Stephane Eranian
3d3916f7aa
perf core: Fix perf_proc_update_handler() bug ...
[ Upstream commit 1a51c5da5acc6c188c917ba572eebac5f8793432 ]
The perf_proc_update_handler() handles /proc/sys/kernel/perf_event_max_sample_rate
syctl variable. When the PMU IRQ handler timing monitoring is disabled, i.e,
when /proc/sys/kernel/perf_cpu_time_max_percent is equal to 0 or 100,
then no modification to sysctl_perf_event_sample_rate is allowed to prevent
possible hang from wrong values.
The problem is that the test to prevent modification is made after the
sysctl variable is modified in perf_proc_update_handler().
You get an error:
$ echo 10001 >/proc/sys/kernel/perf_event_max_sample_rate
echo: write error: invalid argument
But the value is still modified causing all sorts of inconsistencies:
$ cat /proc/sys/kernel/perf_event_max_sample_rate
10001
This patch fixes the problem by moving the parsing of the value after
the test.
Committer testing:
# echo 100 > /proc/sys/kernel/perf_cpu_time_max_percent
# echo 10001 > /proc/sys/kernel/perf_event_max_sample_rate
-bash: echo: write error: Invalid argument
# cat /proc/sys/kernel/perf_event_max_sample_rate
10001
#
Signed-off-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1547169436-6266-1-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-13 14:04:55 -07:00
bpf: check pending signals while verifying programs
2018-12-21 14:11:38 +01:00
config: android: enable CONFIG_SECCOMP
2016-10-11 15:06:32 -07:00
kdb: use memmove instead of overlapping memcpy
2018-12-08 13:05:05 +01:00
perf core: Fix perf_proc_update_handler() bug
2019-03-13 14:04:55 -07:00
gcov: support GCC 7.1
2017-09-02 07:07:53 +02:00
genirq: Fix race on spurious interrupt detection
2018-11-13 11:17:01 -08:00
livepatch/module: make TAINT_LIVEPATCH module-specific
2016-08-26 14:42:08 +02:00
locking/rwsem: Fix (possible) missed wakeup
2019-03-05 17:57:05 +01:00
PM / sleep: wakeup: Fix build error caused by missing SRCU support
2018-09-09 20:01:23 +02:00
printk: Fix panic caused by passing log_buf_len to command line
2018-11-13 11:17:01 -08:00
rcu: Call touch_nmi_watchdog() while printing stall warnings
2018-05-30 07:50:50 +02:00
sched/core: Allow __sched_setscheduler() in interrupts when PI is not used
2018-12-01 09:44:25 +01:00
timekeeping: Use proper seqcount initializer
2019-02-12 19:44:54 +01:00
tracing: Use cpumask_available() to check if cpumask variable may be used
2019-02-27 10:07:02 +01:00
kernel/acct.c: fix the acct->needcheck check in check_free_space()
2018-01-10 09:29:51 +01:00
kernel/async.c: revert "async: simplify lowest_in_progress()"
2018-02-17 13:21:18 +01:00
audit: return on memory error to avoid null pointer dereference
2018-05-30 07:50:49 +02:00
Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit
2016-07-29 17:54:17 -07:00
audit: cleanup prune_tree_thread
2016-04-04 09:46:47 -04:00
audit: fix use-after-free in audit_add_watch
2018-09-26 08:36:37 +02:00
audit: allow not equal op for audit by executable
2018-08-03 07:55:25 +02:00
audit: allow not equal op for audit by executable
2018-08-03 07:55:25 +02:00
kbuild: fix kernel/bounds.c 'W=1' warning
2018-11-13 11:16:57 -08:00
ptrace: Capture the ptracer's creds not PT_PTRACE_CAP
2017-01-06 10:40:13 +01:00
cgroup: Fix deadlock in cpu hotplug path
2018-10-13 09:18:56 +02:00
cgroup/pids: remove spurious suspicious RCU usage warning
2017-03-26 13:05:58 +02:00
Revert "x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation"
2018-11-23 12:57:41 +01:00
sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs
2017-10-12 11:51:25 +02:00
cred: Reject inodes with invalid ids in set_create_file_as()
2016-06-30 18:05:09 -05:00
kernel/exit.c: release ptraced tasks before zap_pid_ns_processes
2019-02-06 17:33:29 +01:00
kernel/extable.c: mark core_kernel_text notrace
2017-07-21 07:42:21 +02:00
fork: record start_time late
2019-01-13 10:03:51 +01:00
freezer, oom: check TIF_MEMDIE on the correct task
2016-07-28 16:07:41 -07:00
