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UPSTREAM: lib/vsprintf: Prepare for more general use of ptr_to_id()

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Move the function and its dependencies up so it can be called from
special pointer type formatting routines.

Bug: 78533979
Link: http://lkml.kernel.org/r/20181011084249.4520-2-geert+renesas@glider.be
To: "Tobin C . Harding" <me@tobin.cc>
To: Andrew Morton <akpm@linux-foundation.org>
To: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[pmladek@suse.com: Split into separate patch]
Signed-off-by: Petr Mladek <pmladek@suse.com>
(cherry picked from commit 9073dac14e397f26603b14d5c0929186a0404a53)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I8331506dc5b873ae333312e0614f5ad2c37c4f7e
This commit is contained in:
Geert Uytterhoeven 2018-10-11 10:42:47 +02:00 committed by Eric Biggers
parent 8fd5652b23
commit eb8143f946
1 changed files with 86 additions and 86 deletions
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172
lib/vsprintf.c
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@ -629,6 +629,92 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec)
return widen_string(buf, len, end, spec);
}
static noinline_for_stack
char *pointer_string(char *buf, char *end, const void *ptr,
struct printf_spec spec)
{
spec.base = 16;
spec.flags |= SMALL;
if (spec.field_width == -1) {
spec.field_width = 2 * sizeof(ptr);
spec.flags |= ZEROPAD;
}
return number(buf, end, (unsigned long int)ptr, spec);
}
static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
static siphash_key_t ptr_key __read_mostly;
static void enable_ptr_key_workfn(struct work_struct *work)
{
get_random_bytes(&ptr_key, sizeof(ptr_key));
/* Needs to run from preemptible context */
static_branch_disable(&not_filled_random_ptr_key);
}
static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
static void fill_random_ptr_key(struct random_ready_callback *unused)
{
/* This may be in an interrupt handler. */
queue_work(system_unbound_wq, &enable_ptr_key_work);
}
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) {
/* This is in preemptible context */
enable_ptr_key_workfn(&enable_ptr_key_work);
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, const void *ptr,
struct printf_spec spec)
{
unsigned long hashval;
const int default_width = 2 * sizeof(ptr);
if (static_branch_unlikely(&not_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)
@ -1669,92 +1755,6 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
return widen_string(buf, buf - buf_start, end, spec);
}
static noinline_for_stack
char *pointer_string(char *buf, char *end, const void *ptr,
struct printf_spec spec)
{
spec.base = 16;
spec.flags |= SMALL;
if (spec.field_width == -1) {
spec.field_width = 2 * sizeof(ptr);
spec.flags |= ZEROPAD;
}
return number(buf, end, (unsigned long int)ptr, spec);
}
static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
static siphash_key_t ptr_key __read_mostly;
static void enable_ptr_key_workfn(struct work_struct *work)
{
get_random_bytes(&ptr_key, sizeof(ptr_key));
/* Needs to run from preemptible context */
static_branch_disable(&not_filled_random_ptr_key);
}
static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
static void fill_random_ptr_key(struct random_ready_callback *unused)
{
/* This may be in an interrupt handler. */
queue_work(system_unbound_wq, &enable_ptr_key_work);
}
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) {
/* This is in preemptible context */
enable_ptr_key_workfn(&enable_ptr_key_work);
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, const void *ptr,
struct printf_spec spec)
{
unsigned long hashval;
const int default_width = 2 * sizeof(ptr);
if (static_branch_unlikely(&not_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