xref: /openbmc/linux/tools/lib/bpf/bpf_tracing.h (revision 47010c04)
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 #else
31 
32 /* Fall back to what the compiler says */
33 #if defined(__x86_64__)
34 	#define bpf_target_x86
35 	#define bpf_target_defined
36 #elif defined(__s390__)
37 	#define bpf_target_s390
38 	#define bpf_target_defined
39 #elif defined(__arm__)
40 	#define bpf_target_arm
41 	#define bpf_target_defined
42 #elif defined(__aarch64__)
43 	#define bpf_target_arm64
44 	#define bpf_target_defined
45 #elif defined(__mips__)
46 	#define bpf_target_mips
47 	#define bpf_target_defined
48 #elif defined(__powerpc__)
49 	#define bpf_target_powerpc
50 	#define bpf_target_defined
51 #elif defined(__sparc__)
52 	#define bpf_target_sparc
53 	#define bpf_target_defined
54 #elif defined(__riscv) && __riscv_xlen == 64
55 	#define bpf_target_riscv
56 	#define bpf_target_defined
57 #endif /* no compiler target */
58 
59 #endif
60 
61 #ifndef __BPF_TARGET_MISSING
62 #define __BPF_TARGET_MISSING "GCC error \"Must specify a BPF target arch via __TARGET_ARCH_xxx\""
63 #endif
64 
65 #if defined(bpf_target_x86)
66 
67 #if defined(__KERNEL__) || defined(__VMLINUX_H__)
68 
69 #define __PT_PARM1_REG di
70 #define __PT_PARM2_REG si
71 #define __PT_PARM3_REG dx
72 #define __PT_PARM4_REG cx
73 #define __PT_PARM5_REG r8
74 #define __PT_RET_REG sp
75 #define __PT_FP_REG bp
76 #define __PT_RC_REG ax
77 #define __PT_SP_REG sp
78 #define __PT_IP_REG ip
79 /* syscall uses r10 for PARM4 */
80 #define PT_REGS_PARM4_SYSCALL(x) ((x)->r10)
81 #define PT_REGS_PARM4_CORE_SYSCALL(x) BPF_CORE_READ(x, r10)
82 
83 #else
84 
85 #ifdef __i386__
86 
87 #define __PT_PARM1_REG eax
88 #define __PT_PARM2_REG edx
89 #define __PT_PARM3_REG ecx
90 /* i386 kernel is built with -mregparm=3 */
91 #define __PT_PARM4_REG __unsupported__
92 #define __PT_PARM5_REG __unsupported__
93 #define __PT_RET_REG esp
94 #define __PT_FP_REG ebp
95 #define __PT_RC_REG eax
96 #define __PT_SP_REG esp
97 #define __PT_IP_REG eip
98 
99 #else /* __i386__ */
100 
101 #define __PT_PARM1_REG rdi
102 #define __PT_PARM2_REG rsi
103 #define __PT_PARM3_REG rdx
104 #define __PT_PARM4_REG rcx
105 #define __PT_PARM5_REG r8
106 #define __PT_RET_REG rsp
107 #define __PT_FP_REG rbp
108 #define __PT_RC_REG rax
109 #define __PT_SP_REG rsp
110 #define __PT_IP_REG rip
111 /* syscall uses r10 for PARM4 */
112 #define PT_REGS_PARM4_SYSCALL(x) ((x)->r10)
113 #define PT_REGS_PARM4_CORE_SYSCALL(x) BPF_CORE_READ(x, r10)
114 
115 #endif /* __i386__ */
116 
117 #endif /* __KERNEL__ || __VMLINUX_H__ */
118 
119 #elif defined(bpf_target_s390)
120 
121 struct pt_regs___s390 {
122 	unsigned long orig_gpr2;
123 };
124 
125 /* s390 provides user_pt_regs instead of struct pt_regs to userspace */
126 #define __PT_REGS_CAST(x) ((const user_pt_regs *)(x))
127 #define __PT_PARM1_REG gprs[2]
128 #define __PT_PARM2_REG gprs[3]
129 #define __PT_PARM3_REG gprs[4]
130 #define __PT_PARM4_REG gprs[5]
131 #define __PT_PARM5_REG gprs[6]
132 #define __PT_RET_REG grps[14]
133 #define __PT_FP_REG gprs[11]	/* Works only with CONFIG_FRAME_POINTER */
134 #define __PT_RC_REG gprs[2]
135 #define __PT_SP_REG gprs[15]
136 #define __PT_IP_REG psw.addr
137 #define PT_REGS_PARM1_SYSCALL(x) ({ _Pragma("GCC error \"use PT_REGS_PARM1_CORE_SYSCALL() instead\""); 0l; })
138 #define PT_REGS_PARM1_CORE_SYSCALL(x) BPF_CORE_READ((const struct pt_regs___s390 *)(x), orig_gpr2)
139 
140 #elif defined(bpf_target_arm)
141 
