2022-02-19 16:45:27

by Tiezhu Yang

Subject: [PATCH bpf-next v2 0/2] Modify BPF_JIT_ALWAYS_ON and BPF_JIT_DEFAULT_ON

v2:
-- Use the full path /proc/sys/net/core/bpf_jit_enable in the help text.
-- Update the commit message to make it clear in patch #2.

Tiezhu Yang (2):
bpf: Add some description about BPF_JIT_ALWAYS_ON in Kconfig
bpf: Make BPF_JIT_DEFAULT_ON selectable in Kconfig

kernel/bpf/Kconfig | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)

--
2.1.0

2022-02-20 17:55:05

by Tiezhu Yang

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

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 <[email protected]>
---
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

2022-02-22 05:30:48

by Song Liu

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

On Fri, Feb 18, 2022 at 7:15 PM Tiezhu Yang <[email protected]> wrote:
>
> 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 <[email protected]>
> ---
> 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.

nit: "return failure" (no "in").

Other than this,

Acked-by: Song Liu <[email protected]>

> +
> 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
>