[RFC PATCH v2 00/13] module: core code clean up

[RFC PATCH v2 00/13] module: core code clean up

[Aaron Tomlin]

Hi Luis,

As per your suggestion [1], this is an attempt to refactor and split
optional code out of core module support code into separate components.
Unfortunately, nothing has been thoroughly tested yet. Please let me know
your thoughts.

Changes since v1 [2]:

  - Moved module version support code into a new file

[1]: https://lore.kernel.org/lkml/YbEZ4HgSYQEPuRmS@bombadil.infradead.org/
[2]: https://lore.kernel.org/lkml/20211228213041.1356334-1-atomlin@redhat.com/

Aaron Tomlin (13):
  module: Move all into module/
  module: Simple refactor in preparation for split
  module: Move livepatch support to a separate file
  module: Move latched RB-tree support to a separate file
  module: Move arch strict rwx support to a separate file
  module: Move strict rwx support to a separate file
  module: Move extra signature support out of core code
  module: Move kmemleak support to a separate file
  module: Move kallsyms support into a separate file
  module: Move procfs support into a separate file
  module: Move sysfs support into a separate file
  module: Move kdb_modules list out of core code
  module: Move version support into a separate file

 include/linux/module.h                        |   76 +-
 kernel/Makefile                               |    4 +-
 kernel/debug/kdb/kdb_main.c                   |    5 +
 kernel/module-internal.h                      |   31 -
 kernel/module/Makefile                        |   17 +
 kernel/module/arch_strict_rwx.c               |   44 +
 kernel/module/debug_kmemleak.c                |   30 +
 kernel/module/internal.h                      |  169 ++
 kernel/module/kallsyms.c                      |  506 +++++
 kernel/module/livepatch.c                     |   75 +
 kernel/{module.c => module/main.c}            | 1872 +----------------
 kernel/module/procfs.c                        |  111 +
 .../signature.c}                              |    0
 kernel/module/signing.c                       |  120 ++
 kernel/module/strict_rwx.c                    |   83 +
 kernel/module/sysfs.c                         |  426 ++++
 kernel/module/tree_lookup.c                   |  108 +
 kernel/module/version.c                       |  113 +
 kernel/module_signing.c                       |   45 -
 19 files changed, 1968 insertions(+), 1867 deletions(-)
 delete mode 100644 kernel/module-internal.h
 create mode 100644 kernel/module/Makefile
 create mode 100644 kernel/module/arch_strict_rwx.c
 create mode 100644 kernel/module/debug_kmemleak.c
 create mode 100644 kernel/module/internal.h
 create mode 100644 kernel/module/kallsyms.c
 create mode 100644 kernel/module/livepatch.c
 rename kernel/{module.c => module/main.c} (63%)
 create mode 100644 kernel/module/procfs.c
 rename kernel/{module_signature.c => module/signature.c} (100%)
 create mode 100644 kernel/module/signing.c
 create mode 100644 kernel/module/strict_rwx.c
 create mode 100644 kernel/module/sysfs.c
 create mode 100644 kernel/module/tree_lookup.c
 create mode 100644 kernel/module/version.c
 delete mode 100644 kernel/module_signing.c

-- 
2.31.1

[RFC PATCH v2 01/13] module: Move all into module/

[Aaron Tomlin]

No functional changes.

This patch moves all module related code into a separate directory,
modifies each file name and creates a new Makefile. Note: this effort
is in preparation to refactor core module code.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 kernel/Makefile                                   | 4 +---
 kernel/module/Makefile                            | 8 ++++++++
 kernel/{module-internal.h => module/internal.h}   | 0
 kernel/{module.c => module/main.c}                | 2 +-
 kernel/{module_signature.c => module/signature.c} | 0
 kernel/{module_signing.c => module/signing.c}     | 2 +-
 6 files changed, 11 insertions(+), 5 deletions(-)
 create mode 100644 kernel/module/Makefile
 rename kernel/{module-internal.h => module/internal.h} (100%)
 rename kernel/{module.c => module/main.c} (99%)
 rename kernel/{module_signature.c => module/signature.c} (100%)
 rename kernel/{module_signing.c => module/signing.c} (97%)

diff --git a/kernel/Makefile b/kernel/Makefile
index 4df609be42d0..466477d4dafe 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -53,6 +53,7 @@ obj-y += rcu/
 obj-y += livepatch/
 obj-y += dma/
 obj-y += entry/
+obj-y += module/
 
 obj-$(CONFIG_KCMP) += kcmp.o
 obj-$(CONFIG_FREEZER) += freezer.o
@@ -66,9 +67,6 @@ ifneq ($(CONFIG_SMP),y)
 obj-y += up.o
 endif
 obj-$(CONFIG_UID16) += uid16.o
-obj-$(CONFIG_MODULES) += module.o
-obj-$(CONFIG_MODULE_SIG) += module_signing.o
-obj-$(CONFIG_MODULE_SIG_FORMAT) += module_signature.o
 obj-$(CONFIG_KALLSYMS) += kallsyms.o
 obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
 obj-$(CONFIG_CRASH_CORE) += crash_core.o
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
new file mode 100644
index 000000000000..a9cf6e822075
--- /dev/null
+++ b/kernel/module/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for linux kernel module support
+#
+
+obj-$(CONFIG_MODULES) += main.o
+obj-$(CONFIG_MODULE_SIG) += signing.o
+obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
diff --git a/kernel/module-internal.h b/kernel/module/internal.h
similarity index 100%
rename from kernel/module-internal.h
rename to kernel/module/internal.h
diff --git a/kernel/module.c b/kernel/module/main.c
similarity index 99%
rename from kernel/module.c
rename to kernel/module/main.c
index ed13917ea5f3..bc997c3e2c95 100644
--- a/kernel/module.c
+++ b/kernel/module/main.c
@@ -58,7 +58,7 @@
 #include <linux/dynamic_debug.h>
 #include <linux/audit.h>
 #include <uapi/linux/module.h>
-#include "module-internal.h"
+#include "internal.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/module.h>
diff --git a/kernel/module_signature.c b/kernel/module/signature.c
similarity index 100%
rename from kernel/module_signature.c
rename to kernel/module/signature.c
diff --git a/kernel/module_signing.c b/kernel/module/signing.c
similarity index 97%
rename from kernel/module_signing.c
rename to kernel/module/signing.c
index 8723ae70ea1f..8aeb6d2ee94b 100644
--- a/kernel/module_signing.c
+++ b/kernel/module/signing.c
@@ -12,7 +12,7 @@
 #include <linux/string.h>
 #include <linux/verification.h>
 #include <crypto/public_key.h>
-#include "module-internal.h"
+#include "internal.h"
 
 /*
  * Verify the signature on a module.
-- 
2.31.1

[RFC PATCH v2 02/13] module: Simple refactor in preparation for split

[Aaron Tomlin]

No functional change.

This patch makes it possible to move non-essential code
out of core module code.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 kernel/module/internal.h | 22 ++++++++++++++++++++++
 kernel/module/main.c     | 23 ++---------------------
 2 files changed, 24 insertions(+), 21 deletions(-)

diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 33783abc377b..ffc50df010a7 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -7,6 +7,28 @@
 
 #include <linux/elf.h>
 #include <asm/module.h>
+#include <linux/mutex.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)
+#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
+
+extern struct mutex module_mutex;
+extern struct list_head modules;
+
+/* 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;
diff --git a/kernel/module/main.c b/kernel/module/main.c
index bc997c3e2c95..2a6b859716c0 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -63,10 +63,6 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/module.h>
 
-#ifndef ARCH_SHF_SMALL
-#define ARCH_SHF_SMALL 0
-#endif
-
 /*
  * Modules' sections will be aligned on page boundaries
  * to ensure complete separation of code and data, but
@@ -78,9 +74,6 @@
 # define debug_align(X) (X)
 #endif
 
-/* If this is set, the section belongs in the init part of the module */
-#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
-
 /*
  * Mutex protects:
  * 1) List of modules (also safely readable with preempt_disable),
@@ -88,8 +81,8 @@
  * 3) module_addr_min/module_addr_max.
  * (delete and add uses RCU list operations).
  */
-static DEFINE_MUTEX(module_mutex);
-static LIST_HEAD(modules);
+DEFINE_MUTEX(module_mutex);
+LIST_HEAD(modules);
 
 /* Work queue for freeing init sections in success case */
 static void do_free_init(struct work_struct *w);
@@ -408,14 +401,6 @@ static __maybe_unused void *any_section_objs(const struct load_info *info,
 	return (void *)info->sechdrs[sec].sh_addr;
 }
 
-/* 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[];
-
 #ifndef CONFIG_MODVERSIONS
 #define symversion(base, idx) NULL
 #else
@@ -1491,7 +1476,6 @@ struct module_sect_attrs {
 	struct module_sect_attr attrs[];
 };
 
-#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
 static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
 				struct bin_attribute *battr,
 				char *buf, loff_t pos, size_t count)
@@ -4498,9 +4482,6 @@ static void cfi_cleanup(struct module *mod)
 #endif
 }
 
-/* Maximum number of characters written by module_flags() */
-#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
-
 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
 static char *module_flags(struct module *mod, char *buf)
 {
-- 
2.31.1

[RFC PATCH v2 03/13] module: Move livepatch support to a separate file

[Aaron Tomlin]

No functional change.

This patch migrates livepatch support (i.e. used during module
add/or load and remove/or deletion) from core module code into
kernel/module/livepatch.c. At the moment it contains code to
persist Elf information about a given livepatch module, only.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 kernel/module/Makefile    |  1 +
 kernel/module/internal.h  | 12 ++++++
 kernel/module/livepatch.c | 75 +++++++++++++++++++++++++++++++++
 kernel/module/main.c      | 89 +--------------------------------------
 4 files changed, 89 insertions(+), 88 deletions(-)
 create mode 100644 kernel/module/livepatch.c

diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index a9cf6e822075..47d70bb18da3 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -6,3 +6,4 @@
 obj-$(CONFIG_MODULES) += main.o
 obj-$(CONFIG_MODULE_SIG) += signing.o
 obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
+obj-$(CONFIG_LIVEPATCH) += livepatch.o
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index ffc50df010a7..91ef152aeffb 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -51,3 +51,15 @@ struct load_info {
 };
 
 extern int mod_verify_sig(const void *mod, struct load_info *info);
+
+#ifdef CONFIG_LIVEPATCH
+extern int copy_module_elf(struct module *mod, struct load_info *info);
+extern void free_module_elf(struct module *mod);
+extern int check_modinfo_livepatch(struct module *mod, struct load_info *info);
+#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 */
diff --git a/kernel/module/livepatch.c b/kernel/module/livepatch.c
new file mode 100644
index 000000000000..e147f5418327
--- /dev/null
+++ b/kernel/module/livepatch.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * kernel/module/livepatch.c - module livepatch support
+ *
+ * Copyright (C) 2016 Jessica Yu <jeyu@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include "internal.h"
+
+/*
+ * Persist Elf information about a module. Copy the Elf header,
+ * section header table, section string table, and symtab section
+ * index from info to mod->klp_info.
+ */
+int copy_module_elf(struct module *mod, struct load_info *info)
+{
+	unsigned int size, symndx;
+	int ret;
+
+	size = sizeof(*mod->klp_info);
+	mod->klp_info = kmalloc(size, GFP_KERNEL);
+	if (mod->klp_info == NULL)
+		return -ENOMEM;
+
+	/* Elf header */
+	size = sizeof(mod->klp_info->hdr);
+	memcpy(&mod->klp_info->hdr, info->hdr, size);
+
+	/* Elf section header table */
+	size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
+	mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
+	if (mod->klp_info->sechdrs == NULL) {
+		ret = -ENOMEM;
+		goto free_info;
+	}
+
+	/* Elf section name string table */
+	size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
+	mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
+	if (mod->klp_info->secstrings == NULL) {
+		ret = -ENOMEM;
+		goto free_sechdrs;
+	}
+
+	/* Elf symbol section index */
+	symndx = info->index.sym;
+	mod->klp_info->symndx = symndx;
+
+	/*
+	 * For livepatch modules, core_kallsyms.symtab is a complete
+	 * copy of the original symbol table. Adjust sh_addr to point
+	 * to core_kallsyms.symtab since the copy of the symtab in module
+	 * init memory is freed at the end of do_init_module().
+	 */
+	mod->klp_info->sechdrs[symndx].sh_addr = \
+		(unsigned long) mod->core_kallsyms.symtab;
+
+	return 0;
+
+free_sechdrs:
+	kfree(mod->klp_info->sechdrs);
+free_info:
+	kfree(mod->klp_info);
+	return ret;
+}
+
+void free_module_elf(struct module *mod)
+{
+	kfree(mod->klp_info->sechdrs);
+	kfree(mod->klp_info->secstrings);
+	kfree(mod->klp_info);
+}
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 2a6b859716c0..9bcaf251e109 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2043,81 +2043,6 @@ static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
 }
 #endif /*  CONFIG_STRICT_MODULE_RWX */
 
-#ifdef CONFIG_LIVEPATCH
-/*
- * Persist Elf information about a module. Copy the Elf header,
- * section header table, section string table, and symtab section
- * index from info to mod->klp_info.
- */
-static int copy_module_elf(struct module *mod, struct load_info *info)
-{
-	unsigned int size, symndx;
-	int ret;
-
-	size = sizeof(*mod->klp_info);
-	mod->klp_info = kmalloc(size, GFP_KERNEL);
-	if (mod->klp_info == NULL)
-		return -ENOMEM;
-
-	/* Elf header */
-	size = sizeof(mod->klp_info->hdr);
-	memcpy(&mod->klp_info->hdr, info->hdr, size);
-
-	/* Elf section header table */
-	size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
-	mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
-	if (mod->klp_info->sechdrs == NULL) {
-		ret = -ENOMEM;
-		goto free_info;
-	}
-
-	/* Elf section name string table */
-	size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
-	mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
-	if (mod->klp_info->secstrings == NULL) {
-		ret = -ENOMEM;
-		goto free_sechdrs;
-	}
-
-	/* Elf symbol section index */
-	symndx = info->index.sym;
-	mod->klp_info->symndx = symndx;
-
-	/*
-	 * For livepatch modules, core_kallsyms.symtab is a complete
-	 * copy of the original symbol table. Adjust sh_addr to point
-	 * to core_kallsyms.symtab since the copy of the symtab in module
-	 * init memory is freed at the end of do_init_module().
-	 */
-	mod->klp_info->sechdrs[symndx].sh_addr = \
-		(unsigned long) mod->core_kallsyms.symtab;
-
-	return 0;
-
-free_sechdrs:
-	kfree(mod->klp_info->sechdrs);
-free_info:
-	kfree(mod->klp_info);
-	return ret;
-}
-
-static void free_module_elf(struct module *mod)
-{
-	kfree(mod->klp_info->sechdrs);
-	kfree(mod->klp_info->secstrings);
-	kfree(mod->klp_info);
-}
-#else /* !CONFIG_LIVEPATCH */
-static int copy_module_elf(struct module *mod, struct load_info *info)
-{
-	return 0;
-}
-
-static void free_module_elf(struct module *mod)
-{
-}
-#endif /* CONFIG_LIVEPATCH */
-
 void __weak module_memfree(void *module_region)
 {
 	/*
@@ -3052,19 +2977,7 @@ static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned l
 	return 0;
 }
 
-#ifdef CONFIG_LIVEPATCH
-static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
-{
-	if (get_modinfo(info, "livepatch")) {
-		mod->klp = true;
-		add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
-		pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
-			       mod->name);
-	}
-
-	return 0;
-}
-#else /* !CONFIG_LIVEPATCH */
+#ifndef CONFIG_LIVEPATCH
 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
 {
 	if (get_modinfo(info, "livepatch")) {
-- 
2.31.1

Re: [RFC PATCH v2 03/13] module: Move livepatch support to a separate file

[Petr Mladek]

On Thu 2022-01-06 23:43:09, Aaron Tomlin wrote:
> No functional change.
> 
> This patch migrates livepatch support (i.e. used during module
> add/or load and remove/or deletion) from core module code into
> kernel/module/livepatch.c. At the moment it contains code to
> persist Elf information about a given livepatch module, only.
> 
> Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
> ---
>  kernel/module/Makefile    |  1 +
>  kernel/module/internal.h  | 12 ++++++
>  kernel/module/livepatch.c | 75 +++++++++++++++++++++++++++++++++
>  kernel/module/main.c      | 89 +--------------------------------------
>  4 files changed, 89 insertions(+), 88 deletions(-)
>  create mode 100644 kernel/module/livepatch.c
> 
> diff --git a/kernel/module/Makefile b/kernel/module/Makefile
> index a9cf6e822075..47d70bb18da3 100644
> --- a/kernel/module/Makefile
> +++ b/kernel/module/Makefile
> @@ -6,3 +6,4 @@
>  obj-$(CONFIG_MODULES) += main.o
>  obj-$(CONFIG_MODULE_SIG) += signing.o
>  obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
> +obj-$(CONFIG_LIVEPATCH) += livepatch.o
> diff --git a/kernel/module/internal.h b/kernel/module/internal.h
> index ffc50df010a7..91ef152aeffb 100644
> --- a/kernel/module/internal.h
> +++ b/kernel/module/internal.h
> @@ -51,3 +51,15 @@ struct load_info {
>  };
>  
>  extern int mod_verify_sig(const void *mod, struct load_info *info);
> +
> +#ifdef CONFIG_LIVEPATCH
> +extern int copy_module_elf(struct module *mod, struct load_info *info);
> +extern void free_module_elf(struct module *mod);
> +extern int check_modinfo_livepatch(struct module *mod, struct load_info *info);
> +#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) { }

It looks like there is no check_modinfo_livepatch() variant when
CONFIG_LIPATCH is disabled.