142 #define __PT_PARM1_REG uregs[0]
143 #define __PT_PARM2_REG uregs[1]
144 #define __PT_PARM3_REG uregs[2]
145 #define __PT_PARM4_REG uregs[3]
146 #define __PT_PARM5_REG uregs[4]
147 #define __PT_RET_REG uregs[14]
148 #define __PT_FP_REG uregs[11]	/* Works only with CONFIG_FRAME_POINTER */
149 #define __PT_RC_REG uregs[0]
150 #define __PT_SP_REG uregs[13]
151 #define __PT_IP_REG uregs[12]
152 
153 #elif defined(bpf_target_arm64)
154 
155 struct pt_regs___arm64 {
156 	unsigned long orig_x0;
157 };
158 
159 /* arm64 provides struct user_pt_regs instead of struct pt_regs to userspace */
160 #define __PT_REGS_CAST(x) ((const struct user_pt_regs *)(x))
161 #define __PT_PARM1_REG regs[0]
162 #define __PT_PARM2_REG regs[1]
163 #define __PT_PARM3_REG regs[2]
164 #define __PT_PARM4_REG regs[3]
165 #define __PT_PARM5_REG regs[4]
166 #define __PT_RET_REG regs[30]
167 #define __PT_FP_REG regs[29]	/* Works only with CONFIG_FRAME_POINTER */
168 #define __PT_RC_REG regs[0]
169 #define __PT_SP_REG sp
170 #define __PT_IP_REG pc
171 #define PT_REGS_PARM1_SYSCALL(x) ({ _Pragma("GCC error \"use PT_REGS_PARM1_CORE_SYSCALL() instead\""); 0l; })
172 #define PT_REGS_PARM1_CORE_SYSCALL(x) BPF_CORE_READ((const struct pt_regs___arm64 *)(x), orig_x0)
173 
174 #elif defined(bpf_target_mips)
175 
176 #define __PT_PARM1_REG regs[4]
177 #define __PT_PARM2_REG regs[5]
178 #define __PT_PARM3_REG regs[6]
179 #define __PT_PARM4_REG regs[7]
180 #define __PT_PARM5_REG regs[8]
181 #define __PT_RET_REG regs[31]
182 #define __PT_FP_REG regs[30]	/* Works only with CONFIG_FRAME_POINTER */
183 #define __PT_RC_REG regs[2]
184 #define __PT_SP_REG regs[29]
185 #define __PT_IP_REG cp0_epc
186 
187 #elif defined(bpf_target_powerpc)
188 
189 #define __PT_PARM1_REG gpr[3]
190 #define __PT_PARM2_REG gpr[4]
191 #define __PT_PARM3_REG gpr[5]
192 #define __PT_PARM4_REG gpr[6]
193 #define __PT_PARM5_REG gpr[7]
194 #define __PT_RET_REG regs[31]
195 #define __PT_FP_REG __unsupported__
196 #define __PT_RC_REG gpr[3]
197 #define __PT_SP_REG sp
198 #define __PT_IP_REG nip
199 /* powerpc does not select ARCH_HAS_SYSCALL_WRAPPER. */
200 #define PT_REGS_SYSCALL_REGS(ctx) ctx
201 
202 #elif defined(bpf_target_sparc)
203 
204 #define __PT_PARM1_REG u_regs[UREG_I0]
205 #define __PT_PARM2_REG u_regs[UREG_I1]
206 #define __PT_PARM3_REG u_regs[UREG_I2]
207 #define __PT_PARM4_REG u_regs[UREG_I3]
208 #define __PT_PARM5_REG u_regs[UREG_I4]
209 #define __PT_RET_REG u_regs[UREG_I7]
210 #define __PT_FP_REG __unsupported__
211 #define __PT_RC_REG u_regs[UREG_I0]
212 #define __PT_SP_REG u_regs[UREG_FP]
213 /* Should this also be a bpf_target check for the sparc case? */
214 #if defined(__arch64__)
215 #define __PT_IP_REG tpc
216 #else
217 #define __PT_IP_REG pc
218 #endif
219 
220 #elif defined(bpf_target_riscv)
221 
222 #define __PT_REGS_CAST(x) ((const struct user_regs_struct *)(x))
223 #define __PT_PARM1_REG a0
224 #define __PT_PARM2_REG a1
225 #define __PT_PARM3_REG a2
226 #define __PT_PARM4_REG a3
227 #define __PT_PARM5_REG a4
228 #define __PT_RET_REG ra
229 #define __PT_FP_REG s0
230 #define __PT_RC_REG a5
231 #define __PT_SP_REG sp
232 #define __PT_IP_REG pc
233 /* riscv does not select ARCH_HAS_SYSCALL_WRAPPER. */
234 #define PT_REGS_SYSCALL_REGS(ctx) ctx
235 
236 #endif
237 
238 #if defined(bpf_target_defined)
239 
240 struct pt_regs;
241 
242 /* allow some architecutres to override `struct pt_regs` */
243 #ifndef __PT_REGS_CAST
244 #define __PT_REGS_CAST(x) (x)
245 #endif
246 
