Hi, This patch serie adds support for jitted seccomp BPF filters, with the required modifications to make it work on the ARM architecture.
- The first patch in the serie adds the required boiler plate in the core kernel seccomp code to invoke the JIT compilation/free code. - The second patch reworks the ARM BPF JIT code to make the generation process less dependent on struct sk_filter. - The last patch actually implements the ARM part in the BPF jit code. Some benchmarks, on a 1.6Ghz 88f6282 CPU: Each system call is tested in two way (fast/slow): - on the fast version, the tested system call is accepted immediately after checking the architecture (5 BPF instructions). - on the slow version, the tested system call is accepted after previously checking for 85 syscall (90 instructions, including the architecture check). The tested syscall is invoked in a loop 1000000 time, the reported time is the time spent in the loop in seconds. Without Seccomp JIT: Syscall Time-Fast Time-Slow --------------- ---------- ---------- gettimeofday 0.389 1.633 getpid 0.406 1.688 getresuid 1.003 2.266 getcwd 1.342 2.128 With Seccomp JIT: Syscall Time-Fast Time-Slow --------------- ----------- --------- gettimeofday 0.348 0.428 getpid 0.365 0.480 getresuid 0.981 1.060 getcwd 1.237 1.294 For reference, the same code without any seccomp filter: Syscall Time --------------- ----- gettimeofday 0.119 getpid 0.137 getresuid 0.747 getcwd 1.021 The activation of the BPF JIT for seccomp is still controled with the /proc/sys/net/core/bpf_jit_enable sysctl knob. Those changes are based on the latest rmk-for-next branch. V2 Changes: - Document the @bpf_func field in struct seccomp_filter as recommended by Kees Cook. - Invoke seccomp_bpf_load directly from generated code without going via a wrapper. V3 Changes: - add accessors giving access to the fields in struct seccomp_filter as recommended by Andrew Morton. This avoids having to include <linux/filter.h> in <linux/seccomp.h>, and fixes broken include dependencies on x86_64 allmodconfig build. - checkpatch fixes (void*) -> (void *) Regards, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