> +#endif /* CONFIG_LIVEPATCH */
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index 2a6b859716c0..9bcaf251e109 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -3052,19 +2977,7 @@ static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned l
>  	return 0;
>  }
>  
> -#ifdef CONFIG_LIVEPATCH
> -static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
> -{
> -	if (get_modinfo(info, "livepatch")) {
> -		mod->klp = true;
> -		add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
> -		pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
> -			       mod->name);
 > -	}
> -
> -	return 0;
> -}
> -#else /* !CONFIG_LIVEPATCH */
> +#ifndef CONFIG_LIVEPATCH
>  static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
>  {
>  	if (get_modinfo(info, "livepatch")) {

But it exist here.

It would be better to have the two variants close each other. I mean
to have it somewhere like:

#ifdef CONFIG_LIVEPATCH

   variant A

#else

   variant B

#endif


A solution would be to do it a similar way like in
check_modinfo_retpoline(). Have a generic:

static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
{
	if (!get_modinfo(info, "livepatch"))
		return 0;

	if (set_livepatch_module(mod)) {
		add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
		pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
			       mod->name);
		return 0;
       }

       pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
	       mod->name);
       return -ENOEXEC;
}

, where set_livepatch_module(mod) might be defined inline
similar way like is_livepatch_module():

#ifdef CONFIG_LIVEPATCH
static inline bool set_livepatch_module(struct module *mod)
{
	mod->klp = true;
	return true;
}
#else /* !CONFIG_LIVEPATCH */
static inline bool set_livepatch_module(struct module *mod)
{
	return false;
}
#endif /* CONFIG_LIVEPATCH */


Well, it might be matter of taste. Others might prefer another solution.
Adding live-patching mailing list into Cc.

Anyway, if we do any code refactoring, we should do it in a separate
preparatory patch.

Best Regards,
Petr

Re: [RFC PATCH v2 03/13] module: Move livepatch support to a separate file

[David Vernet]

Petr Mladek <pmladek@suse.com> wrote on Wed [2022-Jan-12 17:53:56 +0100]:
> It would be better to have the two variants close each other. I mean
> to have it somewhere like:
> 
> #ifdef CONFIG_LIVEPATCH
> 
>    variant A
> 
> #else
> 
>    variant B
> 
> #endif
> 

<snip>

> #ifdef CONFIG_LIVEPATCH
> static inline bool set_livepatch_module(struct module *mod)
> {
> 	mod->klp = true;
> 	return true;
> }
> #else /* !CONFIG_LIVEPATCH */
> static inline bool set_livepatch_module(struct module *mod)
> {
> 	return false;
> }
> #endif /* CONFIG_LIVEPATCH */
> 
> 
> Well, it might be matter of taste. Others might prefer another solution.
> Adding live-patching mailing list into Cc.

+1 -- this seems like a cleaner approach.

- David

Re: [RFC PATCH v2 03/13] module: Move livepatch support to a separate file

[Aaron Tomlin]

On Wed 2022-01-12 17:53 +0100, Petr Mladek wrote:
> It would be better to have the two variants close each other. I mean
> to have it somewhere like:
> 
> #ifdef CONFIG_LIVEPATCH
> 
>    variant A
> 
> #else
> 
>    variant B
> 
> #endif

Petr,

I agree. I'll incorporate this approach into RFC PATCH v3.


Kind regards,

-- 
Aaron Tomlin

Re: [RFC PATCH v2 03/13] module: Move livepatch support to a separate file

[David Vernet]

Thanks for doing this refactor. +1 to doing this, though Petr had some
suggestions in another thread that I'll wait on before Acking.

Aaron Tomlin <atomlin@redhat.com> wrote on Thu [2022-Jan-06 23:43:09 +0000]:
> diff --git a/kernel/module/livepatch.c b/kernel/module/livepatch.c
> new file mode 100644
> index 000000000000..e147f5418327
> --- /dev/null
> +++ b/kernel/module/livepatch.c
> @@ -0,0 +1,75 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * kernel/module/livepatch.c - module livepatch support
> + *
> + * Copyright (C) 2016 Jessica Yu <jeyu@redhat.com>
> + */

Should the copyright year (and possibly author) be updated? Or just removed
entirely?

- David

Re: [RFC PATCH v2 03/13] module: Move livepatch support to a separate file

[Aaron Tomlin]

On Wed 2022-01-12 10:54 -0800, David Vernet wrote:
> Thanks for doing this refactor. +1 to doing this, though Petr had some
> suggestions in another thread that I'll wait on before Acking.

No problem and yes, I will make the suggested modifications then add you on
Cc.

> Aaron Tomlin <atomlin@redhat.com> wrote on Thu [2022-Jan-06 23:43:09 +0000]:
> > diff --git a/kernel/module/livepatch.c b/kernel/module/livepatch.c
> > new file mode 100644
> > index 000000000000..e147f5418327
> > --- /dev/null
> > +++ b/kernel/module/livepatch.c
> > @@ -0,0 +1,75 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * kernel/module/livepatch.c - module livepatch support
> > + *
> > + * Copyright (C) 2016 Jessica Yu <jeyu@redhat.com>
> > + */
> 
> Should the copyright year (and possibly author) be updated? Or just removed
> entirely?

Who should I specify? I'm not entirely sure. If I understand correctly,
Jessica was the original author of the majority.


Kind regards,

-- 
Aaron Tomlin

Re: [RFC PATCH v2 03/13] module: Move livepatch support to a separate file

[David Vernet]

Aaron Tomlin <atomlin@atomlin.com> wrote on Thu [2022-Jan-13 10:35:31 +0000]:
> Who should I specify? I'm not entirely sure. If I understand correctly,
> Jessica was the original author of the majority.

Personally I would just remove the whole copyright as the SPDX identifier
should be sufficient. I'll let Luis weigh in here as the Modules
maintainer, though.

Re: [RFC PATCH v2 03/13] module: Move livepatch support to a separate file

[Luis Chamberlain]

On Thu, Jan 13, 2022 at 06:16:54AM -0800, David Vernet wrote:
> Aaron Tomlin <atomlin@atomlin.com> wrote on Thu [2022-Jan-13 10:35:31 +0000]:
> > Who should I specify? I'm not entirely sure. If I understand correctly,
> > Jessica was the original author of the majority.
> 
> Personally I would just remove the whole copyright as the SPDX identifier
> should be sufficient. I'll let Luis weigh in here as the Modules
> maintainer, though.

Technically every contributor to the file has a copyright entry added,
one does not need to add the name to the header, that's just common
practice though. If someone goes through the work of at least adding
the name of the main author, that a nice effort. Tons of files don't
have authors listed, so I'd be fine with that too and it keeps things
simple. What we should not do ever is remove the copyright notice so
code which Rusty wrote should be maintained with the notice.

  Luis

[RFC PATCH v2 04/13] module: Move latched RB-tree support to a separate file

[Aaron Tomlin]

No functional change.

This patch migrates module latched RB-tree support
(e.g. see __module_address()) from core module code
into kernel/module/tree_lookup.c.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 include/linux/module.h      |  37 +++++++++-
 kernel/module/Makefile      |   1 +
 kernel/module/main.c        | 134 ------------------------------------
 kernel/module/tree_lookup.c | 108 +++++++++++++++++++++++++++++
 4 files changed, 144 insertions(+), 136 deletions(-)
 create mode 100644 kernel/module/tree_lookup.c

diff --git a/include/linux/module.h b/include/linux/module.h
index 8a298d820dbc..8b4d254a84c0 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -339,11 +339,44 @@ struct module_layout {
 };
 
 #ifdef CONFIG_MODULES_TREE_LOOKUP
+struct mod_tree_root {
+	struct latch_tree_root root;
+	unsigned long addr_min;
+	unsigned long addr_max;
+} mod_tree __cacheline_aligned = {
+	.addr_min = -1UL,
+};
+
+#define module_addr_min mod_tree.addr_min
+#define module_addr_max mod_tree.addr_max
+
+extern void mod_tree_insert(struct module *mod);
+extern void mod_tree_remove_init(struct module *mod);
+extern void mod_tree_remove(struct module *mod);
+extern struct module *mod_find(unsigned long addr);
 /* Only touch one cacheline for common rbtree-for-core-layout case. */
 #define __module_layout_align ____cacheline_aligned
-#else
+#else /* !CONFIG_MODULES_TREE_LOOKUP */
+
+static unsigned long module_addr_min = -1UL, module_addr_max = 0;
+
+static void mod_tree_insert(struct module *mod) { }
+static void mod_tree_remove_init(struct module *mod) { }
+static void mod_tree_remove(struct module *mod) { }
+static struct module *mod_find(unsigned long addr)
+{
+	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;
+}
 #define __module_layout_align
-#endif
+#endif /* CONFIG_MODULES_TREE_LOOKUP */
 
 struct mod_kallsyms {
 	Elf_Sym *symtab;
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 47d70bb18da3..9d593362156d 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_MODULES) += main.o
 obj-$(CONFIG_MODULE_SIG) += signing.o
 obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
 obj-$(CONFIG_LIVEPATCH) += livepatch.o
+obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 9bcaf251e109..692cc520420d 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -89,140 +89,6 @@ static void do_free_init(struct work_struct *w);
 static DECLARE_WORK(init_free_wq, do_free_init);
 static LLIST_HEAD(init_free_list);
 
-#ifdef CONFIG_MODULES_TREE_LOOKUP
-
-/*
- * Use a latched RB-tree for __module_address(); this allows us to use
- * RCU-sched lookups of the address from any context.
- *
- * This is conditional on PERF_EVENTS || TRACING because those can really hit
- * __module_address() hard by doing a lot of stack unwinding; potentially from
- * NMI context.
- */
-
-static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
-{
-	struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
-
-	return (unsigned long)layout->base;
-}
-
-static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
-{
-	struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
-
-	return (unsigned long)layout->size;
-}
-
-static __always_inline bool
-mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
-{
-	return __mod_tree_val(a) < __mod_tree_val(b);
-}
-
-static __always_inline int
-mod_tree_comp(void *key, struct latch_tree_node *n)
-{
-	unsigned long val = (unsigned long)key;
-	unsigned long start, end;
-
-	start = __mod_tree_val(n);
-	if (val < start)
-		return -1;
-
-	end = start + __mod_tree_size(n);
-	if (val >= end)
-		return 1;
-
-	return 0;
-}
-
-static const struct latch_tree_ops mod_tree_ops = {
-	.less = mod_tree_less,
-	.comp = mod_tree_comp,
-};
-
-static struct mod_tree_root {
-	struct latch_tree_root root;
-	unsigned long addr_min;
-	unsigned long addr_max;
-} mod_tree __cacheline_aligned = {
-	.addr_min = -1UL,
-};
-
-#define module_addr_min mod_tree.addr_min
-#define module_addr_max mod_tree.addr_max
-
-static noinline void __mod_tree_insert(struct mod_tree_node *node)
-{
-	latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
-}
-
-static void __mod_tree_remove(struct mod_tree_node *node)
-{
-	latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
-}
-
-/*
- * These modifications: insert, remove_init and remove; are serialized by the
- * module_mutex.
- */
-static void mod_tree_insert(struct module *mod)
-{
-	mod->core_layout.mtn.mod = mod;
-	mod->init_layout.mtn.mod = mod;
-
-	__mod_tree_insert(&mod->core_layout.mtn);
-	if (mod->init_layout.size)
-		__mod_tree_insert(&mod->init_layout.mtn);
-}
-
-static void mod_tree_remove_init(struct module *mod)
-{
-	if (mod->init_layout.size)
-		__mod_tree_remove(&mod->init_layout.mtn);
-}
-
-static void mod_tree_remove(struct module *mod)
-{
-	__mod_tree_remove(&mod->core_layout.mtn);
-	mod_tree_remove_init(mod);
-}
-
-static struct module *mod_find(unsigned long addr)
-{
-	struct latch_tree_node *ltn;
-
-	ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
-	if (!ltn)
-		return NULL;
-
-	return container_of(ltn, struct mod_tree_node, node)->mod;
-}
-
-#else /* MODULES_TREE_LOOKUP */
-
-static unsigned long module_addr_min = -1UL, module_addr_max = 0;
-
-static void mod_tree_insert(struct module *mod) { }
-static void mod_tree_remove_init(struct module *mod) { }
-static void mod_tree_remove(struct module *mod) { }
-
-static struct module *mod_find(unsigned long addr)
-{
-	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 /* MODULES_TREE_LOOKUP */
-
 /*
  * Bounds of module text, for speeding up __module_address.
  * Protected by module_mutex.
diff --git a/kernel/module/tree_lookup.c b/kernel/module/tree_lookup.c
new file mode 100644
index 000000000000..7703687c6e2e
--- /dev/null
+++ b/kernel/module/tree_lookup.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * kernel/module/tree_lookup.c - modules tree lookup
+ *
+ * Copyright (C) 2015 Peter Zijlstra
+ * Copyright (C) 2015 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/rbtree_latch.h>
+
+/*
+ * Use a latched RB-tree for __module_address(); this allows us to use
+ * RCU-sched lookups of the address from any context.
+ *
+ * This is conditional on PERF_EVENTS || TRACING because those can really hit
+ * __module_address() hard by doing a lot of stack unwinding; potentially from
+ * NMI context.
+ */
+
+__always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
+{
+	struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
+
+	return (unsigned long)layout->base;
+}
+
+__always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
+{
+	struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
+
+	return (unsigned long)layout->size;
+}
+
+__always_inline bool
+mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
+{
+	return __mod_tree_val(a) < __mod_tree_val(b);
+}
+
+__always_inline int
+mod_tree_comp(void *key, struct latch_tree_node *n)
+{
+	unsigned long val = (unsigned long)key;
+	unsigned long start, end;
+
+	start = __mod_tree_val(n);
+	if (val < start)
+		return -1;
+
+	end = start + __mod_tree_size(n);
+	if (val >= end)
+		return 1;
+
+	return 0;
+}
+
+const struct latch_tree_ops mod_tree_ops = {
+	.less = mod_tree_less,
+	.comp = mod_tree_comp,
+};
+
+noinline void __mod_tree_insert(struct mod_tree_node *node)
+{
+	latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
+}
+
+void __mod_tree_remove(struct mod_tree_node *node)
+{
+	latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
+}
+
+/*
+ * These modifications: insert, remove_init and remove; are serialized by the
+ * module_mutex.
+ */
+void mod_tree_insert(struct module *mod)
+{
+	mod->core_layout.mtn.mod = mod;
+	mod->init_layout.mtn.mod = mod;
+
+	__mod_tree_insert(&mod->core_layout.mtn);
+	if (mod->init_layout.size)
+		__mod_tree_insert(&mod->init_layout.mtn);
+}
+
+void mod_tree_remove_init(struct module *mod)
+{
+	if (mod->init_layout.size)
+		__mod_tree_remove(&mod->init_layout.mtn);
+}
+
+void mod_tree_remove(struct module *mod)
+{
+	__mod_tree_remove(&mod->core_layout.mtn);
+	mod_tree_remove_init(mod);
+}
+
+struct module *mod_find(unsigned long addr)
+{
+	struct latch_tree_node *ltn;
+
+	ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
+	if (!ltn)
+		return NULL;
+
+	return container_of(ltn, struct mod_tree_node, node)->mod;
+}
-- 
2.31.1

[RFC PATCH v2 05/13] module: Move arch strict rwx support to a separate file

[Aaron Tomlin]

No functional change.

This patch migrates applicable architecture code
that support strict module rwx from core module code
into kernel/module/arch_strict_rwx.c

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 include/linux/module.h          | 16 +++++++++++
 kernel/module/Makefile          |  1 +
 kernel/module/arch_strict_rwx.c | 44 ++++++++++++++++++++++++++++
 kernel/module/main.c            | 51 ---------------------------------
 4 files changed, 61 insertions(+), 51 deletions(-)
 create mode 100644 kernel/module/arch_strict_rwx.c

diff --git a/include/linux/module.h b/include/linux/module.h
index 8b4d254a84c0..caa7212cf754 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -338,6 +338,22 @@ struct module_layout {
 #endif
 };
 
+/*
+ * Modules' sections will be aligned on page boundaries
+ * to ensure complete separation of code and data, but
+ * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
+ */
+#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
+# define debug_align(X) ALIGN(X, PAGE_SIZE)
+
+extern void frob_text(const struct module_layout *layout, int (*set_memory)(unsigned long start, int num_pages));
+extern void module_enable_x(const struct module *mod);
+#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+# define debug_align(X) (X)
+
+static void module_enable_x(const struct module *mod) { }
+#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+
 #ifdef CONFIG_MODULES_TREE_LOOKUP
 struct mod_tree_root {
 	struct latch_tree_root root;
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 9d593362156d..95fad95a0549 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_MODULE_SIG) += signing.o
 obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
 obj-$(CONFIG_LIVEPATCH) += livepatch.o
 obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
+obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
diff --git a/kernel/module/arch_strict_rwx.c b/kernel/module/arch_strict_rwx.c
new file mode 100644
index 000000000000..68e970671ec5
--- /dev/null
+++ b/kernel/module/arch_strict_rwx.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * kernel/module/arch_strict_rwx.c - module arch strict rwx
+ *
+ * Copyright (C) 2015 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/set_memory.h>
+
+/*
+ * LKM RO/NX protection: protect module's text/ro-data
+ * from modification and any data from execution.
+ *
+ * General layout of module is:
+ *          [text] [read-only-data] [ro-after-init] [writable data]
+ * text_size -----^                ^               ^               ^
+ * ro_size ------------------------|               |               |
+ * ro_after_init_size -----------------------------|               |
+ * size -----------------------------------------------------------|
+ *
+ * These values are always page-aligned (as is base)
+ */
+
+/*
+ * Since some arches are moving towards PAGE_KERNEL module allocations instead
+ * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
+ * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
+ * whether we are strict.
+ */
+void frob_text(const struct module_layout *layout,
+		      int (*set_memory)(unsigned long start, int num_pages))
+{
+	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
+	BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
+	set_memory((unsigned long)layout->base,
+		   layout->text_size >> PAGE_SHIFT);
+}
+
+void module_enable_x(const struct module *mod)
+{
+	frob_text(&mod->core_layout, set_memory_x);
+	frob_text(&mod->init_layout, set_memory_x);
+}
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 692cc520420d..a0619256b343 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -13,7 +13,6 @@
 #include <linux/trace_events.h>
 #include <linux/init.h>
 #include <linux/kallsyms.h>
-#include <linux/buildid.h>
 #include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/sysfs.h>
@@ -63,17 +62,6 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/module.h>
 
-/*
- * Modules' sections will be aligned on page boundaries
- * to ensure complete separation of code and data, but
- * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
- */
-#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
-# define debug_align(X) ALIGN(X, PAGE_SIZE)
-#else
-# define debug_align(X) (X)
-#endif
-
 /*
  * Mutex protects:
  * 1) List of modules (also safely readable with preempt_disable),
@@ -1786,45 +1774,6 @@ static void mod_sysfs_teardown(struct module *mod)
 	mod_sysfs_fini(mod);
 }
 
-/*
- * LKM RO/NX protection: protect module's text/ro-data
- * from modification and any data from execution.
- *
- * General layout of module is:
- *          [text] [read-only-data] [ro-after-init] [writable data]
- * text_size -----^                ^               ^               ^
- * ro_size ------------------------|               |               |
- * ro_after_init_size -----------------------------|               |
- * size -----------------------------------------------------------|
- *
- * These values are always page-aligned (as is base)
- */
-
-/*
- * Since some arches are moving towards PAGE_KERNEL module allocations instead
- * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
- * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
- * whether we are strict.
- */
-#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
-static void frob_text(const struct module_layout *layout,
-		      int (*set_memory)(unsigned long start, int num_pages))
-{
-	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
-	BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
-	set_memory((unsigned long)layout->base,
-		   layout->text_size >> PAGE_SHIFT);
-}
-
-static void module_enable_x(const struct module *mod)
-{
-	frob_text(&mod->core_layout, set_memory_x);
-	frob_text(&mod->init_layout, set_memory_x);
-}
-#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
-static void module_enable_x(const struct module *mod) { }
-#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
-
 #ifdef CONFIG_STRICT_MODULE_RWX
 static void frob_rodata(const struct module_layout *layout,
 			int (*set_memory)(unsigned long start, int num_pages))
-- 
2.31.1

[RFC PATCH v2 06/13] module: Move strict rwx support to a separate file

[Aaron Tomlin]

No functional change.

This patch migrates code that makes module text
and rodata memory read-only and non-text memory
non-executable from core module code into
kernel/module/strict_rwx.c.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 include/linux/module.h     | 18 ++++++++
 kernel/module/Makefile     |  1 +
 kernel/module/main.c       | 84 --------------------------------------
 kernel/module/strict_rwx.c | 83 +++++++++++++++++++++++++++++++++++++
 4 files changed, 102 insertions(+), 84 deletions(-)
 create mode 100644 kernel/module/strict_rwx.c

diff --git a/include/linux/module.h b/include/linux/module.h
index caa7212cf754..218ac6768433 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -354,6 +354,24 @@ extern void module_enable_x(const struct module *mod);
 static void module_enable_x(const struct module *mod) { }
 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
 
+#ifdef CONFIG_STRICT_MODULE_RWX
+extern void frob_rodata(const struct module_layout *layout, int (*set_memory)(unsigned long start, int num_pages));
+extern void frob_ro_after_init(const struct module_layout *layout, int (*set_memory)(unsigned long start, int num_pages));
+extern void frob_writable_data(const struct module_layout *layout, int (*set_memory)(unsigned long start, int num_pages));
+extern void module_enable_ro(const struct module *mod, bool after_init);
+extern void module_enable_nx(const struct module *mod);
+extern int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, char *secstrings, struct module *mod);
+
+#else /* !CONFIG_STRICT_MODULE_RWX */
+static void module_enable_nx(const struct module *mod) { }
+static void module_enable_ro(const struct module *mod, bool after_init) {}
+static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+				       char *secstrings, struct module *mod)
+{
+	return 0;
+}
+#endif /* CONFIG_STRICT_MODULE_RWX */
+
 #ifdef CONFIG_MODULES_TREE_LOOKUP
 struct mod_tree_root {
 	struct latch_tree_root root;
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 95fad95a0549..795fe10ac530 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
 obj-$(CONFIG_LIVEPATCH) += livepatch.o
 obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
 obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
+obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
diff --git a/kernel/module/main.c b/kernel/module/main.c
index a0619256b343..c404d00f7958 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1774,90 +1774,6 @@ static void mod_sysfs_teardown(struct module *mod)
 	mod_sysfs_fini(mod);
 }
 
-#ifdef CONFIG_STRICT_MODULE_RWX
-static void frob_rodata(const struct module_layout *layout,
-			int (*set_memory)(unsigned long start, int num_pages))
-{
-	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
-	BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
-	BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
-	set_memory((unsigned long)layout->base + layout->text_size,
-		   (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
-}
-
-static void frob_ro_after_init(const struct module_layout *layout,
-				int (*set_memory)(unsigned long start, int num_pages))
-{
-	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
-	BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
-	BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
-	set_memory((unsigned long)layout->base + layout->ro_size,
-		   (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
-}
-
-static void frob_writable_data(const struct module_layout *layout,
-			       int (*set_memory)(unsigned long start, int num_pages))
-{
-	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
-	BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
-	BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
-	set_memory((unsigned long)layout->base + layout->ro_after_init_size,
-		   (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
-}
-
-static void module_enable_ro(const struct module *mod, bool after_init)
-{
-	if (!rodata_enabled)
-		return;
-
-	set_vm_flush_reset_perms(mod->core_layout.base);
-	set_vm_flush_reset_perms(mod->init_layout.base);
-	frob_text(&mod->core_layout, set_memory_ro);
-
-	frob_rodata(&mod->core_layout, set_memory_ro);
-	frob_text(&mod->init_layout, set_memory_ro);
-	frob_rodata(&mod->init_layout, set_memory_ro);
-
-	if (after_init)
-		frob_ro_after_init(&mod->core_layout, set_memory_ro);
-}
-
-static void module_enable_nx(const struct module *mod)
-{
-	frob_rodata(&mod->core_layout, set_memory_nx);
-	frob_ro_after_init(&mod->core_layout, set_memory_nx);
-	frob_writable_data(&mod->core_layout, set_memory_nx);
-	frob_rodata(&mod->init_layout, set_memory_nx);
-	frob_writable_data(&mod->init_layout, set_memory_nx);
-}
-
-static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
-				       char *secstrings, struct module *mod)
-{
-	const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
-	int i;
-
-	for (i = 0; i < hdr->e_shnum; i++) {
-		if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
-			pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
-				mod->name, secstrings + sechdrs[i].sh_name, i);
-			return -ENOEXEC;
-		}
-	}
-
-	return 0;
-}
-
-#else /* !CONFIG_STRICT_MODULE_RWX */
-static void module_enable_nx(const struct module *mod) { }
-static void module_enable_ro(const struct module *mod, bool after_init) {}
-static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
-				       char *secstrings, struct module *mod)
-{
-	return 0;
-}
-#endif /*  CONFIG_STRICT_MODULE_RWX */
-
 void __weak module_memfree(void *module_region)
 {
 	/*
diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c
new file mode 100644
index 000000000000..8a513ced02c6
--- /dev/null
+++ b/kernel/module/strict_rwx.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * kernel/module/strict_rwx.c - module strict rwx
+ *
+ * Copyright (C) 2015 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/set_memory.h>
+
+void frob_rodata(const struct module_layout *layout,
+			int (*set_memory)(unsigned long start, int num_pages))
+{
+	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
+	BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
+	BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
+	set_memory((unsigned long)layout->base + layout->text_size,
+		   (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
+}
+
+void frob_ro_after_init(const struct module_layout *layout,
+				int (*set_memory)(unsigned long start, int num_pages))
+{
+	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
+	BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
+	BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
+	set_memory((unsigned long)layout->base + layout->ro_size,
+		   (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
+}
+
+void frob_writable_data(const struct module_layout *layout,
+			       int (*set_memory)(unsigned long start, int num_pages))
+{
+	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
+	BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
+	BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
+	set_memory((unsigned long)layout->base + layout->ro_after_init_size,
+		   (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
+}
+
+void module_enable_ro(const struct module *mod, bool after_init)
+{
+	if (!rodata_enabled)
+		return;
+
+	set_vm_flush_reset_perms(mod->core_layout.base);
+	set_vm_flush_reset_perms(mod->init_layout.base);
+	frob_text(&mod->core_layout, set_memory_ro);
+
+	frob_rodata(&mod->core_layout, set_memory_ro);
+	frob_text(&mod->init_layout, set_memory_ro);
+	frob_rodata(&mod->init_layout, set_memory_ro);
+
+	if (after_init)
+		frob_ro_after_init(&mod->core_layout, set_memory_ro);
+}
+
+void module_enable_nx(const struct module *mod)
+{
+	frob_rodata(&mod->core_layout, set_memory_nx);
+	frob_ro_after_init(&mod->core_layout, set_memory_nx);
+	frob_writable_data(&mod->core_layout, set_memory_nx);
+	frob_rodata(&mod->init_layout, set_memory_nx);
+	frob_writable_data(&mod->init_layout, set_memory_nx);
+}
+
+int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+				       char *secstrings, struct module *mod)
+{
+	const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
+	int i;
+
+	for (i = 0; i < hdr->e_shnum; i++) {
+		if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
+			pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
+				mod->name, secstrings + sechdrs[i].sh_name, i);
+			return -ENOEXEC;
+		}
+	}
+
+	return 0;
+}
-- 
2.31.1

[RFC PATCH v2 07/13] module: Move extra signature support out of core code

[Aaron Tomlin]

No functional change.

This patch migrates additional module signature check
code from core module code into kernel/module/signing.c.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 include/linux/module.h   |  5 ++-
 kernel/module/internal.h |  9 +++++
 kernel/module/main.c     | 86 ----------------------------------------
 kernel/module/signing.c  | 75 +++++++++++++++++++++++++++++++++++
 4 files changed, 87 insertions(+), 88 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index 218ac6768433..3383912268af 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -736,8 +736,8 @@ static inline bool is_livepatch_module(struct module *mod)
 }
 #endif /* CONFIG_LIVEPATCH */
 
-bool is_module_sig_enforced(void);
-void set_module_sig_enforced(void);
+extern bool is_module_sig_enforced(void);
+extern void set_module_sig_enforced(void);
 
 #else /* !CONFIG_MODULES... */
 
@@ -927,6 +927,7 @@ static inline bool module_sig_ok(struct module *module)
 {
 	return true;
 }
+#define sig_enforce false
 #endif	/* CONFIG_MODULE_SIG */
 
 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 91ef152aeffb..b4db57bafcd3 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -63,3 +63,12 @@ static inline int copy_module_elf(struct module *mod, struct load_info *info)
 }
 static inline void free_module_elf(struct module *mod) { }
 #endif /* CONFIG_LIVEPATCH */
+
+#ifdef CONFIG_MODULE_SIG
+extern int module_sig_check(struct load_info *info, int flags);
+#else /* !CONFIG_MODULE_SIG */
+static int module_sig_check(struct load_info *info, int flags)
+{
+	return 0;
+}
+#endif /* !CONFIG_MODULE_SIG */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index c404d00f7958..8f8a904d5ba7 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -22,7 +22,6 @@
 #include <linux/vmalloc.h>
 #include <linux/elf.h>
 #include <linux/proc_fs.h>
-#include <linux/security.h>
 #include <linux/seq_file.h>
 #include <linux/syscalls.h>
 #include <linux/fcntl.h>
@@ -114,28 +113,6 @@ static void module_assert_mutex_or_preempt(void)
 #endif
 }
 
-#ifdef CONFIG_MODULE_SIG
-static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
-module_param(sig_enforce, bool_enable_only, 0644);
-
-void set_module_sig_enforced(void)
-{
-	sig_enforce = true;
-}
-#else
-#define sig_enforce false
-#endif
-
-/*
- * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
- * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
- */
-bool is_module_sig_enforced(void)
-{
-	return sig_enforce;
-}
-EXPORT_SYMBOL(is_module_sig_enforced);
-
 /* Block module loading/unloading? */
 int modules_disabled = 0;
 core_param(nomodule, modules_disabled, bint, 0);
@@ -2517,69 +2494,6 @@ static inline void kmemleak_load_module(const struct module *mod,
 }
 #endif
 
-#ifdef CONFIG_MODULE_SIG
-static int module_sig_check(struct load_info *info, int flags)
-{
-	int err = -ENODATA;
-	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
-	const char *reason;
-	const void *mod = info->hdr;
-
-	/*
-	 * Require flags == 0, as a module with version information
-	 * removed is no longer the module that was signed
-	 */
-	if (flags == 0 &&
-	    info->len > markerlen &&
-	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
-		/* We truncate the module to discard the signature */
-		info->len -= markerlen;
-		err = mod_verify_sig(mod, info);
-		if (!err) {
-			info->sig_ok = true;
-			return 0;
-		}
-	}
-
-	/*
-	 * We don't permit modules to be loaded into the trusted kernels
-	 * without a valid signature on them, but if we're not enforcing,
-	 * certain errors are non-fatal.
-	 */
-	switch (err) {
-	case -ENODATA:
-		reason = "unsigned module";
-		break;
-	case -ENOPKG:
-		reason = "module with unsupported crypto";
-		break;
-	case -ENOKEY:
-		reason = "module with unavailable key";
-		break;
-
-	default:
-		/*
-		 * All other errors are fatal, including lack of memory,
-		 * unparseable signatures, and signature check failures --
-		 * even if signatures aren't required.
-		 */
-		return err;
-	}
-
-	if (is_module_sig_enforced()) {
-		pr_notice("Loading of %s is rejected\n", reason);
-		return -EKEYREJECTED;
-	}
-
-	return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
-}
-#else /* !CONFIG_MODULE_SIG */
-static int module_sig_check(struct load_info *info, int flags)
-{
-	return 0;
-}
-#endif /* !CONFIG_MODULE_SIG */
-
 static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
 {
 	unsigned long secend;
diff --git a/kernel/module/signing.c b/kernel/module/signing.c
index 8aeb6d2ee94b..ff41541e982a 100644
--- a/kernel/module/signing.c
+++ b/kernel/module/signing.c
@@ -11,9 +11,28 @@
 #include <linux/module_signature.h>
 #include <linux/string.h>
 #include <linux/verification.h>
+#include <linux/security.h>
 #include <crypto/public_key.h>
 #include "internal.h"
 
+static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
+module_param(sig_enforce, bool_enable_only, 0644);
+
+/*
+ * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
+ * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
+ */
+bool is_module_sig_enforced(void)
+{
+	return sig_enforce;
+}
+EXPORT_SYMBOL(is_module_sig_enforced);
+
+void set_module_sig_enforced(void)
+{
+	sig_enforce = true;
+}
+
 /*
  * Verify the signature on a module.
  */
@@ -43,3 +62,59 @@ int mod_verify_sig(const void *mod, struct load_info *info)
 				      VERIFYING_MODULE_SIGNATURE,
 				      NULL, NULL);
 }
+
+int module_sig_check(struct load_info *info, int flags)
+{
+	int err = -ENODATA;
+	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
+	const char *reason;
+	const void *mod = info->hdr;
+
+	/*
+	 * Require flags == 0, as a module with version information
+	 * removed is no longer the module that was signed
+	 */
+	if (flags == 0 &&
+	    info->len > markerlen &&
+	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
+		/* We truncate the module to discard the signature */
+		info->len -= markerlen;
+		err = mod_verify_sig(mod, info);
+		if (!err) {
+			info->sig_ok = true;
+			return 0;
+		}
+	}
+
+	/*
+	 * We don't permit modules to be loaded into the trusted kernels
+	 * without a valid signature on them, but if we're not enforcing,
+	 * certain errors are non-fatal.
+	 */
+	switch (err) {
+	case -ENODATA:
+		reason = "unsigned module";
+		break;
+	case -ENOPKG:
+		reason = "module with unsupported crypto";
+		break;
+	case -ENOKEY:
+		reason = "module with unavailable key";
+		break;
+
+	default:
+		/*
+		 * All other errors are fatal, including lack of memory,
+		 * unparseable signatures, and signature check failures --
+		 * even if signatures aren't required.
+		 */
+		return err;
+	}
+
+	if (is_module_sig_enforced()) {
+		pr_notice("Loading of %s is rejected\n", reason);
+		return -EKEYREJECTED;
+	}
+
+	return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
+}
-- 
2.31.1

[RFC PATCH v2 08/13] module: Move kmemleak support to a separate file

[Aaron Tomlin]

No functional change.

