From patchwork Tue Apr 19 14:52:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pu Lehui X-Patchwork-Id: 12818688 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A5DBCC433EF for ; Tue, 19 Apr 2022 15:13:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8nItEfkPnl/1uhFBebC63wjnSZNBtRrcNPpmRlR3tf8=; b=3HYjrj7SzGL90q OfSBzMLAmjKbEtckZAPZodhrVGPEthsiFGbTHIJNiNtHhU4RAH282hFXIDuzUP2mf/bJGocWlGoYz Feu6y2EqY6Pii9VtIiRhJvwKfkOUwzxWMFuC+MvduwUczGIOMKztCKh+YCTP0ClAb0j1A93zCv9o8 l0Atmu4MA3fkswyXWci2yZLXv7eEOdRRavlPxKKC4AkE/o64i6eE7oBqxvsxds2asiwv5OYGBBel+ 9L+yNEyDsp3Toea/NUPnxABudfIXfhtHYRiBAIfbpBiG74NUNekhFW16t4Zrhxnx7iJorvR9+7nYl +BDo/zej1Ue9BH0AaCLg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ngpY1-004Yvc-SX; Tue, 19 Apr 2022 15:13:45 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ngoli-004Eac-W5 for linux-riscv@lists.infradead.org; Tue, 19 Apr 2022 14:23:55 +0000 Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KjQxx17wLzfYqr; Tue, 19 Apr 2022 22:23:01 +0800 (CST) Received: from dggpemm500019.china.huawei.com (7.185.36.180) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 19 Apr 2022 22:23:45 +0800 Received: from k04.huawei.com (10.67.174.115) by dggpemm500019.china.huawei.com (7.185.36.180) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 19 Apr 2022 22:23:44 +0800 From: Pu Lehui To: , , , CC: , , , , , , , , , , , Subject: [PATCH v2 bpf-next 2/2] libbpf: Support riscv USDT argument parsing logic Date: Tue, 19 Apr 2022 22:52:38 +0800 Message-ID: <20220419145238.482134-3-pulehui@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220419145238.482134-1-pulehui@huawei.com> References: <20220419145238.482134-1-pulehui@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.115] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500019.china.huawei.com (7.185.36.180) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220419_072351_498029_321FB68E X-CRM114-Status: GOOD ( 12.54 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Add riscv-specific USDT argument specification parsing logic. riscv USDT argument format is shown below: - Memory dereference case: "size@off(reg)", e.g. "-8@-88(s0)" - Constant value case: "size@val", e.g. "4@5" - Register read case: "size@reg", e.g. "-8@a1" s8 will be marked as poison while it's a reg of riscv, we need to alias it in advance. Both RV32 and RV64 have been tested. Signed-off-by: Pu Lehui --- v1-v2: - Add brief test results. - Make reg_map more intuitive. tools/lib/bpf/usdt.c | 107 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c index 8e77a7260..f1c9339cf 100644 --- a/tools/lib/bpf/usdt.c +++ b/tools/lib/bpf/usdt.c @@ -10,6 +10,11 @@ #include #include +/* s8 will be marked as poison while it's a reg of riscv */ +#if defined(__riscv) +#define rv_s8 s8 +#endif + #include "bpf.h" #include "libbpf.h" #include "libbpf_common.h" @@ -1400,6 +1405,108 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec return len; } +#elif defined(__riscv) + +static int calc_pt_regs_off(const char *reg_name) +{ + static struct { + const char *name; + size_t pt_regs_off; + } reg_map[] = { + { "ra", offsetof(struct user_regs_struct, ra) }, + { "sp", offsetof(struct user_regs_struct, sp) }, + { "gp", offsetof(struct user_regs_struct, gp) }, + { "tp", offsetof(struct user_regs_struct, tp) }, + { "a0", offsetof(struct user_regs_struct, a0) }, + { "a1", offsetof(struct user_regs_struct, a1) }, + { "a2", offsetof(struct user_regs_struct, a2) }, + { "a3", offsetof(struct user_regs_struct, a3) }, + { "a4", offsetof(struct user_regs_struct, a4) }, + { "a5", offsetof(struct user_regs_struct, a5) }, + { "a6", offsetof(struct user_regs_struct, a6) }, + { "a7", offsetof(struct user_regs_struct, a7) }, + { "s0", offsetof(struct user_regs_struct, s0) }, + { "s1", offsetof(struct user_regs_struct, s1) }, + { "s2", offsetof(struct user_regs_struct, s2) }, + { "s3", offsetof(struct user_regs_struct, s3) }, + { "s4", offsetof(struct user_regs_struct, s4) }, + { "s5", offsetof(struct user_regs_struct, s5) }, + { "s6", offsetof(struct user_regs_struct, s6) }, + { "s7", offsetof(struct user_regs_struct, s7) }, + { "s8", offsetof(struct user_regs_struct, rv_s8) }, + { "s9", offsetof(struct user_regs_struct, s9) }, + { "s10", offsetof(struct user_regs_struct, s10) }, + { "s11", offsetof(struct user_regs_struct, s11) }, + { "t0", offsetof(struct user_regs_struct, t0) }, + { "t1", offsetof(struct user_regs_struct, t1) }, + { "t2", offsetof(struct user_regs_struct, t2) }, + { "t3", offsetof(struct user_regs_struct, t3) }, + { "t4", offsetof(struct user_regs_struct, t4) }, + { "t5", offsetof(struct user_regs_struct, t5) }, + { "t6", offsetof(struct user_regs_struct, t6) }, + }; + int i; + + for (i = 0; i < ARRAY_SIZE(reg_map); i++) { + if (strcmp(reg_name, reg_map[i].name) == 0) + return reg_map[i].pt_regs_off; + } + + pr_warn("usdt: unrecognized register '%s'\n", reg_name); + return -ENOENT; +} + +static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg) +{ + char *reg_name = NULL; + int arg_sz, len, reg_off; + long off; + + if (sscanf(arg_str, " %d @ %ld ( %m[a-z0-9] ) %n", &arg_sz, &off, ®_name, &len) == 3) { + /* Memory dereference case, e.g., -8@-88(s0) */ + arg->arg_type = USDT_ARG_REG_DEREF; + arg->val_off = off; + reg_off = calc_pt_regs_off(reg_name); + free(reg_name); + if (reg_off < 0) + return reg_off; + arg->reg_off = reg_off; + } else if (sscanf(arg_str, " %d @ %ld %n", &arg_sz, &off, &len) == 2) { + /* Constant value case, e.g., 4@5 */ + arg->arg_type = USDT_ARG_CONST; + arg->val_off = off; + arg->reg_off = 0; + } else if (sscanf(arg_str, " %d @ %m[a-z0-9] %n", &arg_sz, ®_name, &len) == 2) { + /* Register read case, e.g., -8@a1 */ + arg->arg_type = USDT_ARG_REG; + arg->val_off = 0; + reg_off = calc_pt_regs_off(reg_name); + free(reg_name); + if (reg_off < 0) + return reg_off; + arg->reg_off = reg_off; + } else { + pr_warn("usdt: unrecognized arg #%d spec '%s'\n", arg_num, arg_str); + return -EINVAL; + } + + arg->arg_signed = arg_sz < 0; + if (arg_sz < 0) + arg_sz = -arg_sz; + + switch (arg_sz) { + case 1: case 2: case 4: case 8: + arg->arg_bitshift = 64 - arg_sz * 8; + break; + default: + pr_warn("usdt: unsupported arg #%d (spec '%s') size: %d\n", + arg_num, arg_str, arg_sz); + return -EINVAL; + } + + return len; +} + #else static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg)