bpf: respect size hint to BPF_PROG_TEST_RUN if present

Use data_size_out as a size hint when copying test output to user space. ENOSPC is returned if the output buffer is too small. Callers which so far did not set data_size_out are not affected.

Lorenz Bauer committed 7 years ago

Commit b5a36b11 parent d59dd692 files · +18 −4Browse files

Showing the changes to include/uapi/linux (1 of 2 files). Show all

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include/uapi/linux/bpf.h+5−2

@@ -374,8 +374,11 @@ union bpf_attr { · 373 unmodified lines
374	374	struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
375	375	__u32 prog_fd;
376	376	__u32 retval;
377		− __u32 data_size_in;
378		− __u32 data_size_out;
	377	+ __u32 data_size_in; /* input: len of data_in */
	378	+ __u32 data_size_out; /* input/output: len of data_out
	379	+ * returns ENOSPC if data_out
	380	+ * is too small.
	381	+ */
379	382	__aligned_u64 data_in;
380	383	__aligned_u64 data_out;
381	384	__u32 repeat;