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Eric W. Biederman 2dd8083f6d posix-cpu-timers: Use pids not tasks in lookup
The current posix-cpu-timer code uses pids when holding persistent
references in timers.  However the lookups from clock_id_t still return
tasks that need to be converted into pids for use.

This results in usage being pid->task->pid and that can race with
release_task and de_thread.  This can lead to some not wrong but
surprising results.  Surprising enough that Oleg and I both thought
there were some bugs in the code for a while.

This set of changes modifies the code to just lookup, verify, and return
pids from the clockid_t lookups to remove those potentialy troublesome
races.

Eric W. Biederman (3):
      posix-cpu-timers: Extend rcu_read_lock removing task_struct references
      posix-cpu-timers: Replace cpu_timer_pid_type with clock_pid_type
      posix-cpu-timers: Replace __get_task_for_clock with pid_for_clock

 kernel/time/posix-cpu-timers.c | 102 ++++++++++++++++++-----------------------
 1 file changed, 45 insertions(+), 57 deletions(-)

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-04-30 06:43:44 -05:00
Documentation proc: use human-readable values for hidepid 2020-04-22 10:51:22 -05:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch A set of three patches to fix the fallout of the newly added split lock 2020-04-12 10:17:16 -07:00
block block-5.7-2020-04-10 2020-04-10 10:06:54 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto x86: update AS_* macros to binutils >=2.23, supporting ADX and AVX2 2020-04-09 00:12:48 +09:00
drivers Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
fs exec: Remove BUG_ON(has_group_leader_pid) 2020-04-28 16:50:07 -05:00
include signal: Remove has_group_leader_pid 2020-04-28 16:54:25 -05:00
init Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
ipc ipc/util.c: sysvipc_find_ipc() should increase position index 2020-04-10 15:36:22 -07:00
kernel posix-cpu-timers: Use pids not tasks in lookup 2020-04-30 06:43:44 -05:00
lib Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
mm Merge branch 'akpm' (patches from Andrew) 2020-04-10 17:57:48 -07:00
net Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
samples samples/hw_breakpoint: drop use of kallsyms_lookup_name() 2020-04-07 10:43:44 -07:00
scripts kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig 2020-04-09 00:13:45 +09:00
security Use proc_pid_ns() to get pid_namespace from the proc superblock 2020-04-24 16:38:30 -05:00
sound sound fixes for 5.7-rc1 2020-04-10 12:27:06 -07:00
tools proc: use human-readable values for hidepid 2020-04-22 10:51:22 -05:00
usr kbuild: fix comment about missing include guard detection 2020-04-11 12:09:48 +09:00
virt KVM: Pass kvm_init()'s opaque param to additional arch funcs 2020-03-31 10:48:03 -04:00
.clang-format clang-format: Update with the latest for_each macro list 2020-03-06 21:50:05 +01:00
.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 .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
.mailmap mailmap: Add Sedat Dilek (replacement for expired email address) 2020-04-11 09:28:34 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Hand MIPS over to Thomas 2020-02-24 22:43:18 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: sort field names for all entries 2020-04-12 11:04:58 -07:00
Makefile Linux 5.7-rc1 2020-04-12 12:35:55 -07:00
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.