mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
496f2f93b1
This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
106 lines
2.3 KiB
C
106 lines
2.3 KiB
C
#include <linux/module.h>
|
|
#include <linux/interval_tree.h>
|
|
#include <linux/random.h>
|
|
#include <asm/timex.h>
|
|
|
|
#define NODES 100
|
|
#define PERF_LOOPS 100000
|
|
#define SEARCHES 100
|
|
#define SEARCH_LOOPS 10000
|
|
|
|
static struct rb_root root = RB_ROOT;
|
|
static struct interval_tree_node nodes[NODES];
|
|
static u32 queries[SEARCHES];
|
|
|
|
static struct rnd_state rnd;
|
|
|
|
static inline unsigned long
|
|
search(unsigned long query, struct rb_root *root)
|
|
{
|
|
struct interval_tree_node *node;
|
|
unsigned long results = 0;
|
|
|
|
for (node = interval_tree_iter_first(root, query, query); node;
|
|
node = interval_tree_iter_next(node, query, query))
|
|
results++;
|
|
return results;
|
|
}
|
|
|
|
static void init(void)
|
|
{
|
|
int i;
|
|
for (i = 0; i < NODES; i++) {
|
|
u32 a = prandom_u32_state(&rnd);
|
|
u32 b = prandom_u32_state(&rnd);
|
|
if (a <= b) {
|
|
nodes[i].start = a;
|
|
nodes[i].last = b;
|
|
} else {
|
|
nodes[i].start = b;
|
|
nodes[i].last = a;
|
|
}
|
|
}
|
|
for (i = 0; i < SEARCHES; i++)
|
|
queries[i] = prandom_u32_state(&rnd);
|
|
}
|
|
|
|
static int interval_tree_test_init(void)
|
|
{
|
|
int i, j;
|
|
unsigned long results;
|
|
cycles_t time1, time2, time;
|
|
|
|
printk(KERN_ALERT "interval tree insert/remove");
|
|
|
|
prandom_seed_state(&rnd, 3141592653589793238ULL);
|
|
init();
|
|
|
|
time1 = get_cycles();
|
|
|
|
for (i = 0; i < PERF_LOOPS; i++) {
|
|
for (j = 0; j < NODES; j++)
|
|
interval_tree_insert(nodes + j, &root);
|
|
for (j = 0; j < NODES; j++)
|
|
interval_tree_remove(nodes + j, &root);
|
|
}
|
|
|
|
time2 = get_cycles();
|
|
time = time2 - time1;
|
|
|
|
time = div_u64(time, PERF_LOOPS);
|
|
printk(" -> %llu cycles\n", (unsigned long long)time);
|
|
|
|
printk(KERN_ALERT "interval tree search");
|
|
|
|
for (j = 0; j < NODES; j++)
|
|
interval_tree_insert(nodes + j, &root);
|
|
|
|
time1 = get_cycles();
|
|
|
|
results = 0;
|
|
for (i = 0; i < SEARCH_LOOPS; i++)
|
|
for (j = 0; j < SEARCHES; j++)
|
|
results += search(queries[j], &root);
|
|
|
|
time2 = get_cycles();
|
|
time = time2 - time1;
|
|
|
|
time = div_u64(time, SEARCH_LOOPS);
|
|
results = div_u64(results, SEARCH_LOOPS);
|
|
printk(" -> %llu cycles (%lu results)\n",
|
|
(unsigned long long)time, results);
|
|
|
|
return -EAGAIN; /* Fail will directly unload the module */
|
|
}
|
|
|
|
static void interval_tree_test_exit(void)
|
|
{
|
|
printk(KERN_ALERT "test exit\n");
|
|
}
|
|
|
|
module_init(interval_tree_test_init)
|
|
module_exit(interval_tree_test_exit)
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Michel Lespinasse");
|
|
MODULE_DESCRIPTION("Interval Tree test");
|