kernel_optimize_test/kernel
Luis Chamberlain b431ef837e blktrace: ensure our debugfs dir exists
We make an assumption that a debugfs directory exists, but since
this can fail ensure it exists before allowing blktrace setup to
complete. Otherwise we end up stuffing blktrace files on the debugfs
root directory. In the worst case scenario this *in theory* can create
an eventual panic *iff* in the future a similarly named file is created
prior on the debugfs root directory. This theoretical crash can happen
due to a recursive removal followed by a specific dentry removal.

This doesn't fix any known crash, however I have seen the files
go into the main debugfs root directory in cases where the debugfs
directory was not created due to other internal bugs with blktrace
now fixed.

blktrace is also completely useless without this directory, so
this ensures to userspace we only setup blktrace if the kernel
can stuff files where they are supposed to go into.

debugfs directory creations typically aren't checked for, and we have
maintainers doing sweep removals of these checks, but since we need this
check to ensure proper userspace blktrace functionality we make sure
to annotate the justification for the check.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
..
bpf Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
cgroup mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
configs compiler: remove CONFIG_OPTIMIZE_INLINING entirely 2020-04-07 10:43:42 -07:00
debug maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
dma dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL 2020-06-15 08:35:30 +02:00
events Merge branch 'akpm' (patches from Andrew) 2020-06-09 09:54:46 -07:00
gcov treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
irq treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
kcsan kcsan: Support distinguishing volatile accesses 2020-06-11 20:04:01 +02:00
livepatch livepatch: Make klp_apply_object_relocs static 2020-05-11 00:31:38 +02:00
locking The X86 entry, exception and interrupt code rework 2020-06-13 10:05:47 -07:00
power treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
printk One more printk change for 5.8 2020-06-12 12:13:36 -07:00
rcu TTY/Serial driver updates for 5.8-rc1 2020-06-07 09:52:36 -07:00
sched Rebase locking/kcsan to locking/urgent 2020-06-11 20:02:46 +02:00
time The X86 entry, exception and interrupt code rework 2020-06-13 10:05:47 -07:00
trace blktrace: ensure our debugfs dir exists 2020-06-24 09:15:58 -06:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
acct.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
async.c
audit_fsnotify.c fsnotify: use helpers to access data by data_type 2020-03-23 18:19:06 +01:00
audit_tree.c
audit_watch.c \n 2020-04-06 08:58:42 -07:00
audit.c audit/stable-5.8 PR 20200601 2020-06-02 17:13:37 -07:00
audit.h audit: fix a net reference leak in audit_list_rules_send() 2020-04-22 15:23:10 -04:00
auditfilter.c audit: fix a net reference leak in audit_list_rules_send() 2020-04-22 15:23:10 -04:00
auditsc.c audit: add subj creds to NETFILTER_CFG record to 2020-05-20 18:09:19 -04:00
backtracetest.c
bounds.c
capability.c
compat.c uaccess: Selectively open read or write user access 2020-05-01 12:35:21 +10:00
configs.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
context_tracking.c context_tracking: Ensure that the critical path cannot be instrumented 2020-06-11 15:14:36 +02:00
cpu_pm.c kernel/cpu_pm: Fix uninitted local in cpu_pm 2020-05-15 11:44:34 -07:00
cpu.c The changes in this cycle are: 2020-06-03 13:06:42 -07:00
crash_core.c
crash_dump.c crash_dump: Remove no longer used saved_max_pfn 2020-04-15 11:21:54 +02:00
cred.c exec: Teach prepare_exec_creds how exec treats uids & gids 2020-05-20 14:44:21 -05:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
extable.c kernel/extable.c: use address-of operator on section symbols 2020-04-07 10:43:42 -07:00
fail_function.c
fork.c mmap locking API: convert nested write lock sites 2020-06-09 09:39:14 -07:00
freezer.c
futex.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
gen_kheaders.sh kbuild: add variables for compression tools 2020-06-06 23:42:01 +09:00
