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authorLinus Torvalds <torvalds@linux-foundation.org>2022-10-17 01:27:07 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-10-17 01:27:07 +0300
commitf1947d7c8a61db1cb0ef909a6512ede0b1f2115b (patch)
treebbe7f785243bb692f243d08de8bc5ef4a82454d6 /include/linux
parent8636df94ec917019c4cb744ba0a1f94cf9057790 (diff)
parentde492c83cae0af72de370b9404aacda93dafcad5 (diff)
downloadlinux-f1947d7c8a61db1cb0ef909a6512ede0b1f2115b.tar.xz
Merge tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random
Pull more random number generator updates from Jason Donenfeld: "This time with some large scale treewide cleanups. The intent of this pull is to clean up the way callers fetch random integers. The current rules for doing this right are: - If you want a secure or an insecure random u64, use get_random_u64() - If you want a secure or an insecure random u32, use get_random_u32() The old function prandom_u32() has been deprecated for a while now and is just a wrapper around get_random_u32(). Same for get_random_int(). - If you want a secure or an insecure random u16, use get_random_u16() - If you want a secure or an insecure random u8, use get_random_u8() - If you want secure or insecure random bytes, use get_random_bytes(). The old function prandom_bytes() has been deprecated for a while now and has long been a wrapper around get_random_bytes() - If you want a non-uniform random u32, u16, or u8 bounded by a certain open interval maximum, use prandom_u32_max() I say "non-uniform", because it doesn't do any rejection sampling or divisions. Hence, it stays within the prandom_*() namespace, not the get_random_*() namespace. I'm currently investigating a "uniform" function for 6.2. We'll see what comes of that. By applying these rules uniformly, we get several benefits: - By using prandom_u32_max() with an upper-bound that the compiler can prove at compile-time is ≤65536 or ≤256, internally get_random_u16() or get_random_u8() is used, which wastes fewer batched random bytes, and hence has higher throughput. - By using prandom_u32_max() instead of %, when the upper-bound is not a constant, division is still avoided, because prandom_u32_max() uses a faster multiplication-based trick instead. - By using get_random_u16() or get_random_u8() in cases where the return value is intended to indeed be a u16 or a u8, we waste fewer batched random bytes, and hence have higher throughput. This series was originally done by hand while I was on an airplane without Internet. Later, Kees and I worked on retroactively figuring out what could be done with Coccinelle and what had to be done manually, and then we split things up based on that. So while this touches a lot of files, the actual amount of code that's hand fiddled is comfortably small" * tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: prandom: remove unused functions treewide: use get_random_bytes() when possible treewide: use get_random_u32() when possible treewide: use get_random_{u8,u16}() when possible, part 2 treewide: use get_random_{u8,u16}() when possible, part 1 treewide: use prandom_u32_max() when possible, part 2 treewide: use prandom_u32_max() when possible, part 1
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/nodemask.h2
-rw-r--r--include/linux/prandom.h12
-rw-r--r--include/linux/random.h5
3 files changed, 1 insertions, 18 deletions
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 378956c93c94..efef68c9352a 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -516,7 +516,7 @@ static inline int node_random(const nodemask_t *maskp)
bit = first_node(*maskp);
break;
default:
- bit = find_nth_bit(maskp->bits, MAX_NUMNODES, get_random_int() % w);
+ bit = find_nth_bit(maskp->bits, MAX_NUMNODES, prandom_u32_max(w));
break;
}
return bit;
diff --git a/include/linux/prandom.h b/include/linux/prandom.h
index 78db003bc290..e0a0759dd09c 100644
--- a/include/linux/prandom.h
+++ b/include/linux/prandom.h
@@ -12,18 +12,6 @@
#include <linux/percpu.h>
#include <linux/random.h>
-/* Deprecated: use get_random_u32 instead. */
-static inline u32 prandom_u32(void)
-{
- return get_random_u32();
-}
-
-/* Deprecated: use get_random_bytes instead. */
-static inline void prandom_bytes(void *buf, size_t nbytes)
-{
- return get_random_bytes(buf, nbytes);
-}
-
struct rnd_state {
__u32 s1, s2, s3, s4;
};
diff --git a/include/linux/random.h b/include/linux/random.h
index 08322f700cdc..147a5e0d0b8e 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -42,10 +42,6 @@ u8 get_random_u8(void);
u16 get_random_u16(void);
u32 get_random_u32(void);
u64 get_random_u64(void);
-static inline unsigned int get_random_int(void)
-{
- return get_random_u32();
-}
static inline unsigned long get_random_long(void)
{
#if BITS_PER_LONG == 64
@@ -100,7 +96,6 @@ declare_get_random_var_wait(u8, u8)
declare_get_random_var_wait(u16, u16)
declare_get_random_var_wait(u32, u32)
declare_get_random_var_wait(u64, u32)
-declare_get_random_var_wait(int, unsigned int)
declare_get_random_var_wait(long, unsigned long)
#undef declare_get_random_var