public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-08-05 16:54:27 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions
linux/kernel
History
Steven Rostedt (Red Hat) 12cce594fa ftrace/x86: Allow !CONFIG_PREEMPT dynamic ops to use allocated trampolines 
When the static ftrace_ops (like function tracer) enables tracing, and it
is the only callback that is referencing a function, a trampoline is
dynamically allocated to the function that calls the callback directly
instead of calling a loop function that iterates over all the registered
ftrace ops (if more than one ops is registered).

But when it comes to dynamically allocated ftrace_ops, where they may be
freed, on a CONFIG_PREEMPT kernel there's no way to know when it is safe
to free the trampoline. If a task was preempted while executing on the
trampoline, there's currently no way to know when it will be off that
trampoline.

But this is not true when it comes to !CONFIG_PREEMPT. The current method
of calling schedule_on_each_cpu() will force tasks off the trampoline,
becaues they can not schedule while on it (kernel preemption is not
configured). That means it is safe to free a dynamically allocated
ftrace ops trampoline when CONFIG_PREEMPT is not configured.

Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-11 12:41:52 -05:00
..
bpf bpf: add search pruning optimization to verifier 2014-10-01 21:30:33 -04:00
configs x86: Add "make tinyconfig" to configure the tiniest possible kernel 2014-08-08 16:30:24 -07:00
debug kdb: replace strnicmp with strncasecmp 2014-10-14 02:18:25 +02:00
events Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
gcov ARM: 8153/1: Enable gcov support on the ARM architecture 2014-09-26 14:39:57 +01:00
irq Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
locking Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:51:40 +02:00
power Merge branch 'pm-domains' 2014-10-07 01:18:12 +02:00
printk Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
rcu rcu: Eliminate deadlock between CPU hotplug and expedited grace periods 2014-09-18 16:22:27 -07:00
sched Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
time Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
trace ftrace/x86: Allow !CONFIG_PREEMPT dynamic ops to use allocated trampolines 2014-11-11 12:41:52 -05:00
.gitignore
acct.c acct: eliminate compile warning 2014-10-09 22:26:04 -04:00
async.c kernel/async.c: switch to pr_foo() 2014-10-09 22:26:04 -04:00
audit.c Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
audit.h audit: reduce scope of audit_log_fcaps 2014-09-23 16:37:51 -04:00
audit_tree.c audit: rename audit_log_remove_rule to disambiguate for trees 2014-10-10 15:30:25 -04:00
audit_watch.c audit: invalid op= values for rules 2014-09-23 16:37:53 -04:00
auditfilter.c Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
auditsc.c Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
backtracetest.c
bounds.c page-cgroup: get rid of NR_PCG_FLAGS 2014-08-08 15:57:18 -07:00
capability.c CAPABILITIES: remove undefined caps from all processes 2014-07-24 21:53:47 +10:00
cgroup.c Merge branch 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-10 07:26:02 -04:00
cgroup_freezer.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
compat.c compat: nanosleep: Clarify error handling 2014-09-06 12:58:18 +02:00
configs.c
context_tracking.c
cpu.c rcu: Eliminate deadlock between CPU hotplug and expedited grace periods 2014-09-18 16:22:27 -07:00
cpu_pm.c
cpuset.c Merge branch 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2014-10-10 07:24:40 -04:00
crash_dump.c crash_dump: Make is_kdump_kernel() accessible from modules 2014-08-25 15:42:19 -07:00
cred.c
delayacct.c delayacct: Remove braindamaged type conversions 2014-07-23 10:18:06 -07:00
dma.c
elfcore.c
exec_domain.c
exit.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 16:23:15 +02:00
extable.c
fork.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 16:23:15 +02:00
freezer.c
futex.c futex: Ensure get_futex_key_refs() always implies a barrier 2014-10-18 09:28:51 -07:00
futex_compat.c
groups.c
hung_task.c
irq_work.c Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
jump_label.c
kallsyms.c kernel/kallsyms.c: use __seq_open_private() 2014-10-14 02:18:16 +02:00
kcmp.c kcmp: fix standard comparison bug 2014-09-10 15:42:12 -07:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER 2014-07-16 14:57:13 +02:00
Kconfig.preempt
kexec.c kexec: remove the unused function parameter 2014-10-14 02:18:21 +02:00
kmod.c
kprobes.c kprobes: Skip kretprobe hit in NMI context to avoid deadlock 2014-08-08 10:38:04 +02:00
ksysfs.c
kthread.c kernel/kthread.c: partial revert of 81c98869fa ("kthread: ensure locality of task_struct allocations") 2014-10-09 22:25:51 -04:00
latencytop.c
Makefile bin2c: move bin2c in scripts/basic 2014-08-08 15:57:32 -07:00
module-internal.h
module.c A single panic fix for a rare race, stable CC'd. 2014-10-18 10:24:26 -07:00
module_signing.c
notifier.c
nsproxy.c namespaces: Use task_lock and not rcu to protect nsproxy 2014-07-29 18:08:50 -07:00
padata.c
panic.c panic: add TAINT_SOFTLOCKUP 2014-08-08 15:57:24 -07:00
params.c kernel/param: consolidate __{start,stop}___param[] in <linux/moduleparam.h> 2014-10-14 02:18:28 +02:00
pid.c
pid_namespace.c
profile.c
ptrace.c sched: Remove proliferation of wait_on_bit() action functions 2014-07-16 15:10:39 +02:00
range.c
reboot.c kernel: add support for kernel restart handler call chain 2014-09-26 00:00:06 -07:00
relay.c
res_counter.c
resource.c x86: optimize resource lookups for ioremap 2014-10-14 02:18:22 +02:00
seccomp.c Merge branch 'x86-seccomp-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-14 02:27:06 +02:00
signal.c Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
smp.c Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
smpboot.c
smpboot.h
softirq.c Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
stacktrace.c
stop_machine.c
sys.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 16:23:15 +02:00
sys_ni.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-10-08 21:40:54 -04:00
sysctl.c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:44:12 +02:00
sysctl_binary.c dmaengine-3.17 2014-10-07 20:39:25 -04:00
system_certificates.S
system_keyring.c KEYS: validate certificate trust only with builtin keys 2014-07-17 09:35:17 -04:00
task_work.c
taskstats.c scheduler: Replace __get_cpu_var with this_cpu_ptr 2014-08-26 13:45:45 -04:00
test_kprobes.c kernel/test_kprobes.c: use current logging functions 2014-08-08 15:57:18 -07:00
torture.c torture: Address race in module cleanup 2014-09-16 13:41:06 -07:00
tracepoint.c
tsacct.c sched: Make task->start_time nanoseconds based 2014-07-23 10:18:05 -07:00
uid16.c
up.c
user-return-notifier.c scheduler: Replace __get_cpu_var with this_cpu_ptr 2014-08-26 13:45:45 -04:00
user.c
user_namespace.c proc: constify seq_operations 2014-08-08 15:57:22 -07:00
utsname.c namespaces: Use task_lock and not rcu to protect nsproxy 2014-07-29 18:08:50 -07:00
utsname_sysctl.c
watchdog.c Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
workqueue.c workqueue: Use cond_resched_rcu_qs macro 2014-10-06 05:58:26 -07:00
workqueue_internal.h