This patch migrates kmemleak code out of core module
code into kernel/module/debug_kmemleak.c

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 kernel/module/Makefile         |  1 +
 kernel/module/debug_kmemleak.c | 30 ++++++++++++++++++++++++++++++
 kernel/module/internal.h       |  7 +++++++
 kernel/module/main.c           | 27 ---------------------------
 4 files changed, 38 insertions(+), 27 deletions(-)
 create mode 100644 kernel/module/debug_kmemleak.c

diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 795fe10ac530..2e03da799833 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_LIVEPATCH) += livepatch.o
 obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
 obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
 obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
+obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
diff --git a/kernel/module/debug_kmemleak.c b/kernel/module/debug_kmemleak.c
new file mode 100644
index 000000000000..818c9d168aed
--- /dev/null
+++ b/kernel/module/debug_kmemleak.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * kernel/module/debug_kmemleak.c - module kmemleak support
+ *
+ * Copyright (C) 2009 Catalin Marinas
+ */
+
+#include <linux/module.h>
+#include <linux/kmemleak.h>
+#include "internal.h"
+
+void kmemleak_load_module(const struct module *mod,
+				 const struct load_info *info)
+{
+	unsigned int i;
+
+	/* only scan the sections containing data */
+	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
+
+	for (i = 1; i < info->hdr->e_shnum; i++) {
+		/* Scan all writable sections that's not executable */
+		if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
+		    !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
+		    (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
+			continue;
+
+		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
+				   info->sechdrs[i].sh_size, GFP_KERNEL);
+	}
+}
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index b4db57bafcd3..31d767416f0c 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -6,6 +6,7 @@
  */
 
 #include <linux/elf.h>
+#include <linux/compiler.h>
 #include <asm/module.h>
 #include <linux/mutex.h>
 
@@ -72,3 +73,9 @@ static int module_sig_check(struct load_info *info, int flags)
 	return 0;
 }
 #endif /* !CONFIG_MODULE_SIG */
+
+#ifdef CONFIG_DEBUG_KMEMLEAK
+extern void kmemleak_load_module(const struct module *mod, const struct load_info *info);
+#else /* !CONFIG_DEBUG_KMEMLEAK */
+static inline void __maybe_unused kmemleak_load_module(const struct module *mod, const struct load_info *info) { }
+#endif /* CONFIG_DEBUG_KMEMLEAK */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 8f8a904d5ba7..672a977b1320 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2467,33 +2467,6 @@ bool __weak module_exit_section(const char *name)
 	return strstarts(name, ".exit");
 }
 
-#ifdef CONFIG_DEBUG_KMEMLEAK
-static void kmemleak_load_module(const struct module *mod,
-				 const struct load_info *info)
-{
-	unsigned int i;
-
-	/* only scan the sections containing data */
-	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
-
-	for (i = 1; i < info->hdr->e_shnum; i++) {
-		/* Scan all writable sections that's not executable */
-		if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
-		    !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
-		    (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
-			continue;
-
-		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
-				   info->sechdrs[i].sh_size, GFP_KERNEL);
-	}
-}
-#else
-static inline void kmemleak_load_module(const struct module *mod,
-					const struct load_info *info)
-{
-}
-#endif
-
 static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
 {
 	unsigned long secend;
-- 
2.31.1

[RFC PATCH v2 09/13] module: Move kallsyms support into a separate file

[Aaron Tomlin]

No functional change.

This patch migrates kallsyms code out of core module
code kernel/module/kallsyms.c

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 kernel/module/Makefile   |   1 +
 kernel/module/internal.h |  20 ++
 kernel/module/kallsyms.c | 506 ++++++++++++++++++++++++++++++++++++++
 kernel/module/main.c     | 516 +--------------------------------------
 4 files changed, 531 insertions(+), 512 deletions(-)
 create mode 100644 kernel/module/kallsyms.c

diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 2e03da799833..23582011ab08 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
 obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
 obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
 obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
+obj-$(CONFIG_KALLSYMS) += kallsyms.o
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 31d767416f0c..119d42c304a1 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -79,3 +79,23 @@ extern void kmemleak_load_module(const struct module *mod, const struct load_inf
 #else /* !CONFIG_DEBUG_KMEMLEAK */
 static inline void __maybe_unused kmemleak_load_module(const struct module *mod, const struct load_info *info) { }
 #endif /* CONFIG_DEBUG_KMEMLEAK */
+
+#ifdef CONFIG_KALLSYMS
+#ifdef CONFIG_STACKTRACE_BUILD_ID
+extern void init_build_id(struct module *mod, const struct load_info *info);
+#else /* !CONFIG_STACKTRACE_BUILD_ID */
+static inline void init_build_id(struct module *mod, const struct load_info *info) { }
+
+#endif
+extern void layout_symtab(struct module *mod, struct load_info *info);
+extern void add_kallsyms(struct module *mod, const struct load_info *info);
+extern bool sect_empty(const Elf_Shdr *sect);
+extern const char *find_kallsyms_symbol(struct module *mod, unsigned long addr, unsigned long *size, unsigned long *offset);
+#else /* !CONFIG_KALLSYMS */
+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) { }
+static inline char *find_kallsyms_symbol(struct module *mod, unsigned long addr, unsigned long *size, unsigned long *offset)
+{
+	return NULL;
+}
+#endif /* CONFIG_KALLSYMS */
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
new file mode 100644
index 000000000000..f682415459fe
--- /dev/null
+++ b/kernel/module/kallsyms.c
@@ -0,0 +1,506 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * kernel/module/kallsyms.c - module kallsyms support
+ *
+ * Copyright (C) 2010 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/buildid.h>
+#include <linux/bsearch.h>
+#include "internal.h"
+
+extern struct module *find_module_all(const char *name, size_t len, bool even_unformed);
+extern unsigned long kernel_symbol_value(const struct kernel_symbol *sym);
+extern int cmp_name(const void *name, const void *sym);
+extern long get_offset(struct module *mod, unsigned int *size, Elf_Shdr *sechdr, unsigned int section);
+
+/* Lookup exported symbol in given range of kernel_symbols */
+static const struct kernel_symbol *lookup_exported_symbol(const char *name,
+							  const struct kernel_symbol *start,
+							  const struct kernel_symbol *stop)
+{
+	return bsearch(name, start, stop - start,
+			sizeof(struct kernel_symbol), cmp_name);
+}
+
+static int is_exported(const char *name, unsigned long value,
+		       const struct module *mod)
+{
+	const struct kernel_symbol *ks;
+	if (!mod)
+		ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
+	else
+		ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
+
+	return ks != NULL && kernel_symbol_value(ks) == value;
+}
+
+/* As per nm */
+static char elf_type(const Elf_Sym *sym, const struct load_info *info)
+{
+	const Elf_Shdr *sechdrs = info->sechdrs;
+
+	if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
+		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
+			return 'v';
+		else
+			return 'w';
+	}
+	if (sym->st_shndx == SHN_UNDEF)
+		return 'U';
+	if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
+		return 'a';
+	if (sym->st_shndx >= SHN_LORESERVE)
+		return '?';
+	if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
+		return 't';
+	if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
+	    && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
+		if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
+			return 'r';
+		else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
+			return 'g';
+		else
+			return 'd';
+	}
+	if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
+		if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
+			return 's';
+		else
+			return 'b';
+	}
+	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
+		      ".debug")) {
+		return 'n';
+	}
+	return '?';
+}
+
+static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
+			unsigned int shnum, unsigned int pcpundx)
+{
+	const Elf_Shdr *sec;
+
+	if (src->st_shndx == SHN_UNDEF
+	    || src->st_shndx >= shnum
+	    || !src->st_name)
+		return false;
+
+#ifdef CONFIG_KALLSYMS_ALL
+	if (src->st_shndx == pcpundx)
+		return true;
+#endif
+
+	sec = sechdrs + src->st_shndx;
+	if (!(sec->sh_flags & SHF_ALLOC)
+#ifndef CONFIG_KALLSYMS_ALL
+	    || !(sec->sh_flags & SHF_EXECINSTR)
+#endif
+	    || (sec->sh_entsize & INIT_OFFSET_MASK))
+		return false;
+
+	return true;
+}
+
+/*
+ * We only allocate and copy the strings needed by the parts of symtab
+ * we keep.  This is simple, but has the effect of making multiple
+ * copies of duplicates.  We could be more sophisticated, see
+ * linux-kernel thread starting with
+ * <73defb5e4bca04a6431392cc341112b1@localhost>.
+ */
+void layout_symtab(struct module *mod, struct load_info *info)
+{
+	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
+	Elf_Shdr *strsect = info->sechdrs + info->index.str;
+	const Elf_Sym *src;
+	unsigned int i, nsrc, ndst, strtab_size = 0;
+
+	/* Put symbol section at end of init part of module. */
+	symsect->sh_flags |= SHF_ALLOC;
+	symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
+					 info->index.sym) | INIT_OFFSET_MASK;
+	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
+
+	src = (void *)info->hdr + symsect->sh_offset;
+	nsrc = symsect->sh_size / sizeof(*src);
+
+	/* Compute total space required for the core symbols' strtab. */
+	for (ndst = i = 0; i < nsrc; i++) {
+		if (i == 0 || is_livepatch_module(mod) ||
+		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
+				   info->index.pcpu)) {
+			strtab_size += strlen(&info->strtab[src[i].st_name])+1;
+			ndst++;
+		}
+	}
+
+	/* Append room for core symbols at end of core part. */
+	info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
+	info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
+	mod->core_layout.size += strtab_size;
+	info->core_typeoffs = mod->core_layout.size;
+	mod->core_layout.size += ndst * sizeof(char);
+	mod->core_layout.size = debug_align(mod->core_layout.size);
+
+	/* Put string table section at end of init part of module. */
+	strsect->sh_flags |= SHF_ALLOC;
+	strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
+					 info->index.str) | INIT_OFFSET_MASK;
+	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
+
+	/* We'll tack temporary mod_kallsyms on the end. */
+	mod->init_layout.size = ALIGN(mod->init_layout.size,
+				      __alignof__(struct mod_kallsyms));
+	info->mod_kallsyms_init_off = mod->init_layout.size;
+	mod->init_layout.size += sizeof(struct mod_kallsyms);
+	info->init_typeoffs = mod->init_layout.size;
+	mod->init_layout.size += nsrc * sizeof(char);
+	mod->init_layout.size = debug_align(mod->init_layout.size);
+}
+
+/*
+ * We use the full symtab and strtab which layout_symtab arranged to
+ * be appended to the init section.  Later we switch to the cut-down
+ * core-only ones.
+ */
+void add_kallsyms(struct module *mod, const struct load_info *info)
+{
+	unsigned int i, ndst;
+	const Elf_Sym *src;
+	Elf_Sym *dst;
+	char *s;
+	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
+
+	/* Set up to point into init section. */
+	mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
+
+	mod->kallsyms->symtab = (void *)symsec->sh_addr;
+	mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
+	/* Make sure we get permanent strtab: don't use info->strtab. */
+	mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
+	mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
+
+	/*
+	 * Now populate the cut down core kallsyms for after init
+	 * and set types up while we still have access to sections.
+	 */
+	mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
+	mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
+	mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
+	src = mod->kallsyms->symtab;
+	for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
+		mod->kallsyms->typetab[i] = elf_type(src + i, info);
+		if (i == 0 || is_livepatch_module(mod) ||
+		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
+				   info->index.pcpu)) {
+			mod->core_kallsyms.typetab[ndst] =
+			    mod->kallsyms->typetab[i];
+			dst[ndst] = src[i];
+			dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
+			s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
+				     KSYM_NAME_LEN) + 1;
+		}
+	}
+	mod->core_kallsyms.num_symtab = ndst;
+}
+
+inline bool sect_empty(const Elf_Shdr *sect)
+{
+	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
+}
+
+#ifdef CONFIG_STACKTRACE_BUILD_ID
+void init_build_id(struct module *mod, const struct load_info *info)
+{
+	const Elf_Shdr *sechdr;
+	unsigned int i;
+
+	for (i = 0; i < info->hdr->e_shnum; i++) {
+		sechdr = &info->sechdrs[i];
+		if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
+		    !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
+					sechdr->sh_size))
+			break;
+	}
+}
+#endif
+
+/*
+ * This ignores the intensely annoying "mapping symbols" found
+ * in ARM ELF files: $a, $t and $d.
+ */
+static inline int is_arm_mapping_symbol(const char *str)
+{
+	if (str[0] == '.' && str[1] == 'L')
+		return true;
+	return str[0] == '$' && strchr("axtd", str[1])
+	       && (str[2] == '\0' || str[2] == '.');
+}
+
+static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
+{
+	return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
+}
+
+/*
+ * Given a module and address, find the corresponding symbol and return its name
+ * while providing its size and offset if needed.
+ */
+const char *find_kallsyms_symbol(struct module *mod,
+					unsigned long addr,
+					unsigned long *size,
+					unsigned long *offset)
+{
+	unsigned int i, best = 0;
+	unsigned long nextval, bestval;
+	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
+
+	/* At worse, next value is at end of module */
+	if (within_module_init(addr, mod))
+		nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
+	else
+		nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
+
+	bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
+
+	/*
+	 * Scan for closest preceding symbol, and next symbol. (ELF
+	 * starts real symbols at 1).
+	 */
+	for (i = 1; i < kallsyms->num_symtab; i++) {
+		const Elf_Sym *sym = &kallsyms->symtab[i];
+		unsigned long thisval = kallsyms_symbol_value(sym);
+
+		if (sym->st_shndx == SHN_UNDEF)
+			continue;
+
+		/*
+		 * We ignore unnamed symbols: they're uninformative
+		 * and inserted at a whim.
+		 */
+		if (*kallsyms_symbol_name(kallsyms, i) == '\0'
+		    || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
+			continue;
+
+		if (thisval <= addr && thisval > bestval) {
+			best = i;
+			bestval = thisval;
+		}
+		if (thisval > addr && thisval < nextval)
+			nextval = thisval;
+	}
+
+	if (!best)
+		return NULL;
+
+	if (size)
+		*size = nextval - bestval;
+	if (offset)
+		*offset = addr - bestval;
+
+	return kallsyms_symbol_name(kallsyms, best);
+}
+
+void * __weak dereference_module_function_descriptor(struct module *mod,
+						     void *ptr)
+{
+	return ptr;
+}
+
+/*
+ * For kallsyms to ask for address resolution.  NULL means not found.  Careful
+ * not to lock to avoid deadlock on oopses, simply disable preemption.
+ */
+const char *module_address_lookup(unsigned long addr,
+			    unsigned long *size,
+			    unsigned long *offset,
+			    char **modname,
+			    const unsigned char **modbuildid,
+			    char *namebuf)
+{
+	const char *ret = NULL;
+	struct module *mod;
+
+	preempt_disable();
+	mod = __module_address(addr);
+	if (mod) {
+		if (modname)
+			*modname = mod->name;
+		if (modbuildid) {
+#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
+			*modbuildid = mod->build_id;
+#else
+			*modbuildid = NULL;
+#endif
+		}
+
+		ret = find_kallsyms_symbol(mod, addr, size, offset);
+	}
+	/* Make a copy in here where it's safe */
+	if (ret) {
+		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
+		ret = namebuf;
+	}
+	preempt_enable();
+
+	return ret;
+}
+
+int lookup_module_symbol_name(unsigned long addr, char *symname)
+{
+	struct module *mod;
+
+	preempt_disable();
+	list_for_each_entry_rcu(mod, &modules, list) {
+		if (mod->state == MODULE_STATE_UNFORMED)
+			continue;
+		if (within_module(addr, mod)) {
+			const char *sym;
+
+			sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
+			if (!sym)
+				goto out;
+
+			strlcpy(symname, sym, KSYM_NAME_LEN);
+			preempt_enable();
+			return 0;
+		}
+	}
+out:
+	preempt_enable();
+	return -ERANGE;
+}
+
+int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
+			unsigned long *offset, char *modname, char *name)
+{
+	struct module *mod;
+
+	preempt_disable();
+	list_for_each_entry_rcu(mod, &modules, list) {
+		if (mod->state == MODULE_STATE_UNFORMED)
+			continue;
+		if (within_module(addr, mod)) {
+			const char *sym;
+
+			sym = find_kallsyms_symbol(mod, addr, size, offset);
+			if (!sym)
+				goto out;
+			if (modname)
+				strlcpy(modname, mod->name, MODULE_NAME_LEN);
+			if (name)
+				strlcpy(name, sym, KSYM_NAME_LEN);
+			preempt_enable();
+			return 0;
+		}
+	}
+out:
+	preempt_enable();
+	return -ERANGE;
+}
+
+int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
+			char *name, char *module_name, int *exported)
+{
+	struct module *mod;
+
+	preempt_disable();
+	list_for_each_entry_rcu(mod, &modules, list) {
+		struct mod_kallsyms *kallsyms;
+
+		if (mod->state == MODULE_STATE_UNFORMED)
+			continue;
+		kallsyms = rcu_dereference_sched(mod->kallsyms);
+		if (symnum < kallsyms->num_symtab) {
+			const Elf_Sym *sym = &kallsyms->symtab[symnum];
+
+			*value = kallsyms_symbol_value(sym);
+			*type = kallsyms->typetab[symnum];
+			strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
+			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
+			*exported = is_exported(name, *value, mod);
+			preempt_enable();
+			return 0;
+		}
+		symnum -= kallsyms->num_symtab;
+	}
+	preempt_enable();
+	return -ERANGE;
+}
+
+/* Given a module and name of symbol, find and return the symbol's value */
+static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
+{
+	unsigned int i;
+	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
+
+	for (i = 0; i < kallsyms->num_symtab; i++) {
+		const Elf_Sym *sym = &kallsyms->symtab[i];
+
+		if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
+		    sym->st_shndx != SHN_UNDEF)
+			return kallsyms_symbol_value(sym);
+	}
+	return 0;
+}
+
+/* Look for this name: can be of form module:name. */
+unsigned long module_kallsyms_lookup_name(const char *name)
+{
+	struct module *mod;
+	char *colon;
+	unsigned long ret = 0;
+
+	/* Don't lock: we're in enough trouble already. */
+	preempt_disable();
+	if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
+		if ((mod = find_module_all(name, colon - name, false)) != NULL)
+			ret = find_kallsyms_symbol_value(mod, colon+1);
+	} else {
+		list_for_each_entry_rcu(mod, &modules, list) {
+			if (mod->state == MODULE_STATE_UNFORMED)
+				continue;
+			if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
+				break;
+		}
+	}
+	preempt_enable();
+	return ret;
+}
+
+#ifdef CONFIG_LIVEPATCH
+int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
+					     struct module *, unsigned long),
+				   void *data)
+{
+	struct module *mod;
+	unsigned int i;
+	int ret = 0;
+
+	mutex_lock(&module_mutex);
+	list_for_each_entry(mod, &modules, list) {
+		/* We hold module_mutex: no need for rcu_dereference_sched */
+		struct mod_kallsyms *kallsyms = mod->kallsyms;
+
+		if (mod->state == MODULE_STATE_UNFORMED)
+			continue;
+		for (i = 0; i < kallsyms->num_symtab; i++) {
+			const Elf_Sym *sym = &kallsyms->symtab[i];
+
+			if (sym->st_shndx == SHN_UNDEF)
+				continue;
+
+			ret = fn(data, kallsyms_symbol_name(kallsyms, i),
+				 mod, kallsyms_symbol_value(sym));
+			if (ret != 0)
+				goto out;
+		}
+	}
+out:
+	mutex_unlock(&module_mutex);
+	return ret;
+}
+#endif /* CONFIG_LIVEPATCH */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 672a977b1320..9813e1672d8c 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -275,7 +275,7 @@ static bool check_exported_symbol(const struct symsearch *syms,
 	return true;
 }
 
