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17581aa136
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Aleksandr Nogikh 17581aa136 kcov: split ioctl handling into locked and unlocked parts 
Patch series "kcov: improve mmap processing", v3.

Subsequent mmaps of the same kcov descriptor currently do not update the
virtual memory of the task and yet return 0 (success).  This is
counter-intuitive and may lead to unexpected memory access errors.

Also, this unnecessarily limits the functionality of kcov to only the
simplest usage scenarios.  Kcov instances are effectively forever attached
to their first address spaces and it becomes impossible to e.g.  reuse the
same kcov handle in forked child processes without mmapping the memory
first.  This is exactly what we tried to do in syzkaller and inadvertently
came upon this behavior.

This patch series addresses the problem described above.

This patch (of 3):

Currently all ioctls are de facto processed under a spinlock in order to
serialise them.  This, however, prohibits the use of vmalloc and other
memory management functions in the implementations of those ioctls,
unnecessary complicating any further changes to the code.

Let all ioctls first be processed inside the kcov_ioctl() function which
should execute the ones that are not compatible with spinlock and then
pass control to kcov_ioctl_locked() for all other ones.
KCOV_REMOTE_ENABLE is processed both in kcov_ioctl() and
kcov_ioctl_locked() as the steps are easily separable.

Although it is still compatible with a spinlock, move KCOV_INIT_TRACE
handling to kcov_ioctl(), so that the changes from the next commit are
easier to follow.

