CHECK: Macro argument 'off' may be better as '(off)' to avoid precedence issues
#68: FILE: tools/testing/selftests/bpf/progs/verifier_ctx.c:316:
+#define no_rewrite_ctx_access(type, name, off, load_t)			\
 	SEC(type)							\
 	__description(type ": read ctx at fixed offset")		\
 	__success							\
+	int no_rewrite_##name##_fixed(void *ctx)			\
 	{								\
+		char *p = ctx;						\
+		volatile load_t val;					\
+									\
+		val = *(load_t *)(p + off);				\
+		(void)val;						\
+		return 0;						\
 	}								\
 	SEC(type)							\
 	__description(type ": reject variable offset ctx access")	\
 	__failure __msg("variable ctx access var_off=")			\
+	int no_rewrite_##name##_var(void *ctx)			\
 	{								\
+		__u64 off_var = bpf_get_prandom_u32();			\
+		char *p = ctx;						\
+									\
+		off_var &= 4;						\
+		p += off_var;						\
+		return *(load_t *)p;					\
 	}								\
 	SEC(type)							\
 	__description(type ": reject negative offset ctx access")	\
+	__failure __msg("invalid bpf_context access")			\
+	int no_rewrite_##name##_neg(void *ctx)			\
 	{								\
+		char *p = ctx;						\
+									\
+		p -= 612;						\
+		return *(load_t *)p;					\
 	}

WARNING: Use of volatile is usually wrong: see Documentation/process/volatile-considered-harmful.rst
#84: FILE: tools/testing/selftests/bpf/progs/verifier_ctx.c:323:
+		volatile load_t val;					\

total: 0 errors, 1 warnings, 1 checks, 110 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

Commit 1dd942299cde ("selftests/bpf: Convert ctx tests from ASM to C") has style problems, please review.

NOTE: Ignored message types: ALLOC_SIZEOF_STRUCT BAD_REPORTED_BY_LINK CAMELCASE COMMIT_LOG_LONG_LINE FILE_PATH_CHANGES GIT_COMMIT_ID MACRO_ARG_REUSE NO_AUTHOR_SIGN_OFF

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.
total: 0 errors, 1 warnings, 1 checks, 110 lines checked