kernel.git/arch/x86/net, branch linux-4.7.y

bpf, x86: add support for constant blinding

2016-05-16T17:49:32Z

This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

bpf: prepare bpf_int_jit_compile/bpf_prog_select_runtime apis

2016-05-16T17:49:32Z

Since the blinding is strictly only called from inside eBPF JITs, we need to change signatures for bpf_int_jit_compile() and bpf_prog_select_runtime() first in order to prepare that the eBPF program we're dealing with can change underneath. Hence, for call sites, we need to return the latest prog. No functional change in this patch. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

bpf, x86/arm64: remove useless checks on prog

2016-05-16T17:49:32Z

There is never such a situation, where bpf_int_jit_compile() is called with either prog as NULL or len as 0, so the tests are unnecessary and confusing as people would just copy them. s390 doesn't have them, so no change is needed there. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

x86/asm/bpf: Create stack frames in bpf_jit.S

2016-02-24T07:35:44Z

bpf_jit.S has several callable non-leaf functions which don't honor CONFIG_FRAME_POINTER, which can result in bad stack traces. Create a stack frame before the call instructions when CONFIG_FRAME_POINTER is enabled. Signed-off-by: Josh Poimboeuf Acked-by: Alexei Starovoitov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Bernd Petrovitsch Cc: Borislav Petkov Cc: Brian Gerst Cc: Chris J Arges Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jiri Slaby Cc: Linus Torvalds Cc: Michal Marek Cc: Namhyung Kim Cc: Pedro Alves Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: live-patching@vger.kernel.org Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/fa4c41976b438b51954cb8021f06bceb1d1d66cc.1453405861.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar

x86/asm/bpf: Annotate callable functions

2016-02-24T07:35:43Z

bpf_jit.S has several functions which can be called from C code. Give them proper ELF annotations. Signed-off-by: Josh Poimboeuf Acked-by: Alexei Starovoitov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Bernd Petrovitsch Cc: Borislav Petkov Cc: Brian Gerst Cc: Chris J Arges Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jiri Slaby Cc: Linus Torvalds Cc: Michal Marek Cc: Namhyung Kim Cc: Pedro Alves Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: live-patching@vger.kernel.org Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/bbe1de0c299fecd4fc9a1766bae8be2647bedb01.1453405861.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar

bpf, x86: detect/optimize loading 0 immediates

2015-12-18T21:04:51Z

When sometimes structs or variables need to be initialized/'memset' to 0 in an eBPF C program, the x86 BPF JIT converts this to use immediates. We can however save a couple of bytes (f.e. even up to 7 bytes on a single emmission of BPF_LD | BPF_IMM | BPF_DW) in the image by detecting such case and use xor on the dst register instead. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

bpf: move clearing of A/X into classic to eBPF migration prologue

2015-12-18T21:04:51Z

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 83d5b7ef99c9 ("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 f75298f5c3fe ("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. cde66c2d88da ("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 Acked-by: Alexei Starovoitov Reviewed-by: Michael Holzheu Tested-by: Michael Holzheu Cc: Zi Shen Lim Cc: Yang Shi Acked-by: Yang Shi Acked-by: Zi Shen Lim Signed-off-by: David S. Miller

ebpf: migrate bpf_prog's flags to bitfield

2015-10-03T12:02:39Z

As we need to add further flags to the bpf_prog structure, lets migrate both bools to a bitfield representation. The size of the base structure (excluding insns) remains unchanged at 40 bytes. Add also tags for the kmemchecker, so that it doesn't throw false positives. Even in case gcc would generate suboptimal code, it's not being accessed in performance critical paths. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

bpf: Make the bpf_prog_array_map more generic

2015-08-10T05:50:05Z

All the map backends are of generic nature. In order to avoid adding much special code into the eBPF core, rewrite part of the bpf_prog_array map code and make it more generic. So the new perf_event_array map type can reuse most of code with bpf_prog_array map and add fewer lines of special code. Signed-off-by: Wang Nan Signed-off-by: Kaixu Xia Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2015-08-01T06:52:20Z

Conflicts: arch/s390/net/bpf_jit_comp.c drivers/net/ethernet/ti/netcp_ethss.c net/bridge/br_multicast.c net/ipv4/ip_fragment.c All four conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller