linux/kernel
Steven Rostedt 6e94a78037 tracing: Failed to create system directory
Running the following:

 # cd /sys/kernel/debug/tracing
 # echo p:i do_sys_open > kprobe_events
 # echo p:j schedule >> kprobe_events
 # cat kprobe_events
p:kprobes/i do_sys_open
p:kprobes/j schedule
 # echo p:i do_sys_open >> kprobe_events
 # cat kprobe_events
p:kprobes/j schedule
p:kprobes/i do_sys_open
 # ls /sys/kernel/debug/tracing/events/kprobes/
enable  filter  j

Notice that the 'i' is missing from the kprobes directory.

The console produces:

"Failed to create system directory kprobes"

This is because kprobes passes in a allocated name for the system
and the ftrace event subsystem saves off that name instead of creating
a duplicate for it. But the kprobes may free the system name making
the pointer to it invalid.

This bug was introduced by 92edca073c "tracing: Use direct field, type
and system names" which switched from using kstrdup() on the system name
in favor of just keeping apointer to it, as the internal ftrace event
system names are static and exist for the life of the computer being booted.

Instead of reverting back to duplicating system names again, we can use
core_kernel_data() to determine if the passed in name was allocated or
static. Then use the MSB of the ref_count to be a flag to keep track if
the name was allocated or not. Then we can still save from having to duplicate
strings that will always exist, but still copy the ones that may be freed.

