[PATCH v6 bpf-next 08/11] bpf: Add bpf_perf_link_fill_common()
From: Yafang Shao <hidden>
Date: 2023-06-28 11:53:49
Also in:
bpf
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Add a new helper bpf_perf_link_fill_common(), which will be used by perf_link based tracepoint, kprobe and uprobe. Signed-off-by: Yafang Shao <redacted> --- kernel/bpf/syscall.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 4aa6e5776a04..72de91beabbc 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c@@ -3364,6 +3364,40 @@ static void bpf_perf_link_dealloc(struct bpf_link *link) kfree(perf_link); } +static int bpf_perf_link_fill_common(const struct perf_event *event, + char __user *uname, u32 ulen, + u64 *probe_offset, u64 *probe_addr, + u32 *fd_type) +{ + const char *buf; + u32 prog_id; + size_t len; + int err; + + if (!ulen ^ !uname) + return -EINVAL; + if (!uname) + return 0; + + err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, + probe_offset, probe_addr); + if (err) + return err; + + len = strlen(buf); + if (buf) { + err = bpf_copy_to_user(uname, buf, ulen, len); + if (err) + return err; + } else { + char zero = '\0'; + + if (put_user(zero, uname)) + return -EFAULT; + } + return 0; +} + static const struct bpf_link_ops bpf_perf_link_lops = { .release = bpf_perf_link_release, .dealloc = bpf_perf_link_dealloc,
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2.39.3