[PATCH v6 4/7] treewide: use get_random_{u8,u16}() when possible, part 2
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: 2022-10-10 23:09:37
Also in:
dri-devel, kernel-janitors, linux-block, linux-crypto, linux-doc, linux-fsdevel, linux-media, linux-mips, linux-mm, linux-mmc, linux-nvme, linux-patches, linux-rdma, linux-s390, linux-um, linux-usb, linux-wireless, linuxppc-dev, lkml, loongarch, sparclinux
Subsystem:
library code, memory technology devices (mtd), nand flash subsystem, networking [general], rds - reliable datagram sockets, s390 architecture, tc subsystem, the rest, vmalloc · Maintainers:
Andrew Morton, Miquel Raynal, Richard Weinberger, Vignesh Raghavendra, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Allison Henderson, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds, Uladzislau Rezki
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 <redacted>
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(-)
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)) {
--
2.37.3