Cc: stable@vger.kernel.org # 3.10
Reported-by: "zhangwei(Jovi)" <jovi.zhangwei@huawei.com>
Reported-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-01 20:34:22 -04:00
..
cpu rcu/idle: Wrap cpu-idle poll mode within rcu_idle_enter/exit 2013-05-14 17:43:29 +02:00
debug kgdb/sysrq: fix inconstistent help message of sysrq key 2013-04-30 17:04:10 -07:00
events perf: Factor out auxiliary events notification 2013-05-07 13:17:29 +02:00
gcov kernel/gcov: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:39:33 -08:00
irq irqdomain: document the simple domain first_irq 2013-06-08 21:15:09 +01:00
power Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2013-05-02 19:40:34 -07:00
sched Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-05-05 13:23:27 -07:00
time Merge branch 'fortglx/3.10/time' of git://git.linaro.org/people/jstultz/linux into timers/urgent 2013-05-29 09:55:01 +02:00
trace tracing: Failed to create system directory 2013-07-01 20:34:22 -04:00
.gitignore kernel/hz.bc: ignore. 2013-04-22 07:09:06 -07:00
acct.c fs: Fix hang with BSD accounting on frozen filesystem 2013-05-04 14:57:58 -04:00
async.c async: rename and redefine async_func_ptr 2013-03-12 13:59:14 -07:00
audit_tree.c kernel/audit_tree.c: tree will leak memory when failure occurs in audit_trim_trees() 2013-04-29 15:54:26 -07:00
audit_watch.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
audit.c Merge git://git.infradead.org/users/eparis/audit 2013-05-11 14:29:11 -07:00
audit.h Merge git://git.infradead.org/users/eparis/audit 2013-05-11 14:29:11 -07:00
auditfilter.c auditfilter.c: fix kernel-doc warnings 2013-05-24 16:22:52 -07:00
auditsc.c audit: Make testing for a valid loginuid explicit. 2013-05-07 22:27:15 -04:00
backtracetest.c
bounds.c
capability.c Add file_ns_capable() helper function for open-time capability checking 2013-04-14 10:06:31 -07:00
cgroup_freezer.c cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free() 2012-11-19 08:13:38 -08:00
cgroup.c cgroup: warn about mismatching options of a new mount of an existing hierarchy 2013-05-29 07:59:39 +09:00
compat.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-05-01 07:21:43 -07:00
configs.c proc: Supply PDE attribute setting accessor functions 2013-05-01 17:29:18 -04:00
context_tracking.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 18:19:48 -08:00
cpu_pm.c
cpu.c Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:04:55 -08:00
cpuset.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
crash_dump.c
cred.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-18 10:55:28 -08:00
delayacct.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
dma.c
elfcore.c
exec_domain.c
exit.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
extable.c extable: Flip the sorting message 2013-04-15 13:25:16 +02:00
fork.c Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block 2013-05-08 11:51:05 -07:00
freezer.c freezer: change ptrace_stop/do_signal_stop to use freezable_schedule() 2012-10-26 14:27:49 -07:00
futex_compat.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-02-23 18:50:11 -08:00
futex.c futex: fix kernel-doc notation and spello 2013-03-12 20:42:10 -07:00
groups.c
hrtimer.c Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-05-05 13:23:27 -07:00
hung_task.c
irq_work.c Merge branch 'nohz/printk-v8' into irq/core 2013-02-05 00:48:46 +01:00
itimer.c
jump_label.c jump_label: Export jump_label_rate_limit() 2012-08-06 19:00:35 +03:00
kallsyms.c kernel: kallsyms: memory override issue, need check destination buffer length 2013-04-15 15:17:26 +09:30
kcmp.c kcmp: include linux/ptrace.h 2012-12-20 17:40:19 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking: Adjust spin lock inlining Kconfig options 2012-09-13 17:56:13 +02:00
Kconfig.preempt
kexec.c kexec: Use min() and min_t() to simplify logic 2013-04-30 17:04:07 -07:00
kmod.c usermodehelper: check subprocess_info->path != NULL 2013-05-16 12:01:11 -07:00
kprobes.c kprobes: Fix a double lock bug of kprobe_mutex 2013-04-18 08:58:38 -07:00
ksysfs.c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-12-11 18:10:49 -08:00
kthread.c kthread: implement probe_kthread_data() 2013-04-30 17:04:02 -07:00
latencytop.c
lglock.c
lockdep_internals.h
lockdep_proc.c lockdep: Use KSYM_NAME_LEN'ed buffer for __get_key_name() 2012-10-24 12:39:09 +02:00
lockdep_states.h
lockdep.c Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block 2013-05-08 11:51:05 -07:00
Makefile We get rid of the general module prefix confusion with a binary config option, 2013-05-05 10:58:06 -07:00
modsign_certificate.S CONFIG_SYMBOL_PREFIX: cleanup. 2013-03-15 15:09:43 +10:30
modsign_pubkey.c keys: use keyring_alloc() to create module signing keyring 2012-12-20 17:40:21 -08:00
module_signing.c MODSIGN: Don't use enum-type bitfields in module signature info block 2012-12-05 11:27:24 +10:30
module-internal.h MODSIGN: Move the magic string to the end of a module and eliminate the search 2012-10-19 17:30:40 -07:00
module.c kmemleak: No need for scanning specific module sections 2013-05-17 09:53:36 +01:00
mutex-debug.c
mutex-debug.h
mutex.c mutex: Back out architecture specific check for negative mutex count 2013-04-19 09:33:36 +02:00
