diff options
Diffstat (limited to 'random/jitterentropy-base-user.h')
| -rw-r--r-- | random/jitterentropy-base-user.h | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/random/jitterentropy-base-user.h b/random/jitterentropy-base-user.h index 8a8dbd55..f0fd4842 100644 --- a/random/jitterentropy-base-user.h +++ b/random/jitterentropy-base-user.h @@ -131,4 +131,171 @@ jent_fips_enabled(void) } +static inline void jent_memset_secure(void *s, size_t n) +{ + memset(s, 0, n); + __asm__ __volatile__("" : : "r" (s) : "memory"); +} + +static inline long jent_ncpu(void) +{ +#ifdef _POSIX_SOURCE + long ncpu = sysconf(_SC_NPROCESSORS_ONLN); + + if (ncpu == -1) + return -errno; + + if (ncpu == 0) + return -EFAULT; + + return ncpu; +#else + return 1; +#endif +} + +#ifdef __linux__ + +# if defined(_SC_LEVEL1_DCACHE_SIZE) && \ + defined(_SC_LEVEL2_CACHE_SIZE) && \ + defined(_SC_LEVEL3_CACHE_SIZE) + +static inline void jent_get_cachesize(long *l1, long *l2, long *l3) +{ + *l1 = sysconf(_SC_LEVEL1_DCACHE_SIZE); + *l2 = sysconf(_SC_LEVEL2_CACHE_SIZE); + *l3 = sysconf(_SC_LEVEL3_CACHE_SIZE); +} + +# else + +static inline void jent_get_cachesize(long *l1, long *l2, long *l3) +{ +#define JENT_SYSFS_CACHE_DIR "/sys/devices/system/cpu/cpu0/cache" + long val; + unsigned int i; + char buf[10], file[50]; + int fd = 0; + + /* Iterate over all caches */ + for (i = 0; i < 4; i++) { + unsigned int shift = 0; + char *ext; + + /* + * Check the cache type - we are only interested in Unified + * and Data caches. + */ + memset(buf, 0, sizeof(buf)); + snprintf(file, sizeof(file), "%s/index%u/type", + JENT_SYSFS_CACHE_DIR, i); + fd = open(file, O_RDONLY); + if (fd < 0) + continue; + while (read(fd, buf, sizeof(buf)) < 0 && errno == EINTR); + close(fd); + buf[sizeof(buf) - 1] = '\0'; + + if (strncmp(buf, "Data", 4) && strncmp(buf, "Unified", 7)) + continue; + + /* Get size of cache */ + memset(buf, 0, sizeof(buf)); + snprintf(file, sizeof(file), "%s/index%u/size", + JENT_SYSFS_CACHE_DIR, i); + + fd = open(file, O_RDONLY); + if (fd < 0) + continue; + while (read(fd, buf, sizeof(buf)) < 0 && errno == EINTR); + close(fd); + buf[sizeof(buf) - 1] = '\0'; + + ext = strstr(buf, "K"); + if (ext) { + shift = 10; + ext = '\0'; + } else { + ext = strstr(buf, "M"); + if (ext) { + shift = 20; + ext = '\0'; + } + } + + val = strtol(buf, NULL, 10); + if (val == LONG_MAX) + continue; + val <<= shift; + + if (!*l1) + *l1 = val; + else if (!*l2) + *l2 = val; + else { + *l3 = val; + break; + } + } +#undef JENT_SYSFS_CACHE_DIR +} + +# endif + +static inline uint32_t jent_cache_size_roundup(void) +{ + static int checked = 0; + static uint32_t cache_size = 0; + + if (!checked) { + long l1 = 0, l2 = 0, l3 = 0; + + jent_get_cachesize(&l1, &l2, &l3); + checked = 1; + + /* Cache size reported by system */ + if (l1 > 0) + cache_size += (uint32_t)l1; + if (l2 > 0) + cache_size += (uint32_t)l2; + if (l3 > 0) + cache_size += (uint32_t)l3; + + /* + * Force the output_size to be of the form + * (bounding_power_of_2 - 1). + */ + cache_size |= (cache_size >> 1); + cache_size |= (cache_size >> 2); + cache_size |= (cache_size >> 4); + cache_size |= (cache_size >> 8); + cache_size |= (cache_size >> 16); + + if (cache_size == 0) + return 0; + + /* + * Make the output_size the smallest power of 2 strictly + * greater than cache_size. + */ + cache_size++; + } + + return cache_size; +} + +#else /* __linux__ */ + +static inline uint32_t jent_cache_size_roundup(void) +{ + return 0; +} + +#endif /* __linux__ */ + +static inline void jent_yield(void) +{ + sched_yield(); +} + #endif /* GCRYPT_JITTERENTROPY_BASE_USER_H */ |