Merge tag 'modules-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull modules updates from  Luis Chamberlain:

 - It was time to tidy up kernel/module.c and one way of starting with
   that effort was to split it up into files. At my request Aaron Tomlin
   spearheaded that effort with the goal to not introduce any functional
   at all during that endeavour. The penalty for the split is +1322
   bytes total, +112 bytes in data, +1210 bytes in text while bss is
   unchanged. One of the benefits of this other than helping make the
   code easier to read and review is summoning more help on review for
   changes with livepatching so kernel/module/livepatch.c is now pegged
   as maintained by the live patching folks.

   The before and after with just the move on a defconfig on x86-64:

     $ size kernel/module.o
        text    data     bss     dec     hex filename
       38434    4540     104   43078    a846 kernel/module.o

     $ size -t kernel/module/*.o
        text    data     bss     dec     hex filename
       4785     120       0    4905    1329 kernel/module/kallsyms.o
      28577    4416     104   33097    8149 kernel/module/main.o
       1158       8       0    1166     48e kernel/module/procfs.o
        902     108       0    1010     3f2 kernel/module/strict_rwx.o
       3390       0       0    3390     d3e kernel/module/sysfs.o
        832       0       0     832     340 kernel/module/tree_lookup.o
      39644    4652     104   44400    ad70 (TOTALS)

 - Aaron added module unload taint tracking (MODULE_UNLOAD_TAINT_TRACKING),
   to enable tracking unloaded modules which did taint the kernel.

 - Christophe Leroy added CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
   which lets architectures to request having modules data in vmalloc
   area instead of module area. There are three reasons why an
   architecture might want this:

    a) On some architectures (like book3s/32) it is not possible to
       protect against execution on a page basis. The exec stuff can be
       mapped by different arch segment sizes (on book3s/32 that is 256M
       segments). By default the module area is in an Exec segment while
       vmalloc area is in a NoExec segment. Using vmalloc lets you muck
       with module data as NoExec on those architectures whereas before
       you could not.

    b) By pushing more module data to vmalloc you also increase the
       probability of module text to remain within a closer distance
       from kernel core text and this reduces trampolines, this has been
       reported on arm first and powerpc folks are following that lead.

    c) Free'ing module_alloc() (Exec by default) area leaves this
       exposed as Exec by default, some architectures have some security
       enhancements to set this as NoExec on free, and splitting module
       data with text let's future generic special allocators be added
       to the kernel without having developers try to grok the tribal
       knowledge per arch. Work like Rick Edgecombe's permission vmalloc
       interface [0] becomes easier to address over time.

       [0] https://lore.kernel.org/lkml/20201120202426.18009-1-rick.p.edgecombe@intel.com/#r

 - Masahiro Yamada's symbol search enhancements

* tag 'modules-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (33 commits)
  module: merge check_exported_symbol() into find_exported_symbol_in_section()
  module: do not binary-search in __ksymtab_gpl if fsa->gplok is false
  module: do not pass opaque pointer for symbol search
  module: show disallowed symbol name for inherit_taint()
  module: fix [e_shstrndx].sh_size=0 OOB access
  module: Introduce module unload taint tracking
  module: Move module_assert_mutex_or_preempt() to internal.h
  module: Make module_flags_taint() accept a module's taints bitmap and usable outside core code
  module.h: simplify MODULE_IMPORT_NS
  powerpc: Select ARCH_WANTS_MODULES_DATA_IN_VMALLOC on book3s/32 and 8xx
  module: Remove module_addr_min and module_addr_max
  module: Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
  module: Introduce data_layout
  module: Prepare for handling several RB trees
  module: Always have struct mod_tree_root
  module: Rename debug_align() as strict_align()
  module: Rework layout alignment to avoid BUG_ON()s
  module: Move module_enable_x() and frob_text() in strict_rwx.c
  module: Make module_enable_x() independent of CONFIG_ARCH_HAS_STRICT_MODULE_RWX
  module: Move version support into a separate file
  ...

