linux/kernel
Kan Liang 24d3ae2f37 perf/core: Fix the same task check in perf_event_set_output
The same task check in perf_event_set_output has some potential issues
for some usages.

For the current perf code, there is a problem if using of
perf_event_open() to have multiple samples getting into the same mmap’d
memory when they are both attached to the same process.
https://lore.kernel.org/all/92645262-D319-4068-9C44-2409EF44888E@gmail.com/
Because the event->ctx is not ready when the perf_event_set_output() is
invoked in the perf_event_open().

Besides the above issue, before the commit bd27568117 ("perf: Rewrite
core context handling"), perf record can errors out when sampling with
a hardware event and a software event as below.
 $ perf record -e cycles,dummy --per-thread ls
 failed to mmap with 22 (Invalid argument)
That's because that prior to the commit a hardware event and a software
event are from different task context.

The problem should be a long time issue since commit c3f00c7027
("perk: Separate find_get_context() from event initialization").

The task struct is stored in the event->hw.target for each per-thread
event. It is a more reliable way to determine whether two events are
attached to the same task.

The event->hw.target was also introduced several years ago by the
commit 50f16a8bf9 ("perf: Remove type specific target pointers"). It
can not only be used to fix the issue with the current code, but also
back port to fix the issues with an older kernel.

Note: The event->hw.target was introduced later than commit
c3f00c7027. The patch may cannot be applied between the commit
c3f00c7027 and commit 50f16a8bf9. Anybody that wants to back-port
this at that period may have to find other solutions.

