Revert "bpf: fix unpopulated name_len field in perf_event link info"

This reverts commit e5c2b971db which is
commit 4deecdd29c upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: If96fcef48cfa8a3507e6cc3d2d171af12594869c
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Greg Kroah-Hartman 2024-12-02 10:33:55 +00:00
parent d132b93edf
commit 8780507bc3

View File

@ -3440,16 +3440,15 @@ static void bpf_perf_link_dealloc(struct bpf_link *link)
}
static int bpf_perf_link_fill_common(const struct perf_event *event,
char __user *uname, u32 *ulenp,
char __user *uname, u32 ulen,
u64 *probe_offset, u64 *probe_addr,
u32 *fd_type, unsigned long *missed)
{
const char *buf;
u32 prog_id, ulen;
u32 prog_id;
size_t len;
int err;
ulen = *ulenp;
if (!ulen ^ !uname)
return -EINVAL;
@ -3457,17 +3456,10 @@ static int bpf_perf_link_fill_common(const struct perf_event *event,
probe_offset, probe_addr, missed);
if (err)
return err;
if (buf) {
len = strlen(buf);
*ulenp = len + 1;
} else {
*ulenp = 1;
}
if (!uname)
return 0;
if (buf) {
len = strlen(buf);
err = bpf_copy_to_user(uname, buf, ulen, len);
if (err)
return err;
@ -3492,7 +3484,7 @@ static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
ulen = info->perf_event.kprobe.name_len;
err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr,
&type, &missed);
if (err)
return err;
@ -3500,7 +3492,7 @@ static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
else
info->perf_event.type = BPF_PERF_EVENT_KPROBE;
info->perf_event.kprobe.name_len = ulen;
info->perf_event.kprobe.offset = offset;
info->perf_event.kprobe.missed = missed;
if (!kallsyms_show_value(current_cred()))
@ -3522,7 +3514,7 @@ static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
ulen = info->perf_event.uprobe.name_len;
err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr,
&type, NULL);
if (err)
return err;
@ -3531,7 +3523,6 @@ static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
else
info->perf_event.type = BPF_PERF_EVENT_UPROBE;
info->perf_event.uprobe.name_len = ulen;
info->perf_event.uprobe.offset = offset;
info->perf_event.uprobe.cookie = event->bpf_cookie;
return 0;
@ -3557,18 +3548,12 @@ static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
{
char __user *uname;
u32 ulen;
int err;
uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
ulen = info->perf_event.tracepoint.name_len;
err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
if (err)
return err;
info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
info->perf_event.tracepoint.name_len = ulen;
info->perf_event.tracepoint.cookie = event->bpf_cookie;
return 0;
return bpf_perf_link_fill_common(event, uname, ulen, NULL, NULL, NULL, NULL);
}
static int bpf_perf_link_fill_perf_event(const struct perf_event *event,