futex: futex_wake_op, do not fail on invalid op
2018-11-10 07:42:54 -08:00
kernel: make groups_sort calling a responsibility group_info allocators
2018-01-10 09:29:52 +01:00
kernel/hung_task.c: break RCU locks based on jiffies
2019-02-12 19:44:59 +01:00
jump_label: Invoke jump_label_test() via early_initcall()
2017-12-14 09:28:24 +01:00
kcov: ensure irq code sees a valid area
2018-08-03 07:55:12 +02:00
kexec: allow architectures to override boot mapping
2016-08-02 19:35:27 -04:00
objtool, x86: Add several functions and files to the objtool whitelist
2018-06-05 10:28:57 +02:00
kexec: fix double-free when failing to relocate the purgatory
2016-09-01 17:52:01 -07:00
kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()
2018-11-13 11:16:50 -08:00
kexec: add a kexec_crash_loaded() function
2016-08-02 19:35:30 -04:00
kthread, tracing: Don't expose half-written comm when creating kthreads
2018-08-03 07:55:12 +02:00
kernel/watchdog.c: move hardlockup detector to separate file
2017-06-17 06:41:57 +02:00
Fix: Disable sys_membarrier when nohz_full is enabled
2017-03-12 06:41:45 +01:00
mm, devm_memremap_pages: kill mapping "System RAM" support
2019-01-13 10:03:51 +01:00
module: exclude SHN_UNDEF symbols from kallsyms api
2018-10-03 17:01:48 -07:00
KEYS: Move the point of trust determination to __key_link()
2016-04-11 22:43:43 +01:00
padata: free correct variable
2017-05-20 14:28:40 +02:00
panic: avoid deadlocks in re-entrant console drivers
2018-12-29 13:40:16 +01:00
pidns: disable pid allocation if pid_ns_prepare_proc() is failed in alloc_pid()
2018-04-13 19:47:53 +02:00
pid_ns: Sleep in TASK_INTERRUPTIBLE in zap_pid_ns_processes
2017-05-25 15:44:38 +02:00
profile: Convert to hotplug state machine
2016-07-15 10:41:42 +02:00
ptrace: Properly initialize ptracer_cred on fork
2017-06-14 15:05:54 +02:00
kernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE
2018-05-30 07:50:29 +02:00
resource: fix integer overflow at reallocation
2018-04-24 09:34:09 +02:00
seccomp: Move speculation migitation control to arch code
2018-05-22 16:58:02 +02:00
signal: Restore the stop PTRACE_EVENT_EXIT
2019-02-20 10:18:33 +01:00
cpu/hotplug: Fix SMT supported evaluation
2018-08-15 18:14:53 +02:00
kthread/smpboot: do not park in kthread_create_on_cpu()
2016-10-11 15:06:33 -07:00
Mark HI and TASKLET softirq synchronous
2018-08-15 18:14:42 +02:00
stacktrace, lockdep: Fix address, newline ugliness
2017-02-14 15:25:42 -08:00
stop_machine: Use raw spinlocks
2018-08-03 07:55:24 +02:00
sys: don't hold uts_sem while accessing userspace memory
2018-09-09 20:01:24 +02:00
x86/pkeys: Fix pkeys build breakage for some non-x86 arches
2016-09-13 14:41:36 +02:00
proc/sysctl: fix return error for proc_doulongvec_minmax()
2019-02-12 19:44:59 +01:00
kernel/sysctl_binary.c: use generic UUID library
2016-05-20 17:58:30 -07:00
task_work: use READ_ONCE/lockless_dereference, avoid pi_lock if !task_works
2016-08-02 19:35:02 -04:00
taskstats: fix the length of cgroupstats_cmd_get_policy
2016-11-03 16:55:58 -04:00
torture: Convert torture_shutdown() to hrtimer
2016-08-22 10:01:49 -07:00
tracepoint: Do not warn on ENOMEM
2018-05-09 09:50:20 +02:00
kernel/ucount.c: mark user_header with kmemleak_ignore()
2017-06-17 06:41:51 +02:00
kernel: make groups_sort calling a responsibility group_info allocators
2018-01-10 09:29:52 +01:00
smp: Add function to execute a function synchronously on a CPU
2016-09-05 13:52:39 +02:00
userns: move user access out of the mutex
2018-09-09 20:01:24 +02:00
Merge branch 'nsfs-ioctls' into HEAD
2016-09-22 20:00:36 -05:00
sys: don't hold uts_sem while accessing userspace memory
2018-09-09 20:01:24 +02:00
kernel/watchdog: prevent false hardlockup on overloaded system
2017-06-17 06:41:57 +02:00
kernel/watchdog: prevent false hardlockup on overloaded system
2017-06-17 06:41:57 +02:00
workqueue: use put_device() instead of kfree()
2018-05-30 07:50:36 +02:00
workqueue: Fix NULL pointer dereference
2017-11-15 15:53:17 +01:00
3d3916f7aa