247 #define PT_REGS_PARM1(x) (__PT_REGS_CAST(x)->__PT_PARM1_REG)
248 #define PT_REGS_PARM2(x) (__PT_REGS_CAST(x)->__PT_PARM2_REG)
249 #define PT_REGS_PARM3(x) (__PT_REGS_CAST(x)->__PT_PARM3_REG)
250 #define PT_REGS_PARM4(x) (__PT_REGS_CAST(x)->__PT_PARM4_REG)
251 #define PT_REGS_PARM5(x) (__PT_REGS_CAST(x)->__PT_PARM5_REG)
252 #define PT_REGS_RET(x) (__PT_REGS_CAST(x)->__PT_RET_REG)
253 #define PT_REGS_FP(x) (__PT_REGS_CAST(x)->__PT_FP_REG)
254 #define PT_REGS_RC(x) (__PT_REGS_CAST(x)->__PT_RC_REG)
255 #define PT_REGS_SP(x) (__PT_REGS_CAST(x)->__PT_SP_REG)
256 #define PT_REGS_IP(x) (__PT_REGS_CAST(x)->__PT_IP_REG)
257 
258 #define PT_REGS_PARM1_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM1_REG)
259 #define PT_REGS_PARM2_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM2_REG)
260 #define PT_REGS_PARM3_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM3_REG)
261 #define PT_REGS_PARM4_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM4_REG)
262 #define PT_REGS_PARM5_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM5_REG)
263 #define PT_REGS_RET_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_RET_REG)
264 #define PT_REGS_FP_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_FP_REG)
265 #define PT_REGS_RC_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_RC_REG)
266 #define PT_REGS_SP_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_SP_REG)
267 #define PT_REGS_IP_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_IP_REG)
268 
269 #if defined(bpf_target_powerpc)
270 
271 #define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = (ctx)->link; })
272 #define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP
273 
274 #elif defined(bpf_target_sparc)
275 
276 #define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = PT_REGS_RET(ctx); })
277 #define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP
278 
279 #else
280 
281 #define BPF_KPROBE_READ_RET_IP(ip, ctx)					    \
282 	({ bpf_probe_read_kernel(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })
283 #define BPF_KRETPROBE_READ_RET_IP(ip, ctx)				    \
284 	({ bpf_probe_read_kernel(&(ip), sizeof(ip), (void *)(PT_REGS_FP(ctx) + sizeof(ip))); })
285 
286 #endif
287 
288 #ifndef PT_REGS_PARM1_SYSCALL
289 #define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1(x)
290 #endif
291 #define PT_REGS_PARM2_SYSCALL(x) PT_REGS_PARM2(x)
292 #define PT_REGS_PARM3_SYSCALL(x) PT_REGS_PARM3(x)
293 #ifndef PT_REGS_PARM4_SYSCALL
294 #define PT_REGS_PARM4_SYSCALL(x) PT_REGS_PARM4(x)
295 #endif
296 #define PT_REGS_PARM5_SYSCALL(x) PT_REGS_PARM5(x)
297 
298 #ifndef PT_REGS_PARM1_CORE_SYSCALL
299 #define PT_REGS_PARM1_CORE_SYSCALL(x) PT_REGS_PARM1_CORE(x)
300 #endif
301 #define PT_REGS_PARM2_CORE_SYSCALL(x) PT_REGS_PARM2_CORE(x)
302 #define PT_REGS_PARM3_CORE_SYSCALL(x) PT_REGS_PARM3_CORE(x)
303 #ifndef PT_REGS_PARM4_CORE_SYSCALL
304 #define PT_REGS_PARM4_CORE_SYSCALL(x) PT_REGS_PARM4_CORE(x)
305 #endif
306 #define PT_REGS_PARM5_CORE_SYSCALL(x) PT_REGS_PARM5_CORE(x)
307 
308 #else /* defined(bpf_target_defined) */
309 
310 #define PT_REGS_PARM1(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
311 #define PT_REGS_PARM2(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
312 #define PT_REGS_PARM3(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
313 #define PT_REGS_PARM4(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
314 #define PT_REGS_PARM5(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
