[PATCH v4 1/9] vsprintf: Shuffle ptr_to_id() code

From: Petr Mladek
Date: Wed Apr 04 2018 - 04:59:36 EST


This patch just moves ptr_to_id() implementation up in the source
file. We will want to call it earlier.

This patch does not change the existing behavior.

Signed-off-by: Petr Mladek <pmladek@xxxxxxxx>
---
lib/vsprintf.c | 134 ++++++++++++++++++++++++++++-----------------------------
1 file changed, 67 insertions(+), 67 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index d7a708f82559..c0c677c6a833 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -602,6 +602,73 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec)
return widen_string(buf, len, end, spec);
}

+static bool have_filled_random_ptr_key __read_mostly;
+static siphash_key_t ptr_key __read_mostly;
+
+static void fill_random_ptr_key(struct random_ready_callback *unused)
+{
+ get_random_bytes(&ptr_key, sizeof(ptr_key));
+ /*
+ * have_filled_random_ptr_key==true is dependent on get_random_bytes().
+ * ptr_to_id() needs to see have_filled_random_ptr_key==true
+ * after get_random_bytes() returns.
+ */
+ smp_mb();
+ WRITE_ONCE(have_filled_random_ptr_key, true);
+}
+
+static struct random_ready_callback random_ready = {
+ .func = fill_random_ptr_key
+};
+
+static int __init initialize_ptr_random(void)
+{
+ int ret = add_random_ready_callback(&random_ready);
+
+ if (!ret) {
+ return 0;
+ } else if (ret == -EALREADY) {
+ fill_random_ptr_key(&random_ready);
+ return 0;
+ }
+
+ return ret;
+}
+early_initcall(initialize_ptr_random);
+
+/* Maps a pointer to a 32 bit unique identifier. */
+static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
+{
+ unsigned long hashval;
+ const int default_width = 2 * sizeof(ptr);
+
+ if (unlikely(!have_filled_random_ptr_key)) {
+ spec.field_width = default_width;
+ /* string length must be less than default_width */
+ return string(buf, end, "(ptrval)", spec);
+ }
+
+#ifdef CONFIG_64BIT
+ hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
+ /*
+ * Mask off the first 32 bits, this makes explicit that we have
+ * modified the address (and 32 bits is plenty for a unique ID).
+ */
+ hashval = hashval & 0xffffffff;
+#else
+ hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
+#endif
+
+ spec.flags |= SMALL;
+ if (spec.field_width == -1) {
+ spec.field_width = default_width;
+ spec.flags |= ZEROPAD;
+ }
+ spec.base = 16;
+
+ return number(buf, end, hashval, spec);
+}
+
static noinline_for_stack
char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
const char *fmt)
@@ -1659,73 +1726,6 @@ char *pointer_string(char *buf, char *end, const void *ptr,
return number(buf, end, (unsigned long int)ptr, spec);
}

-static bool have_filled_random_ptr_key __read_mostly;
-static siphash_key_t ptr_key __read_mostly;
-
-static void fill_random_ptr_key(struct random_ready_callback *unused)
-{
- get_random_bytes(&ptr_key, sizeof(ptr_key));
- /*
- * have_filled_random_ptr_key==true is dependent on get_random_bytes().
- * ptr_to_id() needs to see have_filled_random_ptr_key==true
- * after get_random_bytes() returns.
- */
- smp_mb();
- WRITE_ONCE(have_filled_random_ptr_key, true);
-}
-
-static struct random_ready_callback random_ready = {
- .func = fill_random_ptr_key
-};
-
-static int __init initialize_ptr_random(void)
-{
- int ret = add_random_ready_callback(&random_ready);
-
- if (!ret) {
- return 0;
- } else if (ret == -EALREADY) {
- fill_random_ptr_key(&random_ready);
- return 0;
- }
-
- return ret;
-}
-early_initcall(initialize_ptr_random);
-
-/* Maps a pointer to a 32 bit unique identifier. */
-static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
-{
- unsigned long hashval;
- const int default_width = 2 * sizeof(ptr);
-
- if (unlikely(!have_filled_random_ptr_key)) {
- spec.field_width = default_width;
- /* string length must be less than default_width */
- return string(buf, end, "(ptrval)", spec);
- }
-
-#ifdef CONFIG_64BIT
- hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
- /*
- * Mask off the first 32 bits, this makes explicit that we have
- * modified the address (and 32 bits is plenty for a unique ID).
- */
- hashval = hashval & 0xffffffff;
-#else
- hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
-#endif
-
- spec.flags |= SMALL;
- if (spec.field_width == -1) {
- spec.field_width = default_width;
- spec.flags |= ZEROPAD;
- }
- spec.base = 16;
-
- return number(buf, end, hashval, spec);
-}
-
/*
* Show a '%p' thing. A kernel extension is that the '%p' is followed
* by an extra set of alphanumeric characters that are extended format
--
2.13.6