From 57bdab2e351835ced7cdc400123545fb120aaa22 Mon Sep 17 00:00:00 2001 From: Borislav Petkov <bp@suse.de> Date: Wed, 18 Oct 2017 17:24:28 +0200 Subject: [PATCH] locking/static_keys: Improve uninitialized key warning Right now it says: static_key_disable_cpuslocked used before call to jump_label_init ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:161 static_key_disable_cpuslocked+0x68/0x70 Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.14.0-rc5+ #1 Hardware name: SGI.COM C2112-4GP3/X10DRT-P-Series, BIOS 2.0a 05/09/2016 task: ffffffff81c0e480 task.stack: ffffffff81c00000 RIP: 0010:static_key_disable_cpuslocked+0x68/0x70 RSP: 0000:ffffffff81c03ef0 EFLAGS: 00010096 ORIG_RAX: 0000000000000000 RAX: 0000000000000041 RBX: ffffffff81c32680 RCX: ffffffff81c5cbf8 RDX: 0000000000000001 RSI: 0000000000000092 RDI: 0000000000000002 RBP: ffff88807fffd240 R08: 726f666562206465 R09: 0000000000000136 R10: 0000000000000000 R11: 696e695f6c656261 R12: ffffffff82158900 R13: ffffffff8215f760 R14: 0000000000000001 R15: 0000000000000008 FS: 0000000000000000(0000) GS:ffff883f7f400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88807ffff000 CR3: 0000000001c09000 CR4: 00000000000606b0 Call Trace: static_key_disable+0x16/0x20 start_kernel+0x15a/0x45d ? load_ucode_intel_bsp+0x11/0x2d secondary_startup_64+0xa5/0xb0 Code: 48 c7 c7 a0 15 cf 81 e9 47 53 4b 00 48 89 df e8 5f fc ff ff eb e8 48 c7 c6 \ c0 97 83 81 48 c7 c7 d0 ff a2 81 31 c0 e8 c5 9d f5 ff <0f> ff eb a7 0f ff eb \ b0 e8 eb a2 4b 00 53 48 89 fb e8 42 0e f0 but it doesn't tell me which key it is. So dump the key's name too: static_key_disable_cpuslocked(): static key 'virt_spin_lock_key' used before call to jump_label_init() And that makes pinpointing which key is causing that a lot easier. include/linux/jump_label.h | 14 +++++++------- include/linux/jump_label_ratelimit.h | 6 +++--- kernel/jump_label.c | 14 +++++++------- 3 files changed, 17 insertions(+), 17 deletions(-) Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20171018152428.ffjgak4o25f7ept6@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Danny Lin <danny@kdrag0n.dev> Signed-off-by: onettboots <blackcocopet@gmail.com> --- include/linux/jump_label.h | 14 +++++++------- include/linux/jump_label_ratelimit.h | 6 +++--- kernel/jump_label.c | 28 ++++++++++++++-------------- 3 files changed, 24 insertions(+), 24 deletions(-) diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index b68d02edd3c1..feee8abc96be 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -82,9 +82,9 @@ extern bool static_key_initialized; -#define STATIC_KEY_CHECK_USE() WARN(!static_key_initialized, \ - "%s used before call to jump_label_init", \ - __func__) +#define STATIC_KEY_CHECK_USE(key) WARN(!static_key_initialized, \ + "%s(): static key '%pS' used before call to jump_label_init()", \ + __func__, (key)) #ifdef HAVE_JUMP_LABEL @@ -276,13 +276,13 @@ static __always_inline bool static_key_true(struct static_key *key) static inline void static_key_slow_inc(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); atomic_inc(&key->enabled); } static inline void static_key_slow_dec(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); atomic_dec(&key->enabled); } @@ -304,7 +304,7 @@ static inline int jump_label_apply_nops(struct module *mod) static inline void static_key_enable(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) != 0) { WARN_ON_ONCE(atomic_read(&key->enabled) != 1); @@ -315,7 +315,7 @@ static inline void static_key_enable(struct static_key *key) static inline void static_key_disable(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) != 1) { WARN_ON_ONCE(atomic_read(&key->enabled) != 0); diff --git a/include/linux/jump_label_ratelimit.h b/include/linux/jump_label_ratelimit.h index 689d7338d449..ade92e039e7d 100644 --- a/include/linux/jump_label_ratelimit.h +++ b/include/linux/jump_label_ratelimit.h @@ -83,18 +83,18 @@ struct static_key_false_deferred { static inline void static_key_slow_dec_deferred(struct static_key_deferred *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); static_key_slow_dec(&key->key); } static inline void static_key_deferred_flush(void *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); } static inline void jump_label_rate_limit(struct static_key_deferred *key, unsigned long rl) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); } #endif /* HAVE_JUMP_LABEL */ #endif /* _LINUX_JUMP_LABEL_RATELIMIT_H */ diff --git a/kernel/jump_label.c b/kernel/jump_label.c index c9a955bfe268..665ccc2861d7 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -104,8 +104,7 @@ void static_key_slow_inc_cpuslocked(struct static_key *key) { int v, v1; - STATIC_KEY_CHECK_USE(); - lockdep_assert_cpus_held(); + STATIC_KEY_CHECK_USE(key); /* * Careful if we get concurrent static_key_slow_inc() calls; @@ -150,8 +149,7 @@ EXPORT_SYMBOL_GPL(static_key_slow_inc); void static_key_enable_cpuslocked(struct static_key *key) { - STATIC_KEY_CHECK_USE(); - lockdep_assert_cpus_held(); + STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) > 0) { WARN_ON_ONCE(atomic_read(&key->enabled) != 1); @@ -181,8 +179,7 @@ EXPORT_SYMBOL_GPL(static_key_enable); void static_key_disable_cpuslocked(struct static_key *key) { - STATIC_KEY_CHECK_USE(); - lockdep_assert_cpus_held(); + STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) != 1) { WARN_ON_ONCE(atomic_read(&key->enabled) != 0); @@ -253,22 +250,25 @@ EXPORT_SYMBOL_GPL(jump_label_update_timeout); void static_key_slow_dec(struct static_key *key) { - STATIC_KEY_CHECK_USE(); - __static_key_slow_dec(key); + STATIC_KEY_CHECK_USE(key); + __static_key_slow_dec(key, 0, NULL); } EXPORT_SYMBOL_GPL(static_key_slow_dec); void static_key_slow_dec_cpuslocked(struct static_key *key) { - STATIC_KEY_CHECK_USE(); - __static_key_slow_dec_cpuslocked(key); + STATIC_KEY_CHECK_USE(key); + __static_key_slow_dec_cpuslocked(key, 0, NULL); } void __static_key_slow_dec_deferred(struct static_key *key, struct delayed_work *work, unsigned long timeout) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); + __static_key_slow_dec(&key->key, key->timeout, &key->work); +} +EXPORT_SYMBOL_GPL(static_key_slow_dec_deferred); if (static_key_slow_try_dec(key)) return; @@ -279,15 +279,15 @@ EXPORT_SYMBOL_GPL(__static_key_slow_dec_deferred); void __static_key_deferred_flush(void *key, struct delayed_work *work) { - STATIC_KEY_CHECK_USE(); - flush_delayed_work(work); + STATIC_KEY_CHECK_USE(key); + flush_delayed_work(&key->work); } EXPORT_SYMBOL_GPL(__static_key_deferred_flush); void jump_label_rate_limit(struct static_key_deferred *key, unsigned long rl) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); key->timeout = rl; INIT_DELAYED_WORK(&key->work, jump_label_update_timeout); }