From patchwork Mon Dec 30 22:30:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Maurer X-Patchwork-Id: 13923549 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 E3F9419D070 for ; Mon, 30 Dec 2024 22:30:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735597835; cv=none; b=iZI9FGJsjwNSZmWmTJ2BHW299EMfZKU3JvhlLJQODlN7NmgGOQH8ziprBh7cFSujutL/znUWNVpcoJjPxrM9G5aZyjHdfDrksQclEalviE+Rlc3R3H5/nrJPBd0EW1eik22V1WAr5P/McI9okEcVHBt6wRbDW9Qpphy9S3qlxjA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735597835; c=relaxed/simple; bh=tppEjhNOJwwUGlS1Ph8ZRVJY08/aOrWg0KTQL1n3GRs=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Do0khTmc4q9oYxakGyUQLnZTi4bAoa/bBfgGuUsvcupKnVFIi9xF9LIFJkBrb8HlohnU/ns7hnXCPuYm61gF1xRdzB2YStIQ7flx5DpAw0FN7gLjpzWONZlT4SC+evfomdQ21psGH3I83YxOZqvreukKjFqH19d7D1m9GqmpID0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mmaurer.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=1vop3WeX; arc=none smtp.client-ip=209.85.216.74 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--mmaurer.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="1vop3WeX" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2ef80d30df1so12547894a91.1 for ; Mon, 30 Dec 2024 14:30:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1735597832; x=1736202632; 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=7kSsX96p1O0aNqgty6si9TtHDszlUQlDB4wm5Geyuc4=; b=1vop3WeXMd1WINEJUPX/Kwvb6+wcptNv4d+XMkxjjuIHroikGCy6+HvbCO68WkEvry lVKhdmrYuwm3bxdX/oU+kf5vmC/Xvp/GFe9vCKtgzIG8reg/CnRCsXxMf8S+Lmk3F17B Pv554NNFIB9qUrATvubyFIojpzT9ifpBUsb8BGw3yVn6ZAqgM2OD31EL2aQAse2O34Go RAbknFq6lOpdriQtBwL7GHPe1D83ELB2NOe+AnXXN2jdg4JkJcsGfmetUyw44KC99axJ YUKjr7BRmRT8ZVJckyI7587EoRUqTKbK8+zftWqxrPtE9XvifBgoVjrMwsNxbTTNKsUt UtCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1735597832; x=1736202632; 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=7kSsX96p1O0aNqgty6si9TtHDszlUQlDB4wm5Geyuc4=; b=aSakYshxyQ2xemIcF7r8hsN0neAMZpEvy02pXj5owzJ3MhJCUgXuMrg5O1LVELkbZT WTvl5GjIkxABNVJXr8Gk6o/aMqbAD+qoefTdlvVluu+sOTcqKWXK+V+c41vRkWkVmLab vxxSay87QaTkw5MMUHYHzgLS6hf6LQFxbdtbOxA/F9t1WiJLtat3qtGv03s1czF/qmhw Ai4SO7iqmaYWgXCveLYWwk1bjdMH5/fUN4LxmBbLoLvz7ZPaR5comipz+KQb4fmE32jG sNs08ew2wvUvbQ6VdfKFOk05VAWa7JwxD6FitjvibbW2bOculUHjg1UpeDpF0UhHOPhF oZHA== X-Forwarded-Encrypted: i=1; AJvYcCXOM5jRQftXE3yETCoCdfiqnURzXsQb7bVagdG+kxnfP/aA/DDqYUTAqO0oAW87S4gyGJx8/56mKwKqNBg=@vger.kernel.org X-Gm-Message-State: AOJu0Yw6pVZR/vBriE9H7xSEeTkYjqij0K+8z9PnurbtzbC9Dj2/NTsr v9PV4Qr/cAR33U892Ix4eN1XGItqhhPGdSW3kQDJlCOLgn7SZMTTRt2FxDtLy3F36PIkpGy3U11 dm3Yh5A== X-Google-Smtp-Source: AGHT+IFER8B66sftlwk+u+XeU4ORZoYyk/SNT6d4TBpm8D3WwkeiX3+QVqO5WJtzOaood2rfcBarE2EDmy1w X-Received: from pjbsc9.prod.google.com ([2002:a17:90b:5109:b0:2e0:aba3:662a]) (user=mmaurer job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:54cb:b0:2ee:d7d3:3019 with SMTP id 98e67ed59e1d1-2f452e22555mr68945181a91.12.1735597832206; Mon, 30 Dec 2024 14:30:32 -0800 (PST) Date: Mon, 30 Dec 2024 22:30:28 +0000 In-Reply-To: <20241230-extended-modversions-v12-0-296a6a0f5151@google.com> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241230-extended-modversions-v12-0-296a6a0f5151@google.com> X-Mailer: b4 0.15-dev Message-ID: <20241230-extended-modversions-v12-1-296a6a0f5151@google.com> Subject: [PATCH v12 1/5] modules: Support extended MODVERSIONS info From: Matthew Maurer To: Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Madhavan Srinivasan , Luis Chamberlain , Petr Pavlu , Sami Tolvanen , Daniel Gomez , Masahiro Yamada , Nathan Chancellor , Nicolas Schier , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Jonathan Corbet Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, linux-kbuild@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org, Matthew Maurer Adds a new format for MODVERSIONS which stores each field in a separate ELF section. This initially adds support for variable length names, but could later be used to add additional fields to MODVERSIONS in a backwards compatible way if needed. Any new fields will be ignored by old user tooling, unlike the current format where user tooling cannot tolerate adjustments to the format (for example making the name field longer). Since PPC munges its version records to strip leading dots, we reproduce the munging for the new format. Other architectures do not appear to have architecture-specific usage of this information. Reviewed-by: Sami Tolvanen Signed-off-by: Matthew Maurer --- arch/powerpc/kernel/module_64.c | 24 ++++++++++- kernel/module/internal.h | 11 +++++ kernel/module/main.c | 92 +++++++++++++++++++++++++++++++++++++---- kernel/module/version.c | 45 ++++++++++++++++++++ 4 files changed, 162 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 45dac7b46aa3cdcb2058a2320b88c0d67e5586b3..34a5aec4908fba3b91a02e914264cb525918942a 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -369,6 +369,24 @@ static void dedotify_versions(struct modversion_info *vers, } } +/* Same as normal versions, remove a leading dot if present. */ +static void dedotify_ext_version_names(char *str_seq, unsigned long size) +{ + unsigned long out = 0; + unsigned long in; + char last = '\0'; + + for (in = 0; in < size; in++) { + /* Skip one leading dot */ + if (last == '\0' && str_seq[in] == '.') + in++; + last = str_seq[in]; + str_seq[out++] = last; + } + /* Zero