diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 16 | ||||
| -rw-r--r-- | lib/Makefile | 2 | ||||
| -rw-r--r-- | lib/bitmap.c | 54 | ||||
| -rw-r--r-- | lib/random32.c | 142 |
4 files changed, 201 insertions, 13 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 756a908..77491e3 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -71,7 +71,7 @@ config LOG_BUF_SHIFT config DETECT_SOFTLOCKUP bool "Detect Soft Lockups" - depends on DEBUG_KERNEL + depends on DEBUG_KERNEL && !S390 default y help Say Y here to enable the kernel to detect "soft lockups", @@ -371,6 +371,20 @@ config FORCED_INLINING become the default in the future, until then this option is there to test gcc for this. +config HEADERS_CHECK + bool "Run 'make headers_check' when building vmlinux" + depends on !UML + help + This option will extract the user-visible kernel headers whenever + building the kernel, and will run basic sanity checks on them to + ensure that exported files do not attempt to include files which + were not exported, etc. + + If you're making modifications to header files which are + relevant for userspace, say 'Y', and check the headers + exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in + your build tree), to make sure they're suitable. + config RCU_TORTURE_TEST tristate "torture tests for RCU" depends on DEBUG_KERNEL diff --git a/lib/Makefile b/lib/Makefile index 8e6662b..cf98fab 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -12,7 +12,7 @@ lib-$(CONFIG_SMP) += cpumask.o lib-y += kobject.o kref.o kobject_uevent.o klist.o -obj-y += sort.o parser.o halfmd4.o iomap_copy.o debug_locks.o +obj-y += sort.o parser.o halfmd4.o iomap_copy.o debug_locks.o random32.o ifeq ($(CONFIG_DEBUG_KOBJECT),y) CFLAGS_kobject.o += -DDEBUG diff --git a/lib/bitmap.c b/lib/bitmap.c index d71e38c..037fa9a 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -316,10 +316,11 @@ int bitmap_scnprintf(char *buf, unsigned int buflen, EXPORT_SYMBOL(bitmap_scnprintf); /** - * bitmap_parse - convert an ASCII hex string into a bitmap. - * @ubuf: pointer to buffer in user space containing string. - * @ubuflen: buffer size in bytes. If string is smaller than this + * __bitmap_parse - convert an ASCII hex string into a bitmap. + * @buf: pointer to buffer containing string. + * @buflen: buffer size in bytes. If string is smaller than this * then it must be terminated with a \0. + * @is_user: location of buffer, 0 indicates kernel space * @maskp: pointer to bitmap array that will contain result. * @nmaskbits: size of bitmap, in bits. * @@ -330,11 +331,13 @@ EXPORT_SYMBOL(bitmap_scnprintf); * characters and for grouping errors such as "1,,5", ",44", "," and "". * Leading and trailing whitespace accepted, but not embedded whitespace. */ -int bitmap_parse(const char __user *ubuf, unsigned int ubuflen, - unsigned long *maskp, int nmaskbits) +int __bitmap_parse(const char *buf, unsigned int buflen, + int is_user, unsigned long *maskp, + int nmaskbits) { int c, old_c, totaldigits, ndigits, nchunks, nbits; u32 chunk; + const char __user *ubuf = buf; bitmap_zero(maskp, nmaskbits); @@ -343,11 +346,15 @@ int bitmap_parse(const char __user *ubuf, unsigned int ubuflen, chunk = ndigits = 0; /* Get the next chunk of the bitmap */ - while (ubuflen) { + while (buflen) { old_c = c; - if (get_user(c, ubuf++)) - return -EFAULT; - ubuflen--; + if (is_user) { + if (__get_user(c, ubuf++)) + return -EFAULT; + } + else + c = *buf++; + buflen--; if (isspace(c)) continue; @@ -388,11 +395,36 @@ int bitmap_parse(const char __user *ubuf, unsigned int ubuflen, nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; if (nbits > nmaskbits) return -EOVERFLOW; - } while (ubuflen && c == ','); + } while (buflen && c == ','); return 0; } -EXPORT_SYMBOL(bitmap_parse); +EXPORT_SYMBOL(__bitmap_parse); + +/** + * bitmap_parse_user() + * + * @ubuf: pointer to user buffer containing string. + * @ulen: buffer size in bytes. If string is smaller than this + * then it must be terminated with a \0. + * @maskp: pointer to bitmap array that will contain result. + * @nmaskbits: size of bitmap, in bits. + * + * Wrapper for __bitmap_parse(), providing it with user buffer. + * + * We cannot have this as an inline function in bitmap.h because it needs + * linux/uaccess.h to get the access_ok() declaration