Commit 99dea2c6 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

selftests/bpf: fix selftest after random: Urandom_read tracepoint removal 



14c17463 ("random: remove unused tracepoints") removed all the
tracepoints from drivers/char/random.c, one of which,
random:urandom_read, was used by stacktrace_build_id selftest to trigger
stack trace capture.

Fix breakage by switching to kprobing urandom_read() function.

Suggested-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220325225643.2606-1-andrii@kernel.org
parent c29a4920

tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c

+2 −10
Original line number Diff line number Diff line
@@ -39,16 +39,8 @@ struct { 
	__type(value, stack_trace_t);

} stack_amap SEC(".maps");



/* taken from /sys/kernel/debug/tracing/events/random/urandom_read/format */

struct random_urandom_args {

	unsigned long long pad;

	int got_bits;

	int pool_left;

	int input_left;

};



SEC("tracepoint/random/urandom_read")

int oncpu(struct random_urandom_args *args)

SEC("kprobe/urandom_read")

int oncpu(struct pt_regs *args)

{

	__u32 max_len = sizeof(struct bpf_stack_build_id)

			* PERF_MAX_STACK_DEPTH;