the trailing portion of the names table for robustness */ + memset(&str_seq[out], 0, size - out); +} + /* * Undefined symbols which refer to .funcname, hack to funcname. Make .TOC. * seem to be defined (value set later). @@ -438,10 +456,12 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr, me->arch.toc_section = i; if (sechdrs[i].sh_addralign < 8) sechdrs[i].sh_addralign = 8; - } - else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0) + } else if (strcmp(secstrings + sechdrs[i].sh_name, "__versions") == 0) dedotify_versions((void *)hdr + sechdrs[i].sh_offset, sechdrs[i].sh_size); + else if (strcmp(secstrings + sechdrs[i].sh_name, "__version_ext_names") == 0) + dedotify_ext_version_names((void *)hdr + sechdrs[i].sh_offset, + sechdrs[i].sh_size); if (sechdrs[i].sh_type == SHT_SYMTAB) dedotify((void *)hdr + sechdrs[i].sh_offset, diff --git a/kernel/module/internal.h b/kernel/module/internal.h index f10dc3ea7ff883b1c91e036b427cdb90502933b8..8ccb922f765cbed85dafee01e074503154ca05d5 100644 --- a/kernel/module/internal.h +++ b/kernel/module/internal.h @@ -86,6 +86,8 @@ struct load_info { unsigned int vers; unsigned int info; unsigned int pcpu; + unsigned int vers_ext_crc; + unsigned int vers_ext_name; } index; }; @@ -389,6 +391,15 @@ void module_layout(struct module *mod, struct modversion_info *ver, struct kerne struct kernel_symbol *ks, struct tracepoint * const *tp); int check_modstruct_version(const struct load_info *info, struct module *mod); int same_magic(const char *amagic, const char *bmagic, bool has_crcs); +struct modversion_info_ext { + size_t remaining; + const s32 *crc; + const char *name; +}; +void modversion_ext_start(const struct load_info *info, struct modversion_info_ext *ver); +void modversion_ext_advance(struct modversion_info_ext *ver); +#define for_each_modversion_info_ext(ver, info) \ + for (modversion_ext_start(info, &ver); ver.remaining > 0; modversion_ext_advance(&ver)) #else /* !CONFIG_MODVERSIONS */ static inline int check_version(const struct load_info *info, const char *symname, diff --git a/kernel/module/main.c b/kernel/module/main.c index 59ea20102b400b5acd68347f61eef48a677c77ce..029c91c01cd0f637910446c7efa3b9a776d95e72 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -2073,6 +2073,82 @@ static int elf_validity_cache_index_str(struct load_info *info) return 0; } +/** + * elf_validity_cache_index_versions() - Validate and cache version indices + * @info: Load info to cache version indices in. + * Must have &load_info->sechdrs and &load_info->secstrings populated. + * @flags: Load flags, relevant to suppress version loading, see + * uapi/linux/module.h + * + * If we're ignoring modversions based on @flags, zero all version indices + * and return validity. Othewrise check: + * + * * If "__version_ext_crcs" is present, "__version_ext_names" is present + * * There is a name present for every crc + * + * Then populate: + * + * * &load_info->index.vers + * * &load_info->index.vers_ext_crc + * * &load_info->index.vers_ext_names + * + * if present. + * + * Return: %0 if valid, %-ENOEXEC on failure. + */ +static int elf_validity_cache_index_versions(struct load_info *info, int flags) +{ + unsigned int vers_ext_crc; + unsigned int vers_ext_name; + size_t crc_count; + size_t remaining_len; + size_t name_size; + char *name; + + /* If modversions were suppressed, pretend we didn't find any */ + if (flags & MODULE_INIT_IGNORE_MODVERSIONS) { + info->index.vers = 0; + info->index.vers_ext_crc = 0; + info->index.vers_ext_name = 0; + return 0; + } + + vers_ext_crc = find_sec(info, "__version_ext_crcs"); + vers_ext_name = find_sec(info, "__version_ext_names"); + + /* If we have one field, we must have the other */ + if (!!vers_ext_crc != !!vers_ext_name) { + pr_err("extended version crc+name presence does not match"); + return -ENOEXEC; + } + + /* + * If we have extended version information, we should have the same + * number of entries in every section. + */ + if (vers_ext_crc) { + crc_count = info->sechdrs[vers_ext_crc].sh_size / sizeof(s32); + name = (void *)info->hdr + + info->sechdrs[vers_ext_name].sh_offset; + remaining_len = info->sechdrs[vers_ext_name].sh_size; + + while (crc_count--) { + name_size = strnlen(name, remaining_len) + 1; + if (name_size > remaining_len) { + pr_err("more extended version crcs than names"); + return -ENOEXEC; + } + remaining_len -= name_size; + name += name_size; + } + } + + info->index.vers = find_sec(info, "__versions"); + info->index.vers_ext_crc = vers_ext_crc; + info->index.vers_ext_name = vers_ext_name; + return 0; +} + /** * elf_validity_cache_index() - Resolve, validate, cache section indices * @info: Load info to read from and update. @@ -2087,9 +2163,7 @@ static int elf_validity_cache_index_str(struct load_info *info) * * elf_validity_cache_index_mod() * * elf_validity_cache_index_sym() * * elf_validity_cache_index_str() - * - * If versioning is not suppressed via flags, load the version index from - * a section called "__versions" with no validation. + * * elf_validity_cache_index_versions() * * If CONFIG_SMP is enabled, load the percpu section by name with no * validation. @@ -2112,11 +2186,9 @@ static int elf_validity_cache_index(struct load_info *info, int flags) err = elf_validity_cache_index_str(info); if (err < 0) return err; - - if (flags & MODULE_INIT_IGNORE_MODVERSIONS) - info->index.vers = 0; /* Pretend no __versions section! */ - else - info->index.vers = find_sec(info, "__versions"); + err = elf_validity_cache_index_versions(info, flags); + if (err < 0) + return err; info->index.pcpu = find_pcpusec(info); @@ -2327,6 +2399,10 @@ static int rewrite_section_headers(struct load_info *info, int flags) /* Track but don't keep modinfo and version sections. */ info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; + info->sechdrs[info->index.vers_ext_crc].sh_flags &= + ~(unsigned long)SHF_ALLOC; + info->sechdrs[info->index.vers_ext_name].sh_flags &= + ~(unsigned long)SHF_ALLOC; info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; return 0; diff --git a/kernel/module/version.c b/kernel/module/version.c index 4e5731d403af20251cb2e3d6dbff8bc59109732b..3e83c8e0654a823eb2186a20f3b0f0e935887ab7 100644 --- a/kernel/module/version.c +++ b/kernel/module/version.c @@ -19,11 +19,28 @@ int check_version(const struct load_info *info, unsigned int versindex = info->index.vers; unsigned int i, num_versions; struct modversion_info *versions; + struct modversion_info_ext version_ext; /* Exporting module didn't supply crcs? OK, we're already tainted. */ if (!crc) return 1; + /* If we have extended version info, rely on it */ + if (info->index.vers_ext_crc) { + for_each_modversion_info_ext(version_ext, info) { + if (strcmp(version_ext.name, symname) != 0) + continue; + if (*version_ext.crc == *crc) + return 1; + pr_debug("Found checksum %X vs module %X\n", + *crc, *version_ext.crc); + goto bad_version; + } + pr_warn_once("%s: no extended symbol version for %s\n", + info->name, symname); + return 1; + } + /* No versions at all? modprobe --force does this. */ if (versindex == 0) return try_to_force_load(mod, symname) == 0; @@ -87,6 +104,34 @@ int same_magic(const char *amagic, const char *bmagic, return strcmp(amagic, bmagic) == 0; } +void modversion_ext_start(const struct load_info *info, + struct modversion_info_ext *start) +{ + unsigned int crc_idx = info->index.vers_ext_crc; + unsigned int name_idx = info->index.vers_ext_name; + Elf_Shdr *sechdrs = info->sechdrs; + + /* + * Both of these fields are needed for this to be useful + * Any future fields should be initialized to NULL if absent. + */ + if (crc_idx == 0 || name_idx == 0) { + start->remaining = 0; + return; + } + + start->crc = (const s32 *)sechdrs[crc_idx].sh_addr; + start->name = (const char *)sechdrs[name_idx].sh_addr; + start->remaining = sechdrs[crc_idx].sh_size / sizeof(*start->crc); +} + +void modversion_ext_advance(struct modversion_info_ext *vers) +{ + vers->remaining--; + vers->crc++; + vers->name += strlen(vers->name) + 1; +} + /* * Generate the signature for all relevant module structures here. * If these change, we don't want to try to parse the module. From patchwork Mon Dec 30 22:30:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Maurer X-Patchwork-Id: 13923550 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 740E919DF62 for ; Mon, 30 Dec 2024 22:30:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735597836; cv=none; b=WhluwMM+F1ldstmyh09+VipPctVdSqdTLVILudfXgKg4A5LppsWTHannSfB86PJryBnClB7cWT6hE6vKuWhOmW7TfcHpPtJbyA4FjQbnhFhUE1Cgsnyyhx7gm8gRjSfhy1wpOvIVDpMwiEwQqvyER0njRVbzh89NWsmed31eBms= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735597836; c=relaxed/simple; bh=LzZzjYtMrjAIOilGNqPDi1aMo2B8A5UAsk+7N50tLOQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=howPaawPuytQg1WHNAzlQI/08nFYusZ77vr9SLjrcedokEdLTW66PY/6gFDDQuPNcla6S5JO097vhAeFMf7MGK6Q1rEls8AZ7/1hg/vNFdVZM1k4WQ2QeDb/mVsUM3bjGf11Pzd4yLAOt0FwcE11rZigfCPEEHNV3kMHJIFE8Mg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mmaurer.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=BhI/KgFn; arc=none smtp.client-ip=209.85.216.74 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--mmaurer.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="BhI/KgFn" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2f46b7851fcso15616952a91.1 for ; Mon, 30 Dec 2024 14:30:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1735597834; x=1736202634; 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=KIRcbYHGQmiiiWpSG/HYzoKu7yqD3/iQMyIqYWEujyM=; b=BhI/KgFnwjyhrwR6lhVwhbJrH3zlwInQwQjlqfg21vE0a8pndA+lwUvDpl+950dPJn a1Czmm0q9EfcYS4AQpilwu48uYPj7VvSRKb5o2QUH3OxpCE9i/31uq5FVHbwqZzA/WpI DcLgZ2JVfElEAqv2uzCGnkN+tXUQQsMn52Pc0VpYSmvmkSq+JJeFSwTSH5F315+Vt7t6 fYtlobE8ifDlJtmRsCK0elydRV/q8bEj01KdF4qGNibKCCMAhJmYFyRBK/bhe5nx950F tPawHnbhSvyPGx7BKRljhY3S3ylLbjDxzLrZ5KepZ+4qS3hhdGyjXewSmROQlwYouT+y 8AfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1735597834; x=1736202634; 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=KIRcbYHGQmiiiWpSG/HYzoKu7yqD3/iQMyIqYWEujyM=; b=t/7d0lnjL9BZwDGB+FBR00c7F5uwmMgogVuHttA0kb/vRbMZZx+nKAeUQQnV3nP6QG jCDtl7zX7K6KSIC0uNP3zDAF2NCkEtx2i0O3EOTb5K+Pmv9SOpJkdiZdjgRVutHbTOBa uMJNc7gsFeye5Xcg4mM/fAnTFm2tV0iaKqg60QP/nI9O7FViqGkO1XgubNP5YG1aCtjf Xm5VSjj3AGHS/sdlAWe7iNotta34x3QFZk/RSOCs2923MfVkWIdqsq0ZCJeUd53CWvT6 tFMhSIEaUFAltTvbYQ0LyPHev/eKfjPtYJ64+WMiOtOvGyGOuKYzk6DcznxuJB7P1GoU 3QsQ== X-Forwarded-Encrypted: i=1; AJvYcCWq4VRlVBmGadRrFlNfFFDoKHv1jEjCJxbYqkF8xlQ9QuNJl0rFAEnZbzEV8kSi8wbB3nCaCbG9R2NOEmg=@vger.kernel.org X-Gm-Message-State: AOJu0YwvDPQ1A4W+SRXqU3Q1O2FyMluvOXNjxrXYpmJmMAr0Pmfw7kGE