Re: [PATCHv2 bpf-next 02/15] bpf: Add minimal bpf() command documentation
From: Yonghong Song <hidden>
Date: 2021-03-03 22:57:35
Also in:
bpf, linux-man
On 3/2/21 9:19 AM, Joe Stringer wrote:
Introduce high-level descriptions of the intent and return codes of the bpf() syscall commands. Subsequent patches may further flesh out the content to provide a more useful programming reference. Acked-by: Toke Høiland-Jørgensen <redacted> Reviewed-by: Quentin Monnet <redacted> Signed-off-by: Joe Stringer <redacted>
With a nit to update NOTES section, Acked-by: Yonghong Song <redacted>
quoted hunk ↗ jump to hunk
--- include/uapi/linux/bpf.h | 368 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 368 insertions(+)diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index fb16c590e6d9..052bbfe65f77 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h@@ -204,6 +204,374 @@ union bpf_iter_link_info { * A new file descriptor (a nonnegative integer), or -1 if an * error occurred (in which case, *errno* is set appropriately). * + * BPF_OBJ_PIN + * Description + * Pin an eBPF program or map referred by the specified *bpf_fd* + * to the provided *pathname* on the filesystem. + * + * Return + * Returns zero on success. On error, -1 is returned and *errno* + * is set appropriately. + * + * BPF_OBJ_GET + * Description + * Open a file descriptor for the eBPF object pinned to the + * specified *pathname*. + * + * Return + * A new file descriptor (a nonnegative integer), or -1 if an + * error occurred (in which case, *errno* is set appropriately). + *
[...]
+ * BPF_PROG_BIND_MAP + * Description + * Bind a map to the lifetime of an eBPF program. + * + * The map identified by *map_fd* is bound to the program + * identified by *prog_fd* and only released when *prog_fd* is + * released. This may be used in cases where metadata should be + * associated with a program which otherwise does not contain any + * references to the map (for example, embedded in the eBPF + * program instructions). + * + * Return + * Returns zero on success. On error, -1 is returned and *errno* + * is set appropriately. + * * NOTES * eBPF objects (maps and programs) can be shared between processes. * For example, after **fork**\ (2), the child inherits file descriptors