-static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
+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);
@@ -304,7 +304,7 @@ static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
 #endif
 }
 
-static int cmp_name(const void *name, const void *sym)
+int cmp_name(const void *name, const void *sym)
 {
 	return strcmp(name, kernel_symbol_name(sym));
 }
@@ -374,7 +374,7 @@ static bool find_symbol(struct find_symbol_arg *fsa)
  * Search for module by name: must hold module_mutex (or preempt disabled
  * for read-only access).
  */
-static struct module *find_module_all(const char *name, size_t len,
+struct module *find_module_all(const char *name, size_t len,
 				      bool even_unformed)
 {
 	struct module *mod;
@@ -1282,13 +1282,6 @@ resolve_symbol_wait(struct module *mod,
 	return ksym;
 }
 
-#ifdef CONFIG_KALLSYMS
-static inline bool sect_empty(const Elf_Shdr *sect)
-{
-	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
-}
-#endif
-
 /*
  * /sys/module/foo/sections stuff
  * J. Corbet <corbet@lwn.net>
@@ -2013,7 +2006,7 @@ unsigned int __weak arch_mod_section_prepend(struct module *mod,
 }
 
 /* Update size with this section: return offset. */
-static long get_offset(struct module *mod, unsigned int *size,
+long get_offset(struct module *mod, unsigned int *size,
 		       Elf_Shdr *sechdr, unsigned int section)
 {
 	long ret;
@@ -2215,228 +2208,6 @@ static void free_modinfo(struct module *mod)
 	}
 }
 
-#ifdef CONFIG_KALLSYMS
-
-/* Lookup exported symbol in given range of kernel_symbols */
-static const struct kernel_symbol *lookup_exported_symbol(const char *name,
-							  const struct kernel_symbol *start,
-							  const struct kernel_symbol *stop)
-{
-	return bsearch(name, start, stop - start,
-			sizeof(struct kernel_symbol), cmp_name);
-}
-
-static int is_exported(const char *name, unsigned long value,
-		       const struct module *mod)
-{
-	const struct kernel_symbol *ks;
-	if (!mod)
-		ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
-	else
-		ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
-
-	return ks != NULL && kernel_symbol_value(ks) == value;
-}
-
-/* As per nm */
-static char elf_type(const Elf_Sym *sym, const struct load_info *info)
-{
-	const Elf_Shdr *sechdrs = info->sechdrs;
-
-	if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
-		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
-			return 'v';
-		else
-			return 'w';
-	}
-	if (sym->st_shndx == SHN_UNDEF)
-		return 'U';
-	if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
-		return 'a';
-	if (sym->st_shndx >= SHN_LORESERVE)
-		return '?';
-	if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
-		return 't';
-	if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
-	    && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
-		if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
-			return 'r';
-		else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
-			return 'g';
-		else
-			return 'd';
-	}
-	if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
-		if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
-			return 's';
-		else
-			return 'b';
-	}
-	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
-		      ".debug")) {
-		return 'n';
-	}
-	return '?';
-}
-
-static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
-			unsigned int shnum, unsigned int pcpundx)
-{
-	const Elf_Shdr *sec;
-
-	if (src->st_shndx == SHN_UNDEF
-	    || src->st_shndx >= shnum
-	    || !src->st_name)
-		return false;
-
-#ifdef CONFIG_KALLSYMS_ALL
-	if (src->st_shndx == pcpundx)
-		return true;
-#endif
-
-	sec = sechdrs + src->st_shndx;
-	if (!(sec->sh_flags & SHF_ALLOC)
-#ifndef CONFIG_KALLSYMS_ALL
-	    || !(sec->sh_flags & SHF_EXECINSTR)
-#endif
-	    || (sec->sh_entsize & INIT_OFFSET_MASK))
-		return false;
-
-	return true;
-}
-
-/*
- * We only allocate and copy the strings needed by the parts of symtab
- * we keep.  This is simple, but has the effect of making multiple
- * copies of duplicates.  We could be more sophisticated, see
- * linux-kernel thread starting with
- * <73defb5e4bca04a6431392cc341112b1@localhost>.
- */
-static void layout_symtab(struct module *mod, struct load_info *info)
-{
-	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
-	Elf_Shdr *strsect = info->sechdrs + info->index.str;
-	const Elf_Sym *src;
-	unsigned int i, nsrc, ndst, strtab_size = 0;
-
-	/* Put symbol section at end of init part of module. */
-	symsect->sh_flags |= SHF_ALLOC;
-	symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
-					 info->index.sym) | INIT_OFFSET_MASK;
-	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
-
-	src = (void *)info->hdr + symsect->sh_offset;
-	nsrc = symsect->sh_size / sizeof(*src);
-
-	/* Compute total space required for the core symbols' strtab. */
-	for (ndst = i = 0; i < nsrc; i++) {
-		if (i == 0 || is_livepatch_module(mod) ||
-		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
-				   info->index.pcpu)) {
-			strtab_size += strlen(&info->strtab[src[i].st_name])+1;
-			ndst++;
-		}
-	}
-
-	/* Append room for core symbols at end of core part. */
-	info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
-	info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
-	mod->core_layout.size += strtab_size;
-	info->core_typeoffs = mod->core_layout.size;
-	mod->core_layout.size += ndst * sizeof(char);
-	mod->core_layout.size = debug_align(mod->core_layout.size);
-
-	/* Put string table section at end of init part of module. */
-	strsect->sh_flags |= SHF_ALLOC;
-	strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
-					 info->index.str) | INIT_OFFSET_MASK;
-	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
-
-	/* We'll tack temporary mod_kallsyms on the end. */
-	mod->init_layout.size = ALIGN(mod->init_layout.size,
-				      __alignof__(struct mod_kallsyms));
-	info->mod_kallsyms_init_off = mod->init_layout.size;
-	mod->init_layout.size += sizeof(struct mod_kallsyms);
-	info->init_typeoffs = mod->init_layout.size;
-	mod->init_layout.size += nsrc * sizeof(char);
-	mod->init_layout.size = debug_align(mod->init_layout.size);
-}
-
-/*
- * We use the full symtab and strtab which layout_symtab arranged to
- * be appended to the init section.  Later we switch to the cut-down
- * core-only ones.
- */
-static void add_kallsyms(struct module *mod, const struct load_info *info)
-{
-	unsigned int i, ndst;
-	const Elf_Sym *src;
-	Elf_Sym *dst;
-	char *s;
-	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
-
-	/* Set up to point into init section. */
-	mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
-
-	mod->kallsyms->symtab = (void *)symsec->sh_addr;
-	mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
-	/* Make sure we get permanent strtab: don't use info->strtab. */
-	mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
-	mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
-
-	/*
-	 * Now populate the cut down core kallsyms for after init
-	 * and set types up while we still have access to sections.
-	 */
-	mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
-	mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
-	mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
-	src = mod->kallsyms->symtab;
-	for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
-		mod->kallsyms->typetab[i] = elf_type(src + i, info);
-		if (i == 0 || is_livepatch_module(mod) ||
-		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
-				   info->index.pcpu)) {
-			mod->core_kallsyms.typetab[ndst] =
-			    mod->kallsyms->typetab[i];
-			dst[ndst] = src[i];
-			dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
-			s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
-				     KSYM_NAME_LEN) + 1;
-		}
-	}
-	mod->core_kallsyms.num_symtab = ndst;
-}
-#else
-static inline void layout_symtab(struct module *mod, struct load_info *info)
-{
-}
-
-static void add_kallsyms(struct module *mod, const struct load_info *info)
-{
-}
-#endif /* CONFIG_KALLSYMS */
-
-#if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
-static void init_build_id(struct module *mod, const struct load_info *info)
-{
-	const Elf_Shdr *sechdr;
-	unsigned int i;
-
-	for (i = 0; i < info->hdr->e_shnum; i++) {
-		sechdr = &info->sechdrs[i];
-		if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
-		    !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
-					sechdr->sh_size))
-			break;
-	}
-}
-#else
-static void init_build_id(struct module *mod, const struct load_info *info)
-{
-}
-#endif
-
 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
 {
 	if (!debug)
@@ -3702,285 +3473,6 @@ static inline int within(unsigned long addr, void *start, unsigned long size)
 	return ((void *)addr >= start && (void *)addr < start + size);
 }
 
-#ifdef CONFIG_KALLSYMS
-/*
- * This ignores the intensely annoying "mapping symbols" found
- * in ARM ELF files: $a, $t and $d.
- */
-static inline int is_arm_mapping_symbol(const char *str)
-{
-	if (str[0] == '.' && str[1] == 'L')
-		return true;
-	return str[0] == '$' && strchr("axtd", str[1])
-	       && (str[2] == '\0' || str[2] == '.');
-}
-
-static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
-{
-	return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
-}
-
-/*
- * Given a module and address, find the corresponding symbol and return its name
- * while providing its size and offset if needed.
- */
-static const char *find_kallsyms_symbol(struct module *mod,
-					unsigned long addr,
-					unsigned long *size,
-					unsigned long *offset)
-{
-	unsigned int i, best = 0;
-	unsigned long nextval, bestval;
-	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
-
-	/* At worse, next value is at end of module */
-	if (within_module_init(addr, mod))
-		nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
-	else
-		nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
-
-	bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
-
-	/*
-	 * Scan for closest preceding symbol, and next symbol. (ELF
-	 * starts real symbols at 1).
-	 */
-	for (i = 1; i < kallsyms->num_symtab; i++) {
-		const Elf_Sym *sym = &kallsyms->symtab[i];
-		unsigned long thisval = kallsyms_symbol_value(sym);
-
-		if (sym->st_shndx == SHN_UNDEF)
-			continue;
-
-		/*
-		 * We ignore unnamed symbols: they're uninformative
-		 * and inserted at a whim.
-		 */
-		if (*kallsyms_symbol_name(kallsyms, i) == '\0'
-		    || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
-			continue;
-
-		if (thisval <= addr && thisval > bestval) {
-			best = i;
-			bestval = thisval;
-		}
-		if (thisval > addr && thisval < nextval)
-			nextval = thisval;
-	}
-
-	if (!best)
-		return NULL;
-
-	if (size)
-		*size = nextval - bestval;
-	if (offset)
-		*offset = addr - bestval;
-
-	return kallsyms_symbol_name(kallsyms, best);
-}
-
-void * __weak dereference_module_function_descriptor(struct module *mod,
-						     void *ptr)
-{
-	return ptr;
-}
-
-/*
- * For kallsyms to ask for address resolution.  NULL means not found.  Careful
- * not to lock to avoid deadlock on oopses, simply disable preemption.
- */
-const char *module_address_lookup(unsigned long addr,
-			    unsigned long *size,
-			    unsigned long *offset,
-			    char **modname,
-			    const unsigned char **modbuildid,
-			    char *namebuf)
-{
-	const char *ret = NULL;
-	struct module *mod;
-
-	preempt_disable();
-	mod = __module_address(addr);
-	if (mod) {
-		if (modname)
-			*modname = mod->name;
-		if (modbuildid) {
-#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
-			*modbuildid = mod->build_id;
-#else
-			*modbuildid = NULL;
-#endif
-		}
-
-		ret = find_kallsyms_symbol(mod, addr, size, offset);
-	}
-	/* Make a copy in here where it's safe */
-	if (ret) {
-		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
-		ret = namebuf;
-	}
-	preempt_enable();
-
-	return ret;
-}
-
-int lookup_module_symbol_name(unsigned long addr, char *symname)
-{
-	struct module *mod;
-
-	preempt_disable();
-	list_for_each_entry_rcu(mod, &modules, list) {
-		if (mod->state == MODULE_STATE_UNFORMED)
-			continue;
-		if (within_module(addr, mod)) {
-			const char *sym;
-
-			sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
-			if (!sym)
-				goto out;
-
-			strlcpy(symname, sym, KSYM_NAME_LEN);
-			preempt_enable();
-			return 0;
-		}
-	}
-out:
-	preempt_enable();
-	return -ERANGE;
-}
-
-int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
-			unsigned long *offset, char *modname, char *name)
-{
-	struct module *mod;
-
-	preempt_disable();
-	list_for_each_entry_rcu(mod, &modules, list) {
-		if (mod->state == MODULE_STATE_UNFORMED)
-			continue;
-		if (within_module(addr, mod)) {
-			const char *sym;
-
-			sym = find_kallsyms_symbol(mod, addr, size, offset);
-			if (!sym)
-				goto out;
-			if (modname)
-				strlcpy(modname, mod->name, MODULE_NAME_LEN);
-			if (name)
-				strlcpy(name, sym, KSYM_NAME_LEN);
-			preempt_enable();
-			return 0;
-		}
-	}
-out:
-	preempt_enable();
-	return -ERANGE;
-}
-
-int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
-			char *name, char *module_name, int *exported)
-{
-	struct module *mod;
-
-	preempt_disable();
-	list_for_each_entry_rcu(mod, &modules, list) {
-		struct mod_kallsyms *kallsyms;
-
-		if (mod->state == MODULE_STATE_UNFORMED)
-			continue;
-		kallsyms = rcu_dereference_sched(mod->kallsyms);
-		if (symnum < kallsyms->num_symtab) {
-			const Elf_Sym *sym = &kallsyms->symtab[symnum];
-
-			*value = kallsyms_symbol_value(sym);
-			*type = kallsyms->typetab[symnum];
-			strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
-			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
-			*exported = is_exported(name, *value, mod);
-			preempt_enable();
-			return 0;
-		}
-		symnum -= kallsyms->num_symtab;
-	}
-	preempt_enable();
-	return -ERANGE;
-}
-
-/* Given a module and name of symbol, find and return the symbol's value */
-static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
-{
-	unsigned int i;
-	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
-
-	for (i = 0; i < kallsyms->num_symtab; i++) {
-		const Elf_Sym *sym = &kallsyms->symtab[i];
-
-		if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
-		    sym->st_shndx != SHN_UNDEF)
-			return kallsyms_symbol_value(sym);
-	}
-	return 0;
-}
-
-/* Look for this name: can be of form module:name. */
-unsigned long module_kallsyms_lookup_name(const char *name)
-{
-	struct module *mod;
-	char *colon;
-	unsigned long ret = 0;
-
-	/* Don't lock: we're in enough trouble already. */
-	preempt_disable();
-	if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
-		if ((mod = find_module_all(name, colon - name, false)) != NULL)
-			ret = find_kallsyms_symbol_value(mod, colon+1);
-	} else {
-		list_for_each_entry_rcu(mod, &modules, list) {
-			if (mod->state == MODULE_STATE_UNFORMED)
-				continue;
-			if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
-				break;
-		}
-	}
-	preempt_enable();
-	return ret;
-}
-
-#ifdef CONFIG_LIVEPATCH
-int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
-					     struct module *, unsigned long),
-				   void *data)
-{
-	struct module *mod;
-	unsigned int i;
-	int ret = 0;
-
-	mutex_lock(&module_mutex);
-	list_for_each_entry(mod, &modules, list) {
-		/* We hold module_mutex: no need for rcu_dereference_sched */
-		struct mod_kallsyms *kallsyms = mod->kallsyms;
-
-		if (mod->state == MODULE_STATE_UNFORMED)
-			continue;
-		for (i = 0; i < kallsyms->num_symtab; i++) {
-			const Elf_Sym *sym = &kallsyms->symtab[i];
-
-			if (sym->st_shndx == SHN_UNDEF)
-				continue;
-
-			ret = fn(data, kallsyms_symbol_name(kallsyms, i),
-				 mod, kallsyms_symbol_value(sym));
-			if (ret != 0)
-				goto out;
-		}
-	}
-out:
-	mutex_unlock(&module_mutex);
-	return ret;
-}
-#endif /* CONFIG_LIVEPATCH */
-#endif /* CONFIG_KALLSYMS */
-
 static void cfi_init(struct module *mod)
 {
 #ifdef CONFIG_CFI_CLANG
-- 
2.31.1

