From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1618A440A36; Fri, 25 Sep 2026 19:15:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790363720; cv=none; b=B1724cL7srk6Qkpm+8LYuX80xOf/N+lngw9DAYZ6ToNiXvgVranMtpZPjrkO49k4aAsBgu+kt4k4KCkkZ7RX7SoTLGacsyayArcHxdvpVtugU8TEsVfj70UfQXgnEFx1fc5VZqvd/g2pD549e2eUjQMoxL7rymbToI1arb7rYQ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790363720; c=relaxed/simple; bh=9LsdzWwl3/a+wzsFlcAhkgBaJ2b+qzo3D4JCV0XXuFs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=cW/u5LzMrez3OTT0gFMzUa+v04p/8juJ/PALyhszsbR+LtXL+4WLDCL1rseeTE59fxtgnkpfMROt+tsDhe6QRLlCVy+/qZoXJzTlr8CYkwdRFSrdUg43wIj62Z/EAkgMZcIWV7W4t2B8Rrtcw65o7RpMp5zG7Z9Bzua3iC4jSPk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=vHSkmA8C; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="vHSkmA8C" Received: by smtp.kernel.org (Postfix) with ESMTPS id 4A656C2BD01; Fri, 25 Sep 2026 19:15:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1790363718; bh=9LsdzWwl3/a+wzsFlcAhkgBaJ2b+qzo3D4JCV0XXuFs=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=vHSkmA8COseTcz6XXrHHdM2wFGbT/LvwDenLsse96VX7jbY+QF5s63j3pTHJelKBK XlCN7SW3HlamgHDafV7TOVoUMqFhkURWzvdj11BjKtu/lv0UTmz3x/0dDBoVqAAJE8 PD+iA9HSpENPVFkd1FEUBTYpgK1IcTAryJqG5yOSSk9CUTJ3H5MLNBzHidjgG/YvOI HGW+pEBXMjtQkLUmpv8608u7KJ74aOmb16L3ILMkS0eqdzB9Th6ClMRC32Ksk1gNXQ MUaMhqXZhQYAiAM+lewtLsJ4CGbenkGsNdkxcLSxw7c/3cNoTljDkltsUJ0hjR7Xkh EuvTSwc5o4lxw== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35229C98321; Fri, 25 Sep 2026 19:15:18 +0000 (UTC) From: Alireza Haghdoost via B4 Relay Date: Fri, 25 Sep 2026 12:09:40 -0700 Subject: [PATCH v3 3/6] perf symbols: Factor out duplicate symbol selection Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260925-perf-symbol-memory-send-v3-3-3e4e234c363b@uber.com> References: <20260925-perf-symbol-memory-send-v3-0-3e4e234c363b@uber.com> In-Reply-To: <20260925-perf-symbol-memory-send-v3-0-3e4e234c363b@uber.com> To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , Alexei Starovoitov , Andrii Nakryiko Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Alireza Haghdoost X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=5397; i=haghdoost@uber.com; h=from:subject:message-id; bh=RhZqrA5L9MptonumK5bU5HqWIUrFBxToq4a957HwMGo=; b=owEBiQJ2/ZANAwAIAVNlBDxl2ALYAcsmYgBqtshDbfNVHXNFON9XlaHuQGbwDn7SsagfbWdrF YURuOFArg2JAk8EAAEIADkWIQS5+sFL3gX/8PrA0S1TZQQ8ZdgC2AUCarbIQxsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMiwwLDMACgkQU2UEPGXYAthLyQ//TkrGnCAD/OQdC1XnTDY23gvYbpdVT/8 ODpF1b7EnqPm1i0UfCbGp/R9i4nag4OXBAmCPBCzrS9Xvmw/GKGXaUopJrsGKPo426zOFJutwTv tvF2qt6mfDkvhuLzuSXvp+tnScOJN9ma1MwfSwhuVrkGavcmBvOoECVfgXF+KWAK0+y/qINECDl IUvK36z16FGmXnUqJQCI6Aeuz7pvdm3TwRDcIz+cJRpV9wW49hETduP31BZTxwTSDwHIjsCjNdv OEblnu6QqUm0YdyAOKmNK3QhgF48ro9uvzcyeZvIOMxwGBWWwogaNFSP2UzY8F3lVmsMfVEBouV MK3iZOBgK49hcaTRQ04AtnZE7akMqoGdmVOdllsH7TognRcF8zmqo9nk69+le4Nbc4S9YK8RoHh pGPaD3LbQTyGSSnU6Wr5vo53nihI2+PiqVzYJ8Ohc/G8QSOP9Gqe0kM5J/al9y4Dg7/wzWsZIt7 +E3/6rlUiiTUPrbTXH9XSbE40AJIs27Z3+FjKIKdC/BhMXbLYS6GZarXEkQoick/IVwyph+CnnX +D7oL6vgymZmYu0Zm5YIzKim9GDDoGAYZjd06N88xDnJmbJcb/pLqiugiVTj6T3NFLdWge6eyQ3 becBBVO841paqc0K22ddFrkoY99zeOCQHGupfcQ5aUxB8D8HDFGI= X-Developer-Key: i=haghdoost@uber.com; a=openpgp; fpr=B9FAC14BDE05FFF0FAC0D12D5365043C65D802D8 X-Endpoint-Received: by B4 Relay for haghdoost@uber.com/default with auth_id=764 X-Original-From: Alireza Haghdoost Reply-To: haghdoost@uber.com From: Alireza Haghdoost symbols__fixup_duplicate() chooses between symbols with the same start address through choose_best_symbol(), which needs fully constructed struct symbol objects. A loader that selects among aliases before allocating symbols cannot use it. Move the policy into symbol__choose_best(), which compares the size, name, type and binding of two candidates described by struct symbol_candidate, and pass the same description to the arch__choose_best_symbol() hook. choose_best_symbol() becomes a wrapper that describes two struct symbols. No functional change intended. Signed-off-by: Alireza Haghdoost --- tools/perf/arch/powerpc/util/sym-handling.c | 6 ++-- tools/perf/util/symbol.c | 43 +++++++++++++++++++++-------- tools/perf/util/symbol.h | 14 +++++++++- 3 files changed, 47 insertions(+), 16 deletions(-) diff --git a/tools/perf/arch/powerpc/util/sym-handling.c b/tools/perf/arch/powerpc/util/sym-handling.c index 947bfad7aa59..c263cbfefba5 100644 --- a/tools/perf/arch/powerpc/util/sym-handling.c +++ b/tools/perf/arch/powerpc/util/sym-handling.c @@ -10,10 +10,10 @@ #include "probe-event.h" #include "probe-file.h" -int arch__choose_best_symbol(struct symbol *syma, - struct symbol *symb __maybe_unused) +int arch__choose_best_symbol(const struct symbol_candidate *syma, + const struct symbol_candidate *symb __maybe_unused) { - char *sym = syma->name; + const char *sym = syma->name; #if !defined(_CALL_ELF) || _CALL_ELF != 2 /* Skip over any initial dot */ diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 163652f071c6..4b50250d07fa 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -145,8 +145,8 @@ int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb, return strncmp(namea, nameb, n); } -int __weak arch__choose_best_symbol(struct symbol *syma, - struct symbol *symb __maybe_unused) +int __weak arch__choose_best_symbol(const struct symbol_candidate *syma, + const struct symbol_candidate *symb __maybe_unused) { /* Avoid "SyS" kernel syscall aliases */ if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3)) @@ -157,38 +157,39 @@ int __weak arch__choose_best_symbol(struct symbol *syma, return SYMBOL_A; } -static int choose_best_symbol(struct symbol *syma, struct symbol *symb) +int symbol__choose_best(const struct symbol_candidate *syma, + const struct symbol_candidate *symb) { s64 a; s64 b; size_t na, nb; /* Prefer a symbol with non zero length */ - a = syma->end - syma->start; - b = symb->end - symb->start; + a = syma->size; + b = symb->size; if ((b == 0) && (a > 0)) return SYMBOL_A; else if ((a == 0) && (b > 0)) return SYMBOL_B; - if (symbol__type(syma) != symbol__type(symb)) { - if (symbol__type(syma) == STT_NOTYPE) + if (syma->type != symb->type) { + if (syma->type == STT_NOTYPE) return SYMBOL_B; - if (symbol__type(symb) == STT_NOTYPE) + if (symb->type == STT_NOTYPE) return SYMBOL_A; } /* Prefer a non weak symbol over a weak one */ - a = symbol__binding(syma) == STB_WEAK; - b = symbol__binding(symb) == STB_WEAK; + a = syma->binding == STB_WEAK; + b = symb->binding == STB_WEAK; if (b && !a) return SYMBOL_A; if (a && !b) return SYMBOL_B; /* Prefer a global symbol over a non global one */ - a = symbol__binding(syma) == STB_GLOBAL; - b = symbol__binding(symb) == STB_GLOBAL; + a = syma->binding == STB_GLOBAL; + b = symb->binding == STB_GLOBAL; if (a && !b) return SYMBOL_A; if (b && !a) @@ -213,6 +214,24 @@ static int choose_best_symbol(struct symbol *syma, struct symbol *symb) return arch__choose_best_symbol(syma, symb); } +static int choose_best_symbol(struct symbol *syma, struct symbol *symb) +{ + struct symbol_candidate a = { + .size = syma->end - syma->start, + .name = syma->name, + .type = symbol__type(syma), + .binding = symbol__binding(syma), + }; + struct symbol_candidate b = { + .size = symb->end - symb->start, + .name = symb->name, + .type = symbol__type(symb), + .binding = symbol__binding(symb), + }; + + return symbol__choose_best(&a, &b); +} + void symbols__fixup_duplicate(struct rb_root_cached *symbols) { struct rb_node *nd; diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h index 46b1649c64fc..b9fa722a9a14 100644 --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -299,10 +299,22 @@ const char *arch__normalize_symbol_name(const char *name); #define SYMBOL_A 0 #define SYMBOL_B 1 +/* Attributes used to choose between symbols that share a start address. */ +struct symbol_candidate { + u64 size; + const char *name; + u8 type; + u8 binding; +}; + +int symbol__choose_best(const struct symbol_candidate *a, + const struct symbol_candidate *b); + int arch__compare_symbol_names(const char *namea, const char *nameb); int arch__compare_symbol_names_n(const char *namea, const char *nameb, unsigned int n); -int arch__choose_best_symbol(struct symbol *syma, struct symbol *symb); +int arch__choose_best_symbol(const struct symbol_candidate *a, + const struct symbol_candidate *b); enum symbol_tag_include { SYMBOL_TAG_INCLUDE__NONE = 0, -- Git-157)