From nobody Wed Dec 17 14:37:27 2025 Received: from mail-qk1-f202.google.com (mail-qk1-f202.google.com [209.85.222.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A225D2D595D for ; Mon, 13 Oct 2025 18:16:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760379386; cv=none; b=bvneiUCqBfmX61G/FNGTQluOJ1YsGD2rEUoYlZz4fTE5+R2rVkmANJdifyAJ08fcAScRT2a1Mks4vH3JCUPDMdzilfi5BX/prV6RV/Q/F9UTAr6HlEbUKf061/aV9g1OA7lpbnsreEJQO6jtZIPVBCZdhaLDnK967rLOeK9gfWI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760379386; c=relaxed/simple; bh=WCMovf1Hp3z/2wqmOlu9KCY6h/OjWugr9o717BGY0T8=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=R2uMqBI5cNo05VxP1L13Fu8xlAdvAGh/hsv5Tm8FJ7Avbem4tllOBGgxE89d0FRbZDYOJ1sKEQ8FtA5W5xoAaWSH8n46pD6CrLXkHvWYhnsOADYxjJKs77TPNL7uthSVQdROfKaa3O1+KVAaGo7OFKOpCSl89tGN+Q3VNYul+CI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--zecheng.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=tlafQ1as; arc=none smtp.client-ip=209.85.222.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--zecheng.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="tlafQ1as" Received: by mail-qk1-f202.google.com with SMTP id af79cd13be357-8635d475527so3090947085a.0 for ; Mon, 13 Oct 2025 11:16:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1760379384; x=1760984184; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=9/Q4qrmylQ0ZahaRzO6Ct5R5403rZDLx7xSWotYEXoA=; b=tlafQ1asDhcMrC6zMHnbGppdhxT/Gmo/LasMRUcofEiwXC9VC5YUOn+IDhfiunGKT6 l3ADpX5hJ6P3hRau4oNH3iQNBugUFCU9KGhYF4b/wamZYvB19tBxnfaB/J/hSmld2MiA +VDZlRT1tc4Mzp8lMLYkOWR8RFxSnyi3PCBAcN6gQyUTTakssy4UY/phfXBS0TR8+3ty 2L+8tqs7ZMZq8teO3Hv2JYzlcLOc/MgX/kFzxIscnbQHdCgFscNdbTRePhOBAvRtXdJL 4RucPnyFxPWDC6oWRFTFTeA1gaL3yWJFrRDcyDxWjGxnYY0bmPj/0RibtfJN5UqIFQ68 LGVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760379384; x=1760984184; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=9/Q4qrmylQ0ZahaRzO6Ct5R5403rZDLx7xSWotYEXoA=; b=qkrqcLvrJVa/pm7PtZfZj/66s0MZRt4g2kwq9/eqnPxuI0tii+oMikghnGK+Vvk6EW NlSvxeqRH3azAFx2V/GJlTCmNG3SWQd5Ai8W2kPea5HLX8tw/LK6Le4j+LoEgKD4v7Iz qCN3VYIhmU3wJVHlYnd7Wn849RP2fjfd4WkwsAWuRZvScxBLqLBmNYp+VMGa8+iFm+Dj 22HEBDO2Oa9ohRUgmPN+PPFIS65SycR6kfTXCgWMWi4II3yVOWT8il9GkVsVY/Ijl2xJ de8/JQ/TwaLQAIB3ti2AGkiNE8LurEXxBj4h49aNkIDldVmc8RxcgHmjSgeDhESVkj+t fxnA== X-Forwarded-Encrypted: i=1; AJvYcCWcRKchXCQ52gofPVIoWQDRxJRA58UaXvnlW8oDQxbThJ835VTkyPTCHmwF46+n3F+OY7f8VQNQN5VYcgM=@vger.kernel.org X-Gm-Message-State: AOJu0YzUYoczOMjgPMEegNPT4Ri4vmu8rMShLieNkzYkSRKrZ2JHY2z9 OsxBl4VX0Z+nE7MOyEBMB1y2qZ+fNloFxrSDURiG/62QJfRNfVPTWrxQAEszZsM149CNFgiypQD TP/iD6LVP+g== X-Google-Smtp-Source: AGHT+IGM2AoaSd3nDrndaQjFdiYhooI9Py/X2tre2/qsfMZIxxhQcfC3sDhJx0tB1eNWuUGf+Ey469hBnirw X-Received: from qkox14.prod.google.com ([2002:a05:620a:258e:b0:845:8e5b:c8a4]) (user=zecheng job=prod-delivery.src-stubby-dispatcher) by 2002:a05:620a:458c:b0:868:54ba:7c42 with SMTP id af79cd13be357-88352f83d61mr3042209185a.25.1760379383634; Mon, 13 Oct 2025 11:16:23 -0700 (PDT) Date: Mon, 13 Oct 2025 18:16:03 +0000 In-Reply-To: <20251013181607.2745653-1-zecheng@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251013181607.2745653-1-zecheng@google.com> X-Mailer: git-send-email 2.51.0.788.g6d19910ace-goog Message-ID: <20251013181607.2745653-7-zecheng@google.com> Subject: [PATCH v4 6/9] perf dwarf-aux: Skip check_variable for die_find_variable_by_reg From: Zecheng Li To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Masami Hiramatsu Cc: Xu Liu , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Zecheng Li Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" In die_find_variable_by_reg, match_var_offset already performs sufficient checking and type matching. The additional check_variable call is redundant, and its need_pointer logic is only a heuristic. Since DWARF encodes accurate type information, which match_var_offset verifies, skipping check_variable improves both coverage and accuracy. Return type from die_find_variable_by_reg via a new `type` field in find_var_data. Signed-off-by: Zecheng Li --- tools/perf/util/annotate-data.c | 8 +++++--- tools/perf/util/dwarf-aux.c | 18 +++++++++++------- tools/perf/util/dwarf-aux.h | 2 +- 3 files changed, 17 insertions(+), 11 deletions(-) diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-dat= a.c index e183c6104d59..4b08331b9dd3 100644 --- a/tools/perf/util/annotate-data.c +++ b/tools/perf/util/annotate-data.c @@ -1603,19 +1603,21 @@ static int find_data_type_die(struct data_loc_info = *dloc, Dwarf_Die *type_die) if (!die_find_variable_by_addr(&scopes[i], dloc->var_addr, &var_die, &type_offset)) continue; + /* Found a variable, see if it's correct */ + result =3D check_variable(dloc, &var_die, &mem_die, reg, + type_offset, is_fbreg); } else { /* Look up variables/parameters in this scope */ if (!die_find_variable_by_reg(&scopes[i], pc, reg, - &type_offset, is_fbreg, &var_die)) + &mem_die, &type_offset, is_fbreg, &var_die)) continue; + result =3D PERF_TMR_OK; } =20 pr_debug_dtp("found \"%s\" (die: %#lx) in scope=3D%d/%d (die: %#lx) ", dwarf_diename(&var_die), (long)dwarf_dieoffset(&var_die), i+1, nr_scopes, (long)dwarf_dieoffset(&scopes[i])); =20 - /* Found a variable, see if it's correct */ - result =3D check_variable(dloc, &var_die, &mem_die, reg, type_offset, is= _fbreg); if (result =3D=3D PERF_TMR_OK) { if (reg =3D=3D DWARF_REG_PC) { pr_debug_dtp("addr=3D%#"PRIx64" type_offset=3D%#x\n", diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index 9267af204c7d..b57cdc8860f0 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -1378,6 +1378,8 @@ struct find_var_data { Dwarf_Addr addr; /* Target register */ unsigned reg; + /* Access data type */ + Dwarf_Die type; /* Access offset, set for global data */ int offset; /* True if the current register is the frame base */ @@ -1390,7 +1392,6 @@ struct find_var_data { static bool match_var_offset(Dwarf_Die *die_mem, struct find_var_data *dat= a, s64 addr_offset, s64 addr_type, bool is_pointer) { - Dwarf_Die type_die; Dwarf_Word size; s64 offset =3D addr_offset - addr_type; =20 @@ -1403,16 +1404,16 @@ static bool match_var_offset(Dwarf_Die *die_mem, st= ruct find_var_data *data, if (offset < 0) return false; =20 - if (die_get_real_type(die_mem, &type_die) =3D=3D NULL) + if (die_get_real_type(die_mem, &data->type) =3D=3D NULL) return false; =20 - if (is_pointer && dwarf_tag(&type_die) =3D=3D DW_TAG_pointer_type) { + if (is_pointer && dwarf_tag(&data->type) =3D=3D DW_TAG_pointer_type) { /* Get the target type of the pointer */ - if (die_get_real_type(&type_die, &type_die) =3D=3D NULL) + if (die_get_real_type(&data->type, &data->type) =3D=3D NULL) return false; } =20 - if (dwarf_aggregate_size(&type_die, &size) < 0) + if (dwarf_aggregate_size(&data->type, &size) < 0) return false; =20 if ((u64)offset >=3D size) @@ -1529,7 +1530,7 @@ static int __die_find_var_reg_cb(Dwarf_Die *die_mem, = void *arg) * when the variable is in the stack. */ Dwarf_Die *die_find_variable_by_reg(Dwarf_Die *sc_die, Dwarf_Addr pc, int = reg, - int *poffset, bool is_fbreg, + Dwarf_Die *type_die, int *poffset, bool is_fbreg, Dwarf_Die *die_mem) { struct find_var_data data =3D { @@ -1541,8 +1542,11 @@ Dwarf_Die *die_find_variable_by_reg(Dwarf_Die *sc_di= e, Dwarf_Addr pc, int reg, Dwarf_Die *result; =20 result =3D die_find_child(sc_die, __die_find_var_reg_cb, &data, die_mem); - if (result) + if (result) { *poffset =3D data.offset; + *type_die =3D data.type; + } + return result; } =20 diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h index cd481ec9c5a1..b3ee5df0b6be 100644 --- a/tools/perf/util/dwarf-aux.h +++ b/tools/perf/util/dwarf-aux.h @@ -163,7 +163,7 @@ int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_= die, struct strbuf *buf); =20 /* Find a variable saved in the 'reg' at given address */ Dwarf_Die *die_find_variable_by_reg(Dwarf_Die *sc_die, Dwarf_Addr pc, int = reg, - int *poffset, bool is_fbreg, + Dwarf_Die *type_die, int *poffset, bool is_fbreg, Dwarf_Die *die_mem); =20 /* Find a (global) variable located in the 'addr' */ --=20 2.51.0.788.g6d19910ace-goog