Currently, only x86, arm64 and s390 select ARCH_WANT_DEFAULT_BPF_JIT, the other archs do not select ARCH_WANT_DEFAULT_BPF_JIT. On the archs without ARCH_WANT_DEFAULT_BPF_JIT, if we want to set bpf_jit_enable to 1 by default, the only way is to enable CONFIG_BPF_JIT_ALWAYS_ON, then the users can not change it to 0 or 2, it seems bad for some users. We can select ARCH_WANT_DEFAULT_BPF_JIT for those archs if it is proper, but at least for now, make BPF_JIT_DEFAULT_ON selectable can give them a chance. Additionally, with this patch, under !BPF_JIT_ALWAYS_ON, we can disable BPF_JIT_DEFAULT_ON on the archs with ARCH_WANT_DEFAULT_BPF_JIT when make menuconfig, it seems flexible for some developers. Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> --- kernel/bpf/Kconfig | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig index f3db15a..8521874 100644 --- a/kernel/bpf/Kconfig +++ b/kernel/bpf/Kconfig @@ -54,6 +54,7 @@ config BPF_JIT config BPF_JIT_ALWAYS_ON bool "Permanently enable BPF JIT and remove BPF interpreter" depends on BPF_SYSCALL && HAVE_EBPF_JIT && BPF_JIT + select BPF_JIT_DEFAULT_ON help Enables BPF JIT and removes BPF interpreter to avoid speculative execution of BPF instructions by the interpreter. @@ -63,8 +64,16 @@ config BPF_JIT_ALWAYS_ON failure. config BPF_JIT_DEFAULT_ON - def_bool ARCH_WANT_DEFAULT_BPF_JIT || BPF_JIT_ALWAYS_ON - depends on HAVE_EBPF_JIT && BPF_JIT + bool "Enable BPF JIT by default" + default y if ARCH_WANT_DEFAULT_BPF_JIT + depends on BPF_SYSCALL && HAVE_EBPF_JIT && BPF_JIT + help + Enables BPF JIT by default to avoid speculative execution of BPF + instructions by the interpreter. + + When CONFIG_BPF_JIT_DEFAULT_ON is enabled but CONFIG_BPF_JIT_ALWAYS_ON + is disabled, /proc/sys/net/core/bpf_jit_enable is set to 1 by default + and can be changed to 0 or 2. config BPF_UNPRIV_DEFAULT_OFF bool "Disable unprivileged BPF by default" -- 2.1.0
