Merge tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Support multiple hook locations for maint scripts of Debian package

 - Remove 'cpio' from the build tool requirement

 - Introduce gendwarfksyms tool, which computes CRCs for export symbols
   based on the DWARF information

 - Support CONFIG_MODVERSIONS for Rust

 - Resolve all conflicts in the genksyms parser

 - Fix several syntax errors in genksyms

* tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (64 commits)
  kbuild: fix Clang LTO with CONFIG_OBJTOOL=n
  kbuild: Strip runtime const RELA sections correctly
  kconfig: fix memory leak in sym_warn_unmet_dep()
  kconfig: fix file name in warnings when loading KCONFIG_DEFCONFIG_LIST
  genksyms: fix syntax error for attribute before init-declarator
  genksyms: fix syntax error for builtin (u)int*x*_t types
  genksyms: fix syntax error for attribute after 'union'
  genksyms: fix syntax error for attribute after 'struct'
  genksyms: fix syntax error for attribute after abstact_declarator
  genksyms: fix syntax error for attribute before nested_declarator
  genksyms: fix syntax error for attribute before abstract_declarator
  genksyms: decouple ATTRIBUTE_PHRASE from type-qualifier
  genksyms: record attributes consistently for init-declarator
  genksyms: restrict direct-declarator to take one parameter-type-list
  genksyms: restrict direct-abstract-declarator to take one parameter-type-list
  genksyms: remove Makefile hack
  genksyms: fix last 3 shift/reduce conflicts
  genksyms: fix 6 shift/reduce conflicts and 5 reduce/reduce conflicts
  genksyms: reduce type_qualifier directly to decl_specifier
  genksyms: rename cvar_qualifier to type_qualifier
  ...

5 files changed, 223 insertions, 36 deletions

diff --git a/kernel/gen_kheaders.sh b/kernel/gen_kheaders.sh
index 7e1340da5aca..00529c81cc40 100755
--- a/kernel/gen_kheaders.sh
+++ b/kernel/gen_kheaders.sh
@@ -7,20 +7,13 @@ set -e
 sfile="$(readlink -f "$0")"
 outdir="$(pwd)"
 tarfile=$1
-cpio_dir=$outdir/${tarfile%/*}/.tmp_cpio_dir
+tmpdir=$outdir/${tarfile%/*}/.tmp_dir
 
 dir_list="
 include/
 arch/$SRCARCH/include/
 "
 
-if ! command -v cpio >/dev/null; then
-	echo >&2 "***"
-	echo >&2 "*** 'cpio' could not be found."
-	echo >&2 "***"
-	exit 1
-fi
-
 # Support incremental builds by skipping archive generation
 # if timestamps of files being archived are not changed.
 
@@ -48,9 +41,9 @@ all_dirs="$all_dirs $dir_list"
 # check include/generated/autoconf.h explicitly.
 #
 # Ignore them for md5 calculation to avoid pointless regeneration.
-headers_md5="$(find $all_dirs -name "*.h"			|
-		grep -v "include/generated/utsversion.h"	|
-		grep -v "include/generated/autoconf.h"	|
+headers_md5="$(find $all_dirs -name "*.h" -a			\
+		! -path include/generated/utsversion.h -a	\
+		! -path include/generated/autoconf.h		|
 		xargs ls -l | md5sum | cut -d ' ' -f1)"
 
 # Any changes to this script will also cause a rebuild of the archive.
@@ -65,36 +58,43 @@ fi
 
 echo "  GEN     $tarfile"
 
-rm -rf $cpio_dir
-mkdir $cpio_dir
+rm -rf "${tmpdir}"
+mkdir "${tmpdir}"
 
 if [ "$building_out_of_srctree" ]; then
 	(
 		cd $srctree
 		for f in $dir_list
 			do find "$f" -name "*.h";
-		done | cpio --quiet -pd $cpio_dir
+		done | tar -c -f - -T - | tar -xf - -C "${tmpdir}"
 	)
 fi
 
-# The second CPIO can complain if files already exist which can happen with out
-# of tree builds having stale headers in srctree. Just silence CPIO for now.
 for f in $dir_list;
 	do find "$f" -name "*.h";
-done | cpio --quiet -pdu $cpio_dir >/dev/null 2>&1
+done | tar -c -f - -T - | tar -xf - -C "${tmpdir}"
+
+# Always exclude include/generated/utsversion.h
+# Otherwise, the contents of the tarball may vary depending on the build steps.
+rm -f "${tmpdir}/include/generated/utsversion.h"
 
 # Remove comments except SDPX lines
-find $cpio_dir -type f -print0 |
-	xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
+# Use a temporary file to store directory contents to prevent find/xargs from
+# seeing temporary files created by perl.
+find "${tmpdir}" -type f -print0 > "${tmpdir}.contents.txt"
+xargs -0 -P8 -n1 \
+	perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;' \
+	< "${tmpdir}.contents.txt"
+rm -f "${tmpdir}.contents.txt"
 