aDxQio4RKvchpfVsdcM9m1J/xzZzUaqN0f9kYwoodoppDElzr2FgWjdOOrYXGvAIe5szDIuwVxb z1N9V9g== X-Google-Smtp-Source: AGHT+IE9p8I6DZqBUWsXi6TTTO1Du1TPnaF76RNXWmaCOjw5OZ2yqbaR7GBLXXiOJWn9aGXAtnMGxhoY2n1/ X-Received: from pjm7.prod.google.com ([2002:a17:90b:2fc7:b0:2ef:abba:8bfd]) (user=mmaurer job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:2e50:b0:2ea:7cd5:4ad6 with SMTP id 98e67ed59e1d1-2f452eeda66mr50815387a91.32.1735597833878; Mon, 30 Dec 2024 14:30:33 -0800 (PST) Date: Mon, 30 Dec 2024 22:30:29 +0000 In-Reply-To: <20241230-extended-modversions-v12-0-296a6a0f5151@google.com> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241230-extended-modversions-v12-0-296a6a0f5151@google.com> X-Mailer: b4 0.15-dev Message-ID: <20241230-extended-modversions-v12-2-296a6a0f5151@google.com> Subject: [PATCH v12 2/5] modpost: Produce extended MODVERSIONS information From: Matthew Maurer To: Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Madhavan Srinivasan , Luis Chamberlain , Petr Pavlu , Sami Tolvanen , Daniel Gomez , Masahiro Yamada , Nathan Chancellor , Nicolas Schier , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Jonathan Corbet Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, linux-kbuild@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org, Matthew Maurer Generate both the existing modversions format and the new extended one when running modpost. Presence of this metadata in the final .ko is guarded by CONFIG_EXTENDED_MODVERSIONS. We no longer generate an error on long symbols in modpost if CONFIG_EXTENDED_MODVERSIONS is set, as they can now be appropriately encoded in the extended section. These symbols will be skipped in the previous encoding. An error will still be generated if CONFIG_EXTENDED_MODVERSIONS is not set. Reviewed-by: Sami Tolvanen Signed-off-by: Matthew Maurer --- kernel/module/Kconfig | 10 ++++++++ scripts/Makefile.modpost | 1 + scripts/mod/modpost.c | 62 ++++++++++++++++++++++++++++++++++++++++++++---- 3 files changed, 69 insertions(+), 4 deletions(-) diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig index d443fc504ffca0d1001f880ec496ab1f21fe979e..9568b629a03ce8289d3f3597eefc66fc96445720 100644 --- a/kernel/module/Kconfig +++ b/kernel/module/Kconfig @@ -207,6 +207,16 @@ config ASM_MODVERSIONS assembly. This can be enabled only when the target architecture supports it. +config EXTENDED_MODVERSIONS + bool "Extended Module Versioning Support" + depends on MODVERSIONS + help + This enables extended MODVERSIONs support, allowing long symbol + names to be versioned. + + The most likely reason you would enable this is to enable Rust + support. If unsure, say N. + config MODULE_SRCVERSION_ALL bool "Source checksum for all modules" help diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index ab0e94ea62496e11dbaa3ffc289ce546862795ca..40426fc6350985780c0092beb49c6cc29b9eff62 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -43,6 +43,7 @@ MODPOST = $(objtree)/scripts/mod/modpost modpost-args = \ $(if $(CONFIG_MODULES),-M) \ $(if $(CONFIG_MODVERSIONS),-m) \ + $(if $(CONFIG_EXTENDED_MODVERSIONS),-x) \ $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ $(if $(KBUILD_MODPOST_WARN),-w) \ diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index e489983bb8b2850c0f95bcbdfd82f684d4e7f0c3..6324b30f6b97ac24dc517b9229f227c6c369f7d5 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -33,6 +33,8 @@ static bool module_enabled; static bool modversions; /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ static bool all_versions; +/* Is CONFIG_EXTENDED_MODVERSIONS set? */ +static bool extended_modversions; /* If we are modposting external module set to 1 */ static bool external_module; /* Only warn about unresolved symbols */ @@ -1804,6 +1806,49 @@ static void add_exported_symbols(struct buffer *buf, struct module *mod) } } +/** + * Record CRCs for unresolved symbols, supporting long names + */ +static void add_extended_versions(struct buffer *b, struct module *mod) +{ + struct symbol *s; + + if (!extended_modversions) + return; + + buf_printf(b, "\n"); + buf_printf(b, "static const u32 ____version_ext_crcs[]\n"); + buf_printf(b, "__used __section(\"__version_ext_crcs\") = {\n"); + list_for_each_entry(s, &mod->unresolved_symbols, list) { + if (!s->module) + continue; + if (!s->crc_valid) { + warn("\"%s\" [%s.ko] has no CRC!\n", + s->name, mod->name); + continue; + } + buf_printf(b, "\t0x%08x,\n", s->crc); + } + buf_printf(b, "};\n"); + + buf_printf(b, "static const char ____version_ext_names[]\n"); + buf_printf(b, "__used __section(\"__version_ext_names\") =\n"); + list_for_each_entry(s, &mod->unresolved_symbols, list) { + if (!s->module) + continue; + if (!s->crc_valid) + /* + * We already warned on this when producing the crc + * table. + * We need to skip its name too, as the indexes in + * both tables need to align. + */ + continue; + buf_printf(b, "\t\"%s\\0\"\n", s->name); + } + buf_printf(b, ";\n"); +} + /** * Record CRCs for unresolved symbols **/ @@ -1827,9 +1872,14 @@ static void add_versions(struct buffer *b, struct module *mod) continue; } if (strlen(s->name) >= MODULE_NAME_LEN) { - error("too long symbol \"%s\" [%s.ko]\n", - s->name, mod->name); - break; + if (extended_modversions) { + /* this symbol will only be in the extended info */ + continue; + } else { + error("too