From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl1-f73.google.com (mail-dl1-f73.google.com [74.125.82.73]) (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 D971D40759B for ; Fri, 1 May 2026 18:20:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777659631; cv=none; b=Ocr+fSAhCA/1KAwrCS6ZoSsY/cwiYQOVhvISOHBiOrgQ7XFTUfLelGVkx5nmu8ljbZbz7aK0dXpxE6XLBU1CHB1slfqWMoe/8Ig383bo47aHtFmeGIL4gWqiEnKskjaq/nZhrfIVO0Hi8JmEcwu73VAvzkfJQ0N9ueoeneBN1uw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777659631; c=relaxed/simple; bh=5kvUlmCfHm3OIANXNzvUbizuHSm5xhdWMCwQeAJu2yc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=qkT6A+cXPMHDRA9UKlB3Msu8pjwfFW0uxrXGCLAO9FGRQ3hvFeP6SC8qfwUDCb/H9pMJmdal98ddyC+UqRK1p/uIjDbnsJNCL52SiGsiw0nwnU7evM2Fm/NVPHF1EX50tBzqhjTDjZDBUnK2L6Q29Crv0piFfUI6gZiCRvD5H8U= 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=gj2oU3kE; arc=none smtp.client-ip=74.125.82.73 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="gj2oU3kE" Received: by mail-dl1-f73.google.com with SMTP id a92af1059eb24-12c21dbc9c1so67804c88.0 for ; Fri, 01 May 2026 11:20:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777659629; x=1778264429; 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=1E3XrgoGg8Gn6qjWpXRZdhkqAyFGP/uBkNcWZfisKxs=; b=gj2oU3kE/cwLDUHDS88MW1VZ07lNA0DbNceCgxIpHXw2djmGCfj4hF2xBbMUO7d2Ol aAkTU4gkU2TZO1u8Tfyg1nsVhMjuzoQ+/0VUjdjlplYhExM1/CsH60uJu1Yn9vkQiVQf 3LrCPEMJ2nwaEjuqomfwu8qA7/YoYtVVLQrAqB+NhPymCsiMQ4SkddWArZh4262jCQfi YMrGrdVcFieAO3unCDS16DJBTOMxtNQMRVhSEH59z9rtOxtoj6UabxDUR1YXWY/DDTsH +eoqcNHWfhtHXgcRrJnSN5/SlJIdtIpZjAH2pQyyXMh0/RS69DTok8a2gBDVJGsO+O5O SCGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777659629; x=1778264429; 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=1E3XrgoGg8Gn6qjWpXRZdhkqAyFGP/uBkNcWZfisKxs=; b=A6EyFJCkJb417nv61D4oVS0EeFQI4v6TUeAw68jgCYwM5cIE0YC2LtwcNfdExWIWH9 inrMuH0CCXkIW/lAkTKtS/KmXkbqjcqtnPA6p8D/YdSpoYsvKxdSVbHP9Th3aj06biis 9nLsfdJeVCJsF0uW4t4KZSqQDS2fFZXYM7GsFianFvdJgpL7Wc+mqBGgQuNFece8HcRL bXWNI4BnTO8x0jMjdldLZ7Jyp170SkgOAPkkcckrvkPgctrcE+fKOGIys7MhNEyCRkYX m+WVztBIYpVuHZVgZHIeqMkAmxaGfukW/+oQEd/iaOiLWju37wcBnb3j9NQXYc61++WR 6TcA== X-Forwarded-Encrypted: i=1; AFNElJ9FCz1JLf9wURbXlo7SvrP4eofYHZq26ZqNEW+IaTJh7V6DCgvc7xuDlEm5xzeHPy11/V849Z9WhKIK@vger.kernel.org X-Gm-Message-State: AOJu0YwllZfS2xWmas1b6SyX3nI8xAW/VPsNjQq+SEGbnAR5FvzC6jeQ 5K50RivurTRvLukzlxBtrAG9RkczTnXZihwqKiA5cwUvE6FSQZRD3KY6dMbjq6suajxC4+hJcZf cEoI9FDEhDw== X-Received: from dlag5.prod.google.com ([2002:a05:701b:2505:b0:12d:dbf8:a2a8]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:f9c:b0:12d:de3f:d843 with SMTP id a92af1059eb24-12dfd876063mr161957c88.38.1777659628823; Fri, 01 May 2026 11:20:28 -0700 (PDT) Date: Fri, 1 May 2026 11:20:18 -0700 In-Reply-To: <20260501182021.3651851-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260409230620.4176210-2-irogers@google.com> <20260501182021.3651851-1-irogers@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260501182021.3651851-2-irogers@google.com> Subject: [PATCH v7 1/4] perf env: Add perf_env__e_machine helper and use in perf_env__arch From: Ian Rogers To: irogers@google.com, acme@kernel.org, namhyung@kernel.org, tmricht@linux.ibm.com Cc: 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-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 | 197 +++++++++++++++++++++++++++++++------- tools/perf/util/env.h | 1 + tools/perf/util/header.c | 47 +++++++-- tools/perf/util/session.c | 25 ++--- 4 files changed, 212 insertions(+), 58 deletions(-) diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c index 1e54e2c86360..1671769d4441 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 +590,172 @@ void cpu_cache_level__free(struct cpu_cache_level *cache) zfree(&cache->size); } +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 architecture + * naming and those from uname. */ -static const char *normalize_arch(char *arch) -{ - if (!strcmp(arch, "x86_64")) - return "x86"; - if (arch[0] == 'i' && arch[2] == '8' && arch[3] == '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[] = { + {"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 = key; + const struct arch_to_e_machine *map_element = element; + size_t prefix_len = 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, int is_64_bit) +{ + /* Binary search for a matching prefix. */ + const struct arch_to_e_machine *result; + + if (!perf_arch) + return EM_HOST; + + result = 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. If the is_64_bit is unknown (-1) then + * assume 64-bit. We can't use perf_env__kernel_is_64_bit as that + * depends on the arch string. + */ + 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 != 0) || strstarts(perf_arch, "ppc64") ? EM_PPC64 : EM_PPC; + case EM_SPARC: + return (is_64_bit != 0) || !strcmp(perf_arch, "sparc64") ? EM_SPARCV9 : EM_SPARC; + case EM_X86_64: + return (is_64_bit != 0) || !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[] = { + {"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 = 0; i < ARRAY_SIZE(extras); i++) { + if (extras[i].e_machine == e_machine) + return extras[i].prefix; + } + + for (size_t i = 0; i < ARRAY_SIZE(prefix_to_e_machine); i++) { + if (prefix_to_e_machine[i].e_machine == 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 = EF_HOST; + + return EM_HOST; + } + if (env->e_machine == EM_NONE) { + env->e_machine = perf_arch_to_e_machine(env->arch, env->kernel_is_64_bit); + + if (env->e_machine == EM_HOST) + env->e_flags = EF_HOST; + } + if (e_flags) + *e_flags = env->e_flags; + + return env->e_machine; } const char *perf_env__arch(struct perf_env *env) { - char *arch_name; + uint16_t e_machine; + const char *arch; - if (!env || !env->arch) { /* Assume local operation */ - static struct utsname uts = { .machine[0] = '\0', }; - if (uts.machine[0] == '\0' && uname(&uts) < 0) - return NULL; - arch_name = uts.machine; - } else - arch_name = env->arch; + if (!env) + return e_machine_to_perf_arch(EM_HOST); + + if (env->arch) + return env->arch; - return normalize_arch(arch_name); + /* + * Lazily compute/allocate arch. The e_machine may have been + * read from a data file and so may not be EM_HOST. + */ + e_machine = perf_env__e_machine(env, /*e_flags=*/NULL); + arch = e_machine_to_perf_arch(e_machine); + env->arch = strdup(arch); + /* + * Avoid potential crashes on the arch string if memory allocation in + * strdup fails and NULL were to be returned. + */ + return env->arch ?: arch; } #if defined(HAVE_LIBTRACEEVENT) diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h index c7052ac1f856..d36a0fb2cd04 100644 --- a/tools/perf/util/env.h +++ b/tools/perf/util/env.h @@ -187,6 +187,7 @@ int perf_env__read_cpu_topology_map(struct perf_env *env); void