CORE(x) BPF_CORE_READ((x), di)
66 #define PT_REGS_PARM2_CORE(x) BPF_CORE_READ((x), si)
67 #define PT_REGS_PARM3_CORE(x) BPF_CORE_READ((x), dx)
68 #define PT_REGS_PARM4_CORE(x) BPF_CORE_READ((x), cx)
69 #define PT_REGS_PARM5_CORE(x) BPF_CORE_READ((x), r8)
70 #define PT_REGS_RET_CORE(x) BPF_CORE_READ((x), sp)
71 #define PT_REGS_FP_CORE(x) BPF_CORE_READ((x), bp)
72 #define PT_REGS_RC_CORE(x) BPF_CORE_READ((x), ax)
73 #define PT_REGS_SP_CORE(x) BPF_CORE_READ((x), sp)
74 #define PT_REGS_IP_CORE(x) BPF_CORE_READ((x), ip)
75 
76 #else
77 
78 #ifdef __i386__
79 /* i386 kernel is built with -mregparm=3 */
80 #define PT_REGS_PARM1(x) ((x)->eax)
81 #define PT_REGS_PARM2(x) ((x)->edx)
82 #define PT_REGS_PARM3(x) ((x)->ecx)
83 #define PT_REGS_PARM4(x) 0
84 #define PT_REGS_PARM5(x) 0
85 #define PT_REGS_RET(x) ((x)->esp)
86 #define PT_REGS_FP(x) ((x)->ebp)
87 #define PT_REGS_RC(x) ((x)->eax)
88 #define PT_REGS_SP(x) ((x)->esp)
89 #define PT_REGS_IP(x) ((x)->eip)
90 
91 #define PT_REGS_PARM1_CORE(x) BPF_CORE_READ((x), eax)
92 #define PT_REGS_PARM2_CORE(x) BPF_CORE_READ((x), edx)
93 #define PT_REGS_PARM3_CORE(x) BPF_CORE_READ((x), ecx)
94 #define PT_REGS_PARM4_CORE(x) 0
95 #define PT_REGS_PARM5_CORE(x) 0
96 #define PT_REGS_RET_CORE(x) BPF_CORE_READ((x), esp)
97 #define PT_REGS_FP_CORE(x) BPF_CORE_READ((x), ebp)
98 #define PT_REGS_RC_CORE(x) BPF_CORE_READ((x), eax)
99 #define PT_REGS_SP_CORE(x) BPF_CORE_READ((x), esp)
100 #define PT_REGS_IP_CORE(x) BPF_CORE_READ((x), eip)
101 
102 #else
103 
104 #define PT_REGS_PARM1(x) ((x)->rdi)
105 #define PT_REGS_PARM2(x) ((x)->rsi)
106 #define PT_REGS_PARM3(x) ((x)->rdx)
107 #define PT_REGS_PARM4(x) ((x)->rcx)
108 #define PT_REGS_PARM5(x) ((x)->r8)
109 #define PT_REGS_RET(x) ((x)->rsp)
110 #define PT_REGS_FP(x) ((x)->rbp)
111 #define PT_REGS_RC(x) ((x)->rax)
112 #define PT_REGS_SP(x) ((x)->rsp)
113 #define PT_REGS_IP(x) ((x)->rip)
114 
115 #define PT_REGS_PARM1_CORE(x) BPF_CORE_READ((x), rdi)
116 #define PT_REGS_PARM2_CORE(x) BPF_CORE_READ((x), rsi)
117 #define PT_REGS_PARM3_CORE(x) BPF_CORE_READ((x), rdx)
118 #define PT_REGS_PARM4_CORE(x) BPF_CORE_READ((x), rcx)
119 #define PT_REGS_PARM5_CORE(x) BPF_CORE_READ((x), r8)
120 #define PT_REGS_RET_CORE(x) BPF_CORE_READ((x), rsp)
121 #define PT_REGS_FP_CORE(x) BPF_CORE_READ((x), rbp)
122 #define PT_REGS_RC_CORE(x) BPF_CORE_READ((x), rax)
123 #define PT_REGS_SP_CORE(x) BPF_CORE_READ((x), rsp)
124 #define PT_REGS_IP_CORE(x) BPF_CORE_READ((x), rip)
125 
126 #endif
127 #endif
128 
129 #elif defined(bpf_target_s390)
130 
131 /* s390 provides user_pt_regs instead of struct pt_regs to userspace */
132 struct pt_regs;
133 #define PT_REGS_S390 const volatile user_pt_regs
