From patchwork Thu Oct 12 03:50:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namhyung Kim X-Patchwork-Id: 13418239 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B6C61378; Thu, 12 Oct 2023 03:52:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Bt1cO1HK" Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F97A10E3; Wed, 11 Oct 2023 20:51:57 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id d9443c01a7336-1c88b467ef8so4754815ad.0; Wed, 11 Oct 2023 20:51:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697082715; x=1697687515; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:from:to:cc:subject:date :message-id:reply-to; bh=IpeT682jXo8zHQtou6ZhNNKzbowV2y0VimL5UVLWBn8=; b=Bt1cO1HK3G6coroGMGSCNYFwRd4qnfdCkfYk8pVezNvlkWhh0NHgFq/+qFLKFSa/q2 otz+wwWidkFSHfUj4CUGzJJMXvh/mWy+NZKDI+gzld25vKdKhZ2TkOsjqZljYl4qOo/v l7jwqmFbLweTcEgZ5Yxw3g7+PwFBY+ukFg9xO4dKAT2reVP4X1HKKb1g7/BqLpGqFM49 7NXcN1k2si/iuL2IrUwrb/1pmNEhUzTXFbu6XulCIA7j/NzByyvJbgmUi4IKUZL5PEnA z4zIiM1YzbZmlEE56cK7/4dAcjFeZ32IhbdBj+uvLanCTjAX8e7a16u5kkouhQv/+C9c 5Jzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697082715; x=1697687515; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=IpeT682jXo8zHQtou6ZhNNKzbowV2y0VimL5UVLWBn8=; b=Q6O3eVVPCyN3IehfXfvgMz+RORUSJWBnZ0oJbLwn04L1Tj1jahV5sjhrZZmSehUqv7 lRnko1M3aXjI1yDqBn+sJ9+Yw9lAA56cD7ocXwGPiEm1Q97nBJdrWYPD/Dl/2kY3A8vA o+EBAk3izt/HDGGEGQg9phPt8SZKHMqcfkSoAmXF30R4kizGY/p6e5v8IjiyEe7SBRP4 vwmukVyO5GQU/E9mU9GDuvs4wvY4xLyp5PADQTvD2tgjOu9g7B6qjcVe3qx0BnEJvX0J ndpfzDc1VNEQNer7z2bkBmkKyJPD8GfWfRAszcQO/YoFJqQ6F+10uKXx+GugJ3JNvMmy Ys5Q== X-Gm-Message-State: AOJu0YzEYa1s3i6IfzTWhfPwjgiv6A4gw75Dh0h2JBd5SqxgkyFK7kLa OdNP++AaczFVylFhM/ptinhmf3dhGoo= X-Google-Smtp-Source: AGHT+IGObjCpXIRGXvxG2XeisCJpHRn7826etev5dtkSoj7pISBW7/J+f91nhwI9aX8oEoEP+26kOg== X-Received: by 2002:a17:902:c947:b0:1c7:4a8a:32d1 with SMTP id i7-20020a170902c94700b001c74a8a32d1mr24944285pla.28.1697082715545; Wed, 11 Oct 2023 20:51:55 -0700 (PDT) Received: from bangji.hsd1.ca.comcast.net ([2601:647:6780:42e0:b1b9:d490:2f5e:be06]) by smtp.gmail.com with ESMTPSA id w8-20020a170902d70800b001bc18e579aesm711374ply.101.2023.10.11.20.51.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Oct 2023 20:51:55 -0700 (PDT) Sender: Namhyung Kim From: Namhyung Kim To: Arnaldo Carvalho de Melo , Jiri Olsa , Peter Zijlstra Cc: Ian Rogers , Adrian Hunter , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org, Linus Torvalds , Stephane Eranian , Masami Hiramatsu , linux-toolchains@vger.kernel.org, linux-trace-devel@vger.kernel.org Subject: [PATCH 31/48] perf dwarf-aux: Add die_get_cfa() Date: Wed, 11 Oct 2023 20:50:54 -0700 Message-ID: <20231012035111.676789-32-namhyung@kernel.org> X-Mailer: git-send-email 2.42.0.655.g421f12c284-goog In-Reply-To: <20231012035111.676789-1-namhyung@kernel.org> References: <20231012035111.676789-1-namhyung@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-1.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net The die_get_cfa() is to get frame base register and offset at the given instruction address (pc). This info will be used to locate stack variables which have location expression using DW_OP_fbreg. Signed-off-by: Namhyung Kim --- tools/perf/util/dwarf-aux.c | 64 +++++++++++++++++++++++++++++++++++++ tools/perf/util/dwarf-aux.h | 9 ++++++ 2 files changed, 73 insertions(+) diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index 97d9ae56350e..796413eb4e8f 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -1408,6 +1408,70 @@ Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr pc, return result; } +static int reg_from_dwarf_op(Dwarf_Op *op) +{ + switch (op->atom) { + case DW_OP_reg0 ... DW_OP_reg31: + return op->atom - DW_OP_reg0; + case DW_OP_breg0 ... DW_OP_breg31: + return op->atom - DW_OP_breg0; + case DW_OP_regx: + case DW_OP_bregx: + return op->number; + default: + break; + } + return -1; +} + +static int offset_from_dwarf_op(Dwarf_Op *op) +{ + switch (op->atom) { + case DW_OP_reg0 ... DW_OP_reg31: + case DW_OP_regx: + return 0; + case DW_OP_breg0 ... DW_OP_breg31: + return op->number; + case DW_OP_bregx: + return op->number2; + default: + break; + } + return -1; +} + +/** + * die_get_cfa - Get frame base information + * @dwarf: a Dwarf info + * @pc: program address + * @preg: pointer for saved register + * @poffset: pointer for saved offset + * + * This function gets register and offset for CFA (Canonical Frame Address) + * by searching the CIE/FDE info. The CFA usually points to the start address + * of the current stack frame and local variables can be located using an offset + * from the CFA. The @preg and @poffset will be updated if it returns 0. + */ +int die_get_cfa(Dwarf *dwarf, u64 pc, int *preg, int *poffset) +{ + Dwarf_CFI *cfi; + Dwarf_Frame *frame = NULL; + Dwarf_Op *ops = NULL; + size_t nops; + + cfi = dwarf_getcfi(dwarf); + if (cfi == NULL) + return -1; + + if (!dwarf_cfi_addrframe(cfi, pc, &frame) && + !dwarf_frame_cfa(frame, &ops, &nops) && nops == 1) { + *preg = reg_from_dwarf_op(ops); + *poffset = offset_from_dwarf_op(ops); + return 0; + } + return -1; +} + #endif /* diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h index 742098e3ee7e..29a7243b1a45 100644 --- a/tools/perf/util/dwarf-aux.h +++ b/tools/perf/util/dwarf-aux.h @@ -149,6 +149,9 @@ Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr pc, Dwarf_Addr addr, Dwarf_Die *die_mem, int *offset); +/* Get the frame base information from CFA */ +int die_get_cfa(Dwarf *dwarf, u64 pc, int *preg, int *poffset); + #else /* HAVE_DWARF_GETLOCATIONS_SUPPORT */ static inline int die_get_var_range(Dwarf_Die *sp_die __maybe_unused, @@ -175,6 +178,12 @@ static inline Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die __maybe_unu return NULL; } +static inline int die_get_cfa(Dwarf *dwarf __maybe_unused, u64 pc __maybe_unused, + int *preg __maybe_unused, int *poffset __maybe_unused) +{ + return -1; +} + #endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */ #endif /* _DWARF_AUX_H */