mirror of
https://github.com/torvalds/linux.git
synced 2024-09-21 07:23:06 +00:00
1389358bb0
Currently, the timerlat's hrtimer is initialized at the first read of
timerlat_fd, and destroyed at close(). It works, but it causes an error
if the user program open() and close() the file without reading.
Here's an example:
# echo NO_OSNOISE_WORKLOAD > /sys/kernel/debug/tracing/osnoise/options
# echo timerlat > /sys/kernel/debug/tracing/current_tracer
# cat <<EOF > ./timerlat_load.py
# !/usr/bin/env python3
timerlat_fd = open("/sys/kernel/tracing/osnoise/per_cpu/cpu0/timerlat_fd", 'r')
timerlat_fd.close();
EOF
# ./taskset -c 0 ./timerlat_load.py
<BOOM>
BUG: kernel NULL pointer dereference, address: 0000000000000010
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 1 PID: 2673 Comm: python3 Not tainted 6.6.13-200.fc39.x86_64 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014
RIP: 0010:hrtimer_active+0xd/0x50
Code: 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 8b 57 30 <8b> 42 10 a8 01 74 09 f3 90 8b 42 10 a8 01 75 f7 80 7f 38 00 75 1d
RSP: 0018:ffffb031009b7e10 EFLAGS: 00010286
RAX: 000000000002db00 RBX: ffff9118f786db08 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff9117a0e64400 RDI: ffff9118f786db08
RBP: ffff9118f786db80 R08: ffff9117a0ddd420 R09: ffff9117804d4f70
R10: 0000000000000000 R11: 0000000000000000 R12: ffff9118f786db08
R13: ffff91178fdd5e20 R14: ffff9117840978c0 R15: 0000000000000000
FS: 00007f2ffbab1740(0000) GS:ffff9118f7840000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 00000001b402e000 CR4: 0000000000750ee0
PKRU: 55555554
Call Trace:
<TASK>
? __die+0x23/0x70
? page_fault_oops+0x171/0x4e0
? srso_alias_return_thunk+0x5/0x7f
? avc_has_extended_perms+0x237/0x520
? exc_page_fault+0x7f/0x180
? asm_exc_page_fault+0x26/0x30
? hrtimer_active+0xd/0x50
hrtimer_cancel+0x15/0x40
timerlat_fd_release+0x48/0xe0
__fput+0xf5/0x290
__x64_sys_close+0x3d/0x80
do_syscall_64+0x60/0x90
? srso_alias_return_thunk+0x5/0x7f
? __x64_sys_ioctl+0x72/0xd0
? srso_alias_return_thunk+0x5/0x7f
? syscall_exit_to_user_mode+0x2b/0x40
? srso_alias_return_thunk+0x5/0x7f
? do_syscall_64+0x6c/0x90
? srso_alias_return_thunk+0x5/0x7f
? exit_to_user_mode_prepare+0x142/0x1f0
? srso_alias_return_thunk+0x5/0x7f
? syscall_exit_to_user_mode+0x2b/0x40
? srso_alias_return_thunk+0x5/0x7f
? do_syscall_64+0x6c/0x90
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7f2ffb321594
Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d d5 cd 0d 00 00 74 13 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3c c3 0f 1f 00 55 48 89 e5 48 83 ec 10 89 7d
RSP: 002b:00007ffe8d8eef18 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f2ffba4e668 RCX: 00007f2ffb321594
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007ffe8d8eef40 R08: 0000000000000000 R09: 0000000000000000
R10: 55c926e3167eae79 R11: 0000000000000202 R12: 0000000000000003
R13: 00007ffe8d8ef030 R14: 0000000000000000 R15: 00007f2ffba4e668
</TASK>
CR2: 0000000000000010
---[ end trace 0000000000000000 ]---
Move hrtimer_init to timerlat_fd open() to avoid this problem.
Link: https://lore.kernel.org/linux-trace-kernel/7324dd3fc0035658c99b825204a66049389c56e3.1706798888.git.bristot@kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: stable@vger.kernel.org
Fixes:
|
||
---|---|---|
.. | ||
bpf | ||
cgroup | ||
configs | ||
debug | ||
dma | ||
entry | ||
events | ||
futex | ||
gcov | ||
irq | ||
kcsan | ||
livepatch | ||
locking | ||
module | ||
power | ||
printk | ||
rcu | ||
sched | ||
time | ||
trace | ||
.gitignore | ||
acct.c | ||
async.c | ||
audit_fsnotify.c | ||
audit_tree.c | ||
audit_watch.c | ||
audit.c | ||
audit.h | ||
auditfilter.c | ||
auditsc.c | ||
backtracetest.c | ||
bounds.c | ||
capability.c | ||
cfi.c | ||
compat.c | ||
configs.c | ||
context_tracking.c | ||
cpu_pm.c | ||
cpu.c | ||
crash_core.c | ||
crash_dump.c | ||
cred.c | ||
delayacct.c | ||
dma.c | ||
exec_domain.c | ||
exit.c | ||
exit.h | ||
extable.c | ||
fail_function.c | ||
fork.c | ||
freezer.c | ||
gen_kheaders.sh | ||
groups.c | ||
hung_task.c | ||
iomem.c | ||
irq_work.c | ||
jump_label.c | ||
kallsyms_internal.h | ||
kallsyms_selftest.c | ||
kallsyms_selftest.h | ||
kallsyms.c | ||
kcmp.c | ||
Kconfig.freezer | ||
Kconfig.hz | ||
Kconfig.kexec | ||
Kconfig.locks | ||
Kconfig.preempt | ||
kcov.c | ||
kexec_core.c | ||
kexec_elf.c | ||
kexec_file.c | ||
kexec_internal.h | ||
kexec.c | ||
kheaders.c | ||
kprobes.c | ||
ksyms_common.c | ||
ksysfs.c | ||
kthread.c | ||
latencytop.c | ||
Makefile | ||
module_signature.c | ||
notifier.c | ||
nsproxy.c | ||
numa.c | ||
padata.c | ||
panic.c | ||
params.c | ||
pid_namespace.c | ||
pid_sysctl.h | ||
pid.c | ||
profile.c | ||
ptrace.c | ||
range.c | ||
reboot.c | ||
regset.c | ||
relay.c | ||
resource_kunit.c | ||
resource.c | ||
rseq.c | ||
scftorture.c | ||
scs.c | ||
seccomp.c | ||
signal.c | ||
smp.c | ||
smpboot.c | ||
smpboot.h | ||
softirq.c | ||
stackleak.c | ||
stacktrace.c | ||
static_call_inline.c | ||
static_call.c | ||
stop_machine.c | ||
sys_ni.c | ||
sys.c | ||
sysctl-test.c | ||
sysctl.c | ||
task_work.c | ||
taskstats.c | ||
torture.c | ||
tracepoint.c | ||
tsacct.c | ||
ucount.c | ||
uid16.c | ||
uid16.h | ||
umh.c | ||
up.c | ||
user_namespace.c | ||
user-return-notifier.c | ||
user.c | ||
usermode_driver.c | ||
utsname_sysctl.c | ||
utsname.c | ||
vhost_task.c | ||
watch_queue.c | ||
watchdog_buddy.c | ||
watchdog_perf.c | ||
watchdog.c | ||
workqueue_internal.h | ||
workqueue.c |