1 files changed, 302 insertions, 0 deletions

diff --git a/kernel/module/internal.h b/kernel/module/internal.h
new file mode 100644
index 000000000000..bc5507ab8450
--- /dev/null
+++ b/kernel/module/internal.h
@@ -0,0 +1,302 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Module internals
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/elf.h>
+#include <linux/compiler.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+
+#ifndef ARCH_SHF_SMALL
+#define ARCH_SHF_SMALL 0
+#endif
+
+/* If this is set, the section belongs in the init part of the module */
+#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG - 1))
+/* Maximum number of characters written by module_flags() */
+#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
+
+#ifndef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+#define	data_layout core_layout
+#endif
+
+/*
+ * Modules' sections will be aligned on page boundaries
+ * to ensure complete separation of code and data, but
+ * only when CONFIG_STRICT_MODULE_RWX=y
+ */
+#ifdef CONFIG_STRICT_MODULE_RWX
+# define strict_align(X) PAGE_ALIGN(X)
+#else
+# define strict_align(X) (X)
+#endif
+
+extern struct mutex module_mutex;
+extern struct list_head modules;
+
+extern struct module_attribute *modinfo_attrs[];
+extern size_t modinfo_attrs_count;
+
+/* Provided by the linker */
+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[];
+
+struct load_info {
+	const char *name;
+	/* pointer to module in temporary copy, freed at end of load_module() */
+	struct module *mod;
+	Elf_Ehdr *hdr;
+	unsigned long len;
+	Elf_Shdr *sechdrs;
+	char *secstrings, *strtab;
+	unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs;
+	struct _ddebug *debug;
+	unsigned int num_debug;
+	bool sig_ok;
+#ifdef CONFIG_KALLSYMS
+	unsigned long mod_kallsyms_init_off;
+#endif
+#ifdef CONFIG_MODULE_DECOMPRESS
+	struct page **pages;
+	unsigned int max_pages;
+	unsigned int used_pages;
+#endif
+	struct {
+		unsigned int sym, str, mod, vers, info, pcpu;
+	} index;
+};
+
+enum mod_license {
+	NOT_GPL_ONLY,
+	GPL_ONLY,
+};
+
+struct find_symbol_arg {
+	/* Input */
+	const char *name;
+	bool gplok;
+	bool warn;
+
+	/* Output */
+	struct module *owner;
+	const s32 *crc;
+	const struct kernel_symbol *sym;
+	enum mod_license license;
+};
+
+int mod_verify_sig(const void *mod, struct load_info *info);
+int try_to_force_load(struct module *mod, const char *reason);
+bool find_symbol(struct find_symbol_arg *fsa);
+struct module *find_module_all(const char *name, size_t len, bool even_unformed);
+int cmp_name(const void *name, const void *sym);
+long module_get_offset(struct module *mod, unsigned int *size, Elf_Shdr *sechdr,
+		       unsigned int section);
+char *module_flags(struct module *mod, char *buf);
+size_t module_flags_taint(unsigned long taints, char *buf);
+
+static inline void module_assert_mutex_or_preempt(void)
+{
+#ifdef CONFIG_LOCKDEP
+	if (unlikely(!debug_locks))
+		return;
+
+	WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
+		     !lockdep_is_held(&module_mutex));
+#endif
+}
+
+static inline unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
+{
+#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
+	return (unsigned long)offset_to_ptr(&sym->value_offset);
+#else
+	return sym->value;
+#endif
+}
+
+#ifdef CONFIG_LIVEPATCH
+int copy_module_elf(struct module *mod, struct load_info *info);
+void free_module_elf(struct module *mod);
+#else /* !CONFIG_LIVEPATCH */
+static inline int copy_module_elf(struct module *mod, struct load_info *info)
+{
+	return 0;
+}
+
+static inline void free_module_elf(struct module *mod) { }
+#endif /* CONFIG_LIVEPATCH */
+
+static inline bool set_livepatch_module(struct module *mod)
+{
+#ifdef CONFIG_LIVEPATCH
+	mod->klp = true;
+	return true;
+#else
+	return false;
+#endif
+}
+
+#ifdef CONFIG_MODULE_UNLOAD_TAINT_TRACKING
+struct mod_unload_taint {
+	struct list_head list;
+	char name[MODULE_NAME_LEN];
+	unsigned long taints;
+	u64 count;
+};
+
+int try_add_tainted_module(struct module *mod);
+void print_unloaded_tainted_modules(void);
+#else /* !CONFIG_MODULE_UNLOAD_TAINT_TRACKING */
+static inline int try_add_tainted_module(struct module *mod)
+{
+	return 0;
+}
+
+static inline void print_unloaded_tainted_modules(void)
+{
+}
+#endif /* CONFIG_MODULE_UNLOAD_TAINT_TRACKING */
