Daniel Borkmann 81c22041d9 bpf, x86, arm64: Enable jit by default when not built as always-on ... After Spectre 2 fix via 290af86629 ("bpf: introduce BPF_JIT_ALWAYS_ON config") most major distros use BPF_JIT_ALWAYS_ON configuration these days which compiles out the BPF interpreter entirely and always enables the JIT. Also given recent fix in e1608f3fa8 ("bpf: Avoid setting bpf insns pages read-only when prog is jited"), we additionally avoid fragmenting the direct map for the BPF insns pages sitting in the general data heap since they are not used during execution. Latter is only needed when run through the interpreter. Since both x86 and arm64 JITs have seen a lot of exposure over the years, are generally most up to date and maintained, there is more downside in !BPF_JIT_ALWAYS_ON configurations to have the interpreter enabled by default rather than the JIT. Add a ARCH_WANT_DEFAULT_BPF_JIT config which archs can use to set the bpf_jit_{enable,kallsyms} to 1. Back in the days the bpf_jit_kallsyms knob was set to 0 by default since major distros still had /proc/kallsyms addresses exposed to unprivileged user space which is not the case anymore. Hence both knobs are set via BPF_JIT_DEFAULT_ON which is set to 'y' in case of BPF_JIT_ALWAYS_ON or ARCH_WANT_DEFAULT_BPF_JIT. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/f78ad24795c2966efcc2ee19025fa3459f622185.1575903816.git.daniel@iogearbox.net		2019-12-11 16:16:01 -08:00
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Kconfig	bpf, x86, arm64: Enable jit by default when not built as always-on	2019-12-11 16:16:01 -08:00
Makefile	Kbuild: Handle PREEMPT_RT for version string and magic	2019-08-14 01:10:42 +09:00
calibrate.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
do_mounts.c	init: Support mounting root file systems over SMB	2019-10-02 12:15:15 -04:00
do_mounts.h	fs: add do_mknodat() helper and ksys_mknod() wrapper; remove in-kernel calls to syscall	2018-04-02 20:15:56 +02:00
do_mounts_initrd.c	Merge branch 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-01-05 13:25:58 -08:00
do_mounts_md.c	init/: remove ineffective sparse disabling	2018-08-22 10:52:49 -07:00
do_mounts_rd.c	init/: remove ineffective sparse disabling	2018-08-22 10:52:49 -07:00
init_task.c	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-09-17 12:35:15 -07:00
initramfs.c	arm64: use generic free_initrd_mem()	2019-10-16 13:55:25 +01:00
main.c	Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2019-09-28 08:14:15 -07:00
noinitramfs.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 167	2019-05-30 11:26:39 -07:00
version.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00