long symbol \"%s\" [%s.ko]\n", + s->name, mod->name); + break; + } } buf_printf(b, "\t{ 0x%08x, \"%s\" },\n", s->crc, s->name); @@ -1960,6 +2010,7 @@ static void write_mod_c_file(struct module *mod) add_header(&buf, mod); add_exported_symbols(&buf, mod); add_versions(&buf, mod); + add_extended_versions(&buf, mod); add_depends(&buf, mod); buf_printf(&buf, "\n"); @@ -2125,7 +2176,7 @@ int main(int argc, char **argv) LIST_HEAD(dump_lists); struct dump_list *dl, *dl2; - while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) { + while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:x")) != -1) { switch (opt) { case 'e': external_module = true; @@ -2174,6 +2225,9 @@ int main(int argc, char **argv) case 'd': missing_namespace_deps = optarg; break; + case 'x': + extended_modversions = true; + break; default: exit(1); } From patchwork Mon Dec 30 22:30:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Maurer X-Patchwork-Id: 13923551 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 DCC2A19D089 for ; Mon, 30 Dec 2024 22:30:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735597837; cv=none; b=XfnKyOXnXNicyZ+4/wSHbDpt0I/wdAob/JOvKhmtnD8iaw46NBAtGYXEouqka2KeiTrZ90OeuI8HrWmCIEE0aCnXZ0UMsZTxUYNxKu/QW0yuQRkFp39t69J5KGKAcdtSxHMkZZFBhKidpTz0gPPgSN5baZP5+NzlIlRhrsbleck= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735597837; c=relaxed/simple; bh=HpSfhEQsmJDhbi0WozEpulnow31LpruRGqzOvEDchYg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=i4JTLpotjJWRusAEIZNoNbk3DczSy1rvvPqDtvGRfcFZWwXywhMPJxDlWa6iesrgfxJ3MF+nTKRj7EZ6m0gHyllZObwGeG8FpJM054+ToMGaplp/VO7uJcMwf8A0vqej1X3weIeAy0w+1Ihgwqd8x9FjBQurIyJ+MQzXewjo52c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mmaurer.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=GeXOIlsI; arc=none smtp.client-ip=209.85.216.74 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--mmaurer.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="GeXOIlsI" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2efa74481fdso13222085a91.1 for ; Mon, 30 Dec 2024 14:30:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1735597835; x=1736202635; 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=7SdIG/Q/6InqG6fGpzelEgOUniqS646q8n2Ou3Fvqw0=; b=GeXOIlsI9IdwG3WnzVPw9DzPnMpdLAWf9PYU0upKNG8tI2DYiPjdPduFs/nE+mDrTF 4vK+AkkxZ0wfDVfcSeeREbi8K6DqKKfN9iGPlR7Y62DZjvWBuwYk8G60TCmqPPCSApJa ByHc1/Lnei/gtTBmxIi1oYiqFEzAH7X5K663Zs4B+AwyNr8f0wfnIYOb4ZqilBshC/9+ mEpoyV4jwOGXuMfitD5UDy6xb/3tobhT49Gh+QPUSxslbQkEFdfBbkMjAHqI8EvRh6ux ywdqJZu5iELO1Y4h90MlHnKLh0gdN35F42qHgNWO0HHwwlN34hedLsbrhQeAZL0ImtO/ 4cGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1735597835; x=1736202635; 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=7SdIG/Q/6InqG6fGpzelEgOUniqS646q8n2Ou3Fvqw0=; b=oX/DAH/m0vn5TpLLqCTvpiBIJL6PKli3+WOjx1/7VLfcxZ7JNsqt6GwiO6nx+L8E0L Av5sYldA5qbuQuQjm9GPmWwg79Y0IdzYz7s0xbj3DUfc+5dRfXafZHmQIh/F+fQHM79+ ZT8xdVHE1cWDq1/5Z8u8aMvgChh7spIK35zrqQ2p2ovIdfbAvBJ80EnmrilJ51eEcdMV WBt55b75BuIu3vqKK0N9Rei2N+mfXPgykVKR/XH6oCm+67zuiWb2T4QTBCEHHcfy1UcY 05y0Lq9q20SHlX/lx5z8voVI/T8KvmxyHoMsdt2j3tEdN25Awe2Oi5IL9tkjMvsnY391 w/yA== X-Forwarded-Encrypted: i=1; AJvYcCU/N+vj6WIr4Nmi0ZSyvHXIT4SQ5x0Ndyxn2ytbt6EiytWMu8DIHEZ4Ln82dV/2R1ASUWmcE+xJzQtmwjQ=@vger.kernel.org X-Gm-Message-State: AOJu0YxG8vRT7i6Pms+K+4GeXG/YK3yNQ0Jc5RKS7YOTowa8BhAqUNu5 aWh8cZ1xl2iTPtdrbo85Eda1OLAAMNC9jUm0QHWBSST/ElMPkuUBMHYfQqvLUscdyN1oYwUMTX+ sS5EYfA== X-Google-Smtp-Source: AGHT+IGi4L0DnioU3ViuOPQ9hdTSLKvrZaDYmzr68pUHr1qyZseGS+I94UFypBkIbr0Xh4WiRy55BOIz2PpM X-Received: from pjbsq3.prod.google.com ([2002:a17:90b:5303:b0:2ea:6aa8:c4ad]) (user=mmaurer job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90a:dfc7:b0:2ee:b6c5:1def with SMTP id 98e67ed59e1d1-2f452def71bmr63227916a91.8.1735597835253; Mon, 30 Dec 2024 14:30:35 -0800 (PST) Date: Mon, 30 Dec 2024 22:30:30 +0000 In-Reply-To: <20241230-extended-modversions-v12-0-296a6a0f5151@google.com> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241230-extended-modversions-v12-0-296a6a0f5151@google.com> X-Mailer: b4 0.15-dev Message-ID: <20241230-extended-modversions-v12-3-296a6a0f5151@google.com> Subject: [PATCH v12 3/5] modules: Allow extended modversions without basic MODVERSIONS From: Matthew Maurer To: Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Madhavan Srinivasan , Luis Chamberlain , Petr Pavlu , Sami Tolvanen , Daniel Gomez , Masahiro Yamada , Nathan Chancellor , Nicolas Schier , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Jonathan Corbet Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, linux-kbuild@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org, Matthew Maurer If you know that your kernel modules will only ever be loaded by a newer kernel, you can disable BASIC_MODVERSIONS to save space. This also allows easy creation of test modules to see how tooling will respond to modules that only have the new format. Signed-off-by: Matthew Maurer --- kernel/module/Kconfig | 15 +++++++++++++++ scripts/Makefile.modpost | 1 + scripts/mod/modpost.c | 9 +++++++-- 3 files changed, 23 insertions(+), 2 deletions(-) diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig index 9568b629a03ce8289d3f3597eefc66fc96445720..4538f3af63e1ca531d0f74ef45a6f5268e505aec 100644 --- a/kernel/module/Kconfig +++ b/kernel/module/Kconfig @@ -217,6 +217,21 @@ config EXTENDED_MODVERSIONS