AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity
8e04c8397b
kernel_optimize_test/kernel
History
Eric Biggers 8e04c8397b wait: add wake_up_pollfree() 
commit 42288cb44c4b5fff7653bc392b583a2b8bd6a8c0 upstream.

Several ->poll() implementations are special in that they use a
waitqueue whose lifetime is the current task, rather than the struct
file as is normally the case.  This is okay for blocking polls, since a
blocking poll occurs within one task; however, non-blocking polls
require another solution.  This solution is for the queue to be cleared
before it is freed, using 'wake_up_poll(wq, EPOLLHUP | POLLFREE);'.

However, that has a bug: wake_up_poll() calls __wake_up() with
nr_exclusive=1.  Therefore, if there are multiple "exclusive" waiters,
and the wakeup function for the first one returns a positive value, only
that one will be called.  That's *not* what's needed for POLLFREE;
POLLFREE is special in that it really needs to wake up everyone.

Considering the three non-blocking poll systems:

- io_uring poll doesn't handle POLLFREE at all, so it is broken anyway.

- aio poll is unaffected, since it doesn't support exclusive waits.
  However, that's fragile, as someone could add this feature later.

- epoll doesn't appear to be broken by this, since its wakeup function
  returns 0 when it sees POLLFREE.  But this is fragile.