134 #define PT_REGS_PARM1(x) (((PT_REGS_S390 *)(x))->gprs[2])
135 #define PT_REGS_PARM2(x) (((PT_REGS_S390 *)(x))->gprs[3])
136 #define PT_REGS_PARM3(x) (((PT_REGS_S390 *)(x))->gprs[4])
137 #define PT_REGS_PARM4(x) (((PT_REGS_S390 *)(x))->gprs[5])
138 #define PT_REGS_PARM5(x) (((PT_REGS_S390 *)(x))->gprs[6])
139 #define PT_REGS_RET(x) (((PT_REGS_S390 *)(x))->gprs[14])
140 /* Works only with CONFIG_FRAME_POINTER */
141 #define PT_REGS_FP(x) (((PT_REGS_S390 *)(x))->gprs[11])
142 #define PT_REGS_RC(x) (((PT_REGS_S390 *)(x))->gprs[2])
143 #define PT_REGS_SP(x) (((PT_REGS_S390 *)(x))->gprs[15])
144 #define PT_REGS_IP(x) (((PT_REGS_S390 *)(x))->psw.addr)
145 
146 #define PT_REGS_PARM1_CORE(x) BPF_CORE_READ((PT_REGS_S390 *)(x), gprs[2])
147 #define PT_REGS_PARM2_CORE(x) BPF_CORE_READ((PT_REGS_S390 *)(x), gprs[3])
148 #define PT_REGS_PARM3_CORE(x) BPF_CORE_READ((PT_REGS_S390 *)(x), gprs[4])
149 #define PT_REGS_PARM4_CORE(x) BPF_CORE_READ((PT_REGS_S390 *)(x), gprs[5])
150 #define PT_REGS_PARM5_CORE(x) BPF_CORE_READ((PT_REGS_S390 *)(x), gprs[6])
151 #define PT_REGS_RET_CORE(x) BPF_CORE_READ((PT_REGS_S390 *)(x), gprs[14])
152 #define PT_REGS_FP_CORE(x) BPF_CORE_READ((PT_REGS_S390 *)(x), gprs[11])
153 #define PT_REGS_RC_CORE(x) BPF_CORE_READ((PT_REGS_S390 *)(x), gprs[2])
154 #define PT_REGS_SP_CORE(x) BPF_CORE_READ((PT_REGS_S390 *)(x), gprs[15])
155 #define PT_REGS_IP_CORE(x) BPF_CORE_READ((PT_REGS_S390 *)(x), psw.addr)
156 
157 #elif defined(bpf_target_arm)
158 
159 #define PT_REGS_PARM1(x) ((x)->uregs[0])
160 #define PT_REGS_PARM2(x) ((x)->uregs[1])
161 #define PT_REGS_PARM3(x) ((x)->uregs[2])
162 #define PT_REGS_PARM4(x) ((x)->uregs[3])
163 #define PT_REGS_PARM5(x) ((x)->uregs[4])
164 #define PT_REGS_RET(x) ((x)->uregs[14])
165 #define PT_REGS_FP(x) ((x)->uregs[11]) /* Works only with CONFIG_FRAME_POINTER */
166 #define PT_REGS_RC(x) ((x)->uregs[0])
167 #define PT_REGS_SP(x) ((x)->uregs[13])
168 #define PT_REGS_IP(x) ((x)->uregs[12])
169 
170 #define PT_REGS_PARM1_CORE(x) BPF_CORE_READ((x), uregs[0])
171 #define PT_REGS_PARM2_CORE(x) BPF_CORE_READ((x), uregs[1])
172 #define PT_REGS_PARM3_CORE(x) BPF_CORE_READ((x), uregs[2])
173 #define PT_REGS_PARM4_CORE(x) BPF_CORE_READ((x), uregs[3])
174 #define PT_REGS_PARM5_CORE(x) BPF_CORE_READ((x), uregs[4])
175 #define PT_REGS_RET_CORE(x) BPF_CORE_READ((x), uregs[14])
176 #define PT_REGS_FP_CORE(x) BPF_CORE_READ((x), uregs[11])
177 #define PT_REGS_RC_CORE(x) BPF_CORE_READ((x), uregs[0])
178 #define PT_REGS_SP_CORE(x) BPF_CORE_READ((x), uregs[13])
179 #define PT_REGS_IP_CORE(x) BPF_CORE_READ((x), uregs[12])
180 
181 #elif defined(bpf_target_arm64)
182 