 # Create archive and try to normalize metadata for reproducibility.
 tar "${KBUILD_BUILD_TIMESTAMP:+--mtime=$KBUILD_BUILD_TIMESTAMP}" \
     --exclude=".__afs*" --exclude=".nfs*" \
     --owner=0 --group=0 --sort=name --numeric-owner --mode=u=rw,go=r,a+X \
-    -I $XZ -cf $tarfile -C $cpio_dir/ . > /dev/null
+    -I $XZ -cf $tarfile -C "${tmpdir}/" . > /dev/null
 
 echo $headers_md5 > kernel/kheaders.md5
 echo "$this_file_md5" >> kernel/kheaders.md5
 echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
 
-rm -rf $cpio_dir
+rm -rf "${tmpdir}"
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index 74fe976e3b01..d7762ef5949a 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig
@@ -169,6 +169,36 @@ config MODVERSIONS
 	  make them incompatible with the kernel you are running.  If
 	  unsure, say N.
 
+choice
+	prompt "Module versioning implementation"
+	depends on MODVERSIONS
+	help
+	  Select the tool used to calculate symbol versions for modules.
+
+	  If unsure, select GENKSYMS.
+
+config GENKSYMS
+	bool "genksyms (from source code)"
+	help
+	  Calculate symbol versions from pre-processed source code using
+	  genksyms.
+
+	  If unsure, say Y.
+
+config GENDWARFKSYMS
+	bool "gendwarfksyms (from debugging information)"
+	depends on DEBUG_INFO
+	# Requires full debugging information, split DWARF not supported.
+	depends on !DEBUG_INFO_REDUCED && !DEBUG_INFO_SPLIT
+	# Requires ELF object files.
+	depends on !LTO
+	help
+	  Calculate symbol versions from DWARF debugging information using
+	  gendwarfksyms. Requires DEBUG_INFO to be enabled.
+
+	  If unsure, say N.
+endchoice
+
 config ASM_MODVERSIONS
 	bool
 	default HAVE_ASM_MODVERSIONS && MODVERSIONS
@@ -177,6 +207,31 @@ 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 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/kernel/module/internal.h b/kernel/module/internal.h
index b35c0ec54a89..d09b46ef032f 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -55,8 +55,8 @@ extern const struct kernel_symbol __start___ksymtab[];
 extern const struct kernel_symbol __stop___ksymtab[];
 extern const struct kernel_symbol __start___ksymtab_gpl[];
 extern const struct kernel_symbol __stop___ksymtab_gpl[];
-extern const s32 __start___kcrctab[];
-extern const s32 __start___kcrctab_gpl[];
+extern const u32 __start___kcrctab[];
+extern const u32 __start___kcrctab_gpl[];
 
 struct load_info {
 	const char *name;
@@ -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;
 };
 
@@ -102,7 +104,7 @@ struct find_symbol_arg {
 
 	/* Output */
 	struct module *owner;
-	const s32 *crc;
+	const u32 *crc;
 	const struct kernel_symbol *sym;
 	enum mod_license license;
 };
@@ -385,16 +387,25 @@ static inline void init_param_lock(struct module *mod) { }
 
 #ifdef CONFIG_MODVERSIONS
 int check_version(const struct load_info *info,
-		  const char *symname, struct module *mod, const s32 *crc);
+		  const char *symname, struct module *mod, const u32 *crc);
 void module_layout(struct module *mod, struct modversion_info *ver, struct kernel_param *kp,
 		   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 u32 *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,
 				struct module *mod,
-				const s32 *crc)
+				const u32 *crc)
 {
 	return 1;
 }
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 8808b6906d5a..1fb9ad289a6f 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -86,7 +86,7 @@ struct mod_tree_root mod_tree __cacheline_aligned = {
 
 struct symsearch {
 	const struct kernel_symbol *start, *stop;
-	const s32 *crcs;
+	const u32 *crcs;
 	enum mod_license license;
 };
 
@@ -2074,6 +2074,82 @@ static int elf_validity_cache_index_str(struct load_info *info)
 }
 
 /**
+ * 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(u32);
+		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.
  *         &load_info->sechdrs and &load_info->secstrings must be populated.
@@ -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 53f43ac5a73e..3718a8868321 100644
--- a/kernel/module/version.c
+++ b/kernel/module/version.c
@@ -13,17 +13,34 @@
 int check_version(const struct load_info *info,
 		  const char *symname,
 			 struct module *mod,
-			 const s32 *crc)
+			 const u32 *crc)
 {
 	Elf_Shdr *sechdrs = info->sechdrs;
 	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 u32 *)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.