evie/android_kernel_oneplus_msm8998
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
android_kernel_oneplus_msm8998/kernel
History
Jin Yao e582b82c16 perf/core: Drop kernel samples even though :u is specified 
commit cc1582c231ea041fbc68861dfaf957eaf902b829 upstream.

When doing sampling, for example:

  perf record -e cycles:u ...

On workloads that do a lot of kernel entry/exits we see kernel
samples, even though :u is specified. This is due to skid existing.

This might be a security issue because it can leak kernel addresses even
though kernel sampling support is disabled.

The patch drops the kernel samples if exclude_kernel is specified.

For example, test on Haswell desktop:

  perf record -e cycles:u <mgen>
  perf report --stdio

Before patch applied:

    99.77%  mgen     mgen              [.] buf_read
     0.20%  mgen     mgen              [.] rand_buf_init
     0.01%  mgen     [kernel.vmlinux]  [k] apic_timer_interrupt
     0.00%  mgen     mgen              [.] last_free_elem
     0.00%  mgen     libc-2.23.so      [.] __random_r
     0.00%  mgen     libc-2.23.so      [.] _int_malloc
     0.00%  mgen     mgen              [.] rand_array_init
     0.00%  mgen     [kernel.vmlinux]  [k] page_fault
     0.00%  mgen     libc-2.23.so      [.] __random
     0.00%  mgen     libc-2.23.so      [.] __strcasestr
     0.00%  mgen     ld-2.23.so        [.] strcmp
     0.00%  mgen     ld-2.23.so        [.] _dl_start
     0.00%  mgen     libc-2.23.so      [.] sched_setaffinity@@GLIBC_2.3.4
     0.00%  mgen     ld-2.23.so        [.] _start

We can see kernel symbols apic_timer_interrupt and page_fault.

After patch applied:

    99.79%  mgen     mgen           [.] buf_read
     0.19%  mgen     mgen           [.] rand_buf_init
     0.00%  mgen     libc-2.23.so   [.] __random_r
     0.00%  mgen     mgen           [.] rand_array_init
     0.00%  mgen     mgen           [.] last_free_elem
     0.00%  mgen     libc-2.23.so   [.] vfprintf
     0.00%  mgen     libc-2.23.so   [.] rand
     0.00%  mgen     libc-2.23.so   [.] __random
     0.00%  mgen     libc-2.23.so   [.] _int_malloc
     0.00%  mgen     libc-2.23.so   [.] _IO_doallocbuf
     0.00%  mgen     ld-2.23.so     [.] do_lookup_x
     0.00%  mgen     ld-2.23.so     [.] open_verify.constprop.7
     0.00%  mgen     ld-2.23.so     [.] _dl_important_hwcaps
     0.00%  mgen     libc-2.23.so   [.] sched_setaffinity@@GLIBC_2.3.4
     0.00%  mgen     ld-2.23.so     [.] _start