mutex.h
notifier.c
nsproxy.c proc: Split the namespace stuff out into linux/proc_ns.h 2013-05-01 17:29:39 -04:00
padata.c padata: use __this_cpu_read per-cpu helper 2012-12-06 17:16:23 +08:00
panic.c tracing: Disable tracing on warning 2013-06-19 23:32:07 -04:00
params.c params: Fix potential memory leak in add_sysfs_param() 2013-03-18 11:40:21 +00:00
pid_namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
pid.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
posix-cpu-timers.c posix_timers: Fix pre-condition to stop the tick on full dynticks 2013-04-22 19:59:25 +02:00
posix-timers.c posix-timers: Remove unused variable 2013-04-18 12:51:19 +02:00
printk.c aio: don't include aio.h in sched.h 2013-05-07 20:16:25 -07:00
profile.c proc: Supply PDE attribute setting accessor functions 2013-05-01 17:29:18 -04:00
ptrace.c aio: don't include aio.h in sched.h 2013-05-07 20:16:25 -07:00
range.c x86, range: fix missing merge during add range 2013-05-17 11:49:10 -07:00
rcu.h rcu: Provide RCU CPU stall warnings for tiny RCU 2013-01-28 22:06:21 -08:00
rcupdate.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutiny_plugin.h rcu: Provide RCU CPU stall warnings for tiny RCU 2013-01-28 22:06:21 -08:00
rcutiny.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutorture.c rcu: Allow rcutorture to be built at low optimization levels 2013-02-04 12:18:20 -08:00
rcutree_plugin.h rcu: Don't allocate bootmem from rcu_init() 2013-05-15 10:41:12 -07:00
rcutree_trace.c rcutrace: single_open() leaks 2013-05-05 00:16:35 -04:00
rcutree.c Merge commit '8700c95adb03' into timers/nohz 2013-05-02 17:54:19 +02:00
rcutree.h Merge commit '8700c95adb03' into timers/nohz 2013-05-02 17:54:19 +02:00
relay.c Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block 2013-05-08 10:13:35 -07:00
res_counter.c res_counter: return amount of charges after res_counter_uncharge() 2012-12-18 15:02:12 -08:00
resource.c mem hotunplug: fix kfree() of bootmem memory 2013-04-29 15:54:40 -07:00
rtmutex_common.h
rtmutex-debug.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex-debug.h
rtmutex-tester.c locking/rtmutex/tester: Set correct permissions on sysfs files 2013-04-10 14:48:37 +02:00
rtmutex.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex.h
rwsem.c Revert "rw_semaphore: remove up/down_read_non_owner" 2013-03-23 15:53:52 -07:00
seccomp.c seccomp: allow BPF_XOR based ALU instructions. 2013-03-26 11:07:19 +11:00
semaphore.c semaphore: use `bool' type for semaphore_waiter's up 2013-04-30 17:04:08 -07:00
signal.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-05-01 14:08:52 -07:00
smp.c kernel/smp.c: cleanups 2013-04-30 17:04:03 -07:00
smpboot.c kthread: Prevent unpark race which puts threads on the wrong cpu 2013-04-12 14:18:43 +02:00
smpboot.h smpboot: Provide infrastructure for percpu hotplug threads 2012-08-13 17:01:07 +02:00
softirq.c Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-05-05 13:23:27 -07:00
spinlock.c
srcu.c srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock() 2013-02-07 15:19:36 -08:00
stacktrace.c
stop_machine.c stop_machine: Mark per cpu stopper enabled early 2013-02-26 22:25:17 +01:00
sys_ni.c unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE 2013-05-09 13:46:38 -04:00
sys.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-05-01 07:21:43 -07:00
sysctl_binary.c switch compat_sys_sysctl to COMPAT_SYSCALL_DEFINE 2013-05-09 14:53:20 -04:00
sysctl.c tracing: Disable tracing on warning 2013-06-19 23:32:07 -04:00
task_work.c task_work: task_work_add() should not succeed after exit_task_work() 2012-09-13 16:47:34 +02:00
taskstats.c taskstats: cgroupstats_user_cmd() may leak on error 2012-10-06 03:05:31 +09:00
test_kprobes.c kernel/: rename random32() to prandom_u32() 2013-04-29 18:28:42 -07:00
time.c timekeeping: Use inject_offset in warp_clock 2013-03-15 16:50:20 -07:00
timeconst.bc kernel: Replace timeconst.pl with a bc script 2013-02-16 23:17:25 +01:00
timer.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-05-15 14:05:17 -07:00
tracepoint.c Tracing updates for Linux 3.10 2013-04-29 13:55:38 -07:00
tsacct.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
uid16.c make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect 2013-03-03 22:58:33 -05:00
up.c
user_namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
user-return-notifier.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
user.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
utsname_sysctl.c kernel/utsname_sysctl.c: put get/get_uts() into CONFIG_PROC_SYSCTL code block 2013-02-27 19:10:22 -08:00
utsname.c proc: Split the namespace stuff out into linux/proc_ns.h 2013-05-01 17:29:39 -04:00
wait.c propagate name change to comments in kernel source 2012-12-06 10:39:54 +01:00
watchdog.c watchdog: Add comments to explain the watchdog_disabled variable 2013-03-14 08:24:05 +01:00
workqueue_internal.h workqueue: include workqueue info when printing debug dump of a worker task 2013-04-30 17:04:02 -07:00
workqueue.c workqueue: don't perform NUMA-aware allocations on offline nodes in wq_numa_init() 2013-05-15 14:24:24 -07:00