183 /* arm64 provides struct user_pt_regs instead of struct pt_regs to userspace */
184 struct pt_regs;
185 #define PT_REGS_ARM64 const volatile struct user_pt_regs
186 #define PT_REGS_PARM1(x) (((PT_REGS_ARM64 *)(x))->regs[0])
187 #define PT_REGS_PARM2(x) (((PT_REGS_ARM64 *)(x))->regs[1])
188 #define PT_REGS_PARM3(x) (((PT_REGS_ARM64 *)(x))->regs[2])
189 #define PT_REGS_PARM4(x) (((PT_REGS_ARM64 *)(x))->regs[3])
190 #define PT_REGS_PARM5(x) (((PT_REGS_ARM64 *)(x))->regs[4])
191 #define PT_REGS_RET(x) (((PT_REGS_ARM64 *)(x))->regs[30])
192 /* Works only with CONFIG_FRAME_POINTER */
193 #define PT_REGS_FP(x) (((PT_REGS_ARM64 *)(x))->regs[29])
194 #define PT_REGS_RC(x) (((PT_REGS_ARM64 *)(x))->regs[0])
195 #define PT_REGS_SP(x) (((PT_REGS_ARM64 *)(x))->sp)
196 #define PT_REGS_IP(x) (((PT_REGS_ARM64 *)(x))->pc)
197 
198 #define PT_REGS_PARM1_CORE(x) BPF_CORE_READ((PT_REGS_ARM64 *)(x), regs[0])
199 #define PT_REGS_PARM2_CORE(x) BPF_CORE_READ((PT_REGS_ARM64 *)(x), regs[1])
200 #define PT_REGS_PARM3_CORE(x) BPF_CORE_READ((PT_REGS_ARM64 *)(x), regs[2])
201 #define PT_REGS_PARM4_CORE(x) BPF_CORE_READ((PT_REGS_ARM64 *)(x), regs[3])
202 #define PT_REGS_PARM5_CORE(x) BPF_CORE_READ((PT_REGS_ARM64 *)(x), regs[4])
203 #define PT_REGS_RET_CORE(x) BPF_CORE_READ((PT_REGS_ARM64 *)(x), regs[30])
204 #define PT_REGS_FP_CORE(x) BPF_CORE_READ((PT_REGS_ARM64 *)(x), regs[29])
205 #define PT_REGS_RC_CORE(x) BPF_CORE_READ((PT_REGS_ARM64 *)(x), regs[0])
206 #define PT_REGS_SP_CORE(x) BPF_CORE_READ((PT_REGS_ARM64 *)(x), sp)
207 #define PT_REGS_IP_CORE(x) BPF_CORE_READ((PT_REGS_ARM64 *)(x), pc)
208 
209 #elif defined(bpf_target_mips)
210 
211 #define PT_REGS_PARM1(x) ((x)->regs[4])
212 #define PT_REGS_PARM2(x) ((x)->regs[5])
213 #define PT_REGS_PARM3(x) ((x)->regs[6])
214 #define PT_REGS_PARM4(x) ((x)->regs[7])
215 #define PT_REGS_PARM5(x) ((x)->regs[8])
216 #define PT_REGS_RET(x) ((x)->regs[31])
217 #define PT_REGS_FP(x) ((x)->regs[30]) /* Works only with CONFIG_FRAME_POINTER */
218 #define PT_REGS_RC(x) ((x)->regs[1])
219 #define PT_REGS_SP(x) ((x)->regs[29])
220 #define PT_REGS_IP(x) ((x)->cp0_epc)
221 
222 #define PT_REGS_PARM1_CORE(x) BPF_CORE_READ((x), regs[4])
223 #define PT_REGS_PARM2_CORE(x) BPF_CORE_READ((x), regs[5])
224 #define PT_REGS_PARM3_CORE(x) BPF_CORE_READ((x), regs[6])
225 #define PT_REGS_PARM4_CORE(x) BPF_CORE_READ((x), regs[7])
226 #define PT_REGS_PARM5_CORE(x) BPF_CORE_READ((x), regs[8])
227 #define PT_REGS_RET_CORE(x) BPF_CORE_READ((x), regs[31])
228 #define PT_REGS_FP_CORE(x) BPF_CORE_READ((x), regs[30])
229 #define PT_REGS_RC_CORE(x) BPF_CORE_READ((x), regs[1])
230 #define PT_REGS_SP_CORE(x) BPF_CORE_READ((x), regs[29])
