NothingOSS/android_kernel_msm-6.1_nothing_sm7635
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
android_kernel_msm-6.1_noth.../kernel
History
Suren Baghdasaryan 0d9960403c UPSTREAM: fork: lock VMAs of the parent process when forking 
When forking a child process, the parent write-protects anonymous pages
and COW-shares them with the child being forked using copy_present_pte().

We must not take any concurrent page faults on the source vma's as they
are being processed, as we expect both the vma and the pte's behind it
to be stable.  For example, the anon_vma_fork() expects the parents
vma->anon_vma to not change during the vma copy.

A concurrent page fault on a page newly marked read-only by the page
copy might trigger wp_page_copy() and a anon_vma_prepare(vma) on the
source vma, defeating the anon_vma_clone() that wasn't done because the
parent vma originally didn't have an anon_vma, but we now might end up
copying a pte entry for a page that has one.

Before the per-vma lock based changes, the mmap_lock guaranteed
exclusion with concurrent page faults.  But now we need to do a
vma_start_write() to make sure no concurrent faults happen on this vma
while it is being processed.

This fix can potentially regress some fork-heavy workloads.  Kernel
build time did not show noticeable regression on a 56-core machine while
a stress test mapping 10000 VMAs and forking 5000 times in a tight loop
shows ~5% regression.  If such fork time regression is unacceptable,
disabling CONFIG_PER_VMA_LOCK should restore its performance.  Further
optimizations are possible if this regression proves to be problematic.

