From nobody Thu Apr 2 18:46:09 2026 Received: from mail-dy1-f202.google.com (mail-dy1-f202.google.com [74.125.82.202]) (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 BCA2636C0BC for ; Fri, 27 Mar 2026 04:50:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774587040; cv=none; b=uPZvwBITIjxfilDjElBjY0Qh2qJeu3k0gIbF8bDwXMJ7CGXomaCnvMnsuCmrC5fVleuL3e0gGsXNoqCy1OtE1k2i/HbPdV9HB9l89sEqcMN9MvubT5Osd1ot61++vGXu+OGfEZrNN2BFseOXctBYTzXYHilBETOUfzcLb6nlshg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774587040; c=relaxed/simple; bh=uxlEApcoFt3zoagTt4W9dkYrIKl7vQczKfyJY/2/YdM=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=n3RC6TLZNxKck3wu7HwfKPCp9buE2V/XeIwyxJByO84JhwqaHxIVCvZx3AeVCbYK6vubBOcsvhW5dMHA9CPggpxoUpd1A3+8MwguF5BLP2Zqnls7JoLyDwjFqk19wLiMan9NMiLMjwc4lu5n4cGrfAa/bctXrqt6rAWrlRoHLmY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=CyhCju7M; arc=none smtp.client-ip=74.125.82.202 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--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="CyhCju7M" Received: by mail-dy1-f202.google.com with SMTP id 5a478bee46e88-2c0bddb9196so1136674eec.1 for ; Thu, 26 Mar 2026 21:50:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1774587038; x=1775191838; 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=IGyUKvzRwcUnG4/Npnp/POwUnKzsH4cjggqTcUHOoLQ=; b=CyhCju7MVvxPRxfRlEF54EmYfqbqoUAQk7n+CtBSEkJhvoFLnRbZMomoEmnQQaFDOp piCo2nTURkP70CNxWmPUY+1DnNloqhTQqNSEnXE3EvNwsaJTc2oBdk7aw7//KclSMCXt IR7iF60jmF3KfIyQP/1k6NEjnbFgOJyuw8fVIFZQCz4gvV6O9Rn3FdOrA/CEvUGwp3o+ 2wDoGKJI8K3uhmYpHkcms9bvqsoCMrvJ9y8cc92LZVzvYvlPhcly9Ybo0ChssnVlo8yw VDnymFzdclq0CprvEjQjjS7RyoScsJBsWaQkpMYRt+9Apl4DtkKGgZqOq+ndgyFUuyk+ o6tQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774587038; x=1775191838; 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=IGyUKvzRwcUnG4/Npnp/POwUnKzsH4cjggqTcUHOoLQ=; b=NolsdqUhwOZcDRGm4XXKVzqBVUX5vJx2WzcGj1xhygrDaG4YvAFEET1dT6EfARNKhK zchP7qknAWM3c1PFmYS7LHrcwGDhoiENTAk8BtJQPIN3/aL+3E91axAVmnp9D9aOGI74 hoCl5rVl6PmnxU+EflAXTk+nvLNtY9EJTFcduhMVEIT6Q33cBu7JFtwf2zNeyypCRRCg l+s03zaiPaZZevQhpDYZcwOpLJVcu0twywqRkUmlwctjNvvCll1WGTDMi9SGH22giKfb Rx3772TCN4i7zn8rrbvDbTiAc69MlEV1ceL0davWVvz/zOMbp+Fn0zNDL6ydmnQIvcBc JNAw== X-Forwarded-Encrypted: i=1; AJvYcCU7LUk6YARCuTlxoLKGLDCVYiS3J7U1r+fO3E+7/aa/40FdrGfcFVhzTtBiVH8G9OIslRXeSXvfiXjl3Ps=@vger.kernel.org X-Gm-Message-State: AOJu0YxrGThc59eHvxOIXi5zsadLXm8QLJmm9q/0Ikk9AJ4Q+DBTJgyY Cu3h4moaB7MmONhJClX0Dwcwk9XQYVNlXYPq9mARNU6bz/hp+qu09Lk9gheUx9Y5/s6ezQgrPRa p6S8bOZfkLw== X-Received: from dybsi15.prod.google.com ([2002:a05:7301:488f:b0:2c1:e58:5b95]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7301:129b:b0:2c0:be45:6811 with SMTP id 5a478bee46e88-2c185f9710emr544942eec.32.1774587037692; Thu, 26 Mar 2026 21:50:37 -0700 (PDT) Date: Thu, 26 Mar 2026 21:50:24 -0700 In-Reply-To: <20260327045025.2276517-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260326174521.1829203-1-irogers@google.com> <20260327045025.2276517-1-irogers@google.com> X-Mailer: git-send-email 2.53.0.1018.g2bb0e51243-goog Message-ID: <20260327045025.2276517-2-irogers@google.com> Subject: [PATCH v4 1/2] perf env: Add perf_env__e_machine helper and use in perf_env__arch From: Ian Rogers To: acme@kernel.org, namhyung@kernel.org, tmricht@linux.ibm.com Cc: irogers@google.com, agordeev@linux.ibm.com, gor@linux.ibm.com, hca@linux.ibm.com, jameshongleiwang@126.com, japo@linux.ibm.com, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-s390@vger.kernel.org, sumanthk@linux.ibm.