The most likely reason you would enable this is to enable Rust support. If unsure, say N. +config BASIC_MODVERSIONS + bool "Basic Module Versioning Support" + depends on MODVERSIONS + default y + help + This enables basic MODVERSIONS support, allowing older tools or + kernels to potentially load modules. + + Disabling this may cause older `modprobe` or `kmod` to be unable + to read MODVERSIONS information from built modules. With this + disabled, older kernels may treat this module as unversioned. + + This is enabled by default when MODVERSIONS are enabled. + If unsure, say Y. + config MODULE_SRCVERSION_ALL bool "Source checksum for all modules" help diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index 40426fc6350985780c0092beb49c6cc29b9eff62..d7d45067d08b94a82451d66a64eae29b6826e139 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -43,6 +43,7 @@ MODPOST = $(objtree)/scripts/mod/modpost modpost-args = \ $(if $(CONFIG_MODULES),-M) \ $(if $(CONFIG_MODVERSIONS),-m) \ + $(if $(CONFIG_BASIC_MODVERSIONS),-b) \ $(if $(CONFIG_EXTENDED_MODVERSIONS),-x) \ $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 6324b30f6b97ac24dc517b9229f227c6c369f7d5..3784f1e08104dc2ca1da10d45ed92bb8adf4826a 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -33,6 +33,8 @@ static bool module_enabled; static bool modversions; /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ static bool all_versions; +/* Is CONFIG_BASIC_MODVERSIONS set? */ +static bool basic_modversions; /* Is CONFIG_EXTENDED_MODVERSIONS set? */ static bool extended_modversions; /* If we are modposting external module set to 1 */ @@ -1856,7 +1858,7 @@ static void add_versions(struct buffer *b, struct module *mod) { struct symbol *s; - if (!modversions) + if (!basic_modversions) return; buf_printf(b, "\n"); @@ -2176,7 +2178,7 @@ int main(int argc, char **argv) LIST_HEAD(dump_lists); struct dump_list *dl, *dl2; - while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:x")) != -1) { + while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:xb")) != -1) { switch (opt) { case 'e': external_module = true; @@ -2225,6 +2227,9 @@ int main(int argc, char **argv) case 'd': missing_namespace_deps = optarg; break; + case 'b': + basic_modversions = true; + break; case 'x': extended_modversions = true; break; From patchwork Mon Dec 30 22:30:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Maurer X-Patchwork-Id: 13923552 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 8B2BF1A0BD6 for ; Mon, 30 Dec 2024 22:30:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735597839; cv=none; b=OquTkUFjT2VU9YozaW9gNKwT0+iTWqI9Z9BI/8LtmqRrRyGEC/qAovz99Iyzxmq+U8WE0Vbimlpx9voT/2H3OKz93K6D9AbVdsz9jT4GkKL2/o+lsdYpY7ZTI09rCCUNs9iZDiB26qnXngsZN9TbpGW11X9qIFiVEMJTNOLuoek= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735597839; c=relaxed/simple; bh=XKLtg6hasoIGAI7uNbbTgs8kYTxARwPlbSF6Jrbr4s0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GTQUwMQYNSBRM3evDSHOixLmkLgnicBnFn9r2pb5NaXKUKTGJQaUgMXbr2J9JqrxC0MU3bf/szIocU5LnhomZRlFGjJh7KYsm83by6fJzibXJsHoI/FIVjmnfq0Gc8hZoRwFcOmfyaZfcHPZkxWTLgiUKvINtFAi3N6VW018wok= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mmaurer.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=wLShl572; arc=none smtp.client-ip=209.85.216.73 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--mmaurer.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="wLShl572" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-2f129f7717fso13013890a91.0 for ; Mon, 30 Dec 2024 14:30:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1735597837; x=1736202637; 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=Vj7WTgvEC5PveVDeiSHDuXxxtWMFpPRYSD2aMV1KZG0=; b=wLShl572YkeuA5fZGkjJqkpM7xziLF2hODFbzet1Yj/nLXUeHdi3d0ANtzSl3bbyCk /zdzc6+TIrq+8aURasIPqLnoohGx34q7ahWTmNWMg4jUs0/UdNWPdy7PXra+gqGzHsjV nvxk+pKYUuuFWeYRL9tLns3JZAlk35S4saYvKwuEY9eXHOPhiOrQtcstoK2/g3GKphQr pwg6su2bns3++L2NlJJHNBYbo22xVkUlI9r7x2YCpxqSIReu6QB6FlIBnhpm/j4XpRw1 XUL8LYvr//F9PvhwsvxOPEoJnEZb1WhAT8Ga80ooUUwn8aa+ZWd1rH9MoIq7hrSa93OS 3llw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1735597837; x=1736202637; 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=Vj7WTgvEC5PveVDeiSHDuXxxtWMFpPRYSD2aMV1KZG0=; b=DBZFoahfsDXiVo/tQaVPrJHPtRnmqx65q6wWzNKXZ+ISbAMI8g12QPEIf2JCigCOQz Xz59xRcpA3nNVrSH+Gso8LEB0U7wihbvIGwGVPC29L3MBbNSRN9nAc+VQoptjxIuzK6F BnPI49FnNshhDzrMbj8cO5kO8wi7BXGprvlnehGrqD321u5/OOPyTQbcMKH6km1+jNSs MGMgvlosRvhaADfPZ8+2jYUuQmcHErU2ctP8dNaDZwbBJNU13h2ipPZoCfvyohEXXdxs H7odlgOGm1voI1R0nQ9KBaw1ncpIzSOJRFMURYKADqTb+cQX0lDxX3eDoXszoZsWo+2q ySHA== X-Forwarded-Encrypted: i=1; AJvYcCW204xEfvCIigM0E3A/6YP0tRVVZFKBt0impYToMMlB03tDZnwxLa6mzXYOJMuBwae12KkOSTXXor03WBQ=@vger.kernel.org X-Gm-Message-State: AOJu0YxanxsP/hUNvyUbYlRYmWbL5FrjqorLsGQVo9TfPIUeo0nAwAm6 WPt+lPoYn0mwNc8p4qtKQU81VixImpVZ2mtoeAX8XRv8QKZc1+jkHVY6tCxTTGXE7q2JCmnU1Sl chh5Z5A== X-Google-Smtp-Source: AGHT+IH7lc1nyh322CeIPNFTmhSrY+WwroJDc14f4njjj+YFTtVUIi6WYQ2iNzBtq2Ci0HPEKUE6eWlngS24 X-Received: from pjtu11.prod.google.com ([2002:a17:90a:c88b:b0:2f2:e933:8ba6]) (user=mmaurer job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:3d09:b0:2ea:61de:38f7 with SMTP id 98e67ed59e1d1-2f452ee6340mr56277909a91.29.1735597836920; Mon, 30 Dec 2024 14:30:36 -0800 (PST) Date: Mon, 30 Dec 2024 22:30:31 +0000 In-Reply-To: <20241230-extended-modversions-v12-0-296a6a0f5151@google.com> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241230-extended-modversions-v12-0-296a6a0f5151@google.com> X-Mailer: b4 0.15-dev Message-ID: <20241230-extended-modversions-v12-4-296a6a0f5151@google.com> Subject: [PATCH v12 4/5] Documentation/kbuild: Document storage of symbol information From: Matthew Maurer To: Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Madhavan Srinivasan , Luis Chamberlain , Petr Pavlu , Sami Tolvanen , Daniel Gomez , Masahiro Yamada , Nathan Chancellor , Nicolas Schier , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Jonathan Corbet Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, linux-kbuild@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org, Matthew Maurer Document where exported and imported symbols are kept, format options, and limitations. Signed-off-by: Matthew Maurer --- Documentation/kbuild/modules.rst | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/Documentation/kbuild/modules.rst b/Documentation/kbuild/modules.rst index 101de236cd0c9abe1f5684d80063ff3f9a7fc673..a42f00d8cb90ff6ee44677c1278287ef25a84c89 100644 --- a/Documentation/kbuild/modules.rst +++ b/Documentation/kbuild/modules.rst @@ -423,6 +423,26 @@ Symbols From the Kernel (vmlinux + modules) 1) It lists all exported symbols from vmlinux and all modules. 2) It lists the CRC if CONFIG_MODVERSIONS is enabled. +Version Information Formats +--------------------------- + + Exported symbols have information stored in __ksymtab or __ksymtab_gpl + sections. Symbol names and namespaces are stored in __ksymtab_strings, + using a format similar to the string table used for ELF. If + CONFIG_MODVERSIONS is enabled, the CRCs corresponding to exported + symbols will be added to the __kcrctab or __kcrctab_gpl. + + If CONFIG_BASIC_MODVERSIONS is enabled (default with + CONFIG_MODVERSIONS), imported symbols will have their symbol name and + CRC stored in the __versions section of the importing module. This + mode only supports symbols of length up to 64 bytes. + + If CONFIG_EXTENDED_MODVERSIONS is enabled (required to enable both + CONFIG_MODVERSIONS and CONFIG_RUST at the same time), imported symbols + will have their symbol name recorded in the __version_ext_names + section as a series of concatenated, null-terminated strings. CRCs for + these symbols will be recorded in the __version_ext_crcs section. + Symbols and External Modules ---------------------------- From patchwork Mon Dec 30 22:30:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Maurer X-Patchwork-Id: 13923553 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 3B9331B040B for ; Mon, 30 Dec 2024 22:30:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735597842; cv=none; b=Nr3LF8erALLlBlAB5E4AbCsYBJ2ou9ocSTnleSt5XlsHHz5rg7bY+PW+RiwdJJlH3ep7hm004f9bAribtqgW24nVzqfC4wd5QCVX3o3A3ST6DlIqwhJ9NpWrDajlkiuDdTUdp4ibSgVags13EIgrxkOGTYcjfz9/dszp1D0iwmk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735597842; c=relaxed/simple; bh=OfARBdrSO25YJUBOotWgeA+0nMfy8zMZa0sJjFrf0fc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=IYBXVT8w69IoLGOSw6MSo4VgF9qKOtLIRNCNS9lDQ2qAac96rr9JzksTdPLob9eHRKUsXsRkSS2XF8xPhBfh1ZBNTM0Zs9gWniZTzLTj8NMP0mXJGm1qmkOjRN4ejca4NSo8klveN+Z6JyVJZ1uoxY9mNeG2xTl6ZtQOnU7+aJw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mmaurer.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=I/ms1JnD; arc=none smtp.client-ip=209.85.216.73 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--mmaurer.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="I/ms1JnD" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-2ef775ec883so12703225a91.1 for ; Mon, 30 Dec 2024 14:30:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1735597838; x=1736202638; 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=NnqTVWJzvIfhKg7Bjweyg4HBEOW+h34t+hptux0JJqo=; b=I/ms1JnDgCxUTHXMOhxypcwSvfBkyZNaN44E3JRyDvU+MT6a0GX8LAy2QMtHskDWs9 cQH5M7oogYdMOaUI2GOZTf7GeL9ST28v+rZ2JJihvhx6JUIdoSgHFRYO7+oJOio7LhzV bFybTRYvdSJfgqdH/ElA9cxPXt40/96ebRwiCD9grBk8n1g2/AdWlJezMhgN1nMQ2kOI WtSM7zBJ3/4eJB5YHu5LVub6nr4iEu2SR7/qbBHzVQmDCFYcV8vF8LrG5a7xFdlcJcL8 HqLEPVD0j9H1hAnrBcm1K6QwPtnUTjT0niAqlA9sDcLUy0JwSlfxQOdEkLnKk/DVRaZ/ JdhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1735597838; x=1736202638; 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=NnqTVWJzvIfhKg7Bjweyg4HBEOW+h34t+hptux0JJqo=; b=YYiMmJ7ptkunMV2DE4iQ9H3t7z1D8IEil83ppBJMIRMEZ0bBpt9yoOA5GlUzzRCSz4 TyDzWhCCCC1SSrbzE1Esle+XmVhZfBxNdx6HNDqRdDlIRer+mSF+5GnYUkksbFcYem1j AC3deHUUxg8nvj46CjgCRi5CaaQAPhYB5pzPkwANLUlNqLNuehJE8bO5369LRyHABrgt g5M4wUnyMWME4ey7aIQQI797hrQR0epfHqrUTXo05t2mhScZ26LkET3Z8D8Aq50/Gqi2 PLMrggWQ478tmumiWf6Cg6yKe28hHfwzicTv35QO2hUrBkno3CceRoXsxa7RissCERBr 20TA== X-Forwarded-Encrypted: i=1; AJvYcCX0AbCLIn5SjemDqDaTUuM6PTSgf5yfURhN2Hg2yseH8hR0E/2M3EmU54YLlFjquPRX9M4KbGdHV7xRPI0=@vger.kernel.org X-Gm-Message-State: AOJu0YzmfeTrN2DzK5Dnt63fHCemJlsl6JLPKd8+9y9T1K5lU0JjFfZ0 yD5maxq3ZXtjQuvA8gMj5rSEGg345kC2eO2+82AnKC0XfAG2gFZ6KwbD7BqriKwYvJaQfvipta6 AXzZxWg== X-Google-Smtp-Source: AGHT+IFMck7sG1YUWeTfEcOH6dNd+wV09AW/dPHDuIx5ugJMQ49LP0NvW7hR4YYpwEjy4ooSIIuNJ8r5Movf X-Received: from pfbbe16.prod.google.com ([2002:a05:6a00:1f10:b0:724:eefc:69ef]) (user=mmaurer job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:3286:b0:725:b201:2353 with