From patchwork Thu Nov 9 23:59:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namhyung Kim X-Patchwork-Id: 13451903 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 96F48DDAD; Fri, 10 Nov 2023 00:01:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BvvqvxGm" Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 267E744BC; Thu, 9 Nov 2023 16:01:10 -0800 (PST) Received: by mail-pj1-x102c.google.com with SMTP id 98e67ed59e1d1-280200949c3so1314752a91.0; Thu, 09 Nov 2023 16:01:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1699574469; x=1700179269; 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=Ea03R/KMOWK9jWm9N2N4NwL8Qridb15kzrUrffJWfOA=; b=BvvqvxGmiPLRjvVpuOt5oXUjstaaAm2NM3qZS9WVE87uKLEvGHYBQzX3qD0ychvSv6 n4w9lCq1tXomjrP6l6Uk4LDHOWjDN8nnypAOJP+3b+ruQ/Qa4TZ7t/levDeLfjnwMGU4 hgw0Rz/mxCzc7yifTo9BBWb1aSYjSi0NgJObvYEqjC6DvVkdUtrw00GRnI72r//Yk7Rs nTxbCtnm67e1uzh308eN11R11NSydxeGWwB/zxOwOSyB1bVZrjrhqmUqq33x5s3UL9Ln URooexM0zfySHbwY/ElC0XJgppNRll5QCPSc5Hyz/S7lSkpyV7W2bXp4PaONsx/2Ehp+ Ow7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699574469; x=1700179269; 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=Ea03R/KMOWK9jWm9N2N4NwL8Qridb15kzrUrffJWfOA=; b=eqb4iXeH3G8eQ70hi3KVGdtSPWMDxV3WfXwbv5jrbvGVCu0AopN8iGdEFPHHr2G6Yj lre+rG16o1kMzQfRPnWL1S4c9SGWdSvQmkz55qso+antFoWsQZaNICNSJItF94g6B/WX Kl3y7zpp6YJaFV/VjU89qYmrMWjswlGFmWy+tlNNqgSGmdG1QYhIN0ot+uMbsa+HiKo+ wQafA3V+L2YxlxrNeevoYWzflY3cfKXqbmx8//y3LrLzXU+9GIHqFYqJ/3IcIRWSJRIb 914jkYqxNJH2UHtWMail4B6Jm5YI589GzUS0QYU/s3bvBfT9aCWLOuF4PV9JaD4HjTQS qebA== X-Gm-Message-State: AOJu0Yy5S8NsHUaDh+3QiKVVPuLSfbRfD5XHVXV/50Y4DCSAF/4fFDaP Zqz3YVT91rsCqZd+5DOKN6k= X-Google-Smtp-Source: AGHT+IECt0YJd4231LO+X66sGFsIH17Oo36mO+fy8ihhV7GbKGQI2qP7XBBdTxVN4KOudH6rgYujPA== X-Received: by 2002:a17:90b:4b0f:b0:27d:46e5:2d7c with SMTP id lx15-20020a17090b4b0f00b0027d46e52d7cmr3380378pjb.26.1699574469540; Thu, 09 Nov 2023 16:01:09 -0800 (PST) Received: from bangji.corp.google.com ([2620:15c:2c0:5:d45c:ae16:d959:a5f1]) by smtp.gmail.com with ESMTPSA id k32-20020a17090a4ca300b002635db431a0sm371312pjh.45.2023.11.09.16.01.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Nov 2023 16:01:09 -0800 (PST) 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 , Andi Kleen , linux-trace-devel@vger.kernel.org, linux-toolchains@vger.kernel.org Subject: [PATCH 35/52] perf dwarf-aux: Add die_get_cfa() Date: Thu, 9 Nov 2023 15:59:54 -0800 Message-ID: <20231110000012.3538610-36-namhyung@kernel.org> X-Mailer: git-send-email 2.42.0.869.gea05f2083d-goog In-Reply-To: <20231110000012.3538610-1-namhyung@kernel.org> References: <20231110000012.3538610-1-namhyung@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 | 68 ++++++++++++++++++++++++++++++++++++- tools/perf/util/dwarf-aux.h | 15 ++++++++ 2 files changed, 82 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index 7aa5fee0da19..3d42a8613869 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -1407,7 +1407,73 @@ Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr pc, *offset = data.offset; return result; } -#endif +#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */ + +#ifdef HAVE_DWARF_CFI_SUPPORT +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 /* HAVE_DWARF_CFI_SUPPORT */ /* * die_has_loclist - Check if DW_AT_location of @vr_die is a location list diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h index 4e64caac6df8..f209f9162908 100644 --- a/tools/perf/util/dwarf-aux.h +++ b/tools/perf/util/dwarf-aux.h @@ -177,4 +177,19 @@ static inline Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die __maybe_unu #endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */ +#ifdef HAVE_DWARF_CFI_SUPPORT + +/* Get the frame base information from CFA */ +int die_get_cfa(Dwarf *dwarf, u64 pc, int *preg, int *poffset); + +#else /* HAVE_DWARF_CFI_SUPPORT */ + +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_CFI_SUPPORT */ + #endif /* _DWARF_AUX_H */