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
..
agp	char/agp: consolidate {alloc,free}_gatt_pages()	2023-02-13 22:13:12 +01:00
hw_random	hwrng: starfive - Enable compile testing	2023-02-03 12:55:59 +08:00
ipmi	ipmi: ipmb: Fix the MODULE_PARM_DESC associated to 'retry_time_ms'	2023-02-10 07:38:18 -06:00
mwave
pcmcia	Char/Misc and other driver subsystem changes for 6.3-rc1	2023-02-24 12:47:33 -08:00
tpm	tpm: add vendor flag to command code validation	2023-02-13 10:11:20 +02:00
xilinx_hwicap
xillybus	char: xillybus: Fix trivial bug with mutex	2022-11-23 19:44:04 +01:00
adi.c
apm-emulation.c
applicom.c	applicom: Fix PCI device refcount leak in applicom_init()	2023-01-20 13:05:39 +01:00
applicom.h
bsr.c
ds1620.c
dsp56k.c
dtlk.c
hangcheck-timer.c
hpet.c
Kconfig	random: use random.trust_{bootloader,cpu} command line option only	2022-11-18 02:18:10 +01:00
lp.c
Makefile
mem.c	mm/nommu: factor out check for NOMMU shared mappings into is_nommu_shared_mapping()	2023-01-18 17:12:56 -08:00
misc.c	Driver Core changes for 6.2-rc1	2022-12-16 03:54:54 -08:00
mspec.c	mm: replace vma->vm_flags direct modifications with modifier calls	2023-02-09 16:51:39 -08:00
nsc_gpio.c
nvram.c
nwbutton.c
nwbutton.h
nwflash.c
pc8736x_gpio.c
powernv-op-panel.c
ppdev.c
ps3flash.c
random.c	cpumask: fix incorrect cpumask scanning result checks	2023-03-06 12:15:13 -08:00
scx200_gpio.c
sonypi.c	ACPI: make remove callback of ACPI driver void	2022-11-23 19:11:22 +01:00
tlclk.c
toshiba.c
ttyprintk.c
uv_mmtimer.c
virtio_console.c	virtio_console: Use strscpy() to instead of strncpy()	2023-01-20 13:07:54 +01:00