Commit Graph
3 Commits
Author SHA1 Message Date
Hou Tao b822a139e3 libbpf: Use page size as max_entries when probing ring buffer map
Using page size as max_entries when probing ring buffer map, else the
probe may fail on host with 64KB page size (e.g., an ARM64 host).

After the fix, the output of "bpftool feature" on above host will be
correct.

Before :
    eBPF map_type ringbuf is NOT available
    eBPF map_type user_ringbuf is NOT available

After :
    eBPF map_type ringbuf is available
    eBPF map_type user_ringbuf is available

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221116072351.1168938-2-houtao@huaweicloud.com
2022-12-02 22:12:29 -08:00
Hou Tao 04804b4710 bpf: Add bpf_strncmp helper
The helper compares two strings: one string is a null-terminated
read-only string, and another string has const max storage size
but doesn't need to be null-terminated. It can be used to compare
file name in tracing or LSM program.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211210141652.877186-2-houtao1@huawei.com
2021-12-14 17:06:30 -08:00
Hou Tao 133e3603ec libbpf: Support detecting and attaching of writable tracepoint program
Program on writable tracepoint is BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
but its attachment is the same as BPF_PROG_TYPE_RAW_TRACEPOINT.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211004094857.30868-3-hotforest@gmail.com
2021-10-11 12:30:36 -07:00