Link: https://lkml.kernel.org/r/20220117153634.150357-1-nogikh@google.com
Link: https://lkml.kernel.org/r/20220117153634.150357-2-nogikh@google.com
Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-23 19:00:35 -07:00
..
bpf bpf: Add schedule points in batch ops 2022-02-17 10:48:26 -08:00
cgroup cgroup: use irqsave in cgroup_rstat_flush_locked(). 2022-03-23 19:00:34 -07:00
configs configs/debug: restore DEBUG_INFO=y for overriding 2022-03-17 11:02:13 -07:00
debug kdb: Adopt scheduler's task classification 2021-11-03 17:21:37 +00:00
dma swiotlb: rework "fix info leak with DMA_FROM_DEVICE" 2022-03-07 11:26:02 -08:00
entry entry: Snapshot thread flags 2021-12-01 00:06:43 +01:00
events perf: Fix list corruption in perf_cgroup_switch() 2022-02-06 22:37:27 +01:00
futex Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2022-01-17 05:49:30 +02:00
gcov gcov: Remove compiler version check 2021-12-02 17:25:21 +09:00
irq proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
kcsan KCSAN updates for v5.17 2022-01-11 09:51:26 -08:00
livepatch Livepatching changes for 5.17 2022-01-16 10:08:13 +02:00
locking lockdep: Correct lock_classes index mapping 2022-02-11 23:30:02 +01:00
power PM: s2idle: ACPI: Fix wakeup interrupts handling 2022-02-07 21:02:31 +01:00
printk printk: Fix incorrect __user type in proc_dointvec_minmax_sysadmin() 2022-02-03 11:27:38 -08:00
rcu rcu-tasks: Fix computation of CPU-to-list shift counts 2022-01-26 13:04:05 -08:00
sched sched: Fix yet more sched_fork() races 2022-02-19 11:11:05 +01:00
time bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
trace Minor tracing fixes: 2022-03-10 17:23:08 -08:00
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
acct.c kernel: remove spurious blkdev.h includes 2021-10-18 06:17:01 -06:00
async.c Revert "module, async: async_synchronize_full() on module init iff async is used" 2022-02-03 11:20:34 -08:00
audit_fsnotify.c fsnotify: clarify contract for create event hooks 2021-10-27 12:32:34 +02:00
audit_tree.c audit: use struct_size() helper in kmalloc() 2021-12-14 17:39:42 -05:00
audit_watch.c \n 2021-11-06 16:43:20 -07:00
audit.c audit: improve audit queue handling when "audit=1" on cmdline 2022-01-25 13:22:51 -05:00
audit.h audit/stable-5.16 PR 20211101 2021-11-01 21:17:39 -07:00
auditfilter.c audit/stable-5.17 PR 20220110 2022-01-11 13:08:21 -08:00
auditsc.c audit: don't deref the syscall args when checking the openat2 open_how::flags 2022-02-09 16:04:26 -05:00
backtracetest.c
bounds.c
capability.c
cfi.c cfi: Use rcu_read_{un}lock_sched_notrace 2021-08-11 13:11:12 -07:00
compat.c arch: remove compat_alloc_user_space 2021-09-08 15:32:35 -07:00
configs.c
context_tracking.c
cpu_pm.c PM: cpu: Make notifier chain use a raw_spinlock_t 2021-08-16 18:55:32 +02:00
cpu.c sched/scs: Reset task stack state in bringup_cpu() 2021-11-24 12:20:27 +01:00
crash_core.c kernel/crash_core: suppress unknown crashkernel parameter warning 2021-12-25 12:20:55 -08:00
crash_dump.c
cred.c ucounts: Base set_cred_ucounts changes on the real user 2022-02-17 09:11:02 -06:00
delayacct.c delayacct: track delays from memory compact 2022-01-20 08:52:55 +02:00
dma.c
exec_domain.c
exit.c exit: Fix the exit_code for wait_task_zombie 2022-01-08 12:43:57 -06:00
extable.c extable: use is_kernel_text() helper 2021-11-09 10:02:51 -08:00
fail_function.c
fork.c mm: refactor vm_area_struct::anon_vma_name usage code 2022-03-05 11:08:32 -08:00
freezer.c sched: Add get_current_state() 2021-06-18 11:43:08 +02:00
gen_kheaders.sh kbuild: clean up ${quiet} checks in shell scripts 2021-05-27 04:01:50 +09:00
groups.c
hung_task.c hung_task: move hung_task sysctl interface to hung_task.c 2022-01-22 08:33:34 +02:00
iomem.c
irq_work.c irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT 2021-10-15 11:25:18 +02:00
jump_label.c jump_label: Fix jump_label_text_reserved() vs __init 2021-07-05 10:46:20 +02:00
kallsyms.c Livepatching changes for 5.17 2022-01-16 10:08:13 +02:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/rwlock: Provide RT variant 2021-08-17 17:50:51 +02:00
Kconfig.preempt preempt: Restore preemption model selection configs 2021-11-11 13:09:33 +01:00
kcov.c kcov: split ioctl handling into locked and unlocked parts 2022-03-23 19:00:35 -07:00
kexec_core.c exit: Move oops specific logic from do_exit into make_task_dead 2021-12-13 12:04:45 -06:00
kexec_elf.c
kexec_file.c memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED 2021-11-06 13:30:42 -07:00
kexec_internal.h
kexec.c kexec: avoid compat_alloc_user_space 2021-09-08 15:32:34 -07:00
