From patchwork Fri Mar 15 18:28:43 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Schichan X-Patchwork-Id: 2280091 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id 7D3A93FC8F for ; Fri, 15 Mar 2013 18:32:47 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UGZOL-0008Qi-Eq; Fri, 15 Mar 2013 18:30:09 +0000 Received: from smtp4-g21.free.fr ([2a01:e0c:1:1599::13]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UGZOD-0008Ox-Sv for linux-arm-kernel@lists.infradead.org; Fri, 15 Mar 2013 18:30:03 +0000 Received: from daria.iliad.local (unknown [213.36.7.13]) by smtp4-g21.free.fr (Postfix) with ESMTP id F0E8D4C80A7; Fri, 15 Mar 2013 19:29:55 +0100 (CET) From: Nicolas Schichan To: Will Drewry , Mircea Gherzan Subject: [PATCH RFC 3/3] ARM: net: bpf_jit: add support for jitted seccomp filters. Date: Fri, 15 Mar 2013 19:28:43 +0100 Message-Id: <1363372123-8861-4-git-send-email-nschichan@freebox.fr> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1363372123-8861-1-git-send-email-nschichan@freebox.fr> References: <1363372123-8861-1-git-send-email-nschichan@freebox.fr> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130315_143002_765076_E6640BE3 X-CRM114-Status: GOOD ( 11.64 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Russell King , Nicolas Schichan , linux-kernel@vger.kernel.org, Daniel Borkmann , "David S. Miller" , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org This patch selects HAVE_SECCOMP_FILTER_JIT in the ARM Kconfig file, implements and seccomp_jit_compile() and seccomp_jit_free(), and adds support for BPF_S_ANC_SECCOMP_LD_W instruction. BPF_S_ANC_SECCOMP_LD_W instructions trigger the generation of a call to C function jit_get_seccomp_w(). which is a wrapper around seccomp_bpf_load(). Signed-off-by: Nicolas Schichan --- arch/arm/Kconfig | 1 + arch/arm/net/bpf_jit_32.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index dedf02b..b3dce17 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -24,6 +24,7 @@ config ARM select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_TRACEHOOK select HAVE_BPF_JIT + select HAVE_SECCOMP_FILTER_JIT select HAVE_C_RECORDMCOUNT select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_API_DEBUG diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 0ea29e0..5af21be 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -103,6 +103,13 @@ static u64 jit_get_skb_w(struct sk_buff *skb, unsigned offset) return (u64)err << 32 | ntohl(ret); } +#ifdef CONFIG_SECCOMP_FILTER_JIT +static u64 jit_get_seccomp_w(struct sk_buff *skb, unsigned int offset) +{ + return seccomp_bpf_load(offset); +} +#endif + /* * Wrapper that handles both OABI and EABI and assures Thumb2 interworking * (where the assembly routines like __aeabi_uidiv could cause problems). @@ -548,6 +555,16 @@ load_common: emit_err_ret(ARM_COND_NE, ctx); emit(ARM_MOV_R(r_A, ARM_R0), ctx); break; +#ifdef CONFIG_SECCOMP_FILTER_JIT + case BPF_S_ANC_SECCOMP_LD_W: + ctx->seen |= SEEN_CALL; + emit_mov_i(ARM_R3, (u32)jit_get_seccomp_w, ctx); + emit_mov_i(ARM_R0, 0, ctx); + emit_mov_i(ARM_R1, k, ctx); + emit_blx_r(ARM_R3, ctx); + emit(ARM_MOV_R(r_A, ARM_R0), ctx); + break; +#endif case BPF_S_LD_W_IND: load_order = 2; goto load_ind; @@ -956,3 +973,30 @@ void bpf_jit_free(struct sk_filter *fp) schedule_work(work); } } + +#ifdef CONFIG_SECCOMP_FILTER_JIT +void seccomp_jit_compile(struct seccomp_filter *fp) +{ + struct jit_ctx ctx; + + memset(&ctx, 0, sizeof(ctx)); + ctx.prog_len = fp->len; + ctx.prog_insns = fp->insns; + + __bpf_jit_compile(&ctx); + if (ctx.target) + fp->bpf_func = (void*)ctx.target; +} + +void seccomp_jit_free(struct seccomp_filter *fp) +{ + struct work_struct *work; + + if (fp->bpf_func != sk_run_filter) { + work = (struct work_struct *)fp->bpf_func; + + INIT_WORK(work, bpf_jit_free_worker); + schedule_work(work); + } +} +#endif