xref: /openbmc/linux/tools/lib/bpf/bpf_tracing.h (revision 55eb9a6c)
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 #elif defined(__TARGET_ARCH_riscv)
28 	#define bpf_target_riscv
29 	#define bpf_target_defined
30 #elif defined(__TARGET_ARCH_arc)
31 	#define bpf_target_arc
32 	#define bpf_target_defined
33 #else
34 
35 /* Fall back to what the compiler says */
36 #if defined(__x86_64__)
37 	#define bpf_target_x86
38 	#define bpf_target_defined
39 #elif defined(__s390__)
40 	#define bpf_target_s390
41 	#define bpf_target_defined
42 #elif defined(__arm__)
43 	#define bpf_target_arm
44 	#define bpf_target_defined
45 #elif defined(__aarch64__)
46 	#define bpf_target_arm64
47 	#define bpf_target_defined
48 #elif defined(__mips__)
49 	#define bpf_target_mips
50 	#define bpf_target_defined
51 #elif defined(__powerpc__)
52 	#define bpf_target_powerpc
53 	#define bpf_target_defined
54 #elif defined(__sparc__)
55 	#define bpf_target_sparc
56 	#define bpf_target_defined
57 #elif defined(__riscv) && __riscv_xlen == 64
58 	#define bpf_target_riscv
59 	#define bpf_target_defined
60 #elif defined(__arc__)
61 	#define bpf_target_arc
62 	#define bpf_target_defined
63 #endif /* no compiler target */
64 
65 #endif
66 
67 #ifndef __BPF_TARGET_MISSING
68 #define __BPF_TARGET_MISSING "GCC error \"Must specify a BPF target arch via __TARGET_ARCH_xxx\""
69 #endif
70 
71 #if defined(bpf_target_x86)
72 
73 #if defined(__KERNEL__) || defined(__VMLINUX_H__)
74 
75 #define __PT_PARM1_REG di
76 #define __PT_PARM2_REG si
77 #define __PT_PARM3_REG dx
78 #define __PT_PARM4_REG cx
79 #define __PT_PARM5_REG r8
80 #define __PT_RET_REG sp
81 #define __PT_FP_REG bp
82 #define __PT_RC_REG ax
83 #define __PT_SP_REG sp
84 #define __PT_IP_REG ip
85 /* syscall uses r10 for PARM4 */
86 #define PT_REGS_PARM4_SYSCALL(x) ((x)->r10)
87 #define PT_REGS_PARM4_CORE_SYSCALL(x) BPF_CORE_READ(x, r10)
88 
89 #else
90 
91 #ifdef __i386__
92 
93 #define __PT_PARM1_REG eax
94 #define __PT_PARM2_REG edx
95 #define __PT_PARM3_REG ecx
96 /* i386 kernel is built with -mregparm=3 */
97 #define __PT_PARM4_REG __unsupported__
98 #define __PT_PARM5_REG __unsupported__
99 #define __PT_RET_REG esp
100 #define __PT_FP_REG ebp
101 #define __PT_RC_REG eax
102 #define __PT_SP_REG esp
103 #define __PT_IP_REG eip
104 
105 #else /* __i386__ */
106 
107 #define __PT_PARM1_REG rdi
108 #define __PT_PARM2_REG rsi
109 #define __PT_PARM3_REG rdx
110 #define __PT_PARM4_REG rcx
111 #define __PT_PARM5_REG r8
112 #define __PT_RET_REG rsp
113 #define __PT_FP_REG rbp
114 #define __PT_RC_REG rax
115 #define __PT_SP_REG rsp
116 #define __PT_IP_REG rip
117 /* syscall uses r10 for PARM4 */
118 #define PT_REGS_PARM4_SYSCALL(x) ((x)->r10)
119 #define PT_REGS_PARM4_CORE_SYSCALL(x) BPF_CORE_READ(x, r10)
120 
121 #endif /* __i386__ */
122 
123 #endif /* __KERNEL__ || __VMLINUX_H__ */
124 
125 #elif defined(bpf_target_s390)
126 
127 struct pt_regs___s390 {
128 	unsigned long orig_gpr2;
129 };
130 
131 /* s390 provides user_pt_regs instead of struct pt_regs to userspace */
132 #define __PT_REGS_CAST(x) ((const user_pt_regs *)(x))
133 #define __PT_PARM1_REG gprs[2]
134 #define __PT_PARM2_REG gprs[3]
135 #define __PT_PARM3_REG gprs[4]
136 #define __PT_PARM4_REG gprs[5]
137 #define __PT_PARM5_REG gprs[6]
138 #define __PT_RET_REG grps[14]
139 #define __PT_FP_REG gprs[11]	/* Works only with CONFIG_FRAME_POINTER */
140 #define __PT_RC_REG gprs[2]
141 #define __PT_SP_REG gprs[15]
