Linus Torvalds 8ca09d5fa3 cpumask: fix incorrect cpumask scanning result checks ... It turns out that commit 596ff4a09b ("cpumask: re-introduce constant-sized cpumask optimizations") exposed a number of cases of drivers not checking the result of "cpumask_next()" and friends correctly. The documented correct check for "no more cpus in the cpumask" is to check for the result being equal or larger than the number of possible CPU ids, exactly _because_ we've always done those constant-sized cpumask scans using a widened type before. So the return value of a cpumask scan should be checked with if (cpu >= nr_cpu_ids) ... because the cpumask scan did not necessarily stop exactly *at* that maximum CPU id. But a few cases ended up instead using checks like if (cpu == nr_cpumask_bits) ... which used that internal "widened" number of bits. And that used to work pretty much by accident (ok, in this case "by accident" is simply because it matched the historical internal implementation of the cpumask scanning, so it was more of a "intentionally using implementation details rather than an accident"). But the extended constant-sized optimizations then did that internal implementation differently, and now that code that did things wrong but matched the old implementation no longer worked at all. Which then causes subsequent odd problems due to using what ends up being an invalid CPU ID. Most of these cases require either unusual hardware or special uses to hit, but the random.c one triggers quite easily. All you really need is to have a sufficiently small CONFIG_NR_CPUS value for the bit scanning optimization to be triggered, but not enough CPUs to then actually fill that widened cpumask. At that point, the cpumask scanning will return the NR_CPUS constant, which is _not_ the same as nr_cpumask_bits. This just does the mindless fix with sed -i 's/== nr_cpumask_bits/>= nr_cpu_ids/' to fix the incorrect uses. The ones in the SCSI lpfc driver in particular could probably be fixed more cleanly by just removing that repeated pattern entirely, but I am not emptionally invested enough in that driver to care. Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/lkml/481b19b5-83a0-4793-b4fd-194ad7b978c3@roeck-us.net/ Reported-and-tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/lkml/CAMuHMdUKo_Sf7TjKzcNDa8Ve+6QrK+P8nSQrSQ=6LTRmcBKNww@mail.gmail.com/ Reported-by: Vernon Yang <vernon2gm@gmail.com> Link: https://lore.kernel.org/lkml/20230306160651.2016767-1-vernon2gm@gmail.com/ Cc: Yury Norov <yury.norov@gmail.com> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2023-03-06 12:15:13 -08:00
..
selftest	treewide: use get_random_u32_inclusive() when possible	2022-11-18 02:18:02 +01:00
allowedips.c	wireguard: allowedips: don't corrupt stack when detecting overflow	2022-08-02 13:47:50 -07:00
allowedips.h	wireguard: allowedips: free empty intermediate nodes when removing single node	2021-06-04 14:25:14 -07:00
cookie.c
cookie.h
device.c	pm/sleep: Add PM_USERSPACE_AUTOSLEEP Kconfig	2022-07-01 10:39:20 +02:00
device.h	wireguard: receive: use ring buffer for incoming handshakes	2021-11-29 19:50:50 -08:00
main.c	wireguard: main: rename 'mod_init' & 'mod_exit' functions to be module-specific	2021-11-29 19:50:30 -08:00
Makefile	wireguard: do not use -O3	2021-06-04 14:25:14 -07:00
messages.h
netlink.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2022-09-22 13:02:10 -07:00
netlink.h
noise.c	lib/crypto: blake2s: move hmac construction into wireguard	2022-01-18 13:03:55 +01:00
noise.h
peer.c	net: drop the weight argument from netif_napi_add	2022-09-28 18:57:14 -07:00
peer.h	wireguard: peer: allocate in kmem_cache	2021-06-04 14:25:14 -07:00
peerlookup.c
peerlookup.h
queueing.c	wireguard: queueing: use CFI-safe ptr_ring cleanup function	2022-03-30 19:14:08 -07:00
queueing.h	cpumask: fix incorrect cpumask scanning result checks	2023-03-06 12:15:13 -08:00
ratelimiter.c	wireguard: ratelimiter: use kvcalloc() instead of kvzalloc()	2021-11-29 19:50:50 -08:00
ratelimiter.h
receive.c	wireguard: receive: use dev_sw_netstats_rx_add()	2022-06-09 21:53:10 -07:00
send.c	wireguard: queueing: get rid of per-peer ring buffers	2021-02-23 15:59:34 -08:00
socket.c	wireguard: socket: ignore v6 endpoints when ipv6 is disabled	2022-03-30 19:14:09 -07:00
socket.h
timers.c	wireguard: timers: cast enum limits members to int in prints	2022-12-13 19:30:45 -08:00
timers.h
version.h