From nobody Thu Oct 2 11:58:08 2025 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (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 E39842F5A24 for ; Wed, 17 Sep 2025 19:58:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758139101; cv=none; b=nBHZx6NFcrYVLiuDxKxAzrbgKDdnxveendi7o/33C14nRme5iQDsH3dNcuOvr3lF6FHjM01IQ39BTj8gXOLUGp99lApkyX9t8A8m7IuJWWEH6/gGy5TcByEfq/I1POBh2kbEzw8/J2MdsHXllSdMutNP/HS40SPuZ44rVAuDRkk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758139101; c=relaxed/simple; bh=fB/6i1qanI6SJs8QAzxHrArcw2uiQzagwE/LnBHWUVc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=r6t353qcg5Pj4YxQE4yai67NjWJbCvdKsDDSyv0F1DhRPc+ROruvwwHILIe2adfok4uyuYYRUnmJ1QIkY0j40l19Of0zigoOKokMcXuRLwIxddyuOqhj7nnRZCjVEkZdUHGguFBP8ttUg6ivQosLuJDoZnkWFhkAvFNJqeBRJYs= 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=foHAGZAb; arc=none smtp.client-ip=209.85.219.201 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="foHAGZAb" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-e94dfb23622so311313276.3 for ; Wed, 17 Sep 2025 12:58:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1758139099; x=1758743899; 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=T4aZ86fc6szpTU0Yd+pCMzTGqFuiPjIauERb4YlvtW0=; b=foHAGZAbvdXHuRjqYhY+kDfrJdj9PvmEaopotQ8J7innL0lBwwNIt/BIOwmNV6OJqj G3uLkwjheHc/pNeXk29NEjCubXv8XtXc93E+5gEFNvgYT5VqSZL3ezMptOXRtUwFWM3n 7I1SNemcoaxHZhxkNAnvpTua2uBCi8wFRGURxctrAvIinkccP15aP2N5Sp2nDbgX/BHP K56CHewbvyvRfGwPl9C2ZgaVB42e2yFnWE4ftqMpnAN2RW2MTu3SrnS9d0wGFlwM+8Z8 UloFFUZ7+x1s1jllP+h3iJKLw8axbpg9cgdnSE8+bAKwia7zqdTnO1XziCDKBc95WaOO 8vvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758139099; x=1758743899; 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=T4aZ86fc6szpTU0Yd+pCMzTGqFuiPjIauERb4YlvtW0=; b=lmbBzk5itDAvQ6fDG4Mj1dZe9XA75HEqWytbsA5iCAYs7VF9t6n896W8y9ct1OCdBZ 6CgNUaByJQ5lYyVCLCDG3icncnXtO4TSXkgntWljRY8eI2WZaTM7q0qwOMZYKjUlPkvr oRKNkWAaYwefNbaJWkLmDDh227VxrAW6FWo7QJ3jHY20g5Oq6X66hwy7VsNWlevTMb5D v5bFF1ElgGyf/I2H7RF5nx1eXdd6laRhMSLpPlcJlUOS++FXJrKuFHbYu/IMblosAtT/ t9Sv7NMAjqYxayo4Z7waO6lJd+BWpe0WgIJY77bHJJNNodU7l/RWJ8a+1mdG9ZiHQz0d ufNw== X-Forwarded-Encrypted: i=1; AJvYcCXNoCHSXUWSYpGXtLimNVgk275texpHIGYYakRs/JeoyNDvbKpYXUYnWfRmr6l8PVnHWuwXSjl6iQqXOD4=@vger.kernel.org X-Gm-Message-State: AOJu0Yy4xdXfByEwA4XknEToBobLgeis6WzdN9gJ4oHQ4qF69rpy93F/ Jv4SYCglgwm+duTyrOSQPd5ihxEV2QmAg/Di/zQed1lbpEkCJZR7cu/S9WWqZAjea5Fg2l5reC4 MDp4nfwvnFQ== X-Google-Smtp-Source: AGHT+IFbRYoLbefNIf9LIPamUpqMmx0NkDKL+ovOKnmXT2DhvKlRz6nOoq9G+z1EqrxiE2xu8RBFvItx5bky X-Received: from ybey13.prod.google.com ([2002:a25:dc0d:0:b0:ea5:cbb5:9bb9]) (user=zecheng job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6902:1884:b0:ea5:ce42:68c0 with SMTP id 3f1490d57ef6-ea5ce427a12mr812601276.42.1758139098955; Wed, 17 Sep 2025 12:58:18 -0700 (PDT) Date: Wed, 17 Sep 2025 19:58:05 +0000 In-Reply-To: <20250917195808.2514277-1-zecheng@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250917195808.2514277-1-zecheng@google.com> X-Mailer: git-send-email 2.51.0.384.g4c02a37b29-goog Message-ID: <20250917195808.2514277-8-zecheng@google.com> Subject: [PATCH v3 07/10] 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 , "Liang, Kan" , 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 68c69d343bff..7e4c045d0f4d 100644 --- a/tools/perf/util/annotate-data.c +++ b/tools/perf/util/annotate-data.c @@ -1596,19 +1596,21 @@ 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 2.51.0.384.g4c02a37b29-goog