From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sun, 12 Nov 2017 18:44:23 -0800
Subject: /proc/module: use the same logic as /proc/kallsyms for address
exposure
Patch-mainline: v4.15-rc1
Git-commit: 516fb7f2e73dcc303fb97fc3593209fcacf2d982
References: bsc#1109837
The (alleged) users of the module addresses are the same: kernel
profiling.
So just expose the same helper and format macros, and unify the logic.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
include/linux/kallsyms.h | 8 ++++++++
kernel/kallsyms.c | 8 +-------
kernel/module.c | 20 ++++++++++++++++++--
3 files changed, 27 insertions(+), 9 deletions(-)
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -13,6 +13,14 @@
#define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \
2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + 1)
+/* How and when do we show kallsyms values? */
+extern int kallsyms_show_value(void);
+#ifndef CONFIG_64BIT
+# define KALLSYM_FMT "%08lx"
+#else
+# define KALLSYM_FMT "%016lx"
+#endif
+
struct module;
#ifdef CONFIG_KALLSYMS
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -587,12 +587,6 @@ static void s_stop(struct seq_file *m, v
{
}
-#ifndef CONFIG_64BIT
-# define KALLSYM_FMT "%08lx"
-#else
-# define KALLSYM_FMT "%016lx"
-#endif
-
static int s_show(struct seq_file *m, void *p)
{
unsigned long value;
@@ -646,7 +640,7 @@ static inline int kallsyms_for_perf(void
* Otherwise, require CAP_SYSLOG (assuming kptr_restrict isn't set to
* block even that).
*/
-static int kallsyms_show_value(void)
+int kallsyms_show_value(void)
{
switch (kptr_restrict) {
case 0:
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4129,6 +4129,7 @@ static int m_show(struct seq_file *m, vo
{
struct module *mod = list_entry(p, struct module, list);
char buf[MODULE_FLAGS_BUF_SIZE];
+ unsigned long value;
/* We always ignore unformed modules. */
if (mod->state == MODULE_STATE_UNFORMED)
@@ -4144,7 +4145,8 @@ static int m_show(struct seq_file *m, vo
mod->state == MODULE_STATE_COMING ? "Loading" :
"Live");
/* Used by oprofile and other similar tools. */
- seq_printf(m, " 0x%pK", mod->core_layout.base);
+ value = m->private ? 0 : (unsigned long)mod->core_layout.base;
+ seq_printf(m, " 0x" KALLSYM_FMT, value);
/* Taints info */
if (mod->taints)
@@ -4166,9 +4168,23 @@ static const struct seq_operations modul
.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)
{
- return seq_open(file, &modules_op);
+ int err = seq_open(file, &modules_op);
+
+ if (!err) {
+ struct seq_file *m = file->private_data;
+ m->private = kallsyms_show_value() ? NULL : (void *)8ul;
+ }
+
+ return 0;
}
static const struct file_operations proc_modules_operations = {