Fixes: c3f00c7027 ("perf: Separate find_get_context() from event initialization")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Zhengjun Xing <zhengjun.xing@linux.intel.com>
Link: https://lkml.kernel.org/r/20230322202449.512091-1-kan.liang@linux.intel.com
2023-04-05 09:58:46 +02:00
..
bpf bpf: Adjust insufficient default bpf_jit_limit 2023-03-21 12:43:05 -07:00
cgroup Networking changes for 6.3. 2023-02-21 18:24:12 -08:00
configs mm, slob: rename CONFIG_SLOB to CONFIG_SLOB_DEPRECATED 2022-12-01 00:09:20 +01:00
debug kdb: use srcu console list iterator 2022-12-02 11:25:00 +01:00
dma swiotlb: mark swiotlb_memblock_alloc() as __init 2023-02-22 06:44:48 -08:00
entry entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-up 2023-03-21 15:13:15 +01:00
events perf/core: Fix the same task check in perf_event_set_output 2023-04-05 09:58:46 +02:00
futex - Prevent the leaking of a debug timer in futex_waitv() 2023-01-01 11:15:05 -08:00
gcov gcov: add support for checksum field 2022-12-21 14:31:52 -08:00
irq A set of updates for the interrupt susbsystem: 2023-03-05 11:19:16 -08:00
kcsan kcsan: avoid passing -g for test 2023-03-23 17:18:35 -07:00
livepatch Livepatching changes for 6.3 2023-02-23 14:00:10 -08:00
locking RCU pull request for v6.3 2023-02-21 10:45:51 -08:00
module modules-6.3-rc1 2023-02-23 14:05:08 -08:00
power Merge branches 'powercap', 'pm-domains', 'pm-em' and 'pm-opp' 2023-02-15 20:06:26 +01:00
printk printk changes for 6.3 2023-02-23 13:49:45 -08:00
rcu Merge branch 'stall.2023.01.09a' into HEAD 2023-02-02 16:40:07 -08:00
sched sched/fair: Sanitize vruntime of entity being migrated 2023-03-21 14:43:04 +01:00
time Updates for timekeeping, timers and clockevent/source drivers: 2023-02-21 09:45:13 -08:00
trace Tracing fixes for 6.3: 2023-03-19 10:46:02 -07:00
.gitignore
acct.c acct: fix potential integer overflow in encode_comp_t() 2022-11-30 16:13:18 -08:00
async.c
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
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
auditfilter.c
auditsc.c capability: just use a 'u64' instead of a 'u32[2]' array 2023-03-01 10:01:22 -08:00
backtracetest.c
bounds.c mm: multi-gen LRU: minimal implementation 2022-09-26 19:46:09 -07:00
capability.c capability: just use a 'u64' instead of a 'u32[2]' array 2023-03-01 10:01:22 -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 2023-03-14 19:32:38 -07:00
configs.c
context_tracking.c context_tracking: Fix noinstr vs KASAN 2023-01-13 11:48:18 +01:00
cpu_pm.c cpuidle, cpu_pm: Remove RCU fiddling from cpu_pm_{enter,exit}() 2023-01-13 11:48:15 +01:00
cpu.c cpu/hotplug: Do not bail-out in DYING/STARTING sections 2022-12-02 12:43:02 +01:00
crash_core.c mm: remove 'First tail page' members from struct page 2023-02-02 22:32:59 -08:00
crash_dump.c
cred.c cred: Do not default to init_cred in prepare_kernel_cred() 2022-11-01 10:04:52 -07:00
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 arm64 updates for 6.3: 2023-02-21 15:27:48 -08:00
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() 2023-02-08 13:36:22 +01:00
fork.c Fixes for 6.3-rc3: 2023-03-25 12:57:34 -07:00
freezer.c freezer,sched: Rewrite core freezer logic 2022-09-07 21:53:50 +02:00
gen_kheaders.sh kheaders: use standard naming for the temporary directory 2023-01-22 23:43:34 +09:00
groups.c security: Add LSM hook to setgroups() syscall 2022-07-15 18:21:49 +00:00
hung_task.c hung_task: print message when hung_task_warnings gets down to zero. 2023-02-09 17:03:20 -08:00
iomem.c
irq_work.c irq_work: use kasan_record_aux_stack_noalloc() record callstack 2022-04-15 14:49:55 -07:00
jump_label.c jump_label: Prevent key->enabled int overflow 2022-12-01 15:53:05 -08:00
kallsyms_internal.h kallsyms: Reduce the memory occupied by kallsyms_seqs_of_names[] 2022-11-12 18:47:36 -08:00
kallsyms_selftest.c kallsyms: Fix scheduling with interrupts disabled in self-test 2023-01-13 15:09:08 -08:00
kallsyms_selftest.h kallsyms: Add self-test facility 2022-11-15 00:42:02 -08:00
kallsyms.c kallsyms: Add self-test facility 2022-11-15 00:42:02 -08:00
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 mm: replace vma->vm_flags direct modifications with modifier calls 2023-02-09 16:51:39 -08:00
kexec_core.c There is no particular theme here - mainly quick hits all over the tree. 2023-02-23 17:55:40 -08:00