315 #define PT_REGS_RET(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
316 #define PT_REGS_FP(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
317 #define PT_REGS_RC(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
318 #define PT_REGS_SP(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
319 #define PT_REGS_IP(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
320 
321 #define PT_REGS_PARM1_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
322 #define PT_REGS_PARM2_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
323 #define PT_REGS_PARM3_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
324 #define PT_REGS_PARM4_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
325 #define PT_REGS_PARM5_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
326 #define PT_REGS_RET_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
327 #define PT_REGS_FP_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
328 #define PT_REGS_RC_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
329 #define PT_REGS_SP_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
330 #define PT_REGS_IP_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
331 
332 #define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
333 #define BPF_KRETPROBE_READ_RET_IP(ip, ctx) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
334 
335 #define PT_REGS_PARM1_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
336 #define PT_REGS_PARM2_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
337 #define PT_REGS_PARM3_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
338 #define PT_REGS_PARM4_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
339 #define PT_REGS_PARM5_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
340 
341 #define PT_REGS_PARM1_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
342 #define PT_REGS_PARM2_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
343 #define PT_REGS_PARM3_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
344 #define PT_REGS_PARM4_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
345 #define PT_REGS_PARM5_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
346 
347 #endif /* defined(bpf_target_defined) */
348 
349 /*
350  * When invoked from a syscall handler kprobe, returns a pointer to a
351  * struct pt_regs containing syscall arguments and suitable for passing to
352  * PT_REGS_PARMn_SYSCALL() and PT_REGS_PARMn_CORE_SYSCALL().
353  */
354 #ifndef PT_REGS_SYSCALL_REGS
355 /* By default, assume that the arch selects ARCH_HAS_SYSCALL_WRAPPER. */
356 #define PT_REGS_SYSCALL_REGS(ctx) ((struct pt_regs *)PT_REGS_PARM1(ctx))
357 #endif
358 
359 #ifndef ___bpf_concat
360 #define ___bpf_concat(a, b) a ## b
361 #endif
362 #ifndef ___bpf_apply
363 #define ___bpf_apply(fn, n) ___bpf_concat(fn, n)
364 #endif
365 #ifndef ___bpf_nth
366 #define ___bpf_nth(_, _1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, N, ...) N
367 #endif
368 #ifndef ___bpf_narg
369 #define ___bpf_narg(...) ___bpf_nth(_, ##__VA_ARGS__, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
370 #endif
371 
372 #define ___bpf_ctx_cast0()            ctx
373 #define ___bpf_ctx_cast1(x)           ___bpf_ctx_cast0(), (void *)ctx[0]
374 #define ___bpf_ctx_cast2(x, args...)  ___bpf_ctx_cast1(args), (void *)ctx[1]
375 #define ___bpf_ctx_cast3(x, args...)  ___bpf_ctx_cast2(args), (void *)ctx[2]
376 #define ___bpf_ctx_cast4(x, args...)  ___bpf_ctx_cast3(args), (void *)ctx[3]