142 #define __PT_IP_REG psw.addr
143 #define PT_REGS_PARM1_SYSCALL(x) ({ _Pragma("GCC error \"use PT_REGS_PARM1_CORE_SYSCALL() instead\""); 0l; })
144 #define PT_REGS_PARM1_CORE_SYSCALL(x) BPF_CORE_READ((const struct pt_regs___s390 *)(x), orig_gpr2)
145 
146 #elif defined(bpf_target_arm)
147 
148 #define __PT_PARM1_REG uregs[0]
149 #define __PT_PARM2_REG uregs[1]
150 #define __PT_PARM3_REG uregs[2]
151 #define __PT_PARM4_REG uregs[3]
152 #define __PT_PARM5_REG uregs[4]
153 #define __PT_RET_REG uregs[14]
154 #define __PT_FP_REG uregs[11]	/* Works only with CONFIG_FRAME_POINTER */
155 #define __PT_RC_REG uregs[0]
156 #define __PT_SP_REG uregs[13]
157 #define __PT_IP_REG uregs[12]
158 
159 #elif defined(bpf_target_arm64)
160 
161 struct pt_regs___arm64 {
162 	unsigned long orig_x0;
163 };
164 
165 /* arm64 provides struct user_pt_regs instead of struct pt_regs to userspace */
166 #define __PT_REGS_CAST(x) ((const struct user_pt_regs *)(x))
167 #define __PT_PARM1_REG regs[0]
168 #define __PT_PARM2_REG regs[1]
169 #define __PT_PARM3_REG regs[2]
170 #define __PT_PARM4_REG regs[3]
171 #define __PT_PARM5_REG regs[4]
172 #define __PT_RET_REG regs[30]
173 #define __PT_FP_REG regs[29]	/* Works only with CONFIG_FRAME_POINTER */
174 #define __PT_RC_REG regs[0]
175 #define __PT_SP_REG sp
176 #define __PT_IP_REG pc
177 #define PT_REGS_PARM1_SYSCALL(x) ({ _Pragma("GCC error \"use PT_REGS_PARM1_CORE_SYSCALL() instead\""); 0l; })
178 #define PT_REGS_PARM1_CORE_SYSCALL(x) BPF_CORE_READ((const struct pt_regs___arm64 *)(x), orig_x0)
179 
180 #elif defined(bpf_target_mips)
181 
182 #define __PT_PARM1_REG regs[4]
183 #define __PT_PARM2_REG regs[5]
184 #define __PT_PARM3_REG regs[6]
185 #define __PT_PARM4_REG regs[7]
186 #define __PT_PARM5_REG regs[8]
187 #define __PT_RET_REG regs[31]
188 #define __PT_FP_REG regs[30]	/* Works only with CONFIG_FRAME_POINTER */
189 #define __PT_RC_REG regs[2]
190 #define __PT_SP_REG regs[29]
191 #define __PT_IP_REG cp0_epc
192 
193 #elif defined(bpf_target_powerpc)
194 
195 #define __PT_PARM1_REG gpr[3]
196 #define __PT_PARM2_REG gpr[4]
197 #define __PT_PARM3_REG gpr[5]
198 #define __PT_PARM4_REG gpr[6]
199 #define __PT_PARM5_REG gpr[7]
200 #define __PT_RET_REG regs[31]
201 #define __PT_FP_REG __unsupported__
202 #define __PT_RC_REG gpr[3]
203 #define __PT_SP_REG sp
204 #define __PT_IP_REG nip
205 /* powerpc does not select ARCH_HAS_SYSCALL_WRAPPER. */
206 #define PT_REGS_SYSCALL_REGS(ctx) ctx
207 
208 #elif defined(bpf_target_sparc)
209 
210 #define __PT_PARM1_REG u_regs[UREG_I0]
211 #define __PT_PARM2_REG u_regs[UREG_I1]
212 #define __PT_PARM3_REG u_regs[UREG_I2]
213 #define __PT_PARM4_REG u_regs[UREG_I3]
214 #define __PT_PARM5_REG u_regs[UREG_I4]
215 #define __PT_RET_REG u_regs[UREG_I7]
216 #define __PT_FP_REG __unsupported__
217 #define __PT_RC_REG u_regs[UREG_I0]
218 #define __PT_SP_REG u_regs[UREG_FP]
219 /* Should this also be a bpf_target check for the sparc case? */
220 #if defined(__arch64__)
221 #define __PT_IP_REG tpc
222 #else
223 #define __PT_IP_REG pc
224 #endif
225 
226 #elif defined(bpf_target_riscv)
227 
228 #define __PT_REGS_CAST(x) ((const struct user_regs_struct *)(x))
229 #define __PT_PARM1_REG a0
230 #define __PT_PARM2_REG a1
231 #define __PT_PARM3_REG a2
232 #define __PT_PARM4_REG a3
233 #define __PT_PARM5_REG a4
234 #define __PT_RET_REG ra
235 #define __PT_FP_REG s0
236 #define __PT_RC_REG a5
237 #define __PT_SP_REG sp
238 #define __PT_IP_REG pc
