bpf: fix 5.4 verifier problem

andrewstrohman · andrewstrohman · commit 4bcd62f9ef44 · 2026-01-29T18:57:00.000Z
failed prog /host/src/tetragon/bpf/objs/bpf_generic_tracepoint_v53.o kern_version 328959 loadInstance: opening collection '/host/src/tetragon/bpf/objs/bpf_generic_tracepoint_v53.o' failed: program generic_tracepoint_process_event: load program: invalid argument: math between map_value pointer and register with unbounded min value is not allowed (4126 line(s) omitted)

Signed-off-by: Andy Strohman &lt;astrohma@isovalent.com&gt;
diff --git a/bpf/process/types/basic.h b/bpf/process/types/basic.h
@@ -223,7 +223,7 @@ args_off(struct msg_generic_kprobe *e, unsigned long off)
 {
 	asm volatile("%[off] &= 0x3fff;\n"
 		     : [off] "+r"(off));
-	return e->args + off;
+	return e->args + ((unsigned int)off & 0x3fff);
 }
 
 /* Error writer for use when pointer *s is lost to stack and can not

Original file line number	Diff line number	Diff line change
`@@ -223,7 +223,7 @@ args_off(struct msg_generic_kprobe *e, unsigned long off)`
`223`	`223`	`{`
`224`	`224`	`asm volatile("%[off] &= 0x3fff;\n"`
`225`	`225`	`: [off] "+r"(off));`
`226`		`- return e->args + off;`
	`226`	`+ return e->args + ((unsigned int)off & 0x3fff);`
`227`	`227`	`}`
`228`	`228`
`229`	`229`	`/* Error writer for use when pointer *s is lost to stack and can not`