231 #define PT_REGS_IP_CORE(x) BPF_CORE_READ((x), cp0_epc)
232 
233 #elif defined(bpf_target_powerpc)
234 
235 #define PT_REGS_PARM1(x) ((x)->gpr[3])
236 #define PT_REGS_PARM2(x) ((x)->gpr[4])
237 #define PT_REGS_PARM3(x) ((x)->gpr[5])
238 #define PT_REGS_PARM4(x) ((x)->gpr[6])
239 #define PT_REGS_PARM5(x) ((x)->gpr[7])
240 #define PT_REGS_RC(x) ((x)->gpr[3])
241 #define PT_REGS_SP(x) ((x)->sp)
242 #define PT_REGS_IP(x) ((x)->nip)
243 
244 #define PT_REGS_PARM1_CORE(x) BPF_CORE_READ((x), gpr[3])
245 #define PT_REGS_PARM2_CORE(x) BPF_CORE_READ((x), gpr[4])
246 #define PT_REGS_PARM3_CORE(x) BPF_CORE_READ((x), gpr[5])
247 #define PT_REGS_PARM4_CORE(x) BPF_CORE_READ((x), gpr[6])
248 #define PT_REGS_PARM5_CORE(x) BPF_CORE_READ((x), gpr[7])
249 #define PT_REGS_RC_CORE(x) BPF_CORE_READ((x), gpr[3])
250 #define PT_REGS_SP_CORE(x) BPF_CORE_READ((x), sp)
251 #define PT_REGS_IP_CORE(x) BPF_CORE_READ((x), nip)
252 
253 #elif defined(bpf_target_sparc)
254 
255 #define PT_REGS_PARM1(x) ((x)->u_regs[UREG_I0])
256 #define PT_REGS_PARM2(x) ((x)->u_regs[UREG_I1])
257 #define PT_REGS_PARM3(x) ((x)->u_regs[UREG_I2])
258 #define PT_REGS_PARM4(x) ((x)->u_regs[UREG_I3])
259 #define PT_REGS_PARM5(x) ((x)->u_regs[UREG_I4])
260 #define PT_REGS_RET(x) ((x)->u_regs[UREG_I7])
261 #define PT_REGS_RC(x) ((x)->u_regs[UREG_I0])
262 #define PT_REGS_SP(x) ((x)->u_regs[UREG_FP])
263 
264 #define PT_REGS_PARM1_CORE(x) BPF_CORE_READ((x), u_regs[UREG_I0])
265 #define PT_REGS_PARM2_CORE(x) BPF_CORE_READ((x), u_regs[UREG_I1])
266 #define PT_REGS_PARM3_CORE(x) BPF_CORE_READ((x), u_regs[UREG_I2])
267 #define PT_REGS_PARM4_CORE(x) BPF_CORE_READ((x), u_regs[UREG_I3])
268 #define PT_REGS_PARM5_CORE(x) BPF_CORE_READ((x), u_regs[UREG_I4])
269 #define PT_REGS_RET_CORE(x) BPF_CORE_READ((x), u_regs[UREG_I7])
270 #define PT_REGS_RC_CORE(x) BPF_CORE_READ((x), u_regs[UREG_I0])
271 #define PT_REGS_SP_CORE(x) BPF_CORE_READ((x), u_regs[UREG_FP])
272 
273 /* Should this also be a bpf_target check for the sparc case? */
274 #if defined(__arch64__)
275 #define PT_REGS_IP(x) ((x)->tpc)
276 #define PT_REGS_IP_CORE(x) BPF_CORE_READ((x), tpc)
277 #else
278 #define PT_REGS_IP(x) ((x)->pc)
279 #define PT_REGS_IP_CORE(x) BPF_CORE_READ((x), pc)
280 #endif
281 
282 #endif
283 
284 #if defined(bpf_target_powerpc)
285 #define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = (ctx)->link; })
286 #define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP
287 #elif defined(bpf_target_sparc)
288 #define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = PT_REGS_RET(ctx); })
289 #define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP
290 #else
291 #define BPF_KPROBE_READ_RET_IP(ip, ctx)					    \
