Steven Rostedt (Red Hat)
b7ffffbb46
ftrace: Add infrastructure for delayed enabling of module functions ...
Qiu Peiyang pointed out that there's a race when enabling function tracing
and loading a module. In order to make the modifications of converting nops
in the prologue of functions into callbacks, the text needs to be converted
from read-only to read-write. When enabling function tracing, the text
permission is updated, the functions are modified, and then they are put
back.
When loading a module, the updates to convert function calls to mcount is
done before the module text is set to read-only. But after it is done, the
module text is visible by the function tracer. Thus we have the following
race:
CPU 0 CPU 1
----- -----
start function tracing
set text to read-write
load_module
add functions to ftrace
set module text read-only
update all functions to callbacks
modify module functions too
< Can't it's read-only >
When this happens, ftrace detects the issue and disables itself till the
next reboot.
To fix this, a new DISABLED flag is added for ftrace records, which all
module functions get when they are added. Then later, after the module code
is all set, the records will have the DISABLED flag cleared, and they will
be enabled if any callback wants all functions to be traced.
Note, this doesn't add the delay to later. It simply changes the
ftrace_module_init() to do both the setting of DISABLED records, and then
immediately calls the enable code. This helps with testing this new code as
it has the same behavior as previously. Another change will come after this
to have the ftrace_module_enable() called after the text is set to
read-only.
Cc: Qiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-07 15:40:01 -05:00
bpf, verifier: annotate verbose printer with __printf
2015-11-03 11:29:56 -05:00
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-11-15 09:36:24 -08:00
gcov: add support for GCC 5.1
2015-06-30 19:44:57 -07:00
Merge branches 'irq-urgent-for-linus' and 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-11-15 09:30:48 -08:00
livepatch: x86: fix relocation computation with kASLR
2015-11-11 17:36:04 +01:00
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
2015-11-06 17:50:42 -08:00
mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM
2015-11-06 17:50:42 -08:00
printk: prevent userland from spoofing kernel messages
2015-11-06 17:50:42 -08:00
Merge branches 'doc.2015.10.06a', 'percpu-rwsem.2015.10.06a' and 'torture.2015.10.06a' into HEAD
2015-10-07 16:06:25 -07:00
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-11-15 09:35:33 -08:00
Merge branches 'irq-urgent-for-linus' and 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-11-15 09:30:48 -08:00
ftrace: Add infrastructure for delayed enabling of module functions
2016-01-07 15:40:01 -05:00
certs: add .gitignore to stop git nagging about x509_certificate_list
2015-10-21 15:18:35 +01:00
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: audit_tree_match can be boolean
2015-11-04 08:23:51 -05:00
audit: clean simple fsnotify implementation
2015-08-06 16:14:53 -04:00
audit: audit_tree_match can be boolean
2015-11-04 08:23:51 -05:00
Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
2015-09-08 13:34:59 -07:00
audit: fix comment block whitespace
2015-11-04 08:23:51 -05:00
Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
2015-09-08 13:34:59 -07:00
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
2015-11-06 17:50:42 -08:00
cgroup: allow a cgroup subsystem to reject a fork
2015-07-14 17:29:23 -04:00
cgroup: add cgroup_subsys->free() method and use it to fix pids controller
2015-10-15 16:41:53 -04:00
context_tracking: avoid irq_save/irq_restore on guest entry and exit
2015-11-10 12:06:23 +01:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-11-03 18:03:50 -08:00
kernel/cpu_pm: fix cpu_cluster_pm_exit comment
2015-09-03 02:42:20 +02:00
Merge branch 'akpm' (patches from Andrew)
2015-11-05 23:10:54 -08:00
kernel/cred.c: remove unnecessary kdebug atomic reads
2015-09-10 13:29:01 -07:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-11-03 18:03:50 -08:00
kernel/extable.c: remove duplicated include
2015-09-10 13:29:01 -07:00
Merge branch 'akpm' (patches from Andrew)
2015-11-05 23:10:54 -08:00
driver core update for 4.4-rc1
2015-11-04 21:50:37 -08:00
locking/static_keys: Add selftest
2015-08-03 11:34:16 +02:00
kexec: use file name as the output message prefix
2015-11-06 17:50:42 -08:00
kexec: use file name as the output message prefix
2015-11-06 17:50:42 -08:00
kexec: use file name as the output message prefix
2015-11-06 17:50:42 -08:00
kexec: split kexec_file syscall code to kexec_file.c
2015-09-10 13:29:01 -07:00
kmod: don't run async usermode helper as a child of kworker thread
2015-10-23 17:55:10 +09:00
perf/x86/hw_breakpoints: Disallow kernel breakpoints unless kprobe-safe
2015-08-04 10:16:54 +02:00
kexec: split kexec_load syscall from kexec core code
2015-09-10 13:29:01 -07:00
kernel/kthread.c:kthread_create_on_node(): clarify documentation
2015-09-04 16:54:41 -07:00
sys_membarrier(): system-wide memory barrier (generic, x86)
2015-09-11 15:21:34 -07:00
sys_membarrier(): system-wide memory barrier (generic, x86)
2015-09-11 15:21:34 -07:00
libnvdimm for 4.4:
2015-11-10 12:07:22 -08:00
module: Fix locking in symbol_put_addr()
2015-08-24 10:37:01 +09:30
KEYS: Merge the type-specific data with the payload data
2015-10-21 15:18:36 +01:00
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-09-01 08:40:25 -07:00
kernel/panic.c: turn off locks debug before releasing console lock
2015-11-20 16:17:32 -08:00
Nothing exciting, minor tweaks and cleanups.
2015-11-09 15:53:39 -08:00
rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN()
2015-07-22 15:27:32 -07:00
mm: rename alloc_pages_exact_node() to __alloc_pages_node()
2015-09-08 15:35:28 -07:00
seccomp, ptrace: add support for dumping seccomp filters
2015-10-27 19:55:13 -07:00
kexec: split kexec_load syscall from kexec core code
2015-09-10 13:29:01 -07:00
kernel/relay.c: use kvfree() in relay_free_page_array()
2015-06-30 19:44:59 -07:00
mm: enhance region_is_ram() to region_intersects()
2015-08-10 23:07:05 -04:00
seccomp, ptrace: add support for dumping seccomp filters
2015-10-27 19:55:13 -07:00
kernel/signal.c: unexport sigsuspend()
2015-11-20 16:17:32 -08:00
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
2015-11-06 17:50:42 -08:00
stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
2015-10-20 10:23:55 +02:00
sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop()
2015-10-20 10:25:56 +02:00
pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode
2015-11-06 17:50:42 -08:00
mm: mlock: add new mlock system call
2015-11-05 19:34:48 -08:00
kernel/watchdog.c: add sysctl knob hardlockup_panic
2015-11-05 19:34:48 -08:00
task_work: remove fifo ordering guarantee
2015-09-05 13:46:58 -07:00
torture: Consolidate cond_resched_rcu_qs() into stutter_wait()
2015-10-06 11:25:01 -07:00
tracepoint: Give priority to probes of tracepoints
2015-10-25 21:33:54 -04:00
capabilities: ambient capabilities
2015-09-04 16:54:41 -07:00
kernel/watchdog.c: fix race between proc_watchdog_thresh() and watchdog_timer_fn()
2015-11-05 19:34:48 -08:00
Merge branch 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2015-11-05 14:16:27 -08:00
b7ffffbb46