groups.c mm: remove the pgprot argument to __vmalloc 2020-06-02 10:59:11 -07:00
hung_task.c kernel/hung_task.c: introduce sysctl to print all traces when a hung task is detected 2020-06-08 11:05:56 -07:00
iomem.c
irq_work.c irq_work, smp: Allow irq_work on call_single_queue 2020-05-28 10:54:15 +02:00
jump_label.c
kallsyms.c kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol() 2020-04-07 10:43:44 -07:00
kcmp.c kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve 2020-03-25 10:04:01 -05:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: check kcov_softirq in kcov_remote_stop() 2020-06-10 19:14:17 -07:00
kexec_core.c
kexec_elf.c
kexec_file.c kexec_file: don't place kexec images on IORESOURCE_MEM_DRIVER_MANAGED 2020-06-04 19:06:23 -07:00
kexec_internal.h
kexec.c
kheaders.c
kmod.c kmod: make request_module() return an error when autoloading is disabled 2020-04-10 15:36:22 -07:00
kprobes.c kretprobe: Prevent triggering kretprobe from within kprobe_flush_task 2020-06-16 21:21:01 -04:00
ksysfs.c
kthread.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
latencytop.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
Makefile Notifications over pipes + Keyring notifications 2020-06-13 09:56:21 -07:00
module_signature.c
module_signing.c
module-internal.h
module.c module: move the set_fs hack for flush_icache_range to m68k 2020-06-08 11:05:58 -07:00
notifier.c mm: remove vmalloc_sync_(un)mappings() 2020-06-02 10:59:12 -07:00
nsproxy.c nsproxy: attach to namespaces via pidfds 2020-05-13 11:41:22 +02:00
padata.c padata: add basic support for multithreaded jobs 2020-06-03 20:09:45 -07:00
panic.c bug: Annotate WARN/BUG/stackfail as noinstr safe 2020-06-11 15:14:36 +02:00
params.c
pid_namespace.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-06-03 16:27:18 -07:00
pid.c remove the no longer needed pid_alive() check in __task_pid_nr_ns() 2020-04-30 06:40:14 -05:00
profile.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
ptrace.c ptrace: reintroduce usage of subjective credentials in ptrace_has_cap() 2020-01-18 13:51:39 +01:00
range.c
reboot.c printk: Collapse shutdown types into a single dump reason 2020-05-30 10:34:03 -07:00
relay.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
resource.c /dev/mem: Revoke mappings when a driver claims the region 2020-05-27 11:10:05 +02:00
rseq.c
scs.c scs: Report SCS usage in bytes rather than number of entries 2020-06-04 16:14:56 +01:00
seccomp.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
signal.c Merge branch 'work.set_fs-exec' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-06-01 16:21:46 -07:00
smp.c The changes in this cycle are: 2020-06-03 13:06:42 -07:00
smpboot.c
smpboot.h
softirq.c x86/entry: Clarify irq_{enter,exit}_rcu() 2020-06-11 15:15:24 +02:00
stackleak.c
stacktrace.c
stop_machine.c stop_machine: Make stop_cpus() static 2020-01-17 10:19:21 +01:00
sys_ni.c
sys.c Add additional LSM hooks for SafeSetID 2020-06-14 11:39:31 -07:00
sysctl_binary.c
sysctl-test.c kunit: allow kunit tests to be loaded as a module 2020-01-09 16:42:29 -07:00
sysctl.c kernel/sysctl.c: ignore out-of-range taint bits introduced via kernel.tainted 2020-06-08 11:05:56 -07:00
task_work.c task_work_run: don't take ->pi_lock unconditionally 2020-03-02 14:06:33 -07:00
taskstats.c
test_kprobes.c
torture.c CPU (hotplug) updates: 2020-03-30 18:06:39 -07:00
tracepoint.c
tsacct.c
ucount.c ucount: Make sure ucounts in /proc/sys/user don't regress again 2020-04-07 21:51:27 +02:00
uid16.c
uid16.h
umh.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-15 13:48:59 -07:00
up.c smp/up: Make smp_call_function_single() match SMP semantics 2020-02-07 15:34:12 +01:00
user_namespace.c nsproxy: add struct nsset 2020-05-09 13:57:12 +02:00
user-return-notifier.c
user.c user.c: make uidhash_table static 2020-06-04 19:06:24 -07:00
utsname_sysctl.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
utsname.c nsproxy: add struct nsset 2020-05-09 13:57:12 +02:00
watch_queue.c Notifications over pipes + Keyring notifications 2020-06-13 09:56:21 -07:00
watchdog_hld.c
watchdog.c kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases 2020-06-08 11:05:56 -07:00
workqueue_internal.h
workqueue.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00