| Message ID | 20221010230613.1076905-5-Jason@zx2c4.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | treewide cleanup of random integer usage | expand |
On Mon, Oct 10, 2022 at 05:06:10PM -0600, Jason A. Donenfeld wrote: > Rather than truncate a 32-bit value to a 16-bit value or an 8-bit value, > simply use the get_random_{u8,u16}() functions, which are faster than > wasting the additional bytes from a 32-bit value. This was done by hand, > identifying all of the places where one of the random integer functions > was used in a non-32-bit context. > > Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Reviewed-by: Kees Cook <keescook@chromium.org> > Reviewed-by: Yury Norov <yury.norov@gmail.com> > Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> > --- > arch/s390/kernel/process.c | 2 +- For s390: Acked-by: Heiko Carstens <hca@linux.ibm.com>
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 5ec78555dd2e..42af4b3aa02b 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -230,7 +230,7 @@ unsigned long arch_align_stack(unsigned long sp) static inline unsigned long brk_rnd(void) { - return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; + return (get_random_u16() & BRK_RND_MASK) << PAGE_SHIFT; } unsigned long arch_randomize_brk(struct mm_struct *mm) diff --git a/drivers/mtd/nand/raw/nandsim.c b/drivers/mtd/nand/raw/nandsim.c index 50bcf745e816..d211939c8bdd 100644 --- a/drivers/mtd/nand/raw/nandsim.c +++ b/drivers/mtd/nand/raw/nandsim.c @@ -1402,7 +1402,7 @@ static int ns_do_read_error(struct nandsim *ns, int num) static void ns_do_bit_flips(struct nandsim *ns, int num) { - if (bitflips && prandom_u32() < (1 << 22)) { + if (bitflips && get_random_u16() < (1 << 6)) { int flips = 1; if (bitflips > 1) flips = prandom_u32_max(bitflips) + 1; diff --git a/lib/test_vmalloc.c b/lib/test_vmalloc.c index a26bbbf20e62..cf7780572f5b 100644 --- a/lib/test_vmalloc.c +++ b/lib/test_vmalloc.c @@ -80,7 +80,7 @@ static int random_size_align_alloc_test(void) int i; for (i = 0; i < test_loop_count; i++) { - rnd = prandom_u32(); + rnd = get_random_u8(); /* * Maximum 1024 pages, if PAGE_SIZE is 4096. diff --git a/net/rds/bind.c b/net/rds/bind.c index 5b5fb4ca8d3e..97a29172a8ee 100644 --- a/net/rds/bind.c +++ b/net/rds/bind.c @@ -104,7 +104,7 @@ static int rds_add_bound(struct rds_sock *rs, const struct in6_addr *addr, return -EINVAL; last = rover; } else { - rover = max_t(u16, prandom_u32(), 2); + rover = max_t(u16, get_random_u16(), 2); last = rover - 1; } diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c index e2389fa3cff8..0366a1a029a9 100644 --- a/net/sched/sch_sfb.c +++ b/net/sched/sch_sfb.c @@ -379,7 +379,7 @@ static int sfb_enqueue(struct sk_buff *skb, struct Qdisc *sch, goto enqueue; } - r = prandom_u32() & SFB_MAX_PROB; + r = get_random_u16() & SFB_MAX_PROB; if (unlikely(r < p_min)) { if (unlikely(p_min > SFB_MAX_PROB / 2)) {
Rather than truncate a 32-bit value to a 16-bit value or an 8-bit value, simply use the get_random_{u8,u16}() functions, which are faster than wasting the additional bytes from a 32-bit value. This was done by hand, identifying all of the places where one of the random integer functions was used in a non-32-bit context. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> --- arch/s390/kernel/process.c | 2 +- drivers/mtd/nand/raw/nandsim.c | 2 +- lib/test_vmalloc.c | 2 +- net/rds/bind.c | 2 +- net/sched/sch_sfb.c | 2 +- 5 files changed, 5 insertions(+), 5 deletions(-)