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| author | Peter Zijlstra <peterz@infradead.org> | 2020-09-30 12:49:37 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-10-09 09:53:08 +0300 |
| commit | 2bb8945bcc1a768f2bc402a16c9610bba8d5187d (patch) | |
| tree | bf7547f8e6361941a5838adeba9d80c2e55825f4 /kernel/locking/lockdep.c | |
| parent | 583090b1b8232e6eae243a9009699666153a13a9 (diff) | |
| download | linux-2bb8945bcc1a768f2bc402a16c9610bba8d5187d.tar.xz | |
lockdep: Fix usage_traceoverflow
Basically print_lock_class_header()'s for loop is out of sync with the
the size of of ->usage_traces[].
Also clean things up a bit while at it, to avoid such mishaps in the future.
Fixes: 23870f122768 ("locking/lockdep: Fix "USED" <- "IN-NMI" inversions")
Reported-by: Qian Cai <cai@redhat.com>
Debugged-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Qian Cai <cai@redhat.com>
Link: https://lkml.kernel.org/r/20200930094937.GE2651@hirez.programming.kicks-ass.net
Diffstat (limited to 'kernel/locking/lockdep.c')
| -rw-r--r-- | kernel/locking/lockdep.c | 32 |
1 files changed, 15 insertions, 17 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 2facbbd146ec..a430fbb01eb1 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -585,6 +585,8 @@ static const char *usage_str[] = #include "lockdep_states.h" #undef LOCKDEP_STATE [LOCK_USED] = "INITIAL USE", + [LOCK_USED_READ] = "INITIAL READ USE", + /* abused as string storage for verify_lock_unused() */ [LOCK_USAGE_STATES] = "IN-NMI", }; #endif @@ -1939,7 +1941,7 @@ static void print_lock_class_header(struct lock_class *class, int depth) #endif printk(KERN_CONT " {\n"); - for (bit = 0; bit < LOCK_USAGE_STATES; bit++) { + for (bit = 0; bit < LOCK_TRACE_STATES; bit++) { if (class->usage_mask & (1 << bit)) { int len = depth; @@ -3969,7 +3971,7 @@ static int separate_irq_context(struct task_struct *curr, static int mark_lock(struct task_struct *curr, struct held_lock *this, enum lock_usage_bit new_bit) { - unsigned int old_mask, new_mask, ret = 1; + unsigned int new_mask, ret = 1; if (new_bit >= LOCK_USAGE_STATES) { DEBUG_LOCKS_WARN_ON(1); @@ -3996,30 +3998,26 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, if (unlikely(hlock_class(this)->usage_mask & new_mask)) goto unlock; - old_mask = hlock_class(this)->usage_mask; hlock_class(this)->usage_mask |= new_mask; - /* - * Save one usage_traces[] entry and map both LOCK_USED and - * LOCK_USED_READ onto the same entry. - */ - if (new_bit == LOCK_USED || new_bit == LOCK_USED_READ) { - if (old_mask & (LOCKF_USED | LOCKF_USED_READ)) - goto unlock; - new_bit = LOCK_USED; + if (new_bit < LOCK_TRACE_STATES) { + if (!(hlock_class(this)->usage_traces[new_bit] = save_trace())) + return 0; } - if (!(hlock_class(this)->usage_traces[new_bit] = save_trace())) - return 0; - switch (new_bit) { + case 0 ... LOCK_USED-1: + ret = mark_lock_irq(curr, this, new_bit); + if (!ret) + return 0; + break; + case LOCK_USED: debug_atomic_dec(nr_unused_locks); break; + default: - ret = mark_lock_irq(curr, this, new_bit); - if (!ret) - return 0; + break; } unlock: |