From patchwork Fri Mar 15 18:28:42 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Schichan X-Patchwork-Id: 2280081 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id 2804CDF24C for ; Fri, 15 Mar 2013 18:32:41 +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 1UGZO8-0008O3-Fp; Fri, 15 Mar 2013 18:29:56 +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 1UGZO3-0008Ml-RO for linux-arm-kernel@lists.infradead.org; Fri, 15 Mar 2013 18:29:53 +0000 Received: from daria.iliad.local (unknown [213.36.7.13]) by smtp4-g21.free.fr (Postfix) with ESMTP id CECE24C82A5; Fri, 15 Mar 2013 19:29:42 +0100 (CET) From: Nicolas Schichan To: Will Drewry , Mircea Gherzan Subject: [PATCH RFC 2/3] ARM: net: bpf_jit: make code generation less dependent on struct sk_filter. Date: Fri, 15 Mar 2013 19:28:42 +0100 Message-Id: <1363372123-8861-3-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_142952_520458_76CC7246 X-CRM114-Status: GOOD ( 11.72 ) 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 is in preparation of bpf_jit support for seccomp filters. Signed-off-by: Nicolas Schichan --- arch/arm/net/bpf_jit_32.c | 46 ++++++++++++++++++++++++++++----------------- 1 file changed, 29 insertions(+), 17 deletions(-) diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 6828ef6..0ea29e0 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -55,7 +55,8 @@ #define FLAG_NEED_X_RESET (1 << 0) struct jit_ctx { - const struct sk_filter *skf; + unsigned short prog_len; + struct sock_filter *prog_insns; unsigned idx; unsigned prologue_bytes; int ret0_fp_idx; @@ -131,8 +132,8 @@ static u16 saved_regs(struct jit_ctx *ctx) { u16 ret = 0; - if ((ctx->skf->len > 1) || - (ctx->skf->insns[0].code == BPF_S_RET_A)) + if ((ctx->prog_len > 1) || + (ctx->prog_insns[0].code == BPF_S_RET_A)) ret |= 1 << r_A; #ifdef CONFIG_FRAME_POINTER @@ -181,7 +182,7 @@ static inline bool is_load_to_a(u16 inst) static void build_prologue(struct jit_ctx *ctx) { u16 reg_set = saved_regs(ctx); - u16 first_inst = ctx->skf->insns[0].code; + u16 first_inst = ctx->prog_insns[0].code; u16 off; #ifdef CONFIG_FRAME_POINTER @@ -279,7 +280,7 @@ static u16 imm_offset(u32 k, struct jit_ctx *ctx) ctx->imms[i] = k; /* constants go just after the epilogue */ - offset = ctx->offsets[ctx->skf->len]; + offset = ctx->offsets[ctx->prog_len]; offset += ctx->prologue_bytes; offset += ctx->epilogue_bytes; offset += i * 4; @@ -419,7 +420,7 @@ static inline void emit_err_ret(u8 cond, struct jit_ctx *ctx) emit(ARM_MOV_R(ARM_R0, ARM_R0), ctx); } else { _emit(cond, ARM_MOV_I(ARM_R0, 0), ctx); - _emit(cond, ARM_B(b_imm(ctx->skf->len, ctx)), ctx); + _emit(cond, ARM_B(b_imm(ctx->prog_len, ctx)), ctx); } } @@ -469,14 +470,13 @@ static inline void update_on_xread(struct jit_ctx *ctx) static int build_body(struct jit_ctx *ctx) { void *load_func[] = {jit_get_skb_b, jit_get_skb_h, jit_get_skb_w}; - const struct sk_filter *prog = ctx->skf; const struct sock_filter *inst; unsigned i, load_order, off, condt; int imm12; u32 k; - for (i = 0; i < prog->len; i++) { - inst = &(prog->insns[i]); + for (i = 0; i < ctx->prog_len; i++) { + inst = &(ctx->prog_insns[i]); /* K as an immediate value operand */ k = inst->k; @@ -769,8 +769,8 @@ cmp_x: ctx->ret0_fp_idx = i; emit_mov_i(ARM_R0, k, ctx); b_epilogue: - if (i != ctx->skf->len - 1) - emit(ARM_B(b_imm(prog->len, ctx)), ctx); + if (i != ctx->prog_len - 1) + emit(ARM_B(b_imm(ctx->prog_len, ctx)), ctx); break; case BPF_S_MISC_TAX: /* X = A */ @@ -858,7 +858,7 @@ b_epilogue: } -void bpf_jit_compile(struct sk_filter *fp) +static void __bpf_jit_compile(struct jit_ctx *out_ctx) { struct jit_ctx ctx; unsigned tmp_idx; @@ -867,11 +867,10 @@ void bpf_jit_compile(struct sk_filter *fp) if (!bpf_jit_enable) return; - memset(&ctx, 0, sizeof(ctx)); - ctx.skf = fp; + ctx = *out_ctx; ctx.ret0_fp_idx = -1; - ctx.offsets = kzalloc(4 * (ctx.skf->len + 1), GFP_KERNEL); + ctx.offsets = kzalloc(4 * (ctx.prog_len + 1), GFP_KERNEL); if (ctx.offsets == NULL) return; @@ -921,13 +920,26 @@ void bpf_jit_compile(struct sk_filter *fp) print_hex_dump(KERN_INFO, "BPF JIT code: ", DUMP_PREFIX_ADDRESS, 16, 4, ctx.target, alloc_size, false); - - fp->bpf_func = (void *)ctx.target; out: kfree(ctx.offsets); + + *out_ctx = ctx; return; } +void bpf_jit_compile(struct sk_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; +} + static void bpf_jit_free_worker(struct work_struct *work) { module_free(NULL, work);