239 /* riscv does not select ARCH_HAS_SYSCALL_WRAPPER. */
240 #define PT_REGS_SYSCALL_REGS(ctx) ctx
241 
242 #elif defined(bpf_target_arc)
243 
244 /* arc provides struct user_pt_regs instead of struct pt_regs to userspace */
245 #define __PT_REGS_CAST(x) ((const struct user_regs_struct *)(x))
246 #define __PT_PARM1_REG scratch.r0
247 #define __PT_PARM2_REG scratch.r1
248 #define __PT_PARM3_REG scratch.r2
249 #define __PT_PARM4_REG scratch.r3
250 #define __PT_PARM5_REG scratch.r4
251 #define __PT_RET_REG scratch.blink
252 #define __PT_FP_REG __unsupported__
253 #define __PT_RC_REG scratch.r0
254 #define __PT_SP_REG scratch.sp
255 #define __PT_IP_REG scratch.ret
256 /* arc does not select ARCH_HAS_SYSCALL_WRAPPER. */
257 #define PT_REGS_SYSCALL_REGS(ctx) ctx
258 
259 #endif
260 
261 #if defined(bpf_target_defined)
262 
263 struct pt_regs;
264 
265 /* allow some architecutres to override `struct pt_regs` */
266 #ifndef __PT_REGS_CAST
267 #define __PT_REGS_CAST(x) (x)
268 #endif
269 
270 #define PT_REGS_PARM1(x) (__PT_REGS_CAST(x)->__PT_PARM1_REG)
271 #define PT_REGS_PARM2(x) (__PT_REGS_CAST(x)->__PT_PARM2_REG)
272 #define PT_REGS_PARM3(x) (__PT_REGS_CAST(x)->__PT_PARM3_REG)
273 #define PT_REGS_PARM4(x) (__PT_REGS_CAST(x)->__PT_PARM4_REG)
274 #define PT_REGS_PARM5(x) (__PT_REGS_CAST(x)->__PT_PARM5_REG)
275 #define PT_REGS_RET(x) (__PT_REGS_CAST(x)->__PT_RET_REG)
276 #define PT_REGS_FP(x) (__PT_REGS_CAST(x)->__PT_FP_REG)
277 #define PT_REGS_RC(x) (__PT_REGS_CAST(x)->__PT_RC_REG)
278 #define PT_REGS_SP(x) (__PT_REGS_CAST(x)->__PT_SP_REG)
279 #define PT_REGS_IP(x) (__PT_REGS_CAST(x)->__PT_IP_REG)
280 
281 #define PT_REGS_PARM1_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM1_REG)
282 #define PT_REGS_PARM2_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM2_REG)
283 #define PT_REGS_PARM3_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM3_REG)
284 #define PT_REGS_PARM4_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM4_REG)
285 #define PT_REGS_PARM5_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM5_REG)
286 #define PT_REGS_RET_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_RET_REG)
287 #define PT_REGS_FP_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_FP_REG)
288 #define PT_REGS_RC_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_RC_REG)
289 #define PT_REGS_SP_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_SP_REG)
290 #define PT_REGS_IP_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_IP_REG)
291 
292 #if defined(bpf_target_powerpc)
293 
294 #define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = (ctx)->link; })
295 #define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP
296 
297 #elif defined(bpf_target_sparc)
298 
299 #define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = PT_REGS_RET(ctx); })
300 #define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP
301 
302 #else
303 
304 #define BPF_KPROBE_READ_RET_IP(ip, ctx)					    \
305 	({ bpf_probe_read_kernel(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })
306 #define BPF_KRETPROBE_READ_RET_IP(ip, ctx)				    \
307 	({ bpf_probe_read_kernel(&(ip), sizeof(ip), (void *)(PT_REGS_FP(ctx) + sizeof(ip))); })
308 
309 #endif
310 
311 #ifndef PT_REGS_PARM1_SYSCALL
312 #define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1(x)
313 #endif
314 #define PT_REGS_PARM2_SYSCALL(x) PT_REGS_PARM2(x)
315 #define PT_REGS_PARM3_SYSCALL(x) PT_REGS_PARM3(x)
316 #ifndef PT_REGS_PARM4_SYSCALL
