Daniel Borkmann 8b614aebec bpf: move clearing of A/X into classic to eBPF migration prologue ... Back in the days where eBPF (or back then "internal BPF" ;->) was not exposed to user space, and only the classic BPF programs internally translated into eBPF programs, we missed the fact that for classic BPF A and X needed to be cleared. It was fixed back then via 83d5b7ef99 ("net: filter: initialize A and X registers"), and thus classic BPF specifics were added to the eBPF interpreter core to work around it. This added some confusion for JIT developers later on that take the eBPF interpreter code as an example for deriving their JIT. F.e. in f75298f5c3 ("s390/bpf: clear correct BPF accumulator register"), at least X could leak stack memory. Furthermore, since this is only needed for classic BPF translations and not for eBPF (verifier takes care that read access to regs cannot be done uninitialized), more complexity is added to JITs as they need to determine whether they deal with migrations or native eBPF where they can just omit clearing A/X in their prologue and thus reduce image size a bit, see f.e. cde66c2d88 ("s390/bpf: Only clear A and X for converted BPF programs"). In other cases (x86, arm64), A and X is being cleared in the prologue also for eBPF case, which is unnecessary. Lets move this into the BPF migration in bpf_convert_filter() where it actually belongs as long as the number of eBPF JITs are still few. It can thus be done generically; allowing us to remove the quirk from __bpf_prog_run() and to slightly reduce JIT image size in case of eBPF, while reducing code duplication on this matter in current(/future) eBPF JITs. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Zi Shen Lim <zlim.lnx@gmail.com> Cc: Yang Shi <yang.shi@linaro.org> Acked-by: Yang Shi <yang.shi@linaro.org> Acked-by: Zi Shen Lim <zlim.lnx@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2015-12-18 16:04:51 -05:00
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boot	ls2080a/dts: Add little endian property for GPIO IP block	2015-12-11 16:13:03 -08:00
configs	arm64 fixes and clean-ups:	2015-11-12 15:33:11 -08:00
crypto	arm64: crypto: reduce priority of core AES cipher	2015-11-18 12:09:08 +00:00
include	Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-12-13 12:41:10 -08:00
kernel	arm64: update linker script to increased L1_CACHE_BYTES value	2015-12-07 17:22:24 +00:00
kvm	arm64: KVM: Get rid of old vcpu_reg()	2015-12-04 16:30:03 +00:00
lib	arm64: add KASAN support	2015-10-12 17:46:36 +01:00
mm	Revert "arm64: Mark kernel page ranges contiguous"	2015-11-26 15:42:41 +00:00
net	bpf: move clearing of A/X into classic to eBPF migration prologue	2015-12-18 16:04:51 -05:00
xen
Kconfig	arm64 fixes:	2015-11-27 11:09:59 -08:00
Kconfig.debug	arm64: remove redundant FRAME_POINTER kconfig option and force to select it	2015-11-10 10:36:00 +00:00
Kconfig.platforms	ARM: DT updates for v4.4	2015-11-10 15:06:26 -08:00
Makefile	arm64 updates for 4.4:	2015-11-04 14:47:13 -08:00