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| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2018-03-27 19:41:41 +0900 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-03-29 14:41:40 +0200 |
| commit | b3c39758c8a6972f02b43f83dba7fe7a352371b9 (patch) | |
| tree | 8aae08ed6abf7ab3127dcbaaf52d2f6536114d43 /kernel/locking | |
| parent | c28d62cf52d791ba5f6db7ce525ed06b86291c82 (diff) | |
| download | linux-0-day-b3c39758c8a6972f02b43f83dba7fe7a352371b9.tar.gz linux-0-day-b3c39758c8a6972f02b43f83dba7fe7a352371b9.tar.xz | |
lockdep: Make the lock debug output more useful
The lock debug output in print_lock() has a few shortcomings:
- It prints the hlock->acquire_ip field in %px and %pS format. That's
redundant information.
- It lacks information about the lock object itself. The lock class is
not helpful to identify a particular instance of a lock.
Change the output so it prints:
- hlock->instance to allow identification of a particular lock instance.
- only the %pS format of hlock->ip_acquire which is sufficient to decode
the actual code line with faddr2line.
The resulting output is:
3 locks held by a.out/31106:
#0: 00000000b0f753ba (&mm->mmap_sem){++++}, at: copy_process.part.41+0x10d5/0x1fe0
#1: 00000000ef64d539 (&mm->mmap_sem/1){+.+.}, at: copy_process.part.41+0x10fe/0x1fe0
#2: 00000000b41a282e (&mapping->i_mmap_rwsem){++++}, at: copy_process.part.41+0x12f2/0x1fe0
[ tglx: Massaged changelog ]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: linux-mm@kvack.org
Cc: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/201803271941.GBE57310.tVSOJLQOFFOHFM@I-love.SAKURA.ne.jp
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/lockdep.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 12a2805dd64a1..023386338269c 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -556,9 +556,9 @@ static void print_lock(struct held_lock *hlock) return; } + printk(KERN_CONT "%p", hlock->instance); print_lock_name(lock_classes + class_idx - 1); - printk(KERN_CONT ", at: [<%px>] %pS\n", - (void *)hlock->acquire_ip, (void *)hlock->acquire_ip); + printk(KERN_CONT ", at: %pS\n", (void *)hlock->acquire_ip); } static void lockdep_print_held_locks(struct task_struct *curr) |