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| author |   Masami Hiramatsu <mhiramat@kernel.org> | 2021-02-18 23:29:23 +0900 |
|---|---|---|
| committer |   Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-02-19 14:57:12 -0500 |
| commit | c85c9a2c6e368dc94907e63babb18a9788e5c9b6 (patch) | |
| tree | 231d254e73c29794c640a607d6c2c5c20e5456df /kernel/kprobes.c | |
| parent | tracing/tools: Add the latency-collector to tools directory (diff) | |
| download | linux-dev-c85c9a2c6e368dc94907e63babb18a9788e5c9b6.tar.xz linux-dev-c85c9a2c6e368dc94907e63babb18a9788e5c9b6.zip | |
kprobes: Fix to delay the kprobes jump optimization
Commit 36dadef23fcc ("kprobes: Init kprobes in early_initcall")
moved the kprobe setup in early_initcall(), which includes kprobe
jump optimization.
The kprobes jump optimizer involves synchronize_rcu_tasks() which
depends on the ksoftirqd and rcu_spawn_tasks_*(). However, since
those are setup in core_initcall(), kprobes jump optimizer can not
run at the early_initcall().
To avoid this issue, make the kprobe optimization disabled in the
early_initcall() and enables it in subsys_initcall().
Note that non-optimized kprobes is still available after
early_initcall(). Only jump optimization is delayed.
Link: https://lkml.kernel.org/r/161365856280.719838.12423085451287256713.stgit@devnote2
Fixes: 36dadef23fcc ("kprobes: Init kprobes in early_initcall")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: RCU <rcu@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Theodore Y . Ts'o" <tytso@mit.edu>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: stable@vger.kernel.org
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reported-by: Uladzislau Rezki <urezki@gmail.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index dd1d027455c4..745f08fdd7a6 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -861,7 +861,6 @@ out: cpus_read_unlock(); } -#ifdef CONFIG_SYSCTL static void optimize_all_kprobes(void) { struct hlist_head *head; @@ -887,6 +886,7 @@ out: mutex_unlock(&kprobe_mutex); } +#ifdef CONFIG_SYSCTL static void unoptimize_all_kprobes(void) { struct hlist_head *head; @@ -2500,18 +2500,14 @@ static int __init init_kprobes(void) } } -#if defined(CONFIG_OPTPROBES) -#if defined(__ARCH_WANT_KPROBES_INSN_SLOT) - /* Init kprobe_optinsn_slots */ - kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; -#endif - /* By default, kprobes can be optimized */ - kprobes_allow_optimization = true; -#endif - /* By default, kprobes are armed */ kprobes_all_disarmed = false; +#if defined(CONFIG_OPTPROBES) && defined(__ARCH_WANT_KPROBES_INSN_SLOT) + /* Init kprobe_optinsn_slots for allocation */ + kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; +#endif + err = arch_init_kprobes(); if (!err) err = register_die_notifier(&kprobe_exceptions_nb); @@ -2526,6 +2522,21 @@ static int __init init_kprobes(void) } early_initcall(init_kprobes); +#if defined(CONFIG_OPTPROBES) +static int __init init_optprobes(void) +{ + /* + * Enable kprobe optimization - this kicks the optimizer which + * depends on synchronize_rcu_tasks() and ksoftirqd, that is + * not spawned in early initcall. So delay the optimization. + */ + optimize_all_kprobes(); + + return 0; +} +subsys_initcall(init_optprobes); +#endif + #ifdef CONFIG_DEBUG_FS static void report_probe(struct seq_file *pi, struct kprobe *p, const char *sym, int offset, char *modname, struct kprobe *pp) |