[RFC PATCH v2 10/13] module: Move procfs support into a separate file

[Aaron Tomlin]

No functional change.

This patch migrates code that allows one to generate a
list of loaded/or linked modules via /proc when procfs
support is enabled into kernel/module/procfs.c.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 kernel/module/Makefile |   1 +
 kernel/module/main.c   |  98 -------------------------------------
 kernel/module/procfs.c | 108 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 109 insertions(+), 98 deletions(-)
 create mode 100644 kernel/module/procfs.c

diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 23582011ab08..cba3e608b4ca 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
 obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
 obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
 obj-$(CONFIG_KALLSYMS) += kallsyms.o
+obj-$(CONFIG_PROC_FS) += procfs.o
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 9813e1672d8c..2da580c7b069 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -21,7 +21,6 @@
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/elf.h>
-#include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/syscalls.h>
 #include <linux/fcntl.h>
@@ -3529,103 +3528,6 @@ static char *module_flags(struct module *mod, char *buf)
 	return buf;
 }
 
-#ifdef CONFIG_PROC_FS
-/* Called by the /proc file system to return a list of modules. */
-static void *m_start(struct seq_file *m, loff_t *pos)
-{
-	mutex_lock(&module_mutex);
-	return seq_list_start(&modules, *pos);
-}
-
-static void *m_next(struct seq_file *m, void *p, loff_t *pos)
-{
-	return seq_list_next(p, &modules, pos);
-}
-
-static void m_stop(struct seq_file *m, void *p)
-{
-	mutex_unlock(&module_mutex);
-}
-
-static int m_show(struct seq_file *m, void *p)
-{
-	struct module *mod = list_entry(p, struct module, list);
-	char buf[MODULE_FLAGS_BUF_SIZE];
-	void *value;
-
-	/* We always ignore unformed modules. */
-	if (mod->state == MODULE_STATE_UNFORMED)
-		return 0;
-
-	seq_printf(m, "%s %u",
-		   mod->name, mod->init_layout.size + mod->core_layout.size);
-	print_unload_info(m, mod);
-
-	/* Informative for users. */
-	seq_printf(m, " %s",
-		   mod->state == MODULE_STATE_GOING ? "Unloading" :
-		   mod->state == MODULE_STATE_COMING ? "Loading" :
-		   "Live");
-	/* Used by oprofile and other similar tools. */
-	value = m->private ? NULL : mod->core_layout.base;
-	seq_printf(m, " 0x%px", value);
-
-	/* Taints info */
-	if (mod->taints)
-		seq_printf(m, " %s", module_flags(mod, buf));
-
-	seq_puts(m, "\n");
-	return 0;
-}
-
-/*
- * Format: modulename size refcount deps address
- *
- * Where refcount is a number or -, and deps is a comma-separated list
- * of depends or -.
- */
-static const struct seq_operations modules_op = {
-	.start	= m_start,
-	.next	= m_next,
-	.stop	= m_stop,
-	.show	= m_show
-};
-
-/*
- * This also sets the "private" pointer to non-NULL if the
- * kernel pointers should be hidden (so you can just test
- * "m->private" to see if you should keep the values private).
- *
- * We use the same logic as for /proc/kallsyms.
- */
-static int modules_open(struct inode *inode, struct file *file)
-{
-	int err = seq_open(file, &modules_op);
-
-	if (!err) {
-		struct seq_file *m = file->private_data;
-		m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
-	}
-
-	return err;
-}
-
-static const struct proc_ops modules_proc_ops = {
-	.proc_flags	= PROC_ENTRY_PERMANENT,
-	.proc_open	= modules_open,
-	.proc_read	= seq_read,
-	.proc_lseek	= seq_lseek,
-	.proc_release	= seq_release,
-};
-
-static int __init proc_modules_init(void)
-{
-	proc_create("modules", 0, NULL, &modules_proc_ops);
-	return 0;
-}
-module_init(proc_modules_init);
-#endif
-
 /* Given an address, look for it in the module exception tables. */
 const struct exception_table_entry *search_module_extables(unsigned long addr)
 {
diff --git a/kernel/module/procfs.c b/kernel/module/procfs.c
new file mode 100644
index 000000000000..98d898250475
--- /dev/null
+++ b/kernel/module/procfs.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * kernel/module/proc.c - module proc support
+ *
+ * Copyright (C) 2008 Alexey Dobriyan
+ */
+
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/mutex.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include "internal.h"
+
+/* Called by the /proc file system to return a list of modules. */
+static void *m_start(struct seq_file *m, loff_t *pos)
+{
+	mutex_lock(&module_mutex);
+	return seq_list_start(&modules, *pos);
+}
+
+static void *m_next(struct seq_file *m, void *p, loff_t *pos)
+{
+	return seq_list_next(p, &modules, pos);
+}
+
+static void m_stop(struct seq_file *m, void *p)
+{
+	mutex_unlock(&module_mutex);
+}
+
+static int m_show(struct seq_file *m, void *p)
+{
+	struct module *mod = list_entry(p, struct module, list);
+	char buf[MODULE_FLAGS_BUF_SIZE];
+	void *value;
+
+	/* We always ignore unformed modules. */
+	if (mod->state == MODULE_STATE_UNFORMED)
+		return 0;
+
+	seq_printf(m, "%s %u",
+		   mod->name, mod->init_layout.size + mod->core_layout.size);
+	print_unload_info(m, mod);
+
+	/* Informative for users. */
+	seq_printf(m, " %s",
+		   mod->state == MODULE_STATE_GOING ? "Unloading" :
+		   mod->state == MODULE_STATE_COMING ? "Loading" :
+		   "Live");
+	/* Used by oprofile and other similar tools. */
+	value = m->private ? NULL : mod->core_layout.base;
+	seq_printf(m, " 0x%px", value);
+
+	/* Taints info */
+	if (mod->taints)
+		seq_printf(m, " %s", module_flags(mod, buf));
+
+	seq_puts(m, "\n");
+	return 0;
+}
+
+/*
+ * Format: modulename size refcount deps address
+ *
+ * Where refcount is a number or -, and deps is a comma-separated list
+ * of depends or -.
+ */
+static const struct seq_operations modules_op = {
+	.start	= m_start,
+	.next	= m_next,
+	.stop	= m_stop,
+	.show	= m_show
+};
+
+/*
+ * This also sets the "private" pointer to non-NULL if the
+ * kernel pointers should be hidden (so you can just test
+ * "m->private" to see if you should keep the values private).
+ *
+ * We use the same logic as for /proc/kallsyms.
+ */
+static int modules_open(struct inode *inode, struct file *file)
+{
+	int err = seq_open(file, &modules_op);
+
+	if (!err) {
+		struct seq_file *m = file->private_data;
+		m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
+	}
+
+	return err;
+}
+
+static const struct proc_ops modules_proc_ops = {
+	.proc_flags	= PROC_ENTRY_PERMANENT,
+	.proc_open	= modules_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= seq_release,
+};
+
+static int __init proc_modules_init(void)
+{
+	proc_create("modules", 0, NULL, &modules_proc_ops);
+	return 0;
+}
+module_init(proc_modules_init);
-- 
2.31.1

[RFC PATCH v2 11/13] module: Move sysfs support into a separate file

[Aaron Tomlin]

No functional change.

This patch migrates module sysfs support out of core code into
kernel/module/sysfs.c. In addition simple code refactoring to
make this possible.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 kernel/module/Makefile   |   1 +
 kernel/module/internal.h |  20 ++
 kernel/module/main.c     | 462 +--------------------------------------
 kernel/module/procfs.c   |   3 +
 kernel/module/sysfs.c    | 426 ++++++++++++++++++++++++++++++++++++
 5 files changed, 455 insertions(+), 457 deletions(-)
 create mode 100644 kernel/module/sysfs.c

diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index cba3e608b4ca..917910302ac0 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
 obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
 obj-$(CONFIG_KALLSYMS) += kallsyms.o
 obj-$(CONFIG_PROC_FS) += procfs.o
+obj-$(CONFIG_SYSFS) += sysfs.o
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 119d42c304a1..4d81eb1f58ef 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -99,3 +99,23 @@ static inline char *find_kallsyms_symbol(struct module *mod, unsigned long addr,
 	return NULL;
 }
 #endif /* CONFIG_KALLSYMS */
+
+#ifdef CONFIG_SYSFS
+extern int mod_sysfs_setup(struct module *mod, const struct load_info *info, struct kernel_param *kparam, unsigned int num_params);
+extern void mod_sysfs_fini(struct module *mod);
+extern void module_remove_modinfo_attrs(struct module *mod, int end);
+extern void del_usage_links(struct module *mod);
+extern void init_param_lock(struct module *mod);
+#else /* !CONFIG_SYSFS */
+static 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_fini(struct module *mod) { }
+static inline void module_remove_modinfo_attrs(struct module *mod, int end) { }
+static inline void del_usage_links(struct module *mod) { }
+static inline void init_param_lock(struct module *mod) { }
+#endif /* CONFIG_SYSFS */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 2da580c7b069..354fb2697188 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -13,9 +13,7 @@
 #include <linux/trace_events.h>
 #include <linux/init.h>
 #include <linux/kallsyms.h>
-#include <linux/file.h>
 #include <linux/fs.h>
-#include <linux/sysfs.h>
 #include <linux/kernel.h>
 #include <linux/kernel_read_file.h>
 #include <linux/slab.h>
@@ -801,7 +799,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
 	return ret;
 }
 
-static inline void print_unload_info(struct seq_file *m, struct module *mod)
+inline void print_unload_info(struct seq_file *m, struct module *mod)
 {
 	struct module_use *use;
 	int printed_something = 0;
@@ -1017,7 +1015,7 @@ static ssize_t show_taint(struct module_attribute *mattr,
 static struct module_attribute modinfo_taint =
 	__ATTR(taint, 0444, show_taint, NULL);
 
-static struct module_attribute *modinfo_attrs[] = {
+struct module_attribute *modinfo_attrs[] = {
 	&module_uevent,
 	&modinfo_version,
 	&modinfo_srcversion,
@@ -1031,6 +1029,8 @@ static struct module_attribute *modinfo_attrs[] = {
 	NULL,
 };
 
+size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
+
 static const char vermagic[] = VERMAGIC_STRING;
 
 static int try_to_force_load(struct module *mod, const char *reason)
@@ -1281,458 +1281,6 @@ resolve_symbol_wait(struct module *mod,
 	return ksym;
 }
 