SMTP id d2e1a72fcca58-72abdec8856mr57170402b3a.13.1735597838524; Mon, 30 Dec 2024 14:30:38 -0800 (PST) Date: Mon, 30 Dec 2024 22:30:32 +0000 In-Reply-To: <20241230-extended-modversions-v12-0-296a6a0f5151@google.com> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241230-extended-modversions-v12-0-296a6a0f5151@google.com> X-Mailer: b4 0.15-dev Message-ID: <20241230-extended-modversions-v12-5-296a6a0f5151@google.com> Subject: [PATCH v12 5/5] rust: Use gendwarfksyms + extended modversions for CONFIG_MODVERSIONS From: Matthew Maurer To: Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Madhavan Srinivasan , Luis Chamberlain , Petr Pavlu , Sami Tolvanen , Daniel Gomez , Masahiro Yamada , Nathan Chancellor , Nicolas Schier , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Jonathan Corbet Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, linux-kbuild@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org, Matthew Maurer From: Sami Tolvanen Previously, two things stopped Rust from using MODVERSIONS: 1. Rust symbols are occasionally too long to be represented in the original versions table 2. Rust types cannot be properly hashed by the existing genksyms approach because: * Looking up type definitions in Rust is more complex than C * Type layout is potentially dependent on the compiler in Rust, not just the source type declaration. CONFIG_EXTENDED_MODVERSIONS addresses the first point, and CONFIG_GENDWARFKSYMS the second. If Rust wants to use MODVERSIONS, allow it to do so by selecting both features. Signed-off-by: Sami Tolvanen Co-developed-by: Matthew Maurer Signed-off-by: Matthew Maurer --- init/Kconfig | 3 ++- rust/Makefile | 34 ++++++++++++++++++++++++++++++++-- 2 files changed, 34 insertions(+), 3 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index c1f9eb3d5f2e892e977ba1425599502dc830f552..b60acfd9431e0ac2bf401ecb6523b5104ad31150 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1959,7 +1959,8 @@ config RUST bool "Rust support" depends on HAVE_RUST depends on RUST_IS_AVAILABLE - depends on !MODVERSIONS + select EXTENDED_MODVERSIONS if MODVERSIONS + depends on !MODVERSIONS || GENDWARFKSYMS depends on !GCC_PLUGIN_RANDSTRUCT depends on !RANDSTRUCT depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE diff --git a/rust/Makefile b/rust/Makefile index a40a3936126d603836e0ec9b42a1285916b60e45..80f970ad81f7989afe5ff2b5f633f50feb7f6006 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -329,10 +329,11 @@ $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_extra = ; $(obj)/bindings/bindings_helpers_generated.rs: $(src)/helpers/helpers.c FORCE $(call if_changed_dep,bindgen) +rust_exports = $(NM) -p --defined-only $(1) | awk '$$2~/(T|R|D|B)/ && $$3!~/__cfi/ { printf $(2),$(3) }' + quiet_cmd_exports = EXPORTS $@ cmd_exports = \ - $(NM) -p --defined-only $< \ - | awk '$$2~/(T|R|D|B)/ && $$3!~/__cfi/ {printf "EXPORT_SYMBOL_RUST_GPL(%s);\n",$$3}' > $@ + $(call rust_exports,$<,"EXPORT_SYMBOL_RUST_GPL(%s);\n",$$3) > $@ $(obj)/exports_core_generated.h: $(obj)/core.o FORCE $(call if_changed,exports) @@ -401,11 +402,36 @@ ifneq ($(or $(CONFIG_ARM64),$(and $(CONFIG_RISCV),$(CONFIG_64BIT))),) __ashlti3 __lshrti3 endif +ifdef CONFIG_MODVERSIONS +cmd_gendwarfksyms = $(if $(skip_gendwarfksyms),, \ + $(call rust_exports,$@,"%s\n",$$3) | \ + scripts/gendwarfksyms/gendwarfksyms \ + $(if $(KBUILD_GENDWARFKSYMS_STABLE), --stable) \ + $(if $(KBUILD_SYMTYPES), --symtypes $(@:.o=.symtypes),) \ + $@ >> $(dot-target).cmd) +endif + define rule_rustc_library $(call cmd_and_fixdep,rustc_library) $(call cmd,gen_objtooldep) + $(call cmd,gendwarfksyms) endef +define rule_rust_cc_library + $(call if_changed_rule,cc_o_c) + $(call cmd,force_checksrc) + $(call cmd,gendwarfksyms) +endef + +# helpers.o uses the same export mechanism as Rust libraries, so ensure symbol +# versions are calculated for the helpers too. +$(obj)/helpers/helpers.o: $(src)/helpers/helpers.c $(recordmcount_source) FORCE + +$(call if_changed_rule,rust_cc_library) + +# Disable symbol versioning for exports.o to avoid conflicts with the actual +# symbol versions generated from Rust objects. +$(obj)/exports.o: private skip_gendwarfksyms = 1 + $(obj)/core.o: private skip_clippy = 1 $(obj)/core.o: private skip_flags = -Wunreachable_pub $(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--redefine-sym $(sym)=__rust$(sym)) @@ -417,13 +443,16 @@ ifneq ($(or $(CONFIG_X86_64),$(CONFIG_X86_32)),) $(obj)/core.o: scripts/target.json endif +$(obj)/compiler_builtins.o: private skip_gendwarfksyms = 1 $(obj)/compiler_builtins.o: private rustc_objcopy = -w -W '__*' $(obj)/compiler_builtins.o: $(src)/compiler_builtins.rs $(obj)/core.o FORCE +$(call if_changed_rule,rustc_library) +$(obj)/build_error.o: private skip_gendwarfksyms = 1 $(obj)/build_error.o: $(src)/build_error.rs $(obj)/compiler_builtins.o FORCE +$(call if_changed_rule,rustc_library) +$(obj)/ffi.o: private skip_gendwarfksyms = 1 $(obj)/ffi.o: $(src)/ffi.rs $(obj)/compiler_builtins.o FORCE +$(call if_changed_rule,rustc_library) @@ -435,6 +464,7 @@ $(obj)/bindings.o: $(src)/bindings/lib.rs \ +$(call if_changed_rule,rustc_library) $(obj)/uapi.o: private rustc_target_flags = --extern ffi +$(obj)/uapi.o: private skip_gendwarfksyms = 1 $(obj)/uapi.o: $(src)/uapi/lib.rs \ $(obj)/ffi.o \ $(obj)/uapi/uapi_generated.rs FORCE