kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-09 18:15:49 +00:00
Code Issues Releases Packages Activity
No description
890,074 commits 116 branches 5,788 tags 5.6 GiB
  • C 96.9%
  • Assembly 0.9%
  • Rust 0.6%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Thomas Gleixner b46c8fdba5 genirq/proc: Reject invalid affinity masks (again) 
commit cba6437a18 upstream.

Qian Cai reported that the WARN_ON() in the x86/msi affinity setting code,
which catches cases where the affinity setting is not done on the CPU which
is the current target of the interrupt, triggers during CPU hotplug stress
testing.

It turns out that the warning which was added with the commit addressing
the MSI affinity race unearthed yet another long standing bug.

If user space writes a bogus affinity mask, i.e. it contains no online CPUs,
then it calls irq_select_affinity_usr(). This was introduced for ALPHA in

  eee45269b0 ("[PATCH] Alpha: convert to generic irq framework (generic part)")

and subsequently made available for all architectures in

  1840475676 ("genirq: Expose default irq affinity mask (take 3)")

which introduced the circumvention of the affinity setting restrictions for
interrupt which cannot be moved in process context.

The whole exercise is bogus in various aspects:

  1) If the interrupt is already started up then there is absolutely
     no point to honour a bogus interrupt affinity setting from user
     space. The interrupt is already assigned to an online CPU and it
     does not make any sense to reassign it to some other randomly
     chosen online CPU.

  2) If the interupt is not yet started up then there is no point
     either. A subsequent startup of the interrupt will invoke
     irq_setup_affinity() anyway which will chose a valid target CPU.

So the only correct solution is to just return -EINVAL in case user space
wrote an affinity mask which does not contain any online CPUs, except for
ALPHA which has it's own magic sauce for this.

Fixes: 1840475676 ("genirq: Expose default irq affinity mask (take 3)")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Qian Cai <cai@lca.pw>
Link: https://lkml.kernel.org/r/878sl8xdbm.fsf@nanos.tec.linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2020-02-28 17:23:43 +01:00
arch KVM: apic: avoid calculating pending eoi from an uninitialized val 2020-02-28 17:23:40 +01:00
block block, bfq: do not plug I/O for bfq_queues with no proc refs 2020-02-24 08:38:09 +01:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto crypto: rename sm3-256 to sm3 in hash_algo_name 2020-02-28 17:23:43 +01:00
Documentation mm: Avoid creating virtual address aliases in brk()/mmap()/mremap() 2020-02-28 17:23:37 +01:00
drivers staging: greybus: use after free in gb_audio_manager_remove_all() 2020-02-28 17:23:42 +01:00
fs ecryptfs: replace BUG_ON with error handling code 2020-02-28 17:23:43 +01:00
include iommu/vt-d: Fix compile warning from intel-svm.h 2020-02-28 17:23:43 +01:00
init Revert "um: Enable CONFIG_CONSTRUCTORS" 2020-02-01 09:33:00 +00:00
ipc Revert "ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()" 2020-02-28 17:23:36 +01:00
kernel genirq/proc: Reject invalid affinity masks (again) 2020-02-28 17:23:43 +01:00
lib crypto: chacha20poly1305 - prevent integer overflow on large input 2020-02-28 17:23:40 +01:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm: Avoid creating virtual address aliases in brk()/mmap()/mremap() 2020-02-28 17:23:37 +01:00
net sunrpc: Fix potential leaks in sunrpc_cache_unhash() 2020-02-24 08:38:40 +01:00
samples samples/bpf: Set -fno-stack-protector when building BPF programs 2020-02-24 08:38:15 +01:00
scripts bpf, btf: Always output invariant hit in pahole DWARF to BTF transform 2020-02-24 08:38:40 +01:00
security selinux: ensure we cleanup the internal AVC counters on error in avc_update() 2020-02-24 08:38:19 +01:00
sound ASoC: fsl_sai: Fix exiting path on probing failure 2020-02-28 17:23:42 +01:00
tools tc-testing: add missing 'nsPlugin' to basic.json 2020-02-24 08:38:49 +01:00
usr gen_initramfs_list.sh: fix 'bad variable name' error 2020-01-04 00:00:48 +09:00
virt KVM: arm64: Treat emulated TVAL TimerValue as a signed 32-bit integer 2020-02-14 16:53:04 -05:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap MAINTAINERS: update my email address 2020-01-11 14:33:39 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Linux 5.4-rc4 2019-10-29 04:43:29 -06:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: Update drm/i915 bug filing URL 2020-02-28 17:23:36 +01:00
Makefile Linux 5.5.6 2020-02-24 08:38:51 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.