+
+#ifdef CONFIG_MODULE_DECOMPRESS
+int module_decompress(struct load_info *info, const void *buf, size_t size);
+void module_decompress_cleanup(struct load_info *info);
+#else
+static inline int module_decompress(struct load_info *info,
+				    const void *buf, size_t size)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void module_decompress_cleanup(struct load_info *info)
+{
+}
+#endif
+
+struct mod_tree_root {
+#ifdef CONFIG_MODULES_TREE_LOOKUP
+	struct latch_tree_root root;
+#endif
+	unsigned long addr_min;
+	unsigned long addr_max;
+};
+
+extern struct mod_tree_root mod_tree;
+extern struct mod_tree_root mod_data_tree;
+
+#ifdef CONFIG_MODULES_TREE_LOOKUP
+void mod_tree_insert(struct module *mod);
+void mod_tree_remove_init(struct module *mod);
+void mod_tree_remove(struct module *mod);
+struct module *mod_find(unsigned long addr, struct mod_tree_root *tree);
+#else /* !CONFIG_MODULES_TREE_LOOKUP */
+
+static inline void mod_tree_insert(struct module *mod) { }
+static inline void mod_tree_remove_init(struct module *mod) { }
+static inline void mod_tree_remove(struct module *mod) { }
+static inline struct module *mod_find(unsigned long addr, struct mod_tree_root *tree)
+{
+	struct module *mod;
+
+	list_for_each_entry_rcu(mod, &modules, list,
+				lockdep_is_held(&module_mutex)) {
+		if (within_module(addr, mod))
+			return mod;
+	}
+
+	return NULL;
+}
+#endif /* CONFIG_MODULES_TREE_LOOKUP */
+
+void module_enable_ro(const struct module *mod, bool after_init);
+void module_enable_nx(const struct module *mod);
+void module_enable_x(const struct module *mod);
+int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+				char *secstrings, struct module *mod);
+bool module_check_misalignment(const struct module *mod);
+
+#ifdef CONFIG_MODULE_SIG
+int module_sig_check(struct load_info *info, int flags);
+#else /* !CONFIG_MODULE_SIG */
+static inline int module_sig_check(struct load_info *info, int flags)
+{
+	return 0;
+}
+#endif /* !CONFIG_MODULE_SIG */
+
+#ifdef CONFIG_DEBUG_KMEMLEAK
+void kmemleak_load_module(const struct module *mod, const struct load_info *info);
+#else /* !CONFIG_DEBUG_KMEMLEAK */
+static inline void kmemleak_load_module(const struct module *mod,
+					const struct load_info *info) { }
+#endif /* CONFIG_DEBUG_KMEMLEAK */
+
+#ifdef CONFIG_KALLSYMS
+void init_build_id(struct module *mod, const struct load_info *info);
+void layout_symtab(struct module *mod, struct load_info *info);
+void add_kallsyms(struct module *mod, const struct load_info *info);
+unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
+
+static inline bool sect_empty(const Elf_Shdr *sect)
+{
+	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
+}
+#else /* !CONFIG_KALLSYMS */
+static inline void init_build_id(struct module *mod, const struct load_info *info) { }
+static inline void layout_symtab(struct module *mod, struct load_info *info) { }
+static inline void add_kallsyms(struct module *mod, const struct load_info *info) { }
+#endif /* CONFIG_KALLSYMS */
+
+#ifdef CONFIG_SYSFS
+int mod_sysfs_setup(struct module *mod, const struct load_info *info,
+		    struct kernel_param *kparam, unsigned int num_params);
+void mod_sysfs_teardown(struct module *mod);
+void init_param_lock(struct module *mod);
+#else /* !CONFIG_SYSFS */
+static inline int mod_sysfs_setup(struct module *mod,
+			   	  const struct load_info *info,
+			   	  struct kernel_param *kparam,
+			   	  unsigned int num_params)
+{
+	return 0;
+}
+
+static inline void mod_sysfs_teardown(struct module *mod) { }
+static inline void init_param_lock(struct module *mod) { }
+#endif /* CONFIG_SYSFS */
+
+#ifdef CONFIG_MODVERSIONS
+int check_version(const struct load_info *info,
+		  const char *symname, struct module *mod, const s32 *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);
+#else /* !CONFIG_MODVERSIONS */
+static inline int check_version(const struct load_info *info,
+				const char *symname,
+				struct module *mod,
+				const s32 *crc)
+{
+	return 1;
+}
+
+static inline int check_modstruct_version(const struct load_info *info,
+					  struct module *mod)
+{
+	return 1;
+}
+
+static inline int same_magic(const char *amagic, const char *bmagic, bool has_crcs)
+{
+	return strcmp(amagic, bmagic) == 0;
+}
+#endif /* CONFIG_MODVERSIONS */