Although there is a workaround (see epoll), it's better to define a
function which always sends POLLFREE to all waiters.  Add such a
function.  Also make it verify that the queue really becomes empty after
all waiters have been woken up.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211209010455.42744-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 11:32:39 +01:00
..
bpf bpf: Fix the off-by-two error in range markings 2021-12-14 11:32:36 +01:00
cgroup cgroup: Fix rootcg cpu.stat guest double counting 2021-11-18 14:04:13 +01:00
configs
debug kgdb: fix to kill breakpoints on initmem after boot 2021-03-04 11:38:46 +01:00
dma dma-debug: fix sg checks in debug_dma_map_sg() 2021-10-27 09:56:47 +02:00
entry KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest 2021-10-06 15:55:49 +02:00
events Revert "perf: Rework perf_event_exit_event()" 2021-11-26 10:39:22 +01:00
gcov gcov: re-fix clang-11+ support 2021-04-14 08:41:58 +02:00
irq genirq/timings: Fix error return code in irq_timings_test_irqs() 2021-09-15 09:50:29 +02:00
kcsan kcsan: Fix debugfs initcall return type 2021-05-26 12:06:54 +02:00
livepatch
locking lockdep: Let lock_is_held_type() detect recursive read as read 2021-11-18 14:04:02 +01:00
power PM: hibernate: use correct mode for swsusp_close() 2021-12-01 09:19:06 +01:00
printk printk/console: Allow to disable console output by using console="" or console=null 2021-11-12 14:58:33 +01:00
rcu rcu: Always inline rcu_dynticks_task*_{enter,exit}() 2021-11-18 14:04:06 +01:00
sched wait: add wake_up_pollfree() 2021-12-14 11:32:39 +01:00
time posix-cpu-timers: Clear task::posix_cputimers_work in copy_process() 2021-11-18 14:04:29 +01:00
trace tracing/histograms: String compares should not care about signed values 2021-12-08 09:03:22 +01:00
.gitignore kbuild: update config_data.gz only when the content of .config is changed 2021-05-11 14:47:37 +02:00
acct.c
async.c
audit_fsnotify.c fsnotify: generalize handle_inode_event() 2020-12-30 11:54:18 +01:00
audit_tree.c audit: move put_tree() to avoid trim_trees refcount underflow and UAF 2021-09-03 10:09:31 +02:00
audit_watch.c fsnotify: generalize handle_inode_event() 2020-12-30 11:54:18 +01:00
audit.c
audit.h
auditfilter.c
auditsc.c audit: fix possible null-pointer dereference in audit_filter_rules 2021-10-27 09:56:52 +02:00
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c
cpu_pm.c PM: cpu: Make notifier chain use a raw_spinlock_t 2021-09-15 09:50:40 +02:00
cpu.c sched/scs: Reset task stack state in bringup_cpu() 2021-12-01 09:19:08 +01:00
crash_core.c crash_core, vmcoreinfo: append 'SECTION_SIZE_BITS' to vmcoreinfo 2021-06-23 14:42:52 +02:00
crash_dump.c
cred.c Revert "Add a reference to ucounts for each cred" 2021-09-08 08:49:00 +02:00
delayacct.c
dma.c
exec_domain.c
exit.c kernel/io_uring: cancel io_uring before task works 2021-01-30 13:55:18 +01:00
extable.c
fail_function.c fail_function: Remove a redundant mutex unlock 2020-11-19 11:58:16 -08:00
fork.c posix-cpu-timers: Clear task::posix_cputimers_work in copy_process() 2021-11-18 14:04:29 +01:00
freezer.c Revert "kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing" 2021-04-07 15:00:14 +02:00
futex.c mm, futex: fix shared futex pgoff on shmem huge page 2021-06-30 08:47:29 -04:00
gen_kheaders.sh
groups.c
hung_task.c kernel/hung_task.c: make type annotations consistent 2020-11-02 12:14:19 -08:00
iomem.c
irq_work.c
jump_label.c jump_label: Fix jump_label_text_reserved() vs __init 2021-07-20 16:05:58 +02:00
kallsyms.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
kcmp.c exec: Transform exec_update_mutex into a rw_semaphore 2021-01-09 13:46:24 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec_core.c kernel: kexec: remove the lock operation of system_transition_mutex 2021-02-03 23:28:37 +01:00
kexec_elf.c
kexec_file.c kernel: kexec_file: fix error return code of kexec_calculate_store_digests() 2021-05-19 10:13:09 +02:00
kexec_internal.h
kexec.c
kheaders.c
kmod.c
kprobes.c kprobes: Limit max data_size of the kretprobe instances 2021-12-08 09:03:20 +01:00
ksysfs.c
kthread.c kthread: Fix PF_KTHREAD vs to_kthread() race 2021-09-03 10:09:31 +02:00
latencytop.c
Makefile kbuild: update config_data.gz only when the content of .config is changed 2021-05-11 14:47:37 +02:00
module_signature.c module: harden ELF info handling 2021-03-25 09:04:11 +01:00
module_signing.c module: harden ELF info handling 2021-03-25 09:04:11 +01:00
module-internal.h
module.c module: limit enabling module.sig_enforce 2021-06-30 08:47:15 -04:00
notifier.c
nsproxy.c
padata.c
panic.c panic: don't dump stack twice on warn 2020-11-14 11:26:04 -08:00
params.c params: Replace zero-length array with flexible-array member 2020-10-29 17:22:59 -05:00
pid_namespace.c memcg: enable accounting for pids in nested pid namespaces 2021-09-18 13:40:36 +02:00
pid.c exec: Transform exec_update_mutex into a rw_semaphore 2021-01-09 13:46:24 +01:00
profile.c profiling: fix shift-out-of-bounds bugs 2021-09-26 14:08:58 +02:00
ptrace.c ptrace: make ptrace() fail if the tracee changed its pid unexpectedly 2021-05-26 12:06:49 +02:00
range.c
reboot.c reboot: fix overflow parsing reboot cpu number 2020-11-14 11:26:03 -08:00
regset.c
relay.c
resource.c kernel/resource: make walk_mem_res() find all busy IORESOURCE_MEM resources 2021-05-19 10:13:09 +02:00
rseq.c KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest 2021-10-06 15:55:49 +02:00
scftorture.c
scs.c
seccomp.c seccomp: Fix setting loaded filter count during TSYNC 2021-08-18 08:59:06 +02:00
signal.c signal: Remove the bogus sigkill_pending in ptrace_stop 2021-11-18 14:03:47 +01:00
smp.c smp: Fix smp_call_function_single_async prototype 2021-05-14 09:50:46 +02:00
smpboot.c sched/core: Initialize the idle task with preemption disabled 2021-07-14 16:55:50 +02:00
smpboot.h
softirq.c
stackleak.c
stacktrace.c
static_call.c static_call: Fix unused variable warn w/o MODULE 2021-09-08 08:49:00 +02:00
stop_machine.c stop_machine, rcu: Mark functions as notrace 2020-10-26 12:12:27 +01:00
sys_ni.c
sys.c prctl: allow to setup brk for et_dyn executables 2021-09-26 14:08:57 +02:00
sysctl-test.c
sysctl.c sysctl.c: fix underflow value setting risk in vm_table 2021-03-17 17:06:25 +01:00
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c tracepoint: Use rcu get state and cond sync for static call updates 2021-09-03 10:09:30 +02:00
tsacct.c
ucount.c Revert "Add a reference to ucounts for each cred" 2021-09-08 08:49:00 +02:00
uid16.c
uid16.h
umh.c
up.c smp: Fix smp_call_function_single_async prototype 2021-05-14 09:50:46 +02:00
user_namespace.c Revert "Add a reference to ucounts for each cred" 2021-09-08 08:49:00 +02:00
user-return-notifier.c
user.c
usermode_driver.c bpf: Fix umd memory leak in copy_process() 2021-03-30 14:32:03 +02:00
utsname_sysctl.c
utsname.c
watch_queue.c
watchdog_hld.c
watchdog.c watchdog: fix barriers when printing backtraces from all CPUs 2021-05-19 10:13:00 +02:00
workqueue_internal.h
workqueue.c workqueue: make sysfs of unbound kworker cpumask more clever 2021-11-18 14:03:58 +01:00