This is just a preparation step for further changes. The patch does not change the code.
Signed-off-by: Petr Mladek <[email protected]> --- lib/vsprintf.c | 244 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 122 insertions(+), 122 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index b82f0c6c2aec..19fdfe621b40 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -613,6 +613,128 @@ 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); +} + +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) +{ + const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)"; + unsigned long hashval; + + if (unlikely(!have_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); +} + +int kptr_restrict __read_mostly; + +static noinline_for_stack +char *restricted_pointer(char *buf, char *end, const void *ptr, + struct printf_spec spec) +{ + switch (kptr_restrict) { + case 0: + /* Always print %pK values */ + break; + case 1: { + const struct cred *cred; + + /* + * kptr_restrict==1 cannot be used in IRQ context + * because its test for CAP_SYSLOG would be meaningless. + */ + if (in_irq() || in_serving_softirq() || in_nmi()) { + if (spec.field_width == -1) + spec.field_width = 2 * sizeof(ptr); + return string(buf, end, "pK-error", spec); + } + + /* + * Only print the real pointer value if the current + * process has CAP_SYSLOG and is running with the + * same credentials it started with. This is because + * access to files is checked at open() time, but %pK + * checks permission at read() time. We don't want to + * leak pointer values if a binary opens a file using + * %pK and then elevates privileges before reading it. + */ + cred = current_cred(); + if (!has_capability_noaudit(current, CAP_SYSLOG) || + !uid_eq(cred->euid, cred->uid) || + !gid_eq(cred->egid, cred->gid)) + ptr = NULL; + break; + } + case 2: + default: + /* Always print 0's for %pK */ + ptr = NULL; + break; + } + + return pointer_string(buf, end, ptr, spec); +} + +static noinline_for_stack char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec, const char *fmt) { @@ -1358,69 +1480,6 @@ char *uuid_string(char *buf, char *end, const u8 *addr, } 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 -char *restricted_pointer(char *buf, char *end, const void *ptr, - struct printf_spec spec) -{ - switch (kptr_restrict) { - case 0: - /* Always print %pK values */ - break; - case 1: { - const struct cred *cred; - - /* - * kptr_restrict==1 cannot be used in IRQ context - * because its test for CAP_SYSLOG would be meaningless. - */ - if (in_irq() || in_serving_softirq() || in_nmi()) { - if (spec.field_width == -1) - spec.field_width = 2 * sizeof(ptr); - return string(buf, end, "pK-error", spec); - } - - /* - * Only print the real pointer value if the current - * process has CAP_SYSLOG and is running with the - * same credentials it started with. This is because - * access to files is checked at open() time, but %pK - * checks permission at read() time. We don't want to - * leak pointer values if a binary opens a file using - * %pK and then elevates privileges before reading it. - */ - cred = current_cred(); - if (!has_capability_noaudit(current, CAP_SYSLOG) || - !uid_eq(cred->euid, cred->uid) || - !gid_eq(cred->egid, cred->gid)) - ptr = NULL; - break; - } - case 2: - default: - /* Always print 0's for %pK */ - ptr = NULL; - break; - } - - return pointer_string(buf, end, ptr, spec); -} - -static noinline_for_stack char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt) { unsigned long long num; @@ -1654,65 +1713,6 @@ char *device_node_string(char *buf, char *end, struct device_node *dn, return widen_string(buf, buf - buf_start, 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) -{ - const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)"; - unsigned long hashval; - - if (unlikely(!have_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 -- 2.13.6