Suggested-by: David Hildenbrand <david@redhat.com>
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Closes: https://lore.kernel.org/all/dbdef34c-3a07-5951-e1ae-e9c6e3cdf51b@kernel.org/
Reported-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Closes: https://lore.kernel.org/all/b198d649-f4bf-b971-31d0-e8433ec2a34c@applied-asynchrony.com/
Reported-by: Jacob Young <jacobly.alt@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217624
Fixes: 0bff0aaea03e ("x86/mm: try VMA lock-based page fault handling first")
Cc: stable@vger.kernel.org
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit fb49c455323ff8319a123dd312be9082c49a23a5)
Change-Id: Ic5aa9dc51a888b5b0319ec4ec6d2941424573ca0
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2023-07-27 12:19:09 +00:00
..
bpf UPSTREAM: mm: replace vma->vm_flags direct modifications with modifier calls 2023-06-07 14:24:57 +00:00
cgroup ANDROID: Export memcg functions to allow module to add new files 2023-06-23 07:53:18 +00:00
configs Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
debug mm: remove vmacache 2022-09-26 19:46:18 -07:00
dma UPSTREAM: dma-remap: use kvmalloc_array/kvfree for larger dma memory remap 2023-07-13 20:31:00 +00:00
entry entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-up 2023-03-30 12:49:13 +02:00
events UPSTREAM: mm: replace vma->vm_flags direct modifications with modifier calls 2023-06-07 14:24:57 +00:00
futex ANDROID: vendor_hooks: Add hooks for futex 2023-05-11 05:22:29 +00:00
gcov gcov: add support for checksum field 2022-12-31 13:33:11 +01:00
irq Merge 6.1.18 into android14-6.1 2023-03-21 08:22:15 +00:00
kcsan UPSTREAM: kcsan: Avoid READ_ONCE() in read_instrumented_memory() 2023-06-05 15:02:47 +00:00
livepatch Livepatching changes for 6.1 2022-10-10 11:36:19 -07:00
locking ANDROID: Inherit "user-aware property" across rtmutex. 2023-07-27 00:04:07 +00:00
module ANDROID: GKI: Move GKI module headers to generated includes 2023-07-24 17:56:59 +00:00
power ANDROID: vendor hooks: Encrypt snapshot for bootloader based hibernation 2023-06-07 14:25:05 +00:00
printk Merge 6.1.18 into android14-6.1 2023-03-21 08:22:15 +00:00
rcu rcu-tasks: Handle queue-shrink/callback-enqueue race condition 2023-03-10 09:33:48 +01:00
sched ANDROID: Inherit "user-aware property" across rtmutex. 2023-07-27 00:04:07 +00:00
time UPSTREAM: posix-cpu-timers: Implement the missing timer_wait_running callback 2023-06-14 16:40:59 +00:00
trace This is the 6.1.25 stable release 2023-04-26 13:13:19 +00:00
.gitignore ANDROID: add gki_module headers to .gitignore file 2022-04-28 06:43:21 +00:00
acct.c acct: fix potential integer overflow in encode_comp_t() 2022-12-31 13:32:58 +01:00
async.c
audit.c audit: use time_after to compare time 2022-08-29 19:47:03 -04:00
audit.h audit: remove selinux_audit_rule_update() declaration 2022-09-07 11:30:15 -04:00
audit_fsnotify.c audit: fix potential double free on error path from fsnotify_add_inode_mark 2022-08-22 18:50:06 -04:00
audit_tree.c audit: use fsnotify group lock helpers 2022-04-25 14:37:28 +02:00
audit_watch.c audit_init_parent(): constify path 2022-09-01 17:39:30 -04:00
auditfilter.c
auditsc.c audit/stable-6.1 PR 20221003 2022-10-04 11:05:43 -07:00
backtracetest.c
bounds.c mm: multi-gen LRU: minimal implementation 2022-09-26 19:46:09 -07:00
capability.c xfs: don't generate selinux audit messages for capability testing 2022-03-09 10:32:06 -08:00
cfi.c cfi: Switch to -fsanitize=kcfi 2022-09-26 10:13:13 -07:00
compat.c sched_getaffinity: don't assume 'cpumask_size()' is fully initialized 2023-04-06 12:10:40 +02:00
configs.c
context_tracking.c context_tracking: Fix noinstr vs KASAN 2023-03-10 09:33:45 +01:00
cpu.c cpu/hotplug: Do not bail-out in DYING/STARTING sections 2022-12-31 13:31:59 +01:00
cpu_pm.c context_tracking: Take IRQ eqs entrypoints over RCU 2022-07-05 13:32:59 -07:00
crash_core.c vmcoreinfo: add kallsyms_num_syms symbol 2022-08-28 14:02:44 -07:00
crash_dump.c
cred.c ANDROID: kernel: Add restricted vendor hook in creds 2023-04-18 19:28:00 +00:00
delayacct.c delayacct: support re-entrance detection of thrashing accounting 2022-09-26 19:46:07 -07:00
dma.c
exec_domain.c
exit.c ANDROID: vendor_hooks: Add hooks for memory when debug 2023-05-25 21:06:40 +00:00
extable.c context_tracking: Take NMI eqs entrypoints over RCU 2022-07-05 13:32:59 -07:00
fail_function.c kernel/fail_function: fix memory leak with using debugfs_lookup() 2023-03-11 13:55:39 +01:00
fork.c UPSTREAM: fork: lock VMAs of the parent process when forking 2023-07-27 12:19:09 +00:00
freezer.c ANDROID: freezer: Add vendor hook to freezer for GKI purpose. 2023-05-17 00:25:38 +00:00
gen_kheaders.sh FROMLIST: kheaders: dereferences the source tree 2023-06-23 09:09:00 +00:00
groups.c security: Add LSM hook to setgroups() syscall 2022-07-15 18:21:49 +00:00
hung_task.c ANDROID: hung_task: Add vendor hook for hung task detect 2023-01-30 11:14:35 +08:00
iomem.c
irq_work.c Linux 5.18-rc3 2022-04-18 08:32:59 +02:00
jump_label.c jump_label: make initial NOP patching the special case 2022-06-24 09:48:55 +02:00
kallsyms.c kcfi updates for v6.1-rc1 2022-10-03 17:11:07 -07:00
kallsyms_internal.h kallsyms: move declarations to internal header 2022-07-17 17:31:39 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt Revert "signal, x86: Delay calling signals in atomic on RT enabled kernels" 2022-03-31 10:36:55 +02:00
