On Wed, 2018-04-25 at 13:12 +0200, Petr Mladek wrote: > This is just a preparation step for further changes. > > The patch does not change the code. >
Reviewed-by: Andy Shevchenko <[email protected]> > 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 -- Andy Shevchenko <[email protected]> Intel Finland Oy