292 	({ bpf_probe_read(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })
293 #define BPF_KRETPROBE_READ_RET_IP(ip, ctx)				    \
294 	({ bpf_probe_read(&(ip), sizeof(ip),				    \
295 			  (void *)(PT_REGS_FP(ctx) + sizeof(ip))); })
296 #endif
297 
298 #define ___bpf_concat(a, b) a ## b
299 #define ___bpf_apply(fn, n) ___bpf_concat(fn, n)
300 #define ___bpf_nth(_, _1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, N, ...) N
301 #define ___bpf_narg(...) \
302 	___bpf_nth(_, ##__VA_ARGS__, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
303 #define ___bpf_empty(...) \
304 	___bpf_nth(_, ##__VA_ARGS__, N, N, N, N, N, N, N, N, N, N, 0)
305 
306 #define ___bpf_ctx_cast0() ctx
307 #define ___bpf_ctx_cast1(x) ___bpf_ctx_cast0(), (void *)ctx[0]
308 #define ___bpf_ctx_cast2(x, args...) ___bpf_ctx_cast1(args), (void *)ctx[1]
309 #define ___bpf_ctx_cast3(x, args...) ___bpf_ctx_cast2(args), (void *)ctx[2]
310 #define ___bpf_ctx_cast4(x, args...) ___bpf_ctx_cast3(args), (void *)ctx[3]
311 #define ___bpf_ctx_cast5(x, args...) ___bpf_ctx_cast4(args), (void *)ctx[4]
312 #define ___bpf_ctx_cast6(x, args...) ___bpf_ctx_cast5(args), (void *)ctx[5]
313 #define ___bpf_ctx_cast7(x, args...) ___bpf_ctx_cast6(args), (void *)ctx[6]
314 #define ___bpf_ctx_cast8(x, args...) ___bpf_ctx_cast7(args), (void *)ctx[7]
315 #define ___bpf_ctx_cast9(x, args...) ___bpf_ctx_cast8(args), (void *)ctx[8]
316 #define ___bpf_ctx_cast10(x, args...) ___bpf_ctx_cast9(args), (void *)ctx[9]
317 #define ___bpf_ctx_cast11(x, args...) ___bpf_ctx_cast10(args), (void *)ctx[10]
318 #define ___bpf_ctx_cast12(x, args...) ___bpf_ctx_cast11(args), (void *)ctx[11]
319 #define ___bpf_ctx_cast(args...) \
320 	___bpf_apply(___bpf_ctx_cast, ___bpf_narg(args))(args)
321 
322 /*
323  * BPF_PROG is a convenience wrapper for generic tp_btf/fentry/fexit and
324  * similar kinds of BPF programs, that accept input arguments as a single
325  * pointer to untyped u64 array, where each u64 can actually be a typed
326  * pointer or integer of different size. Instead of requring user to write
327  * manual casts and work with array elements by index, BPF_PROG macro
328  * allows user to declare a list of named and typed input arguments in the
329  * same syntax as for normal C function. All the casting is hidden and
330  * performed transparently, while user code can just assume working with
331  * function arguments of specified type and name.
332  *
333  * Original raw context argument is preserved as well as 'ctx' argument.
334  * This is useful when using BPF helpers that expect original context
335  * as one of the parameters (e.g., for bpf_perf_event_output()).