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a helper that lazily computes the e_machine and falls back of EM_HOST. Use the perf_env's arch to compute the e_machine if available. Use a binary search for some efficiency in this, but handle somewhat complex duplicate rules. Switch perf_env__arch to be derived the e_machine for consistency. This switches arch from being uname derived to matching that of the perf binary (via EM_HOST). Update session to use the helper, which may mean using EM_HOST when no threads are available. This also updates the perf data file header that gets the e_machine/e_flags from the session. Signed-off-by: Ian Rogers --- tools/perf/util/env.c | 185 ++++++++++++++++++++++++++++++-------- tools/perf/util/env.h | 1 + tools/perf/util/session.c | 14 +-- 3 files changed, 157 insertions(+), 43 deletions(-) diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c index 93d475a80f14..ae08178870d7 100644 --- a/tools/perf/util/env.c +++ b/tools/perf/util/env.c @@ -1,10 +1,12 @@ // SPDX-License-Identifier: GPL-2.0 #include "cpumap.h" +#include "dwarf-regs.h" #include "debug.h" #include "env.h" #include "util/header.h" #include "util/rwsem.h" #include +#include #include #include #include @@ -588,51 +590,160 @@ void cpu_cache_level__free(struct cpu_cache_level *c= ache) zfree(&cache->size); } =20 +struct arch_to_e_machine { + const char *prefix; + uint16_t e_machine; +}; + /* - * Return architecture name in a normalized form. - * The conversion logic comes from the Makefile. + * A mapping from an arch prefix string to an ELF machine that can be used= in a + * bsearch. Some arch prefixes are shared an need additional processing as + * marked next to the architecture. The prefixes handle both perf's archit= ecture + * naming and those from uname. */ -static const char *normalize_arch(char *arch) -{ - if (!strcmp(arch, "x86_64")) - return "x86"; - if (arch[0] =3D=3D 'i' && arch[2] =3D=3D '8' && arch[3] =3D=3D '6') - return "x86"; - if (!strcmp(arch, "sun4u") || !strncmp(arch, "sparc", 5)) - return "sparc"; - if (!strncmp(arch, "aarch64", 7) || !strncmp(arch, "arm64", 5)) - return "arm64"; - if (!strncmp(arch, "arm", 3) || !strcmp(arch, "sa110")) - return "arm"; - if (!strncmp(arch, "s390", 4)) - return "s390"; - if (!strncmp(arch, "parisc", 6)) - return "parisc"; - if (!strncmp(arch, "powerpc", 7) || !strncmp(arch, "ppc", 3)) - return "powerpc"; - if (!strncmp(arch, "mips", 4)) - return "mips"; - if (!strncmp(arch, "sh", 2) && isdigit(arch[2])) - return "sh"; - if (!strncmp(arch, "loongarch", 9)) - return "loongarch"; - - return arch; +static const struct arch_to_e_machine prefix_to_e_machine[] =3D { + {"aarch64", EM_AARCH64}, + {"alpha", EM_ALPHA}, + {"arc", EM_ARC}, + {"arm", EM_ARM}, /* Check also for EM_AARCH64. */ + {"avr", EM_AVR}, /* Check also for EM_AVR32. */ + {"bfin", EM_BLACKFIN}, + {"blackfin", EM_BLACKFIN}, + {"cris", EM_CRIS}, + {"csky", EM_CSKY}, + {"hppa", EM_PARISC}, + {"i386", EM_386}, + {"i486", EM_386}, + {"i586", EM_386}, + {"i686", EM_386}, + {"loongarch", EM_LOONGARCH}, + {"m32r", EM_M32R}, + {"m68k", EM_68K}, + {"microblaze", EM_MICROBLAZE}, + {"mips", EM_MIPS}, + {"msp430", EM_MSP430}, + {"parisc", EM_PARISC}, + {"powerpc", EM_PPC}, /* Check also for EM_PPC64. */ + {"ppc", EM_PPC}, /* Check also for EM_PPC64. */ + {"riscv", EM_RISCV}, + {"s390", EM_S390}, + {"sa110", EM_ARM}, + {"sh", EM_SH}, + {"sparc", EM_SPARC}, /* Check also for EM_SPARCV9. */ + {"sun4u", EM_SPARC}, + {"x86", EM_X86_64}, /* Check also for EM_386. */ + {"xtensa", EM_XTENSA}, +}; + +static int compare_prefix(const void *key, const void *element) +{ + const char *search_key =3D key; + const struct arch_to_e_machine *map_element =3D element; + size_t prefix_len =3D strlen(map_element->prefix); + + return strncmp(search_key, map_element->prefix, prefix_len); +} + +static uint16_t perf_arch_to_e_machine(const char *perf_arch, bool is_64_b= it) +{ + /* Binary search for a matching prefix. */ + const struct arch_to_e_machine *result; + + if (!perf_arch) + return EM_HOST; + + result =3D bsearch(perf_arch, + prefix_to_e_machine, ARRAY_SIZE(prefix_to_e_machine), + sizeof(prefix_to_e_machine[0]), + compare_prefix); + + if (!result) { + pr_debug("Unknown perf arch for ELF machine mapping: %s\n", perf_arch); + return EM_NONE; + } + + /* Handle conflicting prefixes. */ + switch (result->e_machine) { + case EM_ARM: + return !strcmp(perf_arch, "arm64") ? EM_AARCH64 : EM_ARM; + case EM_AVR: + return !strcmp(perf_arch, "avr32") ? EM_AVR32 : EM_AVR; + case EM_PPC: + return is_64_bit || strstarts(perf_arch, "ppc64") ? EM_PPC64 : EM_PPC; + case EM_SPARC: + return is_64_bit || !strcmp(perf_arch, "sparc64") ? EM_SPARCV9 : EM_SPAR= C; + case EM_X86_64: + return is_64_bit || !strcmp(perf_arch, "x86_64") ? EM_X86_64 : EM_386; + default: + return result->e_machine; + } +} + +static const char *e_machine_to_perf_arch(uint16_t e_machine) +{ + /* + * Table for if either the perf arch string differs from uname or there + * are >1 ELF machine with the prefix. + */ + static const struct arch_to_e_machine extras[] =3D { + {"arm64", EM_AARCH64}, + {"avr32", EM_AVR32}, + {"powerpc", EM_PPC}, + {"powerpc", EM_PPC64}, + {"sparc", EM_SPARCV9}, + {"x86", EM_386}, + {"x86", EM_X86_64}, + {"none", EM_NONE}, + }; + + for (size_t i =3D 0; i < ARRAY_SIZE(extras); i++) { + if (extras[i].e_machine =3D=3D e_machine) + return extras[i].prefix; + } + + for (size_t i =3D 0; i < ARRAY_SIZE(prefix_to_e_machine); i++) { + if (prefix_to_e_machine[i].e_machine =3D=3D e_machine) + return prefix_to_e_machine[i].prefix; + + } + return "unknown"; +} + +uint16_t perf_env__e_machine(struct perf_env *env, uint32_t *e_flags) +{ + if (!env) { + if (e_flags) + *e_flags =3D EF_HOST; + + return EM_HOST; + } + if (env->e_machine =3D=3D EM_NONE) { + env->e_machine =3D perf_arch_to_e_machine(env->arch, env->kernel_is_64_b= it); + + if (env->e_machine =3D=3D EM_HOST) + env->e_flags =3D EF_HOST; + } + if (e_flags) + *e_flags =3D env->e_flags; + + return env->e_machine; } =20 const char *perf_env__arch(struct perf_env *env) { - char *arch_name; + if (!env) + return e_machine_to_perf_arch(EM_HOST); =20 - if (!env || !env->arch) { /* Assume local operation */ - static struct utsname uts =3D { .machine[0] =3D '\0', }; - if (uts.machine[0] =3D=3D '\0' && uname(&uts) < 0) - return NULL; - arch_name =3D uts.machine; - } else - arch_name =3D env->arch; + if (!env->arch) { + /* + * Lazily compute/allocate arch. The e_machine may have been + * read from a data file and so may not be EM_HOST. + */ + uint16_t e_machine =3D perf_env__e_machine(env, /*e_flags=3D*/NULL); =20 - return normalize_arch(arch_name); + env->arch =3D strdup(e_machine_to_perf_arch(e_machine)); + } + return env->arch; } =20 #if defined(HAVE_LIBTRACEEVENT) diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h index a4501cbca375..91ff252712f4 100644 --- a/tools/perf/util/env.h +++ b/tools/perf/util/env.h @@ -186,6 +186,7 @@ int perf_env__read_cpu_topology_map(struct perf_env *en= v); =20 void cpu_cache_level__free(struct cpu_cache_level *cache); =20 +uint16_t perf_env__e_machine(struct perf_env *env, uint32_t *e_flags); const char *perf_env__arch(struct perf_env *env); const char *perf_env__arch_strerrno(struct perf_env *env, int err); const char *perf_env__cpuid(struct perf_env *env); diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 4b465abfa36c..dcc9bef303aa 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -2996,14 +2996,16 @@ uint16_t perf_session__e_machine(struct perf_sessio= n *session, uint32_t *e_flags return EM_HOST; } =20 + /* Is the env caching an e_machine? */ env =3D perf_session__env(session); - if (env && env->e_machine !=3D EM_NONE) { - if (e_flags) - *e_flags =3D env->e_flags; - - return env->e_machine; - } + if (env && env->e_machine !=3D EM_NONE) + return perf_env__e_machine(env, e_flags); =20 + /* + * Compute from threads, note this is more accurate than + * perf_env__e_machine that falls back on EM_HOST and doesn't consider + * mixed 32-bit and 64-bit threads. + */ machines__for_each_thread(&session->machines, perf_session__e_machine_cb, &args); --=20 2.53.0.1018.g2bb0e51243-goog