-/*
- * /sys/module/foo/sections stuff
- * J. Corbet <corbet@lwn.net>
- */
-#ifdef CONFIG_SYSFS
-
-#ifdef CONFIG_KALLSYMS
-struct module_sect_attr {
-	struct bin_attribute battr;
-	unsigned long address;
-};
-
-struct module_sect_attrs {
-	struct attribute_group grp;
-	unsigned int nsections;
-	struct module_sect_attr attrs[];
-};
-
-static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
-				struct bin_attribute *battr,
-				char *buf, loff_t pos, size_t count)
-{
-	struct module_sect_attr *sattr =
-		container_of(battr, struct module_sect_attr, battr);
-	char bounce[MODULE_SECT_READ_SIZE + 1];
-	size_t wrote;
-
-	if (pos != 0)
-		return -EINVAL;
-
-	/*
-	 * Since we're a binary read handler, we must account for the
-	 * trailing NUL byte that sprintf will write: if "buf" is
-	 * too small to hold the NUL, or the NUL is exactly the last
-	 * byte, the read will look like it got truncated by one byte.
-	 * Since there is no way to ask sprintf nicely to not write
-	 * the NUL, we have to use a bounce buffer.
-	 */
-	wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
-			 kallsyms_show_value(file->f_cred)
-				? (void *)sattr->address : NULL);
-	count = min(count, wrote);
-	memcpy(buf, bounce, count);
-
-	return count;
-}
-
-static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
-{
-	unsigned int section;
-
-	for (section = 0; section < sect_attrs->nsections; section++)
-		kfree(sect_attrs->attrs[section].battr.attr.name);
-	kfree(sect_attrs);
-}
-
-static void add_sect_attrs(struct module *mod, const struct load_info *info)
-{
-	unsigned int nloaded = 0, i, size[2];
-	struct module_sect_attrs *sect_attrs;
-	struct module_sect_attr *sattr;
-	struct bin_attribute **gattr;
-
-	/* Count loaded sections and allocate structures */
-	for (i = 0; i < info->hdr->e_shnum; i++)
-		if (!sect_empty(&info->sechdrs[i]))
-			nloaded++;
-	size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
-			sizeof(sect_attrs->grp.bin_attrs[0]));
-	size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
-	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
-	if (sect_attrs == NULL)
-		return;
-
-	/* Setup section attributes. */
-	sect_attrs->grp.name = "sections";
-	sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
-
-	sect_attrs->nsections = 0;
-	sattr = &sect_attrs->attrs[0];
-	gattr = &sect_attrs->grp.bin_attrs[0];
-	for (i = 0; i < info->hdr->e_shnum; i++) {
-		Elf_Shdr *sec = &info->sechdrs[i];
-		if (sect_empty(sec))
-			continue;
-		sysfs_bin_attr_init(&sattr->battr);
-		sattr->address = sec->sh_addr;
-		sattr->battr.attr.name =
-			kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
-		if (sattr->battr.attr.name == NULL)
-			goto out;
-		sect_attrs->nsections++;
-		sattr->battr.read = module_sect_read;
-		sattr->battr.size = MODULE_SECT_READ_SIZE;
-		sattr->battr.attr.mode = 0400;
-		*(gattr++) = &(sattr++)->battr;
-	}
-	*gattr = NULL;
-
-	if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
-		goto out;
-
-	mod->sect_attrs = sect_attrs;
-	return;
-  out:
-	free_sect_attrs(sect_attrs);
-}
-
-static void remove_sect_attrs(struct module *mod)
-{
-	if (mod->sect_attrs) {
-		sysfs_remove_group(&mod->mkobj.kobj,
-				   &mod->sect_attrs->grp);
-		/*
-		 * We are positive that no one is using any sect attrs
-		 * at this point.  Deallocate immediately.
-		 */
-		free_sect_attrs(mod->sect_attrs);
-		mod->sect_attrs = NULL;
-	}
-}
-
-/*
- * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
- */
-
-struct module_notes_attrs {
-	struct kobject *dir;
-	unsigned int notes;
-	struct bin_attribute attrs[];
-};
-
-static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
-				 struct bin_attribute *bin_attr,
-				 char *buf, loff_t pos, size_t count)
-{
-	/*
-	 * The caller checked the pos and count against our size.
-	 */
-	memcpy(buf, bin_attr->private + pos, count);
-	return count;
-}
-
-static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
-			     unsigned int i)
-{
-	if (notes_attrs->dir) {
-		while (i-- > 0)
-			sysfs_remove_bin_file(notes_attrs->dir,
-					      &notes_attrs->attrs[i]);
-		kobject_put(notes_attrs->dir);
-	}
-	kfree(notes_attrs);
-}
-
-static void add_notes_attrs(struct module *mod, const struct load_info *info)
-{
-	unsigned int notes, loaded, i;
-	struct module_notes_attrs *notes_attrs;
-	struct bin_attribute *nattr;
-
-	/* failed to create section attributes, so can't create notes */
-	if (!mod->sect_attrs)
-		return;
-
-	/* Count notes sections and allocate structures.  */
-	notes = 0;
-	for (i = 0; i < info->hdr->e_shnum; i++)
-		if (!sect_empty(&info->sechdrs[i]) &&
-		    (info->sechdrs[i].sh_type == SHT_NOTE))
-			++notes;
-
-	if (notes == 0)
-		return;
-
-	notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
-			      GFP_KERNEL);
-	if (notes_attrs == NULL)
-		return;
-
-	notes_attrs->notes = notes;
-	nattr = &notes_attrs->attrs[0];
-	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
-		if (sect_empty(&info->sechdrs[i]))
-			continue;
-		if (info->sechdrs[i].sh_type == SHT_NOTE) {
-			sysfs_bin_attr_init(nattr);
-			nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
-			nattr->attr.mode = S_IRUGO;
-			nattr->size = info->sechdrs[i].sh_size;
-			nattr->private = (void *) info->sechdrs[i].sh_addr;
-			nattr->read = module_notes_read;
-			++nattr;
-		}
-		++loaded;
-	}
-
-	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
-	if (!notes_attrs->dir)
-		goto out;
-
-	for (i = 0; i < notes; ++i)
-		if (sysfs_create_bin_file(notes_attrs->dir,
-					  &notes_attrs->attrs[i]))
-			goto out;
-
-	mod->notes_attrs = notes_attrs;
-	return;
-
-  out:
-	free_notes_attrs(notes_attrs, i);
-}
-
-static void remove_notes_attrs(struct module *mod)
-{
-	if (mod->notes_attrs)
-		free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
-}
-
-#else
-
-static inline void add_sect_attrs(struct module *mod,
-				  const struct load_info *info)
-{
-}
-
-static inline void remove_sect_attrs(struct module *mod)
-{
-}
-
-static inline void add_notes_attrs(struct module *mod,
-				   const struct load_info *info)
-{
-}
-
-static inline void remove_notes_attrs(struct module *mod)
-{
-}
-#endif /* CONFIG_KALLSYMS */
-
-static void del_usage_links(struct module *mod)
-{
-#ifdef CONFIG_MODULE_UNLOAD
-	struct module_use *use;
-
-	mutex_lock(&module_mutex);
-	list_for_each_entry(use, &mod->target_list, target_list)
-		sysfs_remove_link(use->target->holders_dir, mod->name);
-	mutex_unlock(&module_mutex);
-#endif
-}
-
-static int add_usage_links(struct module *mod)
-{
-	int ret = 0;
-#ifdef CONFIG_MODULE_UNLOAD
-	struct module_use *use;
-
-	mutex_lock(&module_mutex);
-	list_for_each_entry(use, &mod->target_list, target_list) {
-		ret = sysfs_create_link(use->target->holders_dir,
-					&mod->mkobj.kobj, mod->name);
-		if (ret)
-			break;
-	}
-	mutex_unlock(&module_mutex);
-	if (ret)
-		del_usage_links(mod);
-#endif
-	return ret;
-}
-
-static void module_remove_modinfo_attrs(struct module *mod, int end);
-
-static int module_add_modinfo_attrs(struct module *mod)
-{
-	struct module_attribute *attr;
-	struct module_attribute *temp_attr;
-	int error = 0;
-	int i;
-
-	mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
-					(ARRAY_SIZE(modinfo_attrs) + 1)),
-					GFP_KERNEL);
-	if (!mod->modinfo_attrs)
-		return -ENOMEM;
-
-	temp_attr = mod->modinfo_attrs;
-	for (i = 0; (attr = modinfo_attrs[i]); i++) {
-		if (!attr->test || attr->test(mod)) {
-			memcpy(temp_attr, attr, sizeof(*temp_attr));
-			sysfs_attr_init(&temp_attr->attr);
-			error = sysfs_create_file(&mod->mkobj.kobj,
-					&temp_attr->attr);
-			if (error)
-				goto error_out;
-			++temp_attr;
-		}
-	}
-
-	return 0;
-
-error_out:
-	if (i > 0)
-		module_remove_modinfo_attrs(mod, --i);
-	else
-		kfree(mod->modinfo_attrs);
-	return error;
-}
-
-static void module_remove_modinfo_attrs(struct module *mod, int end)
-{
-	struct module_attribute *attr;
-	int i;
-
-	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
-		if (end >= 0 && i > end)
-			break;
-		/* pick a field to test for end of list */
-		if (!attr->attr.name)
-			break;
-		sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
-		if (attr->free)
-			attr->free(mod);
-	}
-	kfree(mod->modinfo_attrs);
-}
-
-static void mod_kobject_put(struct module *mod)
-{
-	DECLARE_COMPLETION_ONSTACK(c);
-	mod->mkobj.kobj_completion = &c;
-	kobject_put(&mod->mkobj.kobj);
-	wait_for_completion(&c);
-}
-
-static int mod_sysfs_init(struct module *mod)
-{
-	int err;
-	struct kobject *kobj;
-
-	if (!module_sysfs_initialized) {
-		pr_err("%s: module sysfs not initialized\n", mod->name);
-		err = -EINVAL;
-		goto out;
-	}
-
-	kobj = kset_find_obj(module_kset, mod->name);
-	if (kobj) {
-		pr_err("%s: module is already loaded\n", mod->name);
-		kobject_put(kobj);
-		err = -EINVAL;
-		goto out;
-	}
-
-	mod->mkobj.mod = mod;
-
-	memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
-	mod->mkobj.kobj.kset = module_kset;
-	err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
-				   "%s", mod->name);
-	if (err)
-		mod_kobject_put(mod);
-
-out:
-	return err;
-}
-
-static int mod_sysfs_setup(struct module *mod,
-			   const struct load_info *info,
-			   struct kernel_param *kparam,
-			   unsigned int num_params)
-{
-	int err;
-
-	err = mod_sysfs_init(mod);
-	if (err)
-		goto out;
-
-	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
-	if (!mod->holders_dir) {
-		err = -ENOMEM;
-		goto out_unreg;
-	}
-
-	err = module_param_sysfs_setup(mod, kparam, num_params);
-	if (err)
-		goto out_unreg_holders;
-
-	err = module_add_modinfo_attrs(mod);
-	if (err)
-		goto out_unreg_param;
-
-	err = add_usage_links(mod);
-	if (err)
-		goto out_unreg_modinfo_attrs;
-
-	add_sect_attrs(mod, info);
-	add_notes_attrs(mod, info);
-
-	return 0;
-
-out_unreg_modinfo_attrs:
-	module_remove_modinfo_attrs(mod, -1);
-out_unreg_param:
-	module_param_sysfs_remove(mod);
-out_unreg_holders:
-	kobject_put(mod->holders_dir);
-out_unreg:
-	mod_kobject_put(mod);
-out:
-	return err;
-}
-
-static void mod_sysfs_fini(struct module *mod)
-{
-	remove_notes_attrs(mod);
-	remove_sect_attrs(mod);
-	mod_kobject_put(mod);
-}
-
-static void init_param_lock(struct module *mod)
-{
-	mutex_init(&mod->param_lock);
-}
-#else /* !CONFIG_SYSFS */
-
-static int mod_sysfs_setup(struct module *mod,
-			   const struct load_info *info,
-			   struct kernel_param *kparam,
-			   unsigned int num_params)
-{
-	return 0;
-}
-
-static void mod_sysfs_fini(struct module *mod)
-{
-}
-
-static void module_remove_modinfo_attrs(struct module *mod, int end)
-{
-}
-
-static void del_usage_links(struct module *mod)
-{
-}
-
-static void init_param_lock(struct module *mod)
-{
-}
-#endif /* CONFIG_SYSFS */
-
 static void mod_sysfs_teardown(struct module *mod)
 {
 	del_usage_links(mod);
@@ -3505,7 +3053,7 @@ static void cfi_cleanup(struct module *mod)
 }
 
 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
-static char *module_flags(struct module *mod, char *buf)
+char *module_flags(struct module *mod, char *buf)
 {
 	int bx = 0;
 
diff --git a/kernel/module/procfs.c b/kernel/module/procfs.c
index 98d898250475..365d5e52ac23 100644
--- a/kernel/module/procfs.c
+++ b/kernel/module/procfs.c
@@ -12,6 +12,9 @@
 #include <linux/proc_fs.h>
 #include "internal.h"
 
+extern void print_unload_info(struct seq_file *m, struct module *mod);
+extern char *module_flags(struct module *mod, char *buf);
+
 /* Called by the /proc file system to return a list of modules. */
 static void *m_start(struct seq_file *m, loff_t *pos)
 {
diff --git a/kernel/module/sysfs.c b/kernel/module/sysfs.c
new file mode 100644
index 000000000000..1cd91c214b72
--- /dev/null
+++ b/kernel/module/sysfs.c
@@ -0,0 +1,426 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * kernel/module/sysfs.c - module sysfs support
+ *
+ * Copyright (C) 2008 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/kallsyms.h>
+#include <linux/mutex.h>
+#include "internal.h"
+
+/*
+ * /sys/module/foo/sections stuff
+ * J. Corbet <corbet@lwn.net>
+ */
+#ifdef CONFIG_KALLSYMS
+struct module_sect_attr {
+	struct bin_attribute battr;
+	unsigned long address;
+};
+
+struct module_sect_attrs {
+	struct attribute_group grp;
+	unsigned int nsections;
+	struct module_sect_attr attrs[];
+};
+
+static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
+				struct bin_attribute *battr,
+				char *buf, loff_t pos, size_t count)
+{
+	struct module_sect_attr *sattr =
+		container_of(battr, struct module_sect_attr, battr);
+	char bounce[MODULE_SECT_READ_SIZE + 1];
+	size_t wrote;
+
+	if (pos != 0)
+		return -EINVAL;
+
+	/*
+	 * Since we're a binary read handler, we must account for the
+	 * trailing NUL byte that sprintf will write: if "buf" is
+	 * too small to hold the NUL, or the NUL is exactly the last
+	 * byte, the read will look like it got truncated by one byte.
+	 * Since there is no way to ask sprintf nicely to not write
+	 * the NUL, we have to use a bounce buffer.
+	 */
+	wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
+			 kallsyms_show_value(file->f_cred)
+				? (void *)sattr->address : NULL);
+	count = min(count, wrote);
+	memcpy(buf, bounce, count);
+
+	return count;
+}
+
+static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
+{
+	unsigned int section;
+
+	for (section = 0; section < sect_attrs->nsections; section++)
+		kfree(sect_attrs->attrs[section].battr.attr.name);
+	kfree(sect_attrs);
+}
+
+static void add_sect_attrs(struct module *mod, const struct load_info *info)
+{
+	unsigned int nloaded = 0, i, size[2];
+	struct module_sect_attrs *sect_attrs;
+	struct module_sect_attr *sattr;
+	struct bin_attribute **gattr;
+
+	/* Count loaded sections and allocate structures */
+	for (i = 0; i < info->hdr->e_shnum; i++)
+		if (!sect_empty(&info->sechdrs[i]))
+			nloaded++;
+	size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
+			sizeof(sect_attrs->grp.bin_attrs[0]));
+	size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
+	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
+	if (sect_attrs == NULL)
+		return;
+
+	/* Setup section attributes. */
+	sect_attrs->grp.name = "sections";
+	sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
+
+	sect_attrs->nsections = 0;
+	sattr = &sect_attrs->attrs[0];
+	gattr = &sect_attrs->grp.bin_attrs[0];
+	for (i = 0; i < info->hdr->e_shnum; i++) {
+		Elf_Shdr *sec = &info->sechdrs[i];
+		if (sect_empty(sec))
+			continue;
+		sysfs_bin_attr_init(&sattr->battr);
+		sattr->address = sec->sh_addr;
+		sattr->battr.attr.name =
+			kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
+		if (sattr->battr.attr.name == NULL)
+			goto out;
+		sect_attrs->nsections++;
+		sattr->battr.read = module_sect_read;
+		sattr->battr.size = MODULE_SECT_READ_SIZE;
+		sattr->battr.attr.mode = 0400;
+		*(gattr++) = &(sattr++)->battr;
+	}
+	*gattr = NULL;
+
+	if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
+		goto out;
+
+	mod->sect_attrs = sect_attrs;
+	return;
+  out:
+	free_sect_attrs(sect_attrs);
+}
+
+static void remove_sect_attrs(struct module *mod)
+{
+	if (mod->sect_attrs) {
+		sysfs_remove_group(&mod->mkobj.kobj,
+				   &mod->sect_attrs->grp);
+		/*
+		 * We are positive that no one is using any sect attrs
+		 * at this point.  Deallocate immediately.
+		 */
+		free_sect_attrs(mod->sect_attrs);
+		mod->sect_attrs = NULL;
+	}
+}
+
+/*
+ * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
+ */
+
+struct module_notes_attrs {
+	struct kobject *dir;
+	unsigned int notes;
+	struct bin_attribute attrs[];
+};
+
+static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
+				 struct bin_attribute *bin_attr,
+				 char *buf, loff_t pos, size_t count)
+{
+	/*
+	 * The caller checked the pos and count against our size.
+	 */
+	memcpy(buf, bin_attr->private + pos, count);
+	return count;
+}
+
+static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
+			     unsigned int i)
+{
+	if (notes_attrs->dir) {
+		while (i-- > 0)
+			sysfs_remove_bin_file(notes_attrs->dir,
+					      &notes_attrs->attrs[i]);
+		kobject_put(notes_attrs->dir);
+	}
+	kfree(notes_attrs);
+}
+
+static void add_notes_attrs(struct module *mod, const struct load_info *info)
+{
+	unsigned int notes, loaded, i;
+	struct module_notes_attrs *notes_attrs;
+	struct bin_attribute *nattr;
+
+	/* failed to create section attributes, so can't create notes */
+	if (!mod->sect_attrs)
+		return;
+
+	/* Count notes sections and allocate structures.  */
+	notes = 0;
+	for (i = 0; i < info->hdr->e_shnum; i++)
+		if (!sect_empty(&info->sechdrs[i]) &&
+		    (info->sechdrs[i].sh_type == SHT_NOTE))
+			++notes;
+
+	if (notes == 0)
+		return;
+
+	notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
+			      GFP_KERNEL);
+	if (notes_attrs == NULL)
+		return;
+
+	notes_attrs->notes = notes;
+	nattr = &notes_attrs->attrs[0];
+	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
+		if (sect_empty(&info->sechdrs[i]))
+			continue;
+		if (info->sechdrs[i].sh_type == SHT_NOTE) {
+			sysfs_bin_attr_init(nattr);
+			nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
+			nattr->attr.mode = S_IRUGO;
+			nattr->size = info->sechdrs[i].sh_size;
+			nattr->private = (void *) info->sechdrs[i].sh_addr;
+			nattr->read = module_notes_read;
+			++nattr;
+		}
+		++loaded;
+	}
+
+	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
+	if (!notes_attrs->dir)
+		goto out;
+
+	for (i = 0; i < notes; ++i)
+		if (sysfs_create_bin_file(notes_attrs->dir,
+					  &notes_attrs->attrs[i]))
+			goto out;
+
+	mod->notes_attrs = notes_attrs;
+	return;
+
+  out:
+	free_notes_attrs(notes_attrs, i);
+}
+
+static void remove_notes_attrs(struct module *mod)
+{
+	if (mod->notes_attrs)
+		free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
+}
+
+#else /* !CONFIG_KALLSYMS */
+static inline void add_sect_attrs(struct module *mod, const struct load_info *info) { }
+static inline void remove_sect_attrs(struct module *mod) { }
+static inline void add_notes_attrs(struct module *mod, const struct load_info *info) { }
+static inline void remove_notes_attrs(struct module *mod) { }
+#endif /* CONFIG_KALLSYMS */
+
+void del_usage_links(struct module *mod)
+{
+#ifdef CONFIG_MODULE_UNLOAD
+	struct module_use *use;
+
+	mutex_lock(&module_mutex);
+	list_for_each_entry(use, &mod->target_list, target_list)
+		sysfs_remove_link(use->target->holders_dir, mod->name);
+	mutex_unlock(&module_mutex);
+#endif
+}
+
+static int add_usage_links(struct module *mod)
+{
+	int ret = 0;
+#ifdef CONFIG_MODULE_UNLOAD
+	struct module_use *use;
+
+	mutex_lock(&module_mutex);
+	list_for_each_entry(use, &mod->target_list, target_list) {
+		ret = sysfs_create_link(use->target->holders_dir,
+					&mod->mkobj.kobj, mod->name);
+		if (ret)
+			break;
+	}
+	mutex_unlock(&module_mutex);
+	if (ret)
+		del_usage_links(mod);
+#endif
+	return ret;
+}
+
+extern struct module_attribute *modinfo_attrs[];
+extern size_t modinfo_attrs_count;
+
+static int module_add_modinfo_attrs(struct module *mod)
+{
+	struct module_attribute *attr;
+	struct module_attribute *temp_attr;
+	int error = 0;
+	int i;
+
+	mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
+					(modinfo_attrs_count + 1)),
+					GFP_KERNEL);
+	if (!mod->modinfo_attrs)
+		return -ENOMEM;
+
+	temp_attr = mod->modinfo_attrs;
+	for (i = 0; (attr = modinfo_attrs[i]); i++) {
+		if (!attr->test || attr->test(mod)) {
+			memcpy(temp_attr, attr, sizeof(*temp_attr));
+			sysfs_attr_init(&temp_attr->attr);
+			error = sysfs_create_file(&mod->mkobj.kobj,
+					&temp_attr->attr);
+			if (error)
+				goto error_out;
+			++temp_attr;
+		}
+	}
+
+	return 0;
+
+error_out:
+	if (i > 0)
+		module_remove_modinfo_attrs(mod, --i);
+	else
+		kfree(mod->modinfo_attrs);
+	return error;
+}
+
+void module_remove_modinfo_attrs(struct module *mod, int end)
+{
+	struct module_attribute *attr;
+	int i;
+
+	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
+		if (end >= 0 && i > end)
+			break;
+		/* pick a field to test for end of list */
+		if (!attr->attr.name)
+			break;
+		sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
+		if (attr->free)
+			attr->free(mod);
+	}
+	kfree(mod->modinfo_attrs);
+}
+
+static void mod_kobject_put(struct module *mod)
+{
+	DECLARE_COMPLETION_ONSTACK(c);
+	mod->mkobj.kobj_completion = &c;
+	kobject_put(&mod->mkobj.kobj);
+	wait_for_completion(&c);
+}
+
+static int mod_sysfs_init(struct module *mod)
+{
+	int err;
+	struct kobject *kobj;
+
+	if (!module_sysfs_initialized) {
+		pr_err("%s: module sysfs not initialized\n", mod->name);
+		err = -EINVAL;
+		goto out;
+	}
+
+	kobj = kset_find_obj(module_kset, mod->name);
+	if (kobj) {
+		pr_err("%s: module is already loaded\n", mod->name);
+		kobject_put(kobj);
+		err = -EINVAL;
+		goto out;
+	}
+
+	mod->mkobj.mod = mod;
+
+	memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
+	mod->mkobj.kobj.kset = module_kset;
+	err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
+				   "%s", mod->name);
+	if (err)
+		mod_kobject_put(mod);
+
+out:
+	return err;
+}
+
+int mod_sysfs_setup(struct module *mod,
+			   const struct load_info *info,
+			   struct kernel_param *kparam,
+			   unsigned int num_params)
+{
+	int err;
+
+	err = mod_sysfs_init(mod);
+	if (err)
+		goto out;
+
+	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
+	if (!mod->holders_dir) {
+		err = -ENOMEM;
+		goto out_unreg;
+	}
+
+	err = module_param_sysfs_setup(mod, kparam, num_params);
+	if (err)
+		goto out_unreg_holders;
+
+	err = module_add_modinfo_attrs(mod);
+	if (err)
+		goto out_unreg_param;
+
+	err = add_usage_links(mod);
+	if (err)
+		goto out_unreg_modinfo_attrs;
+
+	add_sect_attrs(mod, info);
+	add_notes_attrs(mod, info);
+
+	return 0;
+
+out_unreg_modinfo_attrs:
+	module_remove_modinfo_attrs(mod, -1);
+out_unreg_param:
+	module_param_sysfs_remove(mod);
+out_unreg_holders:
+	kobject_put(mod->holders_dir);
+out_unreg:
+	mod_kobject_put(mod);
+out:
+	return err;
+}
+
+void mod_sysfs_fini(struct module *mod)
+{
+	remove_notes_attrs(mod);
+	remove_sect_attrs(mod);
+	mod_kobject_put(mod);
+}
+
+void init_param_lock(struct module *mod)
+{
+	mutex_init(&mod->param_lock);
+}
-- 
2.31.1

