lib/vsprintf: Prepare for more general use of ptr_to_id()
Move the function and its dependencies up so it can be called from special pointer type formatting routines. 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>
This commit is contained in:
Geert Uytterhoeven
Petr Mladek
parent
f31b224c14
commit
9073dac14e
206
lib/vsprintf.c
206
lib/vsprintf.c
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@ -612,6 +612,109 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec)
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return widen_string(buf, len, end, spec);
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}
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static noinline_for_stack
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char *pointer_string(char *buf, char *end, const void *ptr,
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struct printf_spec spec)
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{
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spec.base = 16;
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spec.flags |= SMALL;
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if (spec.field_width == -1) {
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spec.field_width = 2 * sizeof(ptr);
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spec.flags |= ZEROPAD;
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}
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return number(buf, end, (unsigned long int)ptr, spec);
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}
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/* Make pointers available for printing early in the boot sequence. */
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static int debug_boot_weak_hash __ro_after_init;
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static int __init debug_boot_weak_hash_enable(char *str)
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{
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debug_boot_weak_hash = 1;
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pr_info("debug_boot_weak_hash enabled\n");
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return 0;
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}
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early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
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static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
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static siphash_key_t ptr_key __read_mostly;
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static void enable_ptr_key_workfn(struct work_struct *work)
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{
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get_random_bytes(&ptr_key, sizeof(ptr_key));
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/* Needs to run from preemptible context */
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static_branch_disable(¬_filled_random_ptr_key);
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}
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static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
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static void fill_random_ptr_key(struct random_ready_callback *unused)
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{
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/* This may be in an interrupt handler. */
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queue_work(system_unbound_wq, &enable_ptr_key_work);
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}
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static struct random_ready_callback random_ready = {
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.func = fill_random_ptr_key
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};
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static int __init initialize_ptr_random(void)
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{
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int key_size = sizeof(ptr_key);
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int ret;
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/* Use hw RNG if available. */
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if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
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static_branch_disable(¬_filled_random_ptr_key);
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return 0;
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}
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ret = add_random_ready_callback(&random_ready);
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if (!ret) {
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return 0;
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} else if (ret == -EALREADY) {
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/* This is in preemptible context */
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enable_ptr_key_workfn(&enable_ptr_key_work);
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return 0;
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}
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return ret;
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}
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early_initcall(initialize_ptr_random);
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/* Maps a pointer to a 32 bit unique identifier. */
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static char *ptr_to_id(char *buf, char *end, const void *ptr,
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struct printf_spec spec)
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{
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const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
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unsigned long hashval;
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/* When debugging early boot use non-cryptographically secure hash. */
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if (unlikely(debug_boot_weak_hash)) {
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hashval = hash_long((unsigned long)ptr, 32);
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return pointer_string(buf, end, (const void *)hashval, spec);
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}
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if (static_branch_unlikely(¬_filled_random_ptr_key)) {
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spec.field_width = 2 * sizeof(ptr);
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/* string length must be less than default_width */
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return string(buf, end, str, spec);
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}
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#ifdef CONFIG_64BIT
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hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
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/*
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* Mask off the first 32 bits, this makes explicit that we have
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* modified the address (and 32 bits is plenty for a unique ID).
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*/
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hashval = hashval & 0xffffffff;
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#else
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hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
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#endif
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return pointer_string(buf, end, (const void *)hashval, spec);
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}
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static noinline_for_stack
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char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
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const char *fmt)
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@ -1357,20 +1460,6 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
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return string(buf, end, uuid, spec);
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}
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static noinline_for_stack
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char *pointer_string(char *buf, char *end, const void *ptr,
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struct printf_spec spec)
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{
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spec.base = 16;
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spec.flags |= SMALL;
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if (spec.field_width == -1) {
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spec.field_width = 2 * sizeof(ptr);
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spec.flags |= ZEROPAD;
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}
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return number(buf, end, (unsigned long int)ptr, spec);
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}
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int kptr_restrict __read_mostly;
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static noinline_for_stack
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@ -1651,95 +1740,6 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
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return widen_string(buf, buf - buf_start, end, spec);
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}
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/* Make pointers available for printing early in the boot sequence. */
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static int debug_boot_weak_hash __ro_after_init;
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static int __init debug_boot_weak_hash_enable(char *str)
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{
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debug_boot_weak_hash = 1;
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pr_info("debug_boot_weak_hash enabled\n");
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return 0;
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}
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early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
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static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
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static siphash_key_t ptr_key __read_mostly;
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static void enable_ptr_key_workfn(struct work_struct *work)
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{
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get_random_bytes(&ptr_key, sizeof(ptr_key));
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/* Needs to run from preemptible context */
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static_branch_disable(¬_filled_random_ptr_key);
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}
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static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
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static void fill_random_ptr_key(struct random_ready_callback *unused)
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{
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/* This may be in an interrupt handler. */
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queue_work(system_unbound_wq, &enable_ptr_key_work);
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}
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static struct random_ready_callback random_ready = {
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.func = fill_random_ptr_key
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};
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static int __init initialize_ptr_random(void)
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{
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int key_size = sizeof(ptr_key);
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int ret;
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/* Use hw RNG if available. */
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if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
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static_branch_disable(¬_filled_random_ptr_key);
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return 0;
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}
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ret = add_random_ready_callback(&random_ready);
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if (!ret) {
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return 0;
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} else if (ret == -EALREADY) {
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/* This is in preemptible context */
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enable_ptr_key_workfn(&enable_ptr_key_work);
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return 0;
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}
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return ret;
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}
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early_initcall(initialize_ptr_random);
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/* Maps a pointer to a 32 bit unique identifier. */
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static char *ptr_to_id(char *buf, char *end, const void *ptr,
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struct printf_spec spec)
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{
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const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
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unsigned long hashval;
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/* When debugging early boot use non-cryptographically secure hash. */
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if (unlikely(debug_boot_weak_hash)) {
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hashval = hash_long((unsigned long)ptr, 32);
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return pointer_string(buf, end, (const void *)hashval, spec);
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}
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if (static_branch_unlikely(¬_filled_random_ptr_key)) {
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spec.field_width = 2 * sizeof(ptr);
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/* string length must be less than default_width */
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return string(buf, end, str, spec);
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}
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#ifdef CONFIG_64BIT
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hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
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/*
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* Mask off the first 32 bits, this makes explicit that we have
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* modified the address (and 32 bits is plenty for a unique ID).
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*/
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hashval = hashval & 0xffffffff;
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#else
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hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
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#endif
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return pointer_string(buf, end, (const void *)hashval, spec);
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}
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/*
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* Show a '%p' thing. A kernel extension is that the '%p' is followed
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* by an extra set of alphanumeric characters that are extended format
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