[PATCH bpf-next v2 1/2] bpf: Add some description about BPF_JIT_ALWAYS_ON in Kconfig

From: Tiezhu Yang
Date: Fri Feb 18 2022 - 22:15:20 EST


When CONFIG_BPF_JIT_ALWAYS_ON is enabled, /proc/sys/net/core/bpf_jit_enable
is permanently set to 1 and setting any other value than that will return
in failure.

Add the above description in the help text of config BPF_JIT_ALWAYS_ON, and
then we can distinguish between BPF_JIT_ALWAYS_ON and BPF_JIT_DEFAULT_ON.

Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
kernel/bpf/Kconfig | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig
index d24d518..cbf3f65 100644
--- a/kernel/bpf/Kconfig
+++ b/kernel/bpf/Kconfig
@@ -58,6 +58,10 @@ config BPF_JIT_ALWAYS_ON
Enables BPF JIT and removes BPF interpreter to avoid speculative
execution of BPF instructions by the interpreter.

+ When CONFIG_BPF_JIT_ALWAYS_ON is enabled, /proc/sys/net/core/bpf_jit_enable
+ is permanently set to 1 and setting any other value than that will return
+ in failure.
+
config BPF_JIT_DEFAULT_ON
def_bool ARCH_WANT_DEFAULT_BPF_JIT || BPF_JIT_ALWAYS_ON
depends on HAVE_EBPF_JIT && BPF_JIT
--
2.1.0