[RFC PATCH v2 12/13] module: Move kdb_modules list out of core code

[Aaron Tomlin]

No functional change.

This patch migrates kdb_modules list to core kdb code
since the list of added/or loaded modules is no longer
private.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 kernel/debug/kdb/kdb_main.c | 5 +++++
 kernel/module/main.c        | 4 ----
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index d8ee5647b732..ef61fb65671a 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -60,6 +60,11 @@ EXPORT_SYMBOL(kdb_grepping_flag);
 int kdb_grep_leading;
 int kdb_grep_trailing;
 
+#ifdef CONFIG_MODULES
+extern struct list_head modules;
+struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
+#endif /* CONFIG_MODULES */
+
 /*
  * Kernel debugger state flags
  */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 354fb2697188..09012246907a 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -95,10 +95,6 @@ static void mod_update_bounds(struct module *mod)
 		__mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
 }
 
-#ifdef CONFIG_KGDB_KDB
-struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
-#endif /* CONFIG_KGDB_KDB */
-
 static void module_assert_mutex_or_preempt(void)
 {
 #ifdef CONFIG_LOCKDEP
-- 
2.31.1

Re: [RFC PATCH v2 00/13] module: core code clean up

[Allen]

Hi Aaron,

  My apologies for not replying earlier.

  Thank you so much for doing this. I had a very similar approach, to
move code out based on the
  flags. I will am in the process of reviewing and testing the changes
you have posted.

Thanks.

On Thu, Jan 6, 2022 at 3:43 PM Aaron Tomlin <atomlin@redhat.com> wrote:
>
> Hi Luis,
>
> As per your suggestion [1], this is an attempt to refactor and split
> optional code out of core module support code into separate components.
> Unfortunately, nothing has been thoroughly tested yet. Please let me know
> your thoughts.
>
> Changes since v1 [2]:
>
>   - Moved module version support code into a new file
>
> [1]: https://lore.kernel.org/lkml/YbEZ4HgSYQEPuRmS@bombadil.infradead.org/
> [2]: https://lore.kernel.org/lkml/20211228213041.1356334-1-atomlin@redhat.com/
>
> Aaron Tomlin (13):
>   module: Move all into module/
>   module: Simple refactor in preparation for split
>   module: Move livepatch support to a separate file
>   module: Move latched RB-tree support to a separate file
>   module: Move arch strict rwx support to a separate file
>   module: Move strict rwx support to a separate file
>   module: Move extra signature support out of core code
>   module: Move kmemleak support to a separate file
>   module: Move kallsyms support into a separate file
>   module: Move procfs support into a separate file
>   module: Move sysfs support into a separate file
>   module: Move kdb_modules list out of core code
>   module: Move version support into a separate file
>
>  include/linux/module.h                        |   76 +-
>  kernel/Makefile                               |    4 +-
>  kernel/debug/kdb/kdb_main.c                   |    5 +
>  kernel/module-internal.h                      |   31 -
>  kernel/module/Makefile                        |   17 +
>  kernel/module/arch_strict_rwx.c               |   44 +
>  kernel/module/debug_kmemleak.c                |   30 +
>  kernel/module/internal.h                      |  169 ++
>  kernel/module/kallsyms.c                      |  506 +++++
>  kernel/module/livepatch.c                     |   75 +
>  kernel/{module.c => module/main.c}            | 1872 +----------------
>  kernel/module/procfs.c                        |  111 +
>  .../signature.c}                              |    0
>  kernel/module/signing.c                       |  120 ++
>  kernel/module/strict_rwx.c                    |   83 +
>  kernel/module/sysfs.c                         |  426 ++++
>  kernel/module/tree_lookup.c                   |  108 +
>  kernel/module/version.c                       |  113 +
>  kernel/module_signing.c                       |   45 -
>  19 files changed, 1968 insertions(+), 1867 deletions(-)
>  delete mode 100644 kernel/module-internal.h
>  create mode 100644 kernel/module/Makefile
>  create mode 100644 kernel/module/arch_strict_rwx.c
>  create mode 100644 kernel/module/debug_kmemleak.c
>  create mode 100644 kernel/module/internal.h
>  create mode 100644 kernel/module/kallsyms.c
>  create mode 100644 kernel/module/livepatch.c
>  rename kernel/{module.c => module/main.c} (63%)
>  create mode 100644 kernel/module/procfs.c
>  rename kernel/{module_signature.c => module/signature.c} (100%)
>  create mode 100644 kernel/module/signing.c
>  create mode 100644 kernel/module/strict_rwx.c
>  create mode 100644 kernel/module/sysfs.c
>  create mode 100644 kernel/module/tree_lookup.c
>  create mode 100644 kernel/module/version.c
>  delete mode 100644 kernel/module_signing.c
>
> --
> 2.31.1
>


-- 
       - Allen

Re: [RFC PATCH v2 00/13] module: core code clean up

[Allen]

Hi Aaron,

  Was the code compile tested?

  Unfortunately, I could not apply the series cleanly on top of the
latest 5.17-rc1.
  I did rebase the patches and fixed minor compile time failures as
well a few small checkpatch errors.
  I have pushed the series to
https://github.com/allenpais/Linux/commits/refactor_module_v3
  [The series now is based on
   84bfcc0b6994 2022-01-11 Merge tag 'integrity-v5.17' of
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity]

  So far I could only manage to compile test the patches. Will test it
on BM(x86/arm) in a day or two.

Thanks,
- Allen


On Tue, Jan 11, 2022 at 6:55 AM Allen <allen.lkml@gmail.com> wrote:
>
> Hi Aaron,
>
>   My apologies for not replying earlier.
>
>   Thank you so much for doing this. I had a very similar approach, to
> move code out based on the
>   flags. I will am in the process of reviewing and testing the changes
> you have posted.
>
> Thanks.
>
> On Thu, Jan 6, 2022 at 3:43 PM Aaron Tomlin <atomlin@redhat.com> wrote:
> >
> > Hi Luis,
> >
> > As per your suggestion [1], this is an attempt to refactor and split
> > optional code out of core module support code into separate components.
> > Unfortunately, nothing has been thoroughly tested yet. Please let me know
> > your thoughts.
> >
> > Changes since v1 [2]:
> >
> >   - Moved module version support code into a new file
> >
> > [1]: https://lore.kernel.org/lkml/YbEZ4HgSYQEPuRmS@bombadil.infradead.org/
> > [2]: https://lore.kernel.org/lkml/20211228213041.1356334-1-atomlin@redhat.com/
> >
> > Aaron Tomlin (13):
> >   module: Move all into module/
> >   module: Simple refactor in preparation for split
> >   module: Move livepatch support to a separate file
> >   module: Move latched RB-tree support to a separate file
> >   module: Move arch strict rwx support to a separate file
> >   module: Move strict rwx support to a separate file
> >   module: Move extra signature support out of core code
> >   module: Move kmemleak support to a separate file
> >   module: Move kallsyms support into a separate file
> >   module: Move procfs support into a separate file
> >   module: Move sysfs support into a separate file
> >   module: Move kdb_modules list out of core code
> >   module: Move version support into a separate file
> >
> >  include/linux/module.h                        |   76 +-
> >  kernel/Makefile                               |    4 +-
> >  kernel/debug/kdb/kdb_main.c                   |    5 +
> >  kernel/module-internal.h                      |   31 -
> >  kernel/module/Makefile                        |   17 +
> >  kernel/module/arch_strict_rwx.c               |   44 +
> >  kernel/module/debug_kmemleak.c                |   30 +
> >  kernel/module/internal.h                      |  169 ++
> >  kernel/module/kallsyms.c                      |  506 +++++
> >  kernel/module/livepatch.c                     |   75 +
> >  kernel/{module.c => module/main.c}            | 1872 +----------------
> >  kernel/module/procfs.c                        |  111 +
> >  .../signature.c}                              |    0
> >  kernel/module/signing.c                       |  120 ++
> >  kernel/module/strict_rwx.c                    |   83 +
> >  kernel/module/sysfs.c                         |  426 ++++
> >  kernel/module/tree_lookup.c                   |  108 +
> >  kernel/module/version.c                       |  113 +
> >  kernel/module_signing.c                       |   45 -
> >  19 files changed, 1968 insertions(+), 1867 deletions(-)
> >  delete mode 100644 kernel/module-internal.h
> >  create mode 100644 kernel/module/Makefile
> >  create mode 100644 kernel/module/arch_strict_rwx.c
> >  create mode 100644 kernel/module/debug_kmemleak.c
> >  create mode 100644 kernel/module/internal.h
> >  create mode 100644 kernel/module/kallsyms.c
> >  create mode 100644 kernel/module/livepatch.c
> >  rename kernel/{module.c => module/main.c} (63%)
> >  create mode 100644 kernel/module/procfs.c
> >  rename kernel/{module_signature.c => module/signature.c} (100%)
> >  create mode 100644 kernel/module/signing.c
> >  create mode 100644 kernel/module/strict_rwx.c
> >  create mode 100644 kernel/module/sysfs.c
> >  create mode 100644 kernel/module/tree_lookup.c
> >  create mode 100644 kernel/module/version.c
> >  delete mode 100644 kernel/module_signing.c
> >
> > --
> > 2.31.1
> >
>
>
> --
>        - Allen



-- 
       - Allen

Re: [RFC PATCH v2 00/13] module: core code clean up

[Aaron Tomlin]

On Tue 2022-01-11 17:16 -0800, Allen wrote:
> Hi Aaron,

Hi Allen,

>   Was the code compile tested?

Not entirely i.e. not the whole of kernel/module/Makefile, unfortunately.
Furthermore, only x86-64 was compiled tested. At the moment, I felt the
need to share the concept/or approach thus far to simply obtain some
overall feedback before further modifications.

>   Unfortunately, I could not apply the series cleanly on top of the
> latest 5.17-rc1.

Sorry about that: this work was based on Linus' commit 81361b837a34 ("Merge
tag 'kbuild-v5.14' of
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.").

>   I did rebase the patches and fixed minor compile time failures as
> well a few small checkpatch errors.
>   I have pushed the series to
> https://github.com/allenpais/Linux/commits/refactor_module_v3
>   [The series now is based on
>    84bfcc0b6994 2022-01-11 Merge tag 'integrity-v5.17' of
> git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity]

Thanks for that. I'll have a look shortly to incorporate into RFC PATCH v3.

>   So far I could only manage to compile test the patches. Will test it
> on BM(x86/arm) in a day or two.

Much appreciated.


Kind regards,

-- 
Aaron Tomlin

Re: [RFC PATCH v2 00/13] module: core code clean up

[Luis Chamberlain]

On Wed, Jan 12, 2022 at 01:21:04PM +0000, Aaron Tomlin wrote:
> On Tue 2022-01-11 17:16 -0800, Allen wrote:
> > Hi Aaron,
> 
> Hi Allen,
> 
> >   Was the code compile tested?
> 
> Not entirely i.e. not the whole of kernel/module/Makefile, unfortunately.
> Furthermore, only x86-64 was compiled tested. At the moment, I felt the
> need to share the concept/or approach thus far to simply obtain some
> overall feedback before further modifications.
> 
> >   Unfortunately, I could not apply the series cleanly on top of the
> > latest 5.17-rc1.
> 
> Sorry about that: this work was based on Linus' commit 81361b837a34 ("Merge
> tag 'kbuild-v5.14' of
> git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.").

Please work off of modules-next tree:

https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/log/?h=modules-next

That is, this tree on the modules-next branch:

git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git

  Luis

Re: [RFC PATCH v2 00/13] module: core code clean up

[Aaron Tomlin]

On Wed 2022-01-12 07:52 -0800, Luis Chamberlain wrote:
> On Wed, Jan 12, 2022 at 01:21:04PM +0000, Aaron Tomlin wrote:
> Please work off of modules-next tree:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/log/?h=modules-next
> 
> That is, this tree on the modules-next branch:
> 
> git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git

Understood.


Kind regards,

-- 
Aaron Tomlin