cpu_cache_level__free(struct cpu_cache_level *cache); +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/header.c b/tools/perf/util/header.c index f30e48eb3fc3..8d5152bde25d 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -379,21 +379,28 @@ static int write_osrelease(struct feat_fd *ff, return do_write_string(ff, uts.release); } -static int write_arch(struct feat_fd *ff, - struct evlist *evlist __maybe_unused) +static int write_arch(struct feat_fd *ff, struct evlist *evlist) { struct utsname uts; - int ret; + const char *arch = NULL; - ret = uname(&uts); - if (ret < 0) - return -1; + if (evlist->session) { + /* Force the computation in the perf_env of the e_machine of the threads. */ + perf_session__e_machine(evlist->session, /*e_flags=*/NULL); + arch = perf_env__arch(perf_session__env(evlist->session)); + } + + if (!arch) { + int ret = uname(&uts); - return do_write_string(ff, uts.machine); + if (ret < 0) + return -1; + arch = uts.machine; + } + return do_write_string(ff, arch); } -static int write_e_machine(struct feat_fd *ff, - struct evlist *evlist __maybe_unused) +static int write_e_machine(struct feat_fd *ff, struct evlist *evlist) { /* e_machine expanded from 16 to 32-bits for alignment. */ uint32_t e_flags; @@ -2684,10 +2691,30 @@ static int process_##__feat(struct feat_fd *ff, void *data __maybe_unused) \ FEAT_PROCESS_STR_FUN(hostname, hostname); FEAT_PROCESS_STR_FUN(osrelease, os_release); FEAT_PROCESS_STR_FUN(version, version); -FEAT_PROCESS_STR_FUN(arch, arch); FEAT_PROCESS_STR_FUN(cpudesc, cpu_desc); FEAT_PROCESS_STR_FUN(cpuid, cpuid); +static int process_arch(struct feat_fd *ff, void *data __maybe_unused) +{ + uint16_t saved_e_machine = ff->ph->env.e_machine; + + free(ff->ph->env.arch); + ff->ph->env.arch = do_read_string(ff); + if (!ff->ph->env.arch) + return -ENOMEM; + /* + * Make the arch string canonical by computing the e_machine from it, + * then turning the e_machine back into an arch string. + */ + ff->ph->env.e_machine = EM_NONE; + if (perf_env__e_machine(&ff->ph->env, /*e_flags=*/NULL) != EM_NONE) { + zfree(&ff->ph->env.arch); + perf_env__arch(&ff->ph->env); + } + ff->ph->env.e_machine = saved_e_machine; + return 0; +} + static int process_e_machine(struct feat_fd *ff, void *data __maybe_unused) { int ret; diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index fe0de2a0277f..bc7add02a2de 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -3023,14 +3023,19 @@ uint16_t perf_session__e_machine(struct perf_session *session, uint32_t *e_flags return EM_HOST; } + /* + * Is the env caching an e_machine? If not we want to compute from the + * more accurate threads. + */ env = perf_session__env(session); - if (env && env->e_machine != EM_NONE) { - if (e_flags) - *e_flags = env->e_flags; - - return env->e_machine; - } + if (env && env->e_machine != EM_NONE) + return perf_env__e_machine(env, e_flags); + /* + * 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); @@ -3048,10 +3053,8 @@ uint16_t perf_session__e_machine(struct perf_session *session, uint32_t *e_flags /* * Couldn't determine from the perf_env or current set of - * threads. Default to the host. + * threads. Potentially use logic that uses the arch string otherwise + * default to the host. */ - if (e_flags) - *e_flags = EF_HOST; - - return EM_HOST; + return perf_env__e_machine(env, e_flags); } -- 2.54.0.545.g6539524ca2-goog