[PATCH bpf-next v3 1/2] bpf: Add some description about BPF_JIT_ALWAYS_ON in Kconfig

From: Tiezhu Yang
Date: Tue Feb 22 2022 - 04:57:46 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
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>
Acked-by: Song Liu <songliubraving@xxxxxx>
---
kernel/bpf/Kconfig | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig
index d24d518..f3db15a 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
+ 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