317 #define PT_REGS_PARM4_SYSCALL(x) PT_REGS_PARM4(x)
318 #endif
319 #define PT_REGS_PARM5_SYSCALL(x) PT_REGS_PARM5(x)
320 
321 #ifndef PT_REGS_PARM1_CORE_SYSCALL
322 #define PT_REGS_PARM1_CORE_SYSCALL(x) PT_REGS_PARM1_CORE(x)
323 #endif
324 #define PT_REGS_PARM2_CORE_SYSCALL(x) PT_REGS_PARM2_CORE(x)
325 #define PT_REGS_PARM3_CORE_SYSCALL(x) PT_REGS_PARM3_CORE(x)
326 #ifndef PT_REGS_PARM4_CORE_SYSCALL
327 #define PT_REGS_PARM4_CORE_SYSCALL(x) PT_REGS_PARM4_CORE(x)
328 #endif
329 #define PT_REGS_PARM5_CORE_SYSCALL(x) PT_REGS_PARM5_CORE(x)
330 
331 #else /* defined(bpf_target_defined) */
332 
333 #define PT_REGS_PARM1(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
334 #define PT_REGS_PARM2(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
335 #define PT_REGS_PARM3(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
336 #define PT_REGS_PARM4(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
337 #define PT_REGS_PARM5(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
338 #define PT_REGS_RET(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
339 #define PT_REGS_FP(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
340 #define PT_REGS_RC(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
341 #define PT_REGS_SP(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
342 #define PT_REGS_IP(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
343 
344 #define PT_REGS_PARM1_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
345 #define PT_REGS_PARM2_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
346 #define PT_REGS_PARM3_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
347 #define PT_REGS_PARM4_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
348 #define PT_REGS_PARM5_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
349 #define PT_REGS_RET_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
350 #define PT_REGS_FP_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
351 #define PT_REGS_RC_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
352 #define PT_REGS_SP_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
353 #define PT_REGS_IP_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
354 
355 #define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
356 #define BPF_KRETPROBE_READ_RET_IP(ip, ctx) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
357 
358 #define PT_REGS_PARM1_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
359 #define PT_REGS_PARM2_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
360 #define PT_REGS_PARM3_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
361 #define PT_REGS_PARM4_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
362 #define PT_REGS_PARM5_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
363 
364 #define PT_REGS_PARM1_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
365 #define PT_REGS_PARM2_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
366 #define PT_REGS_PARM3_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
367 #define PT_REGS_PARM4_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
368 #define PT_REGS_PARM5_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
369 
370 #endif /* defined(bpf_target_defined) */
371 
372 /*
373  * When invoked from a syscall handler kprobe, returns a pointer to a
374  * struct pt_regs containing syscall arguments and suitable for passing to
375  * PT_REGS_PARMn_SYSCALL() and PT_REGS_PARMn_CORE_SYSCALL().
