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

Aaron Tomlin
2022-01-06T23:43:53Z

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