kcov.c UPSTREAM: mm: replace vma->vm_flags direct modifications with modifier calls 2023-06-07 14:24:57 +00:00
kexec.c panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kexec_core.c kexec: replace kmap() with kmap_local_page() 2022-09-11 21:55:08 -07:00
kexec_elf.c
kexec_file.c panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kexec_internal.h panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kheaders.c
kmod.c
kprobes.c kprobes: Fix to handle forcibly unoptimized kprobes on freeing_list 2023-03-10 09:34:27 +01:00
ksysfs.c kexec: turn all kexec_mutex acquisitions into trylocks 2022-09-11 21:55:06 -07:00
kthread.c Merge 493ffd6605 ("Merge tag 'ucount-rlimits-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace") into android-mainline 2022-10-12 09:37:52 +02:00
latencytop.c latencytop: use the last element of latency_record of system 2022-09-11 21:55:12 -07:00
Makefile cfi: Fix CFI failure with KASAN 2022-12-31 13:33:08 +01:00
module_signature.c
notifier.c notifier: Add blocking/atomic_notifier_chain_register_unique_prio() 2022-05-19 19:30:30 +02:00
nsproxy.c Revert "fs/exec: allow to unshare a time namespace on vfork+exec" 2022-09-13 10:38:43 -07:00
padata.c padata: Fix list iterator in padata_do_serial() 2022-12-31 13:32:34 +01:00
panic.c panic: fix the panic_print NMI backtrace setting 2023-03-10 09:34:25 +01:00
params.c
pid.c Merge 041bc24d86 ("Merge tag 'pci-v6.1-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci") into android-mainline 2022-10-25 14:52:46 +02:00
pid_namespace.c rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes() 2023-03-10 09:32:52 +01:00
profile.c Revert "exit: Remove profile_task_exit & profile_munmap" 2023-03-09 23:13:08 +00:00
ptrace.c freezer,sched: Rewrite core freezer logic 2022-09-07 21:53:50 +02:00
range.c
reboot.c Merge f848b3cda3 ("Merge tag 'pm-6.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm") into android-mainline 2022-10-19 17:54:04 +02:00
regset.c
relay.c UPSTREAM: relayfs: fix out-of-bounds access in relay_file_read 2023-07-04 08:29:35 +01:00
resource.c dax/kmem: Fix leak of memory-hotplug resources 2023-03-10 09:34:25 +01:00
resource_kunit.c
rseq.c rseq: Use pr_warn_once() when deprecated/unknown ABI flags are encountered 2022-11-14 09:58:32 +01:00
scftorture.c scftorture: Fix distribution of short handler delays 2022-04-11 17:07:29 -07:00
scs.c UPSTREAM: scs: add support for dynamic shadow call stacks 2023-05-25 15:37:14 -07:00
seccomp.c seccomp: Add wait_killable semantic to seccomp user notifier 2022-05-03 14:11:58 -07:00
signal.c ANDROID: vendor_hooks: Add hooks for signal 2023-05-19 19:41:20 +00:00
smp.c bitmap patches for v6.1-rc1 2022-10-10 12:49:34 -07:00
smpboot.c smpboot: use atomic_try_cmpxchg in cpu_wait_death and cpu_report_death 2022-09-11 21:55:10 -07:00
smpboot.h
softirq.c ANDROID: softirq: Export irq_handler_exit tracepoint 2023-01-17 18:16:29 +00:00
stackleak.c stackleak: add on/off stack variants 2022-05-08 01:33:09 -07:00
stacktrace.c Merge ed4643521e ("Merge tag 'arm-dt-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc") into android-mainline 2022-04-05 08:12:56 +02:00
static_call.c static_call: Don't make __static_call_return0 static 2022-04-05 09:59:38 +02:00
static_call_inline.c static_call: Don't make __static_call_return0 static 2022-04-05 09:59:38 +02:00
stop_machine.c ANDROID: sched: allow access to critical common code for CPU Pause 2022-09-21 00:09:57 +00:00
sys.c Merge b1644a0031 ("drm/rockchip: vop2: Use regcache_sync() to fix suspend/resume") into android14-6.1 2023-05-16 14:19:59 +00:00
sys_ni.c kernel/sys_ni: add compat entry for fadvise64_64 2022-08-20 15:17:45 -07:00
sysctl-test.c kernel/sysctl-test: use SYSCTL_{ZERO/ONE_HUNDRED} instead of i_{zero/one_hundred} 2022-09-08 16:56:45 -07:00
sysctl.c proc: proc_skip_spaces() shouldn't think it is working on C strings 2022-12-05 12:09:06 -08:00
task_work.c task_work: use try_cmpxchg in task_work_add, task_work_cancel_match and task_work_run 2022-09-11 21:55:10 -07:00
taskstats.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
torture.c torture: Fix hang during kthread shutdown phase 2023-03-10 09:34:07 +01:00
tracepoint.c Merge d4013bc4d4 ("Merge tag 'bitmap-6.1-rc1' of https://github.com/norov/linux") into android-mainline 2022-10-19 13:22:10 +02:00
tsacct.c taskstats: version 12 with thread group and exe info 2022-04-29 14:38:03 -07:00
ucount.c ucounts: Split rlimit and ucount values and max values 2022-05-18 18:24:57 -05:00
uid16.c
uid16.h
umh.c freezer,umh: Fix call_usermode_helper_exec() vs SIGKILL 2023-02-22 12:59:50 +01:00
up.c
user-return-notifier.c
user.c ANDROID: export find_user() & free_uid()for GKI purpose. 2023-05-11 05:22:29 +00:00
user_namespace.c ucounts: Split rlimit and ucount values and max values 2022-10-09 16:24:05 -07:00
usermode_driver.c blob_to_mnt(): kern_unmount() is needed to undo kern_mount() 2022-05-19 23:25:47 -04:00
utsname.c
utsname_sysctl.c kernel/utsname_sysctl.c: Fix hostname polling 2022-10-23 12:01:01 -07:00
watch_queue.c watch_queue: fix IOC_WATCH_QUEUE_SET_SIZE alloc error paths 2023-03-17 08:50:30 +01:00
watchdog.c ANDROID: softlockup: add vendor hook for a softlockup task 2023-03-13 20:34:25 +00:00
watchdog_hld.c Revert "printk: add functions to prefer direct printing" 2022-06-23 18:41:40 +02:00
workqueue.c ANDROID: workqueue: export symbol of the function wq_worker_comm() 2023-05-15 23:43:01 +00:00
workqueue_internal.h