and this causes + * cyclic dependencies. + */ +int bitmap_parse_user(const char __user *ubuf, + unsigned int ulen, unsigned long *maskp, + int nmaskbits) +{ + if (!access_ok(VERIFY_READ, ubuf, ulen)) + return -EFAULT; + return __bitmap_parse((const char *)ubuf, ulen, 1, maskp, nmaskbits); +} +EXPORT_SYMBOL(bitmap_parse_user); /* * bscnl_emit(buf, buflen, rbot, rtop, bp) diff --git a/lib/random32.c b/lib/random32.c new file mode 100644 index 0000000..4a15ce5 --- /dev/null +++ b/lib/random32.c @@ -0,0 +1,142 @@ +/* + This is a maximally equidistributed combined Tausworthe generator + based on code from GNU Scientific Library 1.5 (30 Jun 2004) + + x_n = (s1_n ^ s2_n ^ s3_n) + + s1_{n+1} = (((s1_n & 4294967294) <<12) ^ (((s1_n <<13) ^ s1_n) >>19)) + s2_{n+1} = (((s2_n & 4294967288) << 4) ^ (((s2_n << 2) ^ s2_n) >>25)) + s3_{n+1} = (((s3_n & 4294967280) <<17) ^ (((s3_n << 3) ^ s3_n) >>11)) + + The period of this generator is about 2^88. + + From: P. L'Ecuyer, "Maximally Equidistributed Combined Tausworthe + Generators", Mathematics of Computation, 65, 213 (1996), 203--213. + + This is available on the net from L'Ecuyer's home page, + + http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps + ftp://ftp.iro.umontreal.ca/pub/simulation/lecuyer/papers/tausme.ps + + There is an erratum in the paper "Tables of Maximally + Equidistributed Combined LFSR Generators", Mathematics of + Computation, 68, 225 (1999), 261--269: + http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps + + ... the k_j most significant bits of z_j must be non- + zero, for each j. (Note: this restriction also applies to the + computer code given in [4], but was mistakenly not mentioned in + that paper.) + + This affects the seeding procedure by imposing the requirement + s1 > 1, s2 > 7, s3 > 15. + +*/ + +#include <linux/types.h> +#include <linux/percpu.h> +#include <linux/module.h> +#include <linux/random.h> + +struct rnd_state { + u32 s1, s2, s3; +}; + +static DEFINE_PER_CPU(struct rnd_state, net_rand_state); + +static u32 __random32(struct rnd_state *state) +{ +#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b) + + state->s1 = TAUSWORTHE(state->s1, 13, 19, 4294967294UL, 12); + state->s2 = TAUSWORTHE(state->s2, 2, 25, 4294967288UL, 4); + state->s3 = TAUSWORTHE(state->s3, 3, 11, 4294967280UL, 17); + + return (state->s1 ^ state->s2 ^ state->s3); +} + +static void __set_random32(struct rnd_state *state, unsigned long s) +{ + if (s == 0) + s = 1; /* default seed is 1 */ + +#define LCG(n) (69069 * n) + state->s1 = LCG(s); + state->s2 = LCG(state->s1); + state->s3 = LCG(state->s2); + + /* "warm it up" */ + __random32(state); + __random32(state); + __random32(state); + __random32(state); + __random32(state); + __random32(state); +} + +/** + * random32 - pseudo random number generator + * + * A 32 bit pseudo-random number is generated using a fast + * algorithm suitable for simulation. This algorithm is NOT + * considered safe for cryptographic use. + */ +u32 random32(void) +{ + unsigned long r; + struct rnd_state *state = &get_cpu_var(net_rand_state); + r = __random32(state); + put_cpu_var(state); + return r; +} +EXPORT_SYMBOL(random32); + +/** + * srandom32 - add entropy to pseudo random number generator + * @seed: seed value + * + * Add some additional seeding to the random32() pool. + * Note: this pool is per cpu so it only affects current CPU. + */ +void srandom32(u32 entropy) +{ + struct rnd_state *state = &get_cpu_var(net_rand_state); + __set_random32(state, state->s1 ^ entropy); + put_cpu_var(state); +} +EXPORT_SYMBOL(srandom32); + +/* + * Generate some initially weak seeding values to allow + * to start the random32() engine. + */ +static int __init random32_init(void) +{ + int i; + + for_each_possible_cpu(i) { + struct rnd_state *state = &per_cpu(net_rand_state,i); + __set_random32(state, i + jiffies); + } + return 0; +} +core_initcall(random32_init); + +/* + * Generate better values after random number generator + * is fully initalized. + */ +static int __init random32_reseed(void) +{ + int i; + unsigned long seed; + + for_each_possible_cpu(i) { + struct rnd_state *state = &per_cpu(net_rand_state,i); + + get_random_bytes(&seed, sizeof(seed)); + __set_random32(state, seed); + } + return 0; +} +late_initcall(random32_reseed); |