376  */
377 #ifndef PT_REGS_SYSCALL_REGS
378 /* By default, assume that the arch selects ARCH_HAS_SYSCALL_WRAPPER. */
379 #define PT_REGS_SYSCALL_REGS(ctx) ((struct pt_regs *)PT_REGS_PARM1(ctx))
380 #endif
381 
382 #ifndef ___bpf_concat
383 #define ___bpf_concat(a, b) a ## b
384 #endif
385 #ifndef ___bpf_apply
386 #define ___bpf_apply(fn, n) ___bpf_concat(fn, n)
387 #endif
388 #ifndef ___bpf_nth
389 #define ___bpf_nth(_, _1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, N, ...) N
390 #endif
391 #ifndef ___bpf_narg
392 #define ___bpf_narg(...) ___bpf_nth(_, ##__VA_ARGS__, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
393 #endif
394 
395 #define ___bpf_ctx_cast0()            ctx
396 #define ___bpf_ctx_cast1(x)           ___bpf_ctx_cast0(), (void *)ctx[0]
397 #define ___bpf_ctx_cast2(x, args...)  ___bpf_ctx_cast1(args), (void *)ctx[1]
398 #define ___bpf_ctx_cast3(x, args...)  ___bpf_ctx_cast2(args), (void *)ctx[2]
399 #define ___bpf_ctx_cast4(x, args...)  ___bpf_ctx_cast3(args), (void *)ctx[3]
400 #define ___bpf_ctx_cast5(x, args...)  ___bpf_ctx_cast4(args), (void *)ctx[4]
401 #define ___bpf_ctx_cast6(x, args...)  ___bpf_ctx_cast5(args), (void *)ctx[5]
402 #define ___bpf_ctx_cast7(x, args...)  ___bpf_ctx_cast6(args), (void *)ctx[6]
403 #define ___bpf_ctx_cast8(x, args...)  ___bpf_ctx_cast7(args), (void *)ctx[7]
404 #define ___bpf_ctx_cast9(x, args...)  ___bpf_ctx_cast8(args), (void *)ctx[8]
405 #define ___bpf_ctx_cast10(x, args...) ___bpf_ctx_cast9(args), (void *)ctx[9]
406 #define ___bpf_ctx_cast11(x, args...) ___bpf_ctx_cast10(args), (void *)ctx[10]
407 #define ___bpf_ctx_cast12(x, args...) ___bpf_ctx_cast11(args), (void *)ctx[11]
408 #define ___bpf_ctx_cast(args...)      ___bpf_apply(___bpf_ctx_cast, ___bpf_narg(args))(args)
409 
410 /*
411  * BPF_PROG is a convenience wrapper for generic tp_btf/fentry/fexit and
412  * similar kinds of BPF programs, that accept input arguments as a single
413  * pointer to untyped u64 array, where each u64 can actually be a typed
414  * pointer or integer of different size. Instead of requring user to write
415  * manual casts and work with array elements by index, BPF_PROG macro
416  * allows user to declare a list of named and typed input arguments in the
417  * same syntax as for normal C function. All the casting is hidden and
418  * performed transparently, while user code can just assume working with
419  * function arguments of specified type and name.
420  *
421  * Original raw context argument is preserved as well as 'ctx' argument.
422  * This is useful when using BPF helpers that expect original context
423  * as one of the parameters (e.g., for bpf_perf_event_output()).
424  */
425 #define BPF_PROG(name, args...)						    \
426 name(unsigned long long *ctx);						    \
427 static __attribute__((always_inline)) typeof(name(0))			    \
428 ____##name(unsigned long long *ctx, ##args);				    \
429 typeof(name(0)) name(unsigned long long *ctx)				    \
430 {									    \
431 	_Pragma("GCC diagnostic push")					    \
432 	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
433 	return ____##name(___bpf_ctx_cast(args));			    \
434 	_Pragma("GCC diagnostic pop")					    \
435 }									    \
436 static __attribute__((always_inline)) typeof(name(0))			    \
437 ____##name(unsigned long long *ctx, ##args)
438 
439 struct pt_regs;
440 
441 #define ___bpf_kprobe_args0()           ctx
442 #define ___bpf_kprobe_args1(x)          ___bpf_kprobe_args0(), (void *)PT_REGS_PARM1(ctx)
443 #define ___bpf_kprobe_args2(x, args...) ___bpf_kprobe_args1(args), (void *)PT_REGS_PARM2(ctx)
444 #define ___bpf_kprobe_args3(x, args...) ___bpf_kprobe_args2(args), (void *)PT_REGS_PARM3(ctx)
445 #define ___bpf_kprobe_args4(x, args...) ___bpf_kprobe_args3(args), (void *)PT_REGS_PARM4(ctx)
446 #define ___bpf_kprobe_args5(x, args...) ___bpf_kprobe_args4(args), (void *)PT_REGS_PARM5(ctx)
447 #define ___bpf_kprobe_args(args...)     ___bpf_apply(___bpf_kprobe_args, ___bpf_narg(args))(args)
448 
449 /*
450  * BPF_KPROBE serves the same purpose for kprobes as BPF_PROG for
451  * tp_btf/fentry/fexit BPF programs. It hides the underlying platform-specific
452  * low-level way of getting kprobe input arguments from struct pt_regs, and
453  * provides a familiar typed and named function arguments syntax and
454  * semantics of accessing kprobe input paremeters.
455  *
456  * Original struct pt_regs* context is preserved as 'ctx' argument. This might
457  * be necessary when using BPF helpers like bpf_perf_event_output().