kheaders.c
kmod.c modules: add CONFIG_MODPROBE_PATH 2021-05-07 00:26:33 -07:00
kprobes.c kprobe: move sysctl_kprobes_optimization to kprobes.c 2022-01-22 08:33:36 +02:00
ksysfs.c kernel/ksysfs.c: use helper macro __ATTR_RW 2022-03-23 19:00:33 -07:00
kthread.c Merge branch 'akpm' (patches from Andrew) 2022-01-20 10:41:01 +02:00
latencytop.c
Makefile module: add in-kernel support for decompressing 2022-01-11 18:45:02 -08:00
module_decompress.c module: fix building with sysfs disabled 2022-02-16 12:51:32 -08:00
module_signature.c
module_signing.c
module-internal.h module: add in-kernel support for decompressing 2022-01-11 18:45:02 -08:00
module.c Revert "module, async: async_synchronize_full() on module init iff async is used" 2022-02-03 11:20:34 -08:00
notifier.c notifier: Return an error when a callback has already been registered 2021-12-29 10:37:33 +01:00
nsproxy.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
padata.c padata: Remove repeated verbose license text 2021-08-27 16:30:18 +08:00
panic.c panic: move panic_print before kmsg dumpers 2022-03-23 19:00:35 -07:00
params.c kobject: remove kset from struct kset_uevent_ops callbacks 2021-12-28 11:26:18 +01:00
pid_namespace.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
pid.c pid: add pidfd_get_task() helper 2021-10-14 13:29:18 +02:00
profile.c exit: Remove profile_handoff_task 2022-01-08 12:43:57 -06:00
ptrace.c ptrace: Remove second setting of PT_SEIZED in ptrace_attach 2022-01-08 12:43:57 -06:00
range.c
reboot.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2021-11-12 11:53:16 -08:00
regset.c
relay.c
resource_kunit.c
resource.c proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
rseq.c KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest 2021-09-22 10:24:01 -04:00
scftorture.c scftorture: Always log error message 2021-12-07 16:36:17 -08:00
scs.c scs: Release kasan vmalloc poison in scs_free process 2021-09-30 09:37:27 +01:00
seccomp.c seccomp: Invalidate seccomp mode to catch death failures 2022-02-10 19:09:12 -08:00
signal.c signal: HANDLER_EXIT should clear SIGNAL_UNKILLABLE 2022-02-10 19:08:54 -08:00
smp.c sched: Improve wake_up_all_idle_cpus() take #2 2021-10-22 15:32:46 +02:00
smpboot.c smpboot: Replace deprecated CPU-hotplug functions. 2021-08-10 14:57:42 +02:00
smpboot.h
softirq.c timers/nohz: Last resort update jiffies on nohz_full IRQ entry 2021-12-02 15:07:22 +01:00
stackleak.c gcc-plugins/stackleak: Use noinstr in favor of notrace 2022-02-03 17:02:21 -08:00
stacktrace.c stacktrace: move filter_irq_stacks() to kernel/stacktrace.c 2021-11-06 13:30:43 -07:00
static_call.c static_call: Fix static_call_text_reserved() vs __init 2021-07-05 10:46:33 +02:00
stop_machine.c
sys_ni.c mm/mempolicy: wire up syscall set_mempolicy_home_node 2022-01-15 16:30:30 +02:00
sys.c mm: refactor vm_area_struct::anon_vma_name usage code 2022-03-05 11:08:32 -08:00
sysctl-test.c kernel/sysctl-test: Remove some casts which are no-longer required 2021-06-23 16:41:24 -06:00
sysctl.c x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting 2022-02-21 10:21:47 +01:00
task_work.c kasan: record task_work_add() call stack 2021-04-30 11:20:42 -07:00
taskstats.c taskstats: remove unneeded dead assignment 2022-03-23 19:00:35 -07:00
torture.c locktorture,rcutorture,torture: Always log error message 2021-12-07 16:36:17 -08:00
tracepoint.c tracepoint: Fix kerneldoc comments 2021-08-16 11:39:51 -04:00
tsacct.c taskstats: Cleanup the use of task->exit_code 2022-01-08 12:43:57 -06:00
ucount.c ucounts: Handle wrapping in is_ucounts_overlimit 2022-02-17 09:11:57 -06:00
uid16.c
uid16.h
umh.c kernel/umh.c: fix some spelling mistakes 2021-05-07 00:26:34 -07:00
up.c A set of locking related fixes and updates: 2021-05-09 13:07:03 -07:00
user_namespace.c ucounts: Fix systemd LimitNPROC with private users regression 2022-02-25 10:40:14 -06:00
user-return-notifier.c
user.c fs/epoll: use a per-cpu counter for user's watches count 2021-09-08 11:50:27 -07:00
usermode_driver.c Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-07-03 11:41:14 -07:00
utsname_sysctl.c
utsname.c
watch_queue.c watch_queue: Make comment about setting ->defunct more accurate 2022-03-11 10:17:13 -08:00
watchdog_hld.c
watchdog.c watchdog: move watchdog sysctl interface to watchdog.c 2022-01-22 08:33:34 +02:00
workqueue_internal.h workqueue: Assign a color to barrier work items 2021-08-17 07:49:10 -10:00
workqueue.c Merge branch 'workqueue/for-5.16-fixes' into workqueue/for-5.17 2022-01-10 07:54:04 -10:00