kexec_elf.c
kexec_file.c kexec: introduce sysctl parameters kexec_load_limit_* 2023-02-02 22:50:05 -08:00
kexec_internal.h panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kexec.c kexec: introduce sysctl parameters kexec_load_limit_* 2023-02-02 22:50:05 -08:00
kheaders.c
kmod.c
kprobes.c x86/kprobes: Fix arch_check_optimized_kprobe check within optimized_kprobe range 2023-02-21 08:49:16 +09:00
ksysfs.c kernels/ksysfs.c: export kernel address bits 2023-01-20 14:30:45 +01:00
kthread.c kthread_worker: check all delayed works when destroy kthread worker 2023-02-02 22:50:02 -08:00
latencytop.c latencytop: use the last element of latency_record of system 2022-09-11 21:55:12 -07:00
Makefile kernel hardening fixes for v6.2-rc1 2022-12-23 12:00:24 -08:00
module_signature.c
notifier.c kernel/notifier: Remove CONFIG_SRCU 2023-02-02 16:26:06 -08:00
nsproxy.c fs/exec: switch timens when a task gets a new mm 2022-10-25 15:15:52 -07:00
padata.c Kbuild updates for v6.2 2022-12-19 12:33:32 -06:00
panic.c panic: fix the panic_print NMI backtrace setting 2023-03-02 21:54:23 -08:00
params.c kernel/params.c: Use kstrtobool() instead of strtobool() 2023-01-25 14:07:21 -08:00
pid_namespace.c - Daniel Verkamp has contributed a memfd series ("mm/memfd: add 2023-02-23 17:09:35 -08:00
pid_sysctl.h mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC 2023-01-18 17:12:37 -08:00
pid.c gfs2: Add glockfd debugfs file 2022-06-29 13:07:16 +02:00
profile.c kernel/profile.c: simplify duplicated code in profile_setup() 2022-09-11 21:55:12 -07:00
ptrace.c rseq: Introduce extensible rseq ABI 2022-12-27 12:52:10 +01:00
range.c
reboot.c kernel/reboot: Add SYS_OFF_MODE_RESTART_PREPARE mode 2022-10-04 15:59:36 +02:00
regset.c
relay.c mm: replace vma->vm_flags direct modifications with modifier calls 2023-02-09 16:51:39 -08:00
resource_kunit.c
resource.c dax/kmem: Fix leak of memory-hotplug resources 2023-02-17 14:58:01 -08:00
rseq.c rseq: Extend struct rseq with per-memory-map concurrency ID 2022-12-27 12:52:12 +01:00
scftorture.c scftorture: Fix distribution of short handler delays 2022-04-11 17:07:29 -07:00
scs.c scs: add support for dynamic shadow call stacks 2022-11-09 18:06:35 +00:00
seccomp.c seccomp: fix kernel-doc function name warning 2023-01-13 17:01:06 -08:00
signal.c sched: Introduce per-memory-map concurrency ID 2022-12-27 12:52:11 +01:00
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 context_tracking: Take IRQ eqs entrypoints over RCU 2022-07-05 13:32:59 -07:00
stackleak.c stackleak: add on/off stack variants 2022-05-08 01:33:09 -07:00
stacktrace.c
static_call_inline.c static_call: Add call depth tracking support 2022-10-17 16:41:16 +02:00
static_call.c static_call: Don't make __static_call_return0 static 2022-04-05 09:59:38 +02:00
stop_machine.c Scheduler changes in this cycle were: 2022-05-24 11:11:13 -07:00
sys_ni.c kernel/sys_ni: add compat entry for fadvise64_64 2022-08-20 15:17:45 -07:00
sys.c - Daniel Verkamp has contributed a memfd series ("mm/memfd: add 2023-02-23 17:09:35 -08:00
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 sysctl: fix proc_dobool() usability 2023-02-21 13:34:07 -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 2023-01-05 12:10:35 -08:00
tracepoint.c tracepoint: Allow livepatch module add trace event 2023-02-18 14:34:36 -05:00
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 umh: simplify the capability pointer logic 2023-03-03 16:18:19 -08:00
up.c
user_namespace.c userns: fix a struct's kernel-doc notation 2023-02-02 22:50:04 -08:00
user-return-notifier.c
user.c kernel/user: Allow user_struct::locked_vm to be usable for iommufd 2022-11-30 20:16:49 -04:00
usermode_driver.c blob_to_mnt(): kern_unmount() is needed to undo kern_mount() 2022-05-19 23:25:47 -04:00
utsname_sysctl.c kernel/utsname_sysctl.c: Fix hostname polling 2022-10-23 12:01:01 -07:00
utsname.c
watch_queue.c watch_queue: fix IOC_WATCH_QUEUE_SET_SIZE alloc error paths 2023-03-08 11:44:45 +01:00
watchdog_hld.c Revert "printk: add functions to prefer direct printing" 2022-06-23 18:41:40 +02:00
watchdog.c powerpc updates for 6.0 2022-08-06 16:38:17 -07:00
workqueue_internal.h
workqueue.c workqueue: Fold rebind_worker() within rebind_workers() 2023-01-13 07:50:40 -10:00