There are only userspace symbols.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Cc: kan.liang@intel.com
Cc: mark.rutland@arm.com
Cc: will.deacon@arm.com
Cc: yao.jin@intel.com
Link: http://lkml.kernel.org/r/1495706947-3744-1-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14 13:16:25 +02:00
..
bpf bpf, inode: disallow userns mounts 2016-06-24 10:18:17 -07:00
configs kconfig: tinyconfig: provide whole choice blocks to avoid warnings 2016-09-24 10:07:42 +02:00
debug kernel/debug/debug_core.c: more properly delay for secondary CPUs 2017-01-06 11:16:16 +01:00
events perf/core: Drop kernel samples even though :u is specified 2017-06-14 13:16:25 +02:00
gcov
irq genirq: Fix chained interrupt data ordering 2017-05-25 14:30:17 +02:00
livepatch livepatch: x86: fix relocation computation with kASLR 2015-11-11 17:36:04 +01:00
locking locking/rtmutex: Use READ_ONCE() in rt_mutex_owner() 2016-12-15 08:49:22 -08:00
power PM / sleep: fix device reference leak in test_suspend 2016-11-26 09:54:53 +01:00
printk printk: use rcuidle console tracepoint 2017-02-23 17:43:10 +01:00
rcu rcu: Fix soft lockup for rcu_nocb_kthread 2016-12-08 07:15:24 +01:00
sched sched/fair: Initialize throttle_count for new task-groups lazily 2017-05-25 14:30:12 +02:00
time tick/broadcast: Prevent NULL pointer dereference 2017-01-12 11:22:51 +01:00
trace tracing/kprobes: Enforce kprobes teardown after testing 2017-05-25 14:30:17 +02:00
.gitignore certs: add .gitignore to stop git nagging about x509_certificate_list 2015-10-21 15:18:35 +01:00
acct.c
async.c
audit.c mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
audit.h audit: audit_tree_match can be boolean 2015-11-04 08:23:51 -05:00
audit_fsnotify.c
audit_tree.c audit: audit_tree_match can be boolean 2015-11-04 08:23:51 -05:00
audit_watch.c audit: fix exe_file access in audit_exe_compare 2016-09-24 10:07:36 +02:00
auditfilter.c audit: fix comment block whitespace 2015-11-04 08:23:51 -05:00
auditsc.c audit: fix a double fetch in audit_log_single_execve_arg() 2016-08-20 18:09:22 +02:00
backtracetest.c
bounds.c
capability.c exec: Ensure mm->user_ns contains the execed files 2017-01-06 11:16:14 +01:00
cgroup.c cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups 2017-04-21 09:30:04 +02:00
cgroup_freezer.c cgroup: fix handling of multi-destination migration from subtree_control enabling 2015-12-03 10:18:21 -05:00
cgroup_pids.c cgroup_pids: don't account for the root cgroup 2015-12-03 10:18:21 -05:00
compat.c
configs.c
context_tracking.c context_tracking: avoid irq_save/irq_restore on guest entry and exit 2015-11-10 12:06:23 +01:00
cpu.c stable-fixup: hotplug: fix unused function warning 2017-01-12 11:22:48 +01:00
cpu_pm.c kernel/cpu_pm: fix cpu_cluster_pm_exit comment 2015-09-03 02:42:20 +02:00
cpuset.c cpuset: consider dying css as offline 2017-06-14 13:16:23 +02:00
crash_dump.c
cred.c cred: Reject inodes with invalid ids in set_create_file_as() 2016-09-15 08:27:49 +02:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c wait/ptrace: assume __WALL if the child is traced 2016-06-07 18:14:35 -07:00
extable.c kernel/extable.c: remove duplicated include 2015-09-10 13:29:01 -07:00
fork.c stackprotector: Increase the per-task stack canary's random range from 32 bits to 64 bits on 64-bit platforms 2017-06-14 13:16:23 +02:00
freezer.c
futex.c futex: Add missing error handling to FUTEX_REQUEUE_PI 2017-03-22 12:04:19 +01:00
futex_compat.c ptrace: use fsuid, fsgid, effective creds for fs access checks 2016-02-25 12:01:16 -08:00
groups.c
hung_task.c
irq_work.c treewide: Remove old email address 2015-11-23 09:44:58 +01:00
jump_label.c jump_labels: API for flushing deferred jump label updates 2017-01-19 20:17:19 +01:00
kallsyms.c
kcmp.c ptrace: use fsuid, fsgid, effective creds for fs access checks 2016-02-25 12:01:16 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c kexec: use file name as the output message prefix 2015-11-06 17:50:42 -08:00
kexec_core.c kexec: use file name as the output message prefix 2015-11-06 17:50:42 -08:00
kexec_file.c kexec: fix double-free when failing to relocate the purgatory 2016-09-24 10:07:36 +02:00
kexec_internal.h kexec: split kexec_file syscall code to kexec_file.c 2015-09-10 13:29:01 -07:00
kmod.c kmod: don't run async usermode helper as a child of kworker thread 2015-10-23 17:55:10 +09:00
kprobes.c tracing/kprobes: Enforce kprobes teardown after testing 2017-05-25 14:30:17 +02:00
ksysfs.c kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
kthread.c cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups 2017-04-21 09:30:04 +02:00
latencytop.c
Makefile sys_membarrier(): system-wide memory barrier (generic, x86) 2015-09-11 15:21:34 -07:00
membarrier.c Fix: Disable sys_membarrier when nohz_full is enabled 2017-03-12 06:37:26 +01:00
memremap.c mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done} 2017-01-19 20:17:18 +01:00
module-internal.h
module.c module: Invalidate signatures on force-loaded modules 2016-08-20 18:09:27 +02:00
module_signing.c KEYS: Merge the type-specific data with the payload data 2015-10-21 15:18:36 +01:00
notifier.c
nsproxy.c
padata.c padata: free correct variable 2017-05-20 14:27:02 +02:00
panic.c printk: do cond_resched() between lines while outputting to consoles 2016-02-17 12:30:57 -08:00
params.c Nothing exciting, minor tweaks and cleanups. 2015-11-09 15:53:39 -08:00
pid.c pidns: fix NULL dereference in __task_pid_nr_ns() 2015-11-24 12:03:55 -08:00
pid_namespace.c pid_ns: Sleep in TASK_INTERRUPTIBLE in zap_pid_ns_processes 2017-05-25 14:30:11 +02:00
profile.c mm: rename alloc_pages_exact_node() to __alloc_pages_node() 2015-09-08 15:35:28 -07:00
ptrace.c ptrace: Properly initialize ptracer_cred on fork 2017-06-14 13:16:20 +02:00
range.c
reboot.c kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
relay.c
resource.c kernel/resource.c: fix muxed resource handling in __request_region() 2016-03-03 15:07:29 -08:00
seccomp.c seccomp: always propagate NO_NEW_PRIVS on tsync 2016-03-03 15:07:25 -08:00
signal.c kernel/signal.c: unexport sigsuspend() 2015-11-20 16:17:32 -08:00
smp.c mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
smpboot.c stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark() 2015-10-20 10:23:55 +02:00
smpboot.h
softirq.c
stacktrace.c
stop_machine.c kernel: remove stop_machine() Kconfig dependency 2015-12-12 10:15:34 -08:00
sys.c prctl: take mmap sem for writing to protect against others 2016-02-25 12:01:25 -08:00
sys_ni.c mm: mlock: add new mlock system call 2015-11-05 19:34:48 -08:00
sysctl.c mnt: Add a per mount namespace limit on the number of mounts 2017-04-30 05:49:28 +02:00
sysctl_binary.c fs/coredump: prevent fsuid=0 dumps into user-controlled directories 2016-04-12 09:08:58 -07:00
task_work.c task_work: remove fifo ordering guarantee 2015-09-05 13:46:58 -07:00
taskstats.c
test_kprobes.c
torture.c torture: Consolidate cond_resched_rcu_qs() into stutter_wait() 2015-10-06 11:25:01 -07:00
tracepoint.c tracepoint: Give priority to probes of tracepoints 2015-10-25 21:33:54 -04:00
tsacct.c
uid16.c
up.c
user-return-notifier.c
user.c
user_namespace.c capabilities: ambient capabilities 2015-09-04 16:54:41 -07:00
utsname.c
utsname_sysctl.c
watchdog.c kernel/watchdog: use nmi registers snapshot in hardlockup handler 2017-01-06 11:16:16 +01:00
workqueue.c workqueue: fix rebind bound workers warning 2016-05-18 17:06:50 -07:00
workqueue_internal.h