458  */
459 #define BPF_KPROBE(name, args...)					    \
460 name(struct pt_regs *ctx);						    \
461 static __attribute__((always_inline)) typeof(name(0))			    \
462 ____##name(struct pt_regs *ctx, ##args);				    \
463 typeof(name(0)) name(struct pt_regs *ctx)				    \
464 {									    \
465 	_Pragma("GCC diagnostic push")					    \
466 	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
467 	return ____##name(___bpf_kprobe_args(args));			    \
468 	_Pragma("GCC diagnostic pop")					    \
469 }									    \
470 static __attribute__((always_inline)) typeof(name(0))			    \
471 ____##name(struct pt_regs *ctx, ##args)
472 
473 #define ___bpf_kretprobe_args0()       ctx
474 #define ___bpf_kretprobe_args1(x)      ___bpf_kretprobe_args0(), (void *)PT_REGS_RC(ctx)
475 #define ___bpf_kretprobe_args(args...) ___bpf_apply(___bpf_kretprobe_args, ___bpf_narg(args))(args)
476 
477 /*
478  * BPF_KRETPROBE is similar to BPF_KPROBE, except, it only provides optional
479  * return value (in addition to `struct pt_regs *ctx`), but no input
480  * arguments, because they will be clobbered by the time probed function
481  * returns.
482  */
483 #define BPF_KRETPROBE(name, args...)					    \
484 name(struct pt_regs *ctx);						    \
485 static __attribute__((always_inline)) typeof(name(0))			    \
486 ____##name(struct pt_regs *ctx, ##args);				    \
487 typeof(name(0)) name(struct pt_regs *ctx)				    \
488 {									    \
489 	_Pragma("GCC diagnostic push")					    \
490 	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
491 	return ____##name(___bpf_kretprobe_args(args));			    \
492 	_Pragma("GCC diagnostic pop")					    \
493 }									    \
494 static __always_inline typeof(name(0)) ____##name(struct pt_regs *ctx, ##args)
495 
496 #define ___bpf_syscall_args0()           ctx
497 #define ___bpf_syscall_args1(x)          ___bpf_syscall_args0(), (void *)PT_REGS_PARM1_CORE_SYSCALL(regs)
498 #define ___bpf_syscall_args2(x, args...) ___bpf_syscall_args1(args), (void *)PT_REGS_PARM2_CORE_SYSCALL(regs)
499 #define ___bpf_syscall_args3(x, args...) ___bpf_syscall_args2(args), (void *)PT_REGS_PARM3_CORE_SYSCALL(regs)
500 #define ___bpf_syscall_args4(x, args...) ___bpf_syscall_args3(args), (void *)PT_REGS_PARM4_CORE_SYSCALL(regs)
501 #define ___bpf_syscall_args5(x, args...) ___bpf_syscall_args4(args), (void *)PT_REGS_PARM5_CORE_SYSCALL(regs)
502 #define ___bpf_syscall_args(args...)     ___bpf_apply(___bpf_syscall_args, ___bpf_narg(args))(args)
503 
504 /*
505  * BPF_KPROBE_SYSCALL is a variant of BPF_KPROBE, which is intended for
506  * tracing syscall functions, like __x64_sys_close. It hides the underlying
507  * platform-specific low-level way of getting syscall input arguments from
508  * struct pt_regs, and provides a familiar typed and named function arguments
509  * syntax and semantics of accessing syscall input parameters.
510  *
511  * Original struct pt_regs* context is preserved as 'ctx' argument. This might
512  * be necessary when using BPF helpers like bpf_perf_event_output().
513  *
514  * This macro relies on BPF CO-RE support.
515  */
516 #define BPF_KPROBE_SYSCALL(name, args...)				    \
517 name(struct pt_regs *ctx);						    \
518 static __attribute__((always_inline)) typeof(name(0))			    \
519 ____##name(struct pt_regs *ctx, ##args);				    \
520 typeof(name(0)) name(struct pt_regs *ctx)				    \
521 {									    \
522 	struct pt_regs *regs = PT_REGS_SYSCALL_REGS(ctx);		    \
523 	_Pragma("GCC diagnostic push")					    \
524 	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
525 	return ____##name(___bpf_syscall_args(args));			    \
526 	_Pragma("GCC diagnostic pop")					    \
527 }									    \
528 static __attribute__((always_inline)) typeof(name(0))			    \
529 ____##name(struct pt_regs *ctx, ##args)
530 
531 #endif
532