336  */
337 #define BPF_PROG(name, args...)						    \
338 name(unsigned long long *ctx);						    \
339 static __attribute__((always_inline)) typeof(name(0))			    \
340 ____##name(unsigned long long *ctx, ##args);				    \
341 typeof(name(0)) name(unsigned long long *ctx)				    \
342 {									    \
343 	_Pragma("GCC diagnostic push")					    \
344 	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
345 	return ____##name(___bpf_ctx_cast(args));			    \
346 	_Pragma("GCC diagnostic pop")					    \
347 }									    \
348 static __attribute__((always_inline)) typeof(name(0))			    \
349 ____##name(unsigned long long *ctx, ##args)
350 
351 struct pt_regs;
352 
353 #define ___bpf_kprobe_args0() ctx
354 #define ___bpf_kprobe_args1(x) \
355 	___bpf_kprobe_args0(), (void *)PT_REGS_PARM1(ctx)
356 #define ___bpf_kprobe_args2(x, args...) \
357 	___bpf_kprobe_args1(args), (void *)PT_REGS_PARM2(ctx)
358 #define ___bpf_kprobe_args3(x, args...) \
359 	___bpf_kprobe_args2(args), (void *)PT_REGS_PARM3(ctx)
360 #define ___bpf_kprobe_args4(x, args...) \
361 	___bpf_kprobe_args3(args), (void *)PT_REGS_PARM4(ctx)
362 #define ___bpf_kprobe_args5(x, args...) \
363 	___bpf_kprobe_args4(args), (void *)PT_REGS_PARM5(ctx)
364 #define ___bpf_kprobe_args(args...) \
365 	___bpf_apply(___bpf_kprobe_args, ___bpf_narg(args))(args)
366 
367 /*
368  * BPF_KPROBE serves the same purpose for kprobes as BPF_PROG for
369  * tp_btf/fentry/fexit BPF programs. It hides the underlying platform-specific
370  * low-level way of getting kprobe input arguments from struct pt_regs, and
371  * provides a familiar typed and named function arguments syntax and
372  * semantics of accessing kprobe input paremeters.
373  *
374  * Original struct pt_regs* context is preserved as 'ctx' argument. This might
375  * be necessary when using BPF helpers like bpf_perf_event_output().
376  */
377 #define BPF_KPROBE(name, args...)					    \
378 name(struct pt_regs *ctx);						    \
379 static __attribute__((always_inline)) typeof(name(0))			    \
380 ____##name(struct pt_regs *ctx, ##args);				    \
381 typeof(name(0)) name(struct pt_regs *ctx)				    \
382 {									    \
383 	_Pragma("GCC diagnostic push")					    \
384 	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
385 	return ____##name(___bpf_kprobe_args(args));			    \
386 	_Pragma("GCC diagnostic pop")					    \
387 }									    \
388 static __attribute__((always_inline)) typeof(name(0))			    \
389 ____##name(struct pt_regs *ctx, ##args)
390 
391 #define ___bpf_kretprobe_args0() ctx
392 #define ___bpf_kretprobe_args1(x) \
393 	___bpf_kretprobe_args0(), (void *)PT_REGS_RC(ctx)
394 #define ___bpf_kretprobe_args(args...) \
395 	___bpf_apply(___bpf_kretprobe_args, ___bpf_narg(args))(args)
396 
397 /*
398  * BPF_KRETPROBE is similar to BPF_KPROBE, except, it only provides optional
399  * return value (in addition to `struct pt_regs *ctx`), but no input
400  * arguments, because they will be clobbered by the time probed function
401  * returns.
402  */
403 #define BPF_KRETPROBE(name, args...)					    \
404 name(struct pt_regs *ctx);						    \
405 static __attribute__((always_inline)) typeof(name(0))			    \
406 ____##name(struct pt_regs *ctx, ##args);				    \
407 typeof(name(0)) name(struct pt_regs *ctx)				    \
408 {									    \
409 	_Pragma("GCC diagnostic push")					    \
410 	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
411 	return ____##name(___bpf_kretprobe_args(args));			    \
412 	_Pragma("GCC diagnostic pop")					    \
413 }									    \
414 static __always_inline typeof(name(0)) ____##name(struct pt_regs *ctx, ##args)
415 
416 /*
417  * BPF_SEQ_PRINTF to wrap bpf_seq_printf to-be-printed values
418  * in a structure.
419  */
420 #define BPF_SEQ_PRINTF(seq, fmt, args...)				    \
421 	({								    \
422 		_Pragma("GCC diagnostic push")				    \
423 		_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")	    \
424 		static const char ___fmt[] = fmt;			    \
425 		unsigned long long ___param[] = { args };		    \
426 		_Pragma("GCC diagnostic pop")				    \
427 		int ___ret = bpf_seq_printf(seq, ___fmt, sizeof(___fmt),    \
428 					    ___param, sizeof(___param));    \
429 		___ret;							    \
430 	})
431 
432 #endif
433