From: Kui-Feng Lee thinker.li@gmail.com
[ Upstream commit fedf99200ab086c42a572fca1d7266b06cdc3e3f ]
Only print the warning message if you are writing to "/proc/sys/kernel/unprivileged_bpf_disabled".
The kernel may print an annoying warning when you read "/proc/sys/kernel/unprivileged_bpf_disabled" saying
WARNING: Unprivileged eBPF is enabled with eIBRS on, data leaks possible via Spectre v2 BHB attacks!
However, this message is only meaningful when the feature is disabled or enabled.
Signed-off-by: Kui-Feng Lee kuifeng@meta.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Acked-by: Yonghong Song yhs@fb.com Link: https://lore.kernel.org/bpf/20230502181418.308479-1-kuifeng@meta.com Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/bpf/syscall.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index f1c8733f76b83..5524fcf6fb2a4 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -5394,7 +5394,8 @@ static int bpf_unpriv_handler(struct ctl_table *table, int write, *(int *)table->data = unpriv_enable; }
- unpriv_ebpf_notify(unpriv_enable); + if (write) + unpriv_ebpf_notify(unpriv_enable);
return ret; }