377 #define ___bpf_ctx_cast5(x, args...)  ___bpf_ctx_cast4(args), (void *)ctx[4]
378 #define ___bpf_ctx_cast6(x, args...)  ___bpf_ctx_cast5(args), (void *)ctx[5]
379 #define ___bpf_ctx_cast7(x, args...)  ___bpf_ctx_cast6(args), (void *)ctx[6]
380 #define ___bpf_ctx_cast8(x, args...)  ___bpf_ctx_cast7(args), (void *)ctx[7]
381 #define ___bpf_ctx_cast9(x, args...)  ___bpf_ctx_cast8(args), (void *)ctx[8]
382 #define ___bpf_ctx_cast10(x, args...) ___bpf_ctx_cast9(args), (void *)ctx[9]
383 #define ___bpf_ctx_cast11(x, args...) ___bpf_ctx_cast10(args), (void *)ctx[10]
384 #define ___bpf_ctx_cast12(x, args...) ___bpf_ctx_cast11(args), (void *)ctx[11]
385 #define ___bpf_ctx_cast(args...)      ___bpf_apply(___bpf_ctx_cast, ___bpf_narg(args))(args)
386 
387 /*
388  * BPF_PROG is a convenience wrapper for generic tp_btf/fentry/fexit and
389  * similar kinds of BPF programs, that accept input arguments as a single
390  * pointer to untyped u64 array, where each u64 can actually be a typed
391  * pointer or integer of different size. Instead of requring user to write
392  * manual casts and work with array elements by index, BPF_PROG macro
393  * allows user to declare a list of named and typed input arguments in the
394  * same syntax as for normal C function. All the casting is hidden and
395  * performed transparently, while user code can just assume working with
396  * function arguments of specified type and name.
397  *
398  * Original raw context argument is preserved as well as 'ctx' argument.
399  * This is useful when using BPF helpers that expect original context
400  * as one of the parameters (e.g., for bpf_perf_event_output()).
401  */
402 #define BPF_PROG(name, args...)						    \
403 name(unsigned long long *ctx);						    \
404 static __attribute__((always_inline)) typeof(name(0))			    \
405 ____##name(unsigned long long *ctx, ##args);				    \
406 typeof(name(0)) name(unsigned long long *ctx)				    \
407 {									    \
408 	_Pragma("GCC diagnostic push")					    \
409 	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
410 	return ____##name(___bpf_ctx_cast(args));			    \
411 	_Pragma("GCC diagnostic pop")					    \
412 }									    \
413 static __attribute__((always_inline)) typeof(name(0))			    \
414 ____##name(unsigned long long *ctx, ##args)
415 
416 struct pt_regs;
417 
418 #define ___bpf_kprobe_args0()           ctx
419 #define ___bpf_kprobe_args1(x)          ___bpf_kprobe_args0(), (void *)PT_REGS_PARM1(ctx)
420 #define ___bpf_kprobe_args2(x, args...) ___bpf_kprobe_args1(args), (void *)PT_REGS_PARM2(ctx)
421 #define ___bpf_kprobe_args3(x, args...) ___bpf_kprobe_args2(args), (void *)PT_REGS_PARM3(ctx)
422 #define ___bpf_kprobe_args4(x, args...) ___bpf_kprobe_args3(args), (void *)PT_REGS_PARM4(ctx)
423 #define ___bpf_kprobe_args5(x, args...) ___bpf_kprobe_args4(args), (void *)PT_REGS_PARM5(ctx)
424 #define ___bpf_kprobe_args(args...)     ___bpf_apply(___bpf_kprobe_args, ___bpf_narg(args))(args)
425 
426 /*
427  * BPF_KPROBE serves the same purpose for kprobes as BPF_PROG for
428  * tp_btf/fentry/fexit BPF programs. It hides the underlying platform-specific
429  * low-level way of getting kprobe input arguments from struct pt_regs, and
430  * provides a familiar typed and named function arguments syntax and
431  * semantics of accessing kprobe input paremeters.
432  *
433  * Original struct pt_regs* context is preserved as 'ctx' argument. This might
434  * be necessary when using BPF helpers like bpf_perf_event_output().
