diff options
Diffstat (limited to 'lib/vsprintf.c')
| -rw-r--r-- | lib/vsprintf.c | 206 |
1 files changed, 103 insertions, 103 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index c40fdabbd592..94940ba3a3bc 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -613,6 +613,109 @@ char *string(char *buf, char *end, const char *s, struct printf_spec 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); +} + +/* Make pointers available for printing early in the boot sequence. */ +static int debug_boot_weak_hash __ro_after_init; + +static int __init debug_boot_weak_hash_enable(char *str) +{ + debug_boot_weak_hash = 1; + pr_info("debug_boot_weak_hash enabled\n"); + return 0; +} +early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable); + +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(¬_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 key_size = sizeof(ptr_key); + int ret; + + /* Use hw RNG if available. */ + if (get_random_bytes_arch(&ptr_key, key_size) == key_size) { + static_branch_disable(¬_filled_random_ptr_key); + return 0; + } + + 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) +{ + const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)"; + unsigned long hashval; + + /* When debugging early boot use non-cryptographically secure hash. */ + if (unlikely(debug_boot_weak_hash)) { + hashval = hash_long((unsigned long)ptr, 32); + return pointer_string(buf, end, (const void *)hashval, spec); + } + + if (static_branch_unlikely(¬_filled_random_ptr_key)) { + spec.field_width = 2 * sizeof(ptr); + /* string length must be less than default_width */ + return string(buf, end, str, 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 + return pointer_string(buf, end, (const void *)hashval, spec); +} + +static noinline_for_stack char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec, const char *fmt) { @@ -1357,20 +1460,6 @@ char *uuid_string(char *buf, char *end, const u8 *addr, return string(buf, end, uuid, 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); -} - int kptr_restrict __read_mostly; static noinline_for_stack @@ -1651,95 +1740,6 @@ char *device_node_string(char *buf, char *end, struct device_node *dn, return widen_string(buf, buf - buf_start, end, spec); } -/* Make pointers available for printing early in the boot sequence. */ -static int debug_boot_weak_hash __ro_after_init; - -static int __init debug_boot_weak_hash_enable(char *str) -{ - debug_boot_weak_hash = 1; - pr_info("debug_boot_weak_hash enabled\n"); - return 0; -} -early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable); - -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(¬_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 key_size = sizeof(ptr_key); - int ret; - - /* Use hw RNG if available. */ - if (get_random_bytes_arch(&ptr_key, key_size) == key_size) { - static_branch_disable(¬_filled_random_ptr_key); - return 0; - } - - 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) -{ - const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)"; - unsigned long hashval; - - /* When debugging early boot use non-cryptographically secure hash. */ - if (unlikely(debug_boot_weak_hash)) { - hashval = hash_long((unsigned long)ptr, 32); - return pointer_string(buf, end, (const void *)hashval, spec); - } - - if (static_branch_unlikely(¬_filled_random_ptr_key)) { - spec.field_width = 2 * sizeof(ptr); - /* string length must be less than default_width */ - return string(buf, end, str, 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 - return pointer_string(buf, end, (const void *)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 |