435  */
436 #define BPF_KPROBE(name, args...)					    \
437 name(struct pt_regs *ctx);						    \
438 static __attribute__((always_inline)) typeof(name(0))			    \
439 ____##name(struct pt_regs *ctx, ##args);				    \
440 typeof(name(0)) name(struct pt_regs *ctx)				    \
441 {									    \
442 	_Pragma("GCC diagnostic push")					    \
443 	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
444 	return ____##name(___bpf_kprobe_args(args));			    \
445 	_Pragma("GCC diagnostic pop")					    \
446 }									    \
447 static __attribute__((always_inline)) typeof(name(0))			    \
448 ____##name(struct pt_regs *ctx, ##args)
449 
450 #define ___bpf_kretprobe_args0()       ctx
451 #define ___bpf_kretprobe_args1(x)      ___bpf_kretprobe_args0(), (void *)PT_REGS_RC(ctx)
452 #define ___bpf_kretprobe_args(args...) ___bpf_apply(___bpf_kretprobe_args, ___bpf_narg(args))(args)
453 
454 /*
455  * BPF_KRETPROBE is similar to BPF_KPROBE, except, it only provides optional
456  * return value (in addition to `struct pt_regs *ctx`), but no input
457  * arguments, because they will be clobbered by the time probed function
458  * returns.
459  */
460 #define BPF_KRETPROBE(name, args...)					    \
461 name(struct pt_regs *ctx);						    \
462 static __attribute__((always_inline)) typeof(name(0))			    \
463 ____##name(struct pt_regs *ctx, ##args);				    \
464 typeof(name(0)) name(struct pt_regs *ctx)				    \
465 {									    \
466 	_Pragma("GCC diagnostic push")					    \
467 	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
468 	return ____##name(___bpf_kretprobe_args(args));			    \
469 	_Pragma("GCC diagnostic pop")					    \
470 }									    \
471 static __always_inline typeof(name(0)) ____##name(struct pt_regs *ctx, ##args)
472 
473 #define ___bpf_syscall_args0()           ctx
474 #define ___bpf_syscall_args1(x)          ___bpf_syscall_args0(), (void *)PT_REGS_PARM1_CORE_SYSCALL(regs)
475 #define ___bpf_syscall_args2(x, args...) ___bpf_syscall_args1(args), (void *)PT_REGS_PARM2_CORE_SYSCALL(regs)
476 #define ___bpf_syscall_args3(x, args...) ___bpf_syscall_args2(args), (void *)PT_REGS_PARM3_CORE_SYSCALL(regs)
477 #define ___bpf_syscall_args4(x, args...) ___bpf_syscall_args3(args), (void *)PT_REGS_PARM4_CORE_SYSCALL(regs)
478 #define ___bpf_syscall_args5(x, args...) ___bpf_syscall_args4(args), (void *)PT_REGS_PARM5_CORE_SYSCALL(regs)
479 #define ___bpf_syscall_args(args...)     ___bpf_apply(___bpf_syscall_args, ___bpf_narg(args))(args)
480 
481 /*
482  * BPF_KPROBE_SYSCALL is a variant of BPF_KPROBE, which is intended for
483  * tracing syscall functions, like __x64_sys_close. It hides the underlying
484  * platform-specific low-level way of getting syscall input arguments from
485  * struct pt_regs, and provides a familiar typed and named function arguments
486  * syntax and semantics of accessing syscall input parameters.
487  *
488  * Original struct pt_regs* context is preserved as 'ctx' argument. This might
489  * be necessary when using BPF helpers like bpf_perf_event_output().
490  *
491  * This macro relies on BPF CO-RE support.
492  */
493 #define BPF_KPROBE_SYSCALL(name, args...)				    \
494 name(struct pt_regs *ctx);						    \
495 static __attribute__((always_inline)) typeof(name(0))			    \
496 ____##name(struct pt_regs *ctx, ##args);				    \
497 typeof(name(0)) name(struct pt_regs *ctx)				    \
498 {									    \
499 	struct pt_regs *regs = PT_REGS_SYSCALL_REGS(ctx);		    \
500 	_Pragma("GCC diagnostic push")					    \
501 	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")		    \
502 	return ____##name(___bpf_syscall_args(args));			    \
503 	_Pragma("GCC diagnostic pop")					    \
504 }									    \
505 static __attribute__((always_inline)) typeof(name(0))			    \
506 ____